Outcomes of Research or Clinical Trials Activity Levels Acute Flaccid Paralysis Ageing Anaerobic Threshold Anaesthesia Assistive Technology Brain Cardiorespiratory Cardiovascular Clinical Evaluation Cold Intolerance Complementary Therapies Continence Coping Styles and Strategies Cultural Context Diagnosis and Management Differential Diagnosis Drugs Dysphagia Dysphonia Epidemiology Exercise Falls Fatigue Fractures Gender Differences Immune Response Inflammation Late Effects of Polio Muscle Strength Muscular Atrophy Orthoses Pain Polio Immunisation Post-Polio Motor Unit Psychology Quality of Life Renal Complications Respiratory Complications and Management Restless Legs Syndrome Sleep Analaysis Surgery Vitality Vocational Implications

Title order Author order Journal order Date order
Category: Muscle Strength

Title: An 8-year longitudinal study of muscle strength, muscle fiber size, and dynamic electromyogram in individuals with late polio
Author: Grimby G, Stålberg E, Sandberg A, Sunnerhagen KS
Affiliation: Department of Rehabilitation Medicine, Sahlgrenska University Hospital, Göteborg University, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1998 Nov; 21(11):1428-37
Publication Year and Month: 1998 11

Abstract: Twenty-one subjects with polio 24 to 51 years prior to the first examination were studied on three occasions, each 4 years apart with measurements of muscle strength and endurance for knee extension, macro EMG, and muscle biopsy from vastus lateralis. On average the muscle strength decreased during the 8-year follow-up by 9-15%. Endurance decreased during the observation period. The muscle fiber area was markedly increased in most subjects. There was a decrease in the capillarization during the follow-up. Macro EMG was increased in all subjects (range 3-42 times control) and increased in 20 legs during the 8-year follow-up, but showed a decrease in 8 of 9 legs with an approximative breakpoint when macro MUPs were around 20 times the normal size. Thus, evidence of on-going denervation/reinnervation as well as of failing capacity to maintain large motor units was demonstrated. SFEMG showed a moderate degree of disturbed neuromuscular transmission.

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Category: Muscle Strength

Title: Disability in a 4-year follow-up study of people with post-polio syndrome
Author: Willén C, Thoren-Jönsson AL, Grimby G, Sunnerhagen KS
Affiliation: Institute of Neurosciences and Physiology-Rehabilitation Medicine, Sahlgrenska Academy, Göteborg, Sweden
Journal: Journal of Rehabilitation Medicine
Citation: J Rehabil Med. 2007 Mar;39(2):175-80.
Publication Year and Month: 2007 03

Abstract: OBJECTIVE: To evaluate changes over time in a clinically based cohort of individuals with post-polio syndrome.

DESIGN: A prospective longitudinal study.

SUBJECTS: A total of 106 individuals with poliomyelitis sequelae were included in the study. They were self-referred or had been referred to the post-polio clinic. After 4 years subjects were called for a follow-up and underwent the same measurements as at the initial assessment.

METHODS: The following measurements were conducted at both the initial assessment, and the follow-up: questionnaires including Nottingham Health Profile, muscle strength and walking speed.

RESULTS: Minor changes in disability during a 4-year period were shown. A significant reduction in muscle strength was only seen for 60° flexion in the left leg and for right and left dorsal flexion. No change could be seen in the total Nottingham Health Profile score.

Conclusions: The minor changes in disability found in this study are an indication that we still do not know which subjects are at risk for deterioration. It is difficult to say whether the small changes over time shown in this study are associated with support from the polio clinic or are an expression of the natural history of the syndrome. However, it is hoped that support from the polio clinic may result in self-selected lifestyle changes, which may positively influence the development of symptoms and functional capacity.

Outcome of Research: Not applicable.

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Category: Muscle Strength

Title: Men With Late Effects of Polio Decline More Than Women in Lower Limb Muscle Strength: A 4-Year Longitudinal Study
Author: Flansbjer UB (1), Brogårdh C (2), Horstmann V (3), Lexell J (4)
Affiliation: (1) 1Department of Health Sciences, Lund University, Rehabilitation Medicine Research Group, Box 157, SE221 00 Lund, Sweden; (2) Department of Health Sciences, Lund University, Physiotherapy Research Group, Box 157, SE221 00 Lund, Sweden; Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden; (3) Department of Health Sciences, Lund University, Research Group Active and Healthy Ageing, Box 157, SE221 00 Lund, Sweden; (4) Department of Health Sciences, Lund University, Rehabilitation Medicine Research Group, Box 157, SE221 00 Lund, Sweden; Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden
Journal: PM&R: The Journal of Injury, Function, and Rehabilitation
Citation: PM R. 2015 May 12. pii: S1934-1482(15)00233-6. doi: 10.1016/j.pmrj.2015.05.005
Publication Year and Month: 2015 05

Abstract: BACKGROUND: In persons with prior paralytic poliomyelitis, progressive muscle weakness can occur after a stable period of at least 15 years. Knowledge is limited about which factors influence changes in lower limb muscle strength in these persons.

OBJECTIVE: To assess changes in lower limb muscle strength annually over 4 years in persons with late effects of polio and to identify prognostic factors for changes in muscle strength.

DESIGN: A prospective, longitudinal study.

SETTING: University hospital outpatient program.

PARTICIPANTS: Fifty-two ambulant persons (mean age ± standard deviation: 64 ± 6 years) with verified late effects of polio.

METHODS: Mixed linear models were used to analyze changes in muscle strength and to identify determinants among the following covariates: gender, age, age at acute polio infection, time with late effects of polio, body mass index, and estimated baseline muscle weakness.

MAIN OUTCOME MEASUREMENTS: Knee extensor and flexor and ankle dorsiflexor muscle strength were measured annually with a Biodex dynamometer.

RESULTS: The men (n = 28) had significant linear change over time for all knee muscle strength measurements, from -1.4% (P < .05) per year for isokinetic knee flexion in the less-affected lower limb to -4.2% (P < .001) for isokinetic knee extension in the more-affected lower limb, and for 2 ankle dorsiflexor muscle strength measurements (-3.3%-1.4% per year [P < .05]). The women (n = 24) had a significant linear change over time only for ankle dorsiflexor measurements (4.0%-5.5% per year [P < .01]). Gender was the strongest factor that predicted a change in muscle strength over time.

Conclusions: Over 4 years, men had a greater decline in muscle strength than did women, but the rate of decline did not accelerate. This finding indicates that gender could be a contributing factor to the progressive decline in muscle strength in persons with late effects of polio.

Outcome of Research: Not applicable

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Category: Muscle Strength

Title: Neuromuscular function: comparison of symptomatic and asymptomatic polio subjects to control subjects
Author: Agre JC, Rodriquez AA
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin - Madison Medical School 53792
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1990 Jul; 71(8):545-51
Publication Year and Month: 1990 07

Abstract: The purpose of this study was to determine if there were any differences between symptomatic and asymptomatic polio survivors by history of acute poliomyelitis illness, electromyographic evidence of terminal motor unit reorganization, and neuromuscular function of the quadriceps femoris muscle. Thirty-four symptomatic postpolio subjects, 16 asymptomatic postpolio subjects, and 41 controls were studied. A questionnaire assessed polio history. Peak knee extension torque was measured isokinetically and isometrically. Endurance (time to exhaustion) was measured at 40% of maximal isometric torque. Work capacity was determined as the product of torque and duration. Recovery of isometric strength was measured at regular intervals for ten minutes after exhaustion. Quantitative electromyography was also performed on the quadriceps to determine motor unit action potential duration and amplitude. It was found that symptomatic subjects had evidence of more severe original polio involvement by history (documented electromyographically), were weaker and capable of performing less work than asymptomatic subjects, and recovered strength less readily than controls.

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Category: Muscle Strength

Title: Perceived disability, fatigue, pain and measured isometric muscle strength in patients with post-polio symptoms
Author: Hildegunn L, Jones K, Grenstad T, Dreyer V, Farbu E, Rekand T
Affiliation: Department of Physical Therapy, Haukeland University Hospital, Bergen, Norway
Journal: Physiotherapy Research International
Citation: Physiother Res Int. 2007 Mar;12(1):39-49
Publication Year and Month: 2007 07

Abstract: BACKGROUND AND PURPOSE: Several years after the acute polio illness, patients may develop new post-polio symptoms. The purpose of the present study was to evaluate patients with post-polio symptoms with regard to perceived fatigue, functional ability, muscle strength, pain and with regard to measured physical fitness and isometric muscle strength. In addition, the relationship between the results of these subjective and objective measurements was investigated.

METHOD: This was a prospective cross-sectional study in which 32 patients with post-polio symptoms were included. Main outcome measures were the Fatigue Severity Scale (FSS), the Disability Rating Index (DRI), pain intensity, pain distribution, self-reported and measured muscle strength and oxygen uptake.

RESULTS: A marked reduction in isometric muscle strength compared to normal data, high scores in fatigue, widespread pain, low oxygen uptake and difficulties in performing some daily activities were found. Self-reported general muscle strength, pain intensity and pain distribution correlated significantly with patients' perceived fatigue and function at the activity level. There was no significant correlation between self-reported and measured results except for that found between isometric muscle strength in the legs and patients' perceived general muscle strength and oxygen uptake.

Conclusions: Evaluation of pain intensity, pain distribution, perceived muscle strength, fatigue and ability to perform daily tasks reveals important aspects of health status in patients with post-polio symptoms. Reduction in isometric muscle strength was not reflected in those tests or in reported symptoms, and should be monitored independently using a sensitive assessment tool. Accurate screening of isometric muscle strength in isolated muscle groups contributes to therapeutic management in making a functional diagnosis at the level of body function and structure when designing specific training programmes and in motivating patients. An evaluation combining self-reports with sensitive muscle strength measures provide supplementary information and is appropriate for evaluating these patients in physiotherapy practice.

Outcome of Research: Not applicable

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Category: Muscle Strength

Title: Quantitative muscle ultrasound and quadriceps strength in patients with post-polio syndrome
Author: Bickerstaffe A (1), Beelen A, Zwarts MJ, Nollet F, van Dijk JP
Affiliation: (1) Department of Rehabilitation, Academic Medical Center, Postbus 22660, 1100 DD, Amsterdam, The Netherlands
Journal: Muscle & Nerve
Citation: Muscle Nerve. 2015 Jan;51(1):24-9. doi: 10.1002/mus.24272
Publication Year and Month: 2015 01

Abstract: INTRODUCTION: We investigated whether muscle ultrasound can distinguish muscles affected by post-polio syndrome (PPS) from healthy muscles and whether severity of ultrasound abnormalities is associated with muscle strength.

METHODS: Echo intensity, muscle thickness, and isometric strength of the quadriceps muscles were measured in 48 patients with PPS and 12 healthy controls.

RESULTS: Patients with PPS had significantly higher echo intensity and lower muscle thickness than healthy controls. In patients, both echo intensity and muscle thickness were associated independently with muscle strength. A combined measure of echo intensity and muscle thickness was more strongly related to muscle strength than either parameter alone.

Conclusions: Quantitative ultrasound distinguishes healthy muscles from those affected by PPS, and measures of muscle quality and quantity are associated with muscle strength. Hence, ultrasound could be a useful tool for assessing disease severity and monitoring changes resulting from disease progression or clinical intervention in patients with PPS.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Randomized controlled trial of strength training in post-polio patients
Author: Chan, K. M., Amirjani, N., Sumrain, M., Clarke, A. and Strohschein, F. J.
Affiliation: Funded by Alberta Heritage Foundation and Canada Foundation
Journal: Muscle & Nerve
Citation: Chan, K. M., Amirjani, N., Sumrain, M., Clarke, A. and Strohschein, F. J. (2003), Randomized controlled trial of strength training in post-polio patients. Muscle Nerve, 27: 332–338. doi:10.1002/mus.10327
Publication Year and Month: 2003 02

Abstract: Many post-polio patients develop new muscle weakness decades after the initial illness. However, its mechanism and treatment are controversial. The purpose of this study was to test the hypotheses that: (1) after strength training, post-polio patients show strength improvement comparable to that seen in the healthy elderly; (2) such training does not have a deleterious effect on motor unit (MU) survival; and (3) part of the strength improvement is due to an increase in voluntary motor drive. After baseline measures including maximum voluntary contraction force, voluntary activation index, motor unit number estimate, and the tetanic tension of the thumb muscles had been determined, 10 post-polio patients with hand involvement were randomized to either the training or control group. The progressive resistance training program consisted of three sets of eight isometric contractions, three times weekly for 12 weeks. Seven healthy elderly were also randomized and trained in a similar manner. Changes in the baseline parameters were monitored once every 4 weeks throughout the training period. The trained post-polio patients showed a significant improvement in their strength (P < 0.05). The magnitude of gain was greater than that seen in the healthy elderly (mean ± SE, 41 ± 16% vs. 29 ± 8%). The training did not adversely affect MU survival and the improvement was largely attributable to an increase in voluntary motor drive. We therefore conclude that moderate intensity strength training is safe and effective in post-polio patients.

Conclusions: This study demonstrated moderate intensity strength training of affected hand muscles is safe and effective in post-polio patients.

Outcome of Research: More research required

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Comments (if any): Strength training of more functional muscles (e.g. legs) that consider baseline strength levels, appropriate loading and rest, with regular monitoring is important to evaluate in a randomised control trial to assist with exercise recommendations.

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Category: Muscle Strength

Title: Reduction in thigh muscle cross-sectional area and strength in a 4-year follow-up in late polio
Author: Grimby G, Kvist H, Grangård U
Affiliation: Department of Rehabilitation Medicine, University of Göteborg, Sahlgrenska University Hospital, Sweden
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1996 Oct; 77(10):1044-8
Publication Year and Month: 1996 10

Abstract: OBJECTIVE: To study changes in cross-sectional thigh muscle area and muscle strength in late polio subjects over a 4-year period.

DESIGN: Longitudinal study of a cohort of polio survivors, comparing subjects who acknowledge (unstable) with those who do not acknowledge (stable) new muscle weakness.

SETTING: University hospital.

SUBJECTS: Eighteen subjects (6 men, 12 women) with polio-myelitis sequelae (39 to 46 years of age) were studied on two occasions 4 years apart; the first examination was 37 to 44 years after onset of polio. Subjects were recruited through hospital registers, newspaper advertisement, and a patient organization.

OUTCOME MEASUREMENTS: Thigh muscle and intermuscular and intramuscular adipose tissue (AT) cross-sectional areas were measured by computed tomography. Isometric muscle strength for knee extension and flexion was measured using a Kin-Com dynamometer.

RESULTS: Cross-sectional muscle area decreased on average 1.3 +/- 3.6 cm2 (1.4%, p < .05); the intermuscular and intramuscular AT area increased 1.8 +/- 3.4 cm2 (12.1%, p < .05). When divided by legs in which subjects reported (unstable) or did not report (unstable) or did not report (stable) increased muscle weakness, unstable legs showed significant reduction (p < .05) in muscle area, whereas stable legs did not. Estimated total thigh muscle strength decreased 7.8% +/- 2.9% (p < .01), with a significant (p < .001) reduction in unstable legs (13.4% +/- 4.3%) but not in stable legs. The reduction in strength appears to be greater than the reduction in cross-sectional muscle area, but there is still a significant correlation (r = .44, p < .05).

Conclusions: The present results demonstrate not only progress of muscle weakness, but also of muscle atrophy in postpolio subjects.

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Category: Muscle Strength

Title: Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.
Author: Voorn EL (1,2), Brehm MA (1), Beelen A (1), de Haan A (2), Nollet F (1), Gerrits KH (2)
Affiliation: (1) Department of Rehabilitation, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; (2) MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
Journal: Public Library of Science
Citation: PLoS One. 2014 Jul 14;9(7):e101660. doi: 10.1371/journal.pone.0101660.
Publication Year and Month: 2014 07

Abstract: OBJECTIVE: To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals.

METHODS: Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean).

RESULTS: In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016).

SIGNIFICANCE: This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Conclusions: In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.

Outcome of Research: Not applicable,

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Category: Muscle Strength

Title: Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.
Author: Voorn, E.L., Brehm, M.A., Beelen, A., de Haan, A., Nollet, F., Gerrits, K.H.L.


Affiliation: University of Amsterdam
Journal:
Citation: PLos One
Voorn, E.L., Brehm, M.A., Beelen, A., de Haan, A., Nollet, F., Gerrits, K.H.L. (2014) Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome. PLoS One. Jul 14;9(7):e101660. doi: 10.1371/journal.pone.0101660
Publication Year and Month: 2014 07

Abstract: Objective
To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals.

Methods
Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean).

Results
In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016).

Conclusions
In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.

Significance
This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Conclusions: Both in individuals with PPS and in healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions of the knee extensor muscles is high. The reliability of contractile speed indices is only moderate, except for RT50 in PPS, demonstrating high reliability. Considering these results, the assessment of contractile properties in PPS is sufficiently reliable to identify those patients with impaired contractile functioning of their knee extensor muscles, and, accordingly, to evaluate changes over time or following interventions in this patient group. Based on its potential in PPS, future research may also focus on the feasibility of this method in other slowly progressive neuromuscular diseases where muscle fatigue is a major problem.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio
Author: Flansbjer UB, Lexell J
Affiliation: Department of Rehabilitation, Skåne University Hospital, Orupssjukhuset, Lund, Sweden - [email protected]

Journal: Journal of Rehabilitation Medicine
Citation: J Rehabil Med. 2010 Jun;42(6):588-92. doi: 10.2340/16501977-0561
Publication Year and Month: 2010 06

Abstract: OBJECTIVE: To assess the reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio.

DESIGN: A test-retest reliability study.

SUBJECTS: Thirty men and women (mean age 63 (standard deviation 6.4) years) with verified late effects of polio.

METHODS: Knee extensor and flexor muscle strength in both lower limbs were measured twice 7 days apart using a Biodex dynamometer (isokinetic concentric contractions at 60°/s and isometric contractions with knee flexion angle 90º) and a Leg Extension/Curl Rehab exercise machine with pneumatic resistance (HUR) (isotonic contractions). Reliability was assessed with the intraclass correlation coefficient (ICC1,1), the mean difference between the test sessions (đ) together with the 95% confidence intervals for đ, the standard error of measurement (SEM and SEM%), the smallest real difference (SRD and SRD%) and Bland-Altman graphs.

RESULTS: Test-retest agreements were high, (ICC1,1 0.93–0.99) and measurement errors generally small. The SEM% was 4–14% and the SRD% 11–39%, with the highest values for the isokinetic measurements.

Conclusions: Knee muscle strength can be measured reliably and can be used to detect real changes after an intervention for a group of persons with late effects of polio, whereas the values may be too high for single individuals or to detect smaller short-term changes over time for a group of individuals.

Outcome of Research: Not applicable.

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Category: Muscle Strength

Title: Strength gains without muscle injury after strength training in patients with postpolio muscular atrophy.
Author: Spector, S. A., Gordon, P. L., Feuerstein, I. M., Sivakumar, K., Hurley, B. F. and Dalakas, M. C.
Affiliation: Funded by Henry M. Jackson Foundation for the Advancement of Military Science
Journal: Muscle & Nerve
Citation: Spector, S. A., Gordon, P. L., Feuerstein, I. M., Sivakumar, K., Hurley, B. F. and Dalakas, M. C. (1996), Strength gains without muscle injury after strength training in patients with postpolio muscular atrophy. Muscle Nerve, 19: 1282–1290.
Publication Year and Month: 1996 10

Abstract: We evaluated changes in the dynamic and isometric strength in the newly weakened quadriceps muscles and asymptomatic triceps muscles of 6 patients with postpolio muscular atrophy (PPMA) after 10 weeks of progressive resistance strength training. Alterations in muscle size were determined with magnetic resonance imaging. Serum creatine kinase levels were measured throughout training, and histological signs of muscle injury and changes in muscle fiber size and types were assessed with muscle biopsies before and after training. Exercise training led to an increase in dynamic strength of 41% and 61% for the two knee extensor tests, and 54% and 71% for the two elbow extensor tests. Up to 20% of the improvement was maintained 5 months after cessation of training. Isometric strength, whole muscle cross-sectional areas of quadriceps and triceps muscles, and serum muscle enzymes did not change. No destructive histopathological changes were noted in the repeat muscle biopsies, and no consistent changes in muscle fiber size or fiber type percentages were observed. These results demonstrate that a supervised resistance training program can lead to significant gains in dynamic strength of both symptomatic and asymptomatic muscles of PPMA patients without serological or histological evidence of muscular damage.

Conclusions: This study of 6 patient who had postpolio muscluar atrophy (PPMA) demonstrated a supervised resistance training program can lead to significant gains in dynamic strength of both symptomatic and asymptomatic muscles of PPMA patients without serological or histological evidence of muscular damage.

Outcome of Research: More research required

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Comments (if any): A small sample size and further information regarding the baseline strength values of affected muscles makes it difficult to conclude on the significance of these results.

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Category: Muscle Strength

Title: Strength, endurance, and work capacity after muscle strengthening exercise in postpolio subjects
Author: Agre JC, Rodriquez AA, Franke TM
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin Medical School, Madison, USA
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1997 Jul; 78(7):681-6
Publication Year and Month: 1997 07

Abstract: OBJECTIVE: To determine whether a 12-week home quadriceps muscle strengthening exercise program would increase muscle strength, isometric endurance, and tension time index (TTI) in postpolio syndrome subjects without adversely affecting the surviving motor units or the muscle.

DESIGN: A longitudinal study to investigate the effect of a 12-week exercise program on neuromuscular function and electromyographic variables.

SETTING: Neuromuscular laboratory of a university hospital.

SUBJECTS: Seven subjects were recruited from a cohort of 12 subjects who had participated in a previous exercise study. All subjects had greater than antigravity strength of the quadriceps. Upon completion of a postpolio questionnaire, all acknowledged common postpolio syndrome symptoms such as new fatigue, pain, and weakness; 6 of the 7 acknowledged new strength decline.

INTERVENTION: On Mondays and Thursdays subjects performed three sets of four maximal isometric contractions of the quadriceps held for 5 seconds each. On Tuesdays and Fridays subjects performed three sets of 12 dynamic knee extension exercises with ankle weights.

MAIN OUTCOME MEASURES: Neuromuscular variables of the quadriceps muscles were measured at the beginning and completion of the exercise program and included: isokinetic peak torque (ISOKPT, at 60 degrees/sec angular velocity) and total work performed of four contractions (ISOKTW), isometric peak torque (MVC), endurance (EDUR, time subject could hold isometric contraction at 40% of the initial MVC), isometric tension time index (TTI, product of endurance time and torque at 40% of MVC), and initial and final ankle weight (WGT, kg) lifted. Electromyographic variables included: fiber density (FD), jitter (MCD), and blocking (BLK) from single fiber assessment and median macro amplitude (MACRO). Serum creatine kinase (CK) was also measured initially and at 4-week intervals throughout the study.

RESULTS: The following variables significantly (p < .05) increased: WGT by 47%, ISOKPT, 15%, ISOKTW, 15%; MVC, 36%; EDUR, 21%; TTI, 18%. The following variables did not significantly (p > .05) change: FD, MCD, BLK, MACRO, and CK.

Conclusions: This home exercise program significantly increased strength, endurance, and TTI without apparently adversely affecting the motor units or the muscle, as the EMG and CK variables did not change.

Outcome of Research: Effective

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Category: Muscle Strength

Title: The course of functional status and muscle strength in patients with late-onset sequelae of poliomyelitis: a systematic review
Author: Stolwijk-Swüste JM, Beelen A, Lankhorst GJ, Nollet F; CARPA Study Group
Affiliation: Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam, The Netherlands – [email protected]
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 2005 Aug;86(8):1693-701
Publication Year and Month: 2005 08

Abstract: OBJECTIVES: To review systematically studies of late-onset polio sequelae on the course of functional status and muscle strength over time and to identify prognostic factors of change.

DATA SOURCES: We conducted a computerized literature search up to July 2004 in MEDLINE, EMBASE, CINAHL, Web of Science, PsychInfo, and the Cochrane controlled trial register using the key words: postpolio, postpoliomyelitis, postpoliomyelitis syndrome, post poliomyelitis muscular atrophy, and poliomyelitis.

STUDY SELECTION: Reports were selected by 1 reviewer if the study involved subjects with a history of poliomyelitis, the outcome measures described functional status or muscle strength, and follow-up was for at least 6 months.

DATA EXTRACTION: Studies were summarized with regard to population, design, sample size, outcome measures, results, and methodologic scores. Overlap in populations between studies was checked.

DATA SYNTHESIS: Of 71 potentially relevant studies, 19 were included (2 on functional status, 15 on muscle strength, 2 on both muscle strength and functional status). Two studies on the course of functional status had sufficient quality and reported inconsistent results. Four studies on the course of muscle strength had sufficient quality. Two studies reported a decline in strength and 2 reported no change. Decline in strength was only reported in studies with a follow-up period longer than 2 years. One study reported extent of paresis as a prognostic factor for change in perceived physical mobility.

Conclusions: Conclusions cannot be drawn from the literature with regard to the functional course or prognostic factors in late-onset polio sequelae. The rate of decline in muscle strength is slow, and prognostic factors have not yet been identified. Long-term follow-up studies with unselected study populations and age-matched controls are needed, with specific focus on prognostic factors.

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There are currently 14 papers in this category.

Category: Muscle Strength

Title: Neuromuscular function: comparison of symptomatic and asymptomatic polio subjects to control subjects
Author: Agre JC, Rodriquez AA
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin - Madison Medical School 53792
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1990 Jul; 71(8):545-51
Publication Year and Month: 1990 07

Abstract: The purpose of this study was to determine if there were any differences between symptomatic and asymptomatic polio survivors by history of acute poliomyelitis illness, electromyographic evidence of terminal motor unit reorganization, and neuromuscular function of the quadriceps femoris muscle. Thirty-four symptomatic postpolio subjects, 16 asymptomatic postpolio subjects, and 41 controls were studied. A questionnaire assessed polio history. Peak knee extension torque was measured isokinetically and isometrically. Endurance (time to exhaustion) was measured at 40% of maximal isometric torque. Work capacity was determined as the product of torque and duration. Recovery of isometric strength was measured at regular intervals for ten minutes after exhaustion. Quantitative electromyography was also performed on the quadriceps to determine motor unit action potential duration and amplitude. It was found that symptomatic subjects had evidence of more severe original polio involvement by history (documented electromyographically), were weaker and capable of performing less work than asymptomatic subjects, and recovered strength less readily than controls.

Conclusions:

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Category: Muscle Strength

Title: Strength, endurance, and work capacity after muscle strengthening exercise in postpolio subjects
Author: Agre JC, Rodriquez AA, Franke TM
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin Medical School, Madison, USA
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1997 Jul; 78(7):681-6
Publication Year and Month: 1997 07

Abstract: OBJECTIVE: To determine whether a 12-week home quadriceps muscle strengthening exercise program would increase muscle strength, isometric endurance, and tension time index (TTI) in postpolio syndrome subjects without adversely affecting the surviving motor units or the muscle.

DESIGN: A longitudinal study to investigate the effect of a 12-week exercise program on neuromuscular function and electromyographic variables.

SETTING: Neuromuscular laboratory of a university hospital.

SUBJECTS: Seven subjects were recruited from a cohort of 12 subjects who had participated in a previous exercise study. All subjects had greater than antigravity strength of the quadriceps. Upon completion of a postpolio questionnaire, all acknowledged common postpolio syndrome symptoms such as new fatigue, pain, and weakness; 6 of the 7 acknowledged new strength decline.

INTERVENTION: On Mondays and Thursdays subjects performed three sets of four maximal isometric contractions of the quadriceps held for 5 seconds each. On Tuesdays and Fridays subjects performed three sets of 12 dynamic knee extension exercises with ankle weights.

MAIN OUTCOME MEASURES: Neuromuscular variables of the quadriceps muscles were measured at the beginning and completion of the exercise program and included: isokinetic peak torque (ISOKPT, at 60 degrees/sec angular velocity) and total work performed of four contractions (ISOKTW), isometric peak torque (MVC), endurance (EDUR, time subject could hold isometric contraction at 40% of the initial MVC), isometric tension time index (TTI, product of endurance time and torque at 40% of MVC), and initial and final ankle weight (WGT, kg) lifted. Electromyographic variables included: fiber density (FD), jitter (MCD), and blocking (BLK) from single fiber assessment and median macro amplitude (MACRO). Serum creatine kinase (CK) was also measured initially and at 4-week intervals throughout the study.

RESULTS: The following variables significantly (p < .05) increased: WGT by 47%, ISOKPT, 15%, ISOKTW, 15%; MVC, 36%; EDUR, 21%; TTI, 18%. The following variables did not significantly (p > .05) change: FD, MCD, BLK, MACRO, and CK.

Conclusions: This home exercise program significantly increased strength, endurance, and TTI without apparently adversely affecting the motor units or the muscle, as the EMG and CK variables did not change.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Quantitative muscle ultrasound and quadriceps strength in patients with post-polio syndrome
Author: Bickerstaffe A (1), Beelen A, Zwarts MJ, Nollet F, van Dijk JP
Affiliation: (1) Department of Rehabilitation, Academic Medical Center, Postbus 22660, 1100 DD, Amsterdam, The Netherlands
Journal: Muscle & Nerve
Citation: Muscle Nerve. 2015 Jan;51(1):24-9. doi: 10.1002/mus.24272
Publication Year and Month: 2015 01

Abstract: INTRODUCTION: We investigated whether muscle ultrasound can distinguish muscles affected by post-polio syndrome (PPS) from healthy muscles and whether severity of ultrasound abnormalities is associated with muscle strength.

METHODS: Echo intensity, muscle thickness, and isometric strength of the quadriceps muscles were measured in 48 patients with PPS and 12 healthy controls.

RESULTS: Patients with PPS had significantly higher echo intensity and lower muscle thickness than healthy controls. In patients, both echo intensity and muscle thickness were associated independently with muscle strength. A combined measure of echo intensity and muscle thickness was more strongly related to muscle strength than either parameter alone.

Conclusions: Quantitative ultrasound distinguishes healthy muscles from those affected by PPS, and measures of muscle quality and quantity are associated with muscle strength. Hence, ultrasound could be a useful tool for assessing disease severity and monitoring changes resulting from disease progression or clinical intervention in patients with PPS.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Randomized controlled trial of strength training in post-polio patients
Author: Chan, K. M., Amirjani, N., Sumrain, M., Clarke, A. and Strohschein, F. J.
Affiliation: Funded by Alberta Heritage Foundation and Canada Foundation
Journal: Muscle & Nerve
Citation: Chan, K. M., Amirjani, N., Sumrain, M., Clarke, A. and Strohschein, F. J. (2003), Randomized controlled trial of strength training in post-polio patients. Muscle Nerve, 27: 332–338. doi:10.1002/mus.10327
Publication Year and Month: 2003 02

Abstract: Many post-polio patients develop new muscle weakness decades after the initial illness. However, its mechanism and treatment are controversial. The purpose of this study was to test the hypotheses that: (1) after strength training, post-polio patients show strength improvement comparable to that seen in the healthy elderly; (2) such training does not have a deleterious effect on motor unit (MU) survival; and (3) part of the strength improvement is due to an increase in voluntary motor drive. After baseline measures including maximum voluntary contraction force, voluntary activation index, motor unit number estimate, and the tetanic tension of the thumb muscles had been determined, 10 post-polio patients with hand involvement were randomized to either the training or control group. The progressive resistance training program consisted of three sets of eight isometric contractions, three times weekly for 12 weeks. Seven healthy elderly were also randomized and trained in a similar manner. Changes in the baseline parameters were monitored once every 4 weeks throughout the training period. The trained post-polio patients showed a significant improvement in their strength (P < 0.05). The magnitude of gain was greater than that seen in the healthy elderly (mean ± SE, 41 ± 16% vs. 29 ± 8%). The training did not adversely affect MU survival and the improvement was largely attributable to an increase in voluntary motor drive. We therefore conclude that moderate intensity strength training is safe and effective in post-polio patients.

Conclusions: This study demonstrated moderate intensity strength training of affected hand muscles is safe and effective in post-polio patients.

Outcome of Research: More research required

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Comments (if any): Strength training of more functional muscles (e.g. legs) that consider baseline strength levels, appropriate loading and rest, with regular monitoring is important to evaluate in a randomised control trial to assist with exercise recommendations.

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Category: Muscle Strength

Title: Men With Late Effects of Polio Decline More Than Women in Lower Limb Muscle Strength: A 4-Year Longitudinal Study
Author: Flansbjer UB (1), Brogårdh C (2), Horstmann V (3), Lexell J (4)
Affiliation: (1) 1Department of Health Sciences, Lund University, Rehabilitation Medicine Research Group, Box 157, SE221 00 Lund, Sweden; (2) Department of Health Sciences, Lund University, Physiotherapy Research Group, Box 157, SE221 00 Lund, Sweden; Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden; (3) Department of Health Sciences, Lund University, Research Group Active and Healthy Ageing, Box 157, SE221 00 Lund, Sweden; (4) Department of Health Sciences, Lund University, Rehabilitation Medicine Research Group, Box 157, SE221 00 Lund, Sweden; Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden
Journal: PM&R: The Journal of Injury, Function, and Rehabilitation
Citation: PM R. 2015 May 12. pii: S1934-1482(15)00233-6. doi: 10.1016/j.pmrj.2015.05.005
Publication Year and Month: 2015 05

Abstract: BACKGROUND: In persons with prior paralytic poliomyelitis, progressive muscle weakness can occur after a stable period of at least 15 years. Knowledge is limited about which factors influence changes in lower limb muscle strength in these persons.

OBJECTIVE: To assess changes in lower limb muscle strength annually over 4 years in persons with late effects of polio and to identify prognostic factors for changes in muscle strength.

DESIGN: A prospective, longitudinal study.

SETTING: University hospital outpatient program.

PARTICIPANTS: Fifty-two ambulant persons (mean age ± standard deviation: 64 ± 6 years) with verified late effects of polio.

METHODS: Mixed linear models were used to analyze changes in muscle strength and to identify determinants among the following covariates: gender, age, age at acute polio infection, time with late effects of polio, body mass index, and estimated baseline muscle weakness.

MAIN OUTCOME MEASUREMENTS: Knee extensor and flexor and ankle dorsiflexor muscle strength were measured annually with a Biodex dynamometer.

RESULTS: The men (n = 28) had significant linear change over time for all knee muscle strength measurements, from -1.4% (P < .05) per year for isokinetic knee flexion in the less-affected lower limb to -4.2% (P < .001) for isokinetic knee extension in the more-affected lower limb, and for 2 ankle dorsiflexor muscle strength measurements (-3.3%-1.4% per year [P < .05]). The women (n = 24) had a significant linear change over time only for ankle dorsiflexor measurements (4.0%-5.5% per year [P < .01]). Gender was the strongest factor that predicted a change in muscle strength over time.

Conclusions: Over 4 years, men had a greater decline in muscle strength than did women, but the rate of decline did not accelerate. This finding indicates that gender could be a contributing factor to the progressive decline in muscle strength in persons with late effects of polio.

Outcome of Research: Not applicable

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Category: Muscle Strength

Title: Reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio
Author: Flansbjer UB, Lexell J
Affiliation: Department of Rehabilitation, Skåne University Hospital, Orupssjukhuset, Lund, Sweden - [email protected]

Journal: Journal of Rehabilitation Medicine
Citation: J Rehabil Med. 2010 Jun;42(6):588-92. doi: 10.2340/16501977-0561
Publication Year and Month: 2010 06

Abstract: OBJECTIVE: To assess the reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio.

DESIGN: A test-retest reliability study.

SUBJECTS: Thirty men and women (mean age 63 (standard deviation 6.4) years) with verified late effects of polio.

METHODS: Knee extensor and flexor muscle strength in both lower limbs were measured twice 7 days apart using a Biodex dynamometer (isokinetic concentric contractions at 60°/s and isometric contractions with knee flexion angle 90º) and a Leg Extension/Curl Rehab exercise machine with pneumatic resistance (HUR) (isotonic contractions). Reliability was assessed with the intraclass correlation coefficient (ICC1,1), the mean difference between the test sessions (đ) together with the 95% confidence intervals for đ, the standard error of measurement (SEM and SEM%), the smallest real difference (SRD and SRD%) and Bland-Altman graphs.

RESULTS: Test-retest agreements were high, (ICC1,1 0.93–0.99) and measurement errors generally small. The SEM% was 4–14% and the SRD% 11–39%, with the highest values for the isokinetic measurements.

Conclusions: Knee muscle strength can be measured reliably and can be used to detect real changes after an intervention for a group of persons with late effects of polio, whereas the values may be too high for single individuals or to detect smaller short-term changes over time for a group of individuals.

Outcome of Research: Not applicable.

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Category: Muscle Strength

Title: Reduction in thigh muscle cross-sectional area and strength in a 4-year follow-up in late polio
Author: Grimby G, Kvist H, Grangård U
Affiliation: Department of Rehabilitation Medicine, University of Göteborg, Sahlgrenska University Hospital, Sweden
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1996 Oct; 77(10):1044-8
Publication Year and Month: 1996 10

Abstract: OBJECTIVE: To study changes in cross-sectional thigh muscle area and muscle strength in late polio subjects over a 4-year period.

DESIGN: Longitudinal study of a cohort of polio survivors, comparing subjects who acknowledge (unstable) with those who do not acknowledge (stable) new muscle weakness.

SETTING: University hospital.

SUBJECTS: Eighteen subjects (6 men, 12 women) with polio-myelitis sequelae (39 to 46 years of age) were studied on two occasions 4 years apart; the first examination was 37 to 44 years after onset of polio. Subjects were recruited through hospital registers, newspaper advertisement, and a patient organization.

OUTCOME MEASUREMENTS: Thigh muscle and intermuscular and intramuscular adipose tissue (AT) cross-sectional areas were measured by computed tomography. Isometric muscle strength for knee extension and flexion was measured using a Kin-Com dynamometer.

RESULTS: Cross-sectional muscle area decreased on average 1.3 +/- 3.6 cm2 (1.4%, p < .05); the intermuscular and intramuscular AT area increased 1.8 +/- 3.4 cm2 (12.1%, p < .05). When divided by legs in which subjects reported (unstable) or did not report (unstable) or did not report (stable) increased muscle weakness, unstable legs showed significant reduction (p < .05) in muscle area, whereas stable legs did not. Estimated total thigh muscle strength decreased 7.8% +/- 2.9% (p < .01), with a significant (p < .001) reduction in unstable legs (13.4% +/- 4.3%) but not in stable legs. The reduction in strength appears to be greater than the reduction in cross-sectional muscle area, but there is still a significant correlation (r = .44, p < .05).

Conclusions: The present results demonstrate not only progress of muscle weakness, but also of muscle atrophy in postpolio subjects.

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Category: Muscle Strength

Title: An 8-year longitudinal study of muscle strength, muscle fiber size, and dynamic electromyogram in individuals with late polio
Author: Grimby G, Stålberg E, Sandberg A, Sunnerhagen KS
Affiliation: Department of Rehabilitation Medicine, Sahlgrenska University Hospital, Göteborg University, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1998 Nov; 21(11):1428-37
Publication Year and Month: 1998 11

Abstract: Twenty-one subjects with polio 24 to 51 years prior to the first examination were studied on three occasions, each 4 years apart with measurements of muscle strength and endurance for knee extension, macro EMG, and muscle biopsy from vastus lateralis. On average the muscle strength decreased during the 8-year follow-up by 9-15%. Endurance decreased during the observation period. The muscle fiber area was markedly increased in most subjects. There was a decrease in the capillarization during the follow-up. Macro EMG was increased in all subjects (range 3-42 times control) and increased in 20 legs during the 8-year follow-up, but showed a decrease in 8 of 9 legs with an approximative breakpoint when macro MUPs were around 20 times the normal size. Thus, evidence of on-going denervation/reinnervation as well as of failing capacity to maintain large motor units was demonstrated. SFEMG showed a moderate degree of disturbed neuromuscular transmission.

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Category: Muscle Strength

Title: Perceived disability, fatigue, pain and measured isometric muscle strength in patients with post-polio symptoms
Author: Hildegunn L, Jones K, Grenstad T, Dreyer V, Farbu E, Rekand T
Affiliation: Department of Physical Therapy, Haukeland University Hospital, Bergen, Norway
Journal: Physiotherapy Research International
Citation: Physiother Res Int. 2007 Mar;12(1):39-49
Publication Year and Month: 2007 07

Abstract: BACKGROUND AND PURPOSE: Several years after the acute polio illness, patients may develop new post-polio symptoms. The purpose of the present study was to evaluate patients with post-polio symptoms with regard to perceived fatigue, functional ability, muscle strength, pain and with regard to measured physical fitness and isometric muscle strength. In addition, the relationship between the results of these subjective and objective measurements was investigated.

METHOD: This was a prospective cross-sectional study in which 32 patients with post-polio symptoms were included. Main outcome measures were the Fatigue Severity Scale (FSS), the Disability Rating Index (DRI), pain intensity, pain distribution, self-reported and measured muscle strength and oxygen uptake.

RESULTS: A marked reduction in isometric muscle strength compared to normal data, high scores in fatigue, widespread pain, low oxygen uptake and difficulties in performing some daily activities were found. Self-reported general muscle strength, pain intensity and pain distribution correlated significantly with patients' perceived fatigue and function at the activity level. There was no significant correlation between self-reported and measured results except for that found between isometric muscle strength in the legs and patients' perceived general muscle strength and oxygen uptake.

Conclusions: Evaluation of pain intensity, pain distribution, perceived muscle strength, fatigue and ability to perform daily tasks reveals important aspects of health status in patients with post-polio symptoms. Reduction in isometric muscle strength was not reflected in those tests or in reported symptoms, and should be monitored independently using a sensitive assessment tool. Accurate screening of isometric muscle strength in isolated muscle groups contributes to therapeutic management in making a functional diagnosis at the level of body function and structure when designing specific training programmes and in motivating patients. An evaluation combining self-reports with sensitive muscle strength measures provide supplementary information and is appropriate for evaluating these patients in physiotherapy practice.

Outcome of Research: Not applicable

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Category: Muscle Strength

Title: Strength gains without muscle injury after strength training in patients with postpolio muscular atrophy.
Author: Spector, S. A., Gordon, P. L., Feuerstein, I. M., Sivakumar, K., Hurley, B. F. and Dalakas, M. C.
Affiliation: Funded by Henry M. Jackson Foundation for the Advancement of Military Science
Journal: Muscle & Nerve
Citation: Spector, S. A., Gordon, P. L., Feuerstein, I. M., Sivakumar, K., Hurley, B. F. and Dalakas, M. C. (1996), Strength gains without muscle injury after strength training in patients with postpolio muscular atrophy. Muscle Nerve, 19: 1282–1290.
Publication Year and Month: 1996 10

Abstract: We evaluated changes in the dynamic and isometric strength in the newly weakened quadriceps muscles and asymptomatic triceps muscles of 6 patients with postpolio muscular atrophy (PPMA) after 10 weeks of progressive resistance strength training. Alterations in muscle size were determined with magnetic resonance imaging. Serum creatine kinase levels were measured throughout training, and histological signs of muscle injury and changes in muscle fiber size and types were assessed with muscle biopsies before and after training. Exercise training led to an increase in dynamic strength of 41% and 61% for the two knee extensor tests, and 54% and 71% for the two elbow extensor tests. Up to 20% of the improvement was maintained 5 months after cessation of training. Isometric strength, whole muscle cross-sectional areas of quadriceps and triceps muscles, and serum muscle enzymes did not change. No destructive histopathological changes were noted in the repeat muscle biopsies, and no consistent changes in muscle fiber size or fiber type percentages were observed. These results demonstrate that a supervised resistance training program can lead to significant gains in dynamic strength of both symptomatic and asymptomatic muscles of PPMA patients without serological or histological evidence of muscular damage.

Conclusions: This study of 6 patient who had postpolio muscluar atrophy (PPMA) demonstrated a supervised resistance training program can lead to significant gains in dynamic strength of both symptomatic and asymptomatic muscles of PPMA patients without serological or histological evidence of muscular damage.

Outcome of Research: More research required

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Comments (if any): A small sample size and further information regarding the baseline strength values of affected muscles makes it difficult to conclude on the significance of these results.

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Category: Muscle Strength

Title: The course of functional status and muscle strength in patients with late-onset sequelae of poliomyelitis: a systematic review
Author: Stolwijk-Swüste JM, Beelen A, Lankhorst GJ, Nollet F; CARPA Study Group
Affiliation: Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam, The Netherlands – [email protected]
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 2005 Aug;86(8):1693-701
Publication Year and Month: 2005 08

Abstract: OBJECTIVES: To review systematically studies of late-onset polio sequelae on the course of functional status and muscle strength over time and to identify prognostic factors of change.

DATA SOURCES: We conducted a computerized literature search up to July 2004 in MEDLINE, EMBASE, CINAHL, Web of Science, PsychInfo, and the Cochrane controlled trial register using the key words: postpolio, postpoliomyelitis, postpoliomyelitis syndrome, post poliomyelitis muscular atrophy, and poliomyelitis.

STUDY SELECTION: Reports were selected by 1 reviewer if the study involved subjects with a history of poliomyelitis, the outcome measures described functional status or muscle strength, and follow-up was for at least 6 months.

DATA EXTRACTION: Studies were summarized with regard to population, design, sample size, outcome measures, results, and methodologic scores. Overlap in populations between studies was checked.

DATA SYNTHESIS: Of 71 potentially relevant studies, 19 were included (2 on functional status, 15 on muscle strength, 2 on both muscle strength and functional status). Two studies on the course of functional status had sufficient quality and reported inconsistent results. Four studies on the course of muscle strength had sufficient quality. Two studies reported a decline in strength and 2 reported no change. Decline in strength was only reported in studies with a follow-up period longer than 2 years. One study reported extent of paresis as a prognostic factor for change in perceived physical mobility.

Conclusions: Conclusions cannot be drawn from the literature with regard to the functional course or prognostic factors in late-onset polio sequelae. The rate of decline in muscle strength is slow, and prognostic factors have not yet been identified. Long-term follow-up studies with unselected study populations and age-matched controls are needed, with specific focus on prognostic factors.

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Category: Muscle Strength

Title: Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.
Author: Voorn EL (1,2), Brehm MA (1), Beelen A (1), de Haan A (2), Nollet F (1), Gerrits KH (2)
Affiliation: (1) Department of Rehabilitation, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; (2) MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
Journal: Public Library of Science
Citation: PLoS One. 2014 Jul 14;9(7):e101660. doi: 10.1371/journal.pone.0101660.
Publication Year and Month: 2014 07

Abstract: OBJECTIVE: To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals.

METHODS: Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean).

RESULTS: In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016).

SIGNIFICANCE: This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Conclusions: In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.

Outcome of Research: Not applicable,

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Category: Muscle Strength

Title: Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.
Author: Voorn, E.L., Brehm, M.A., Beelen, A., de Haan, A., Nollet, F., Gerrits, K.H.L.


Affiliation: University of Amsterdam
Journal:
Citation: PLos One
Voorn, E.L., Brehm, M.A., Beelen, A., de Haan, A., Nollet, F., Gerrits, K.H.L. (2014) Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome. PLoS One. Jul 14;9(7):e101660. doi: 10.1371/journal.pone.0101660
Publication Year and Month: 2014 07

Abstract: Objective
To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals.

Methods
Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean).

Results
In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016).

Conclusions
In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.

Significance
This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Conclusions: Both in individuals with PPS and in healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions of the knee extensor muscles is high. The reliability of contractile speed indices is only moderate, except for RT50 in PPS, demonstrating high reliability. Considering these results, the assessment of contractile properties in PPS is sufficiently reliable to identify those patients with impaired contractile functioning of their knee extensor muscles, and, accordingly, to evaluate changes over time or following interventions in this patient group. Based on its potential in PPS, future research may also focus on the feasibility of this method in other slowly progressive neuromuscular diseases where muscle fatigue is a major problem.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Disability in a 4-year follow-up study of people with post-polio syndrome
Author: Willén C, Thoren-Jönsson AL, Grimby G, Sunnerhagen KS
Affiliation: Institute of Neurosciences and Physiology-Rehabilitation Medicine, Sahlgrenska Academy, Göteborg, Sweden
Journal: Journal of Rehabilitation Medicine
Citation: J Rehabil Med. 2007 Mar;39(2):175-80.
Publication Year and Month: 2007 03

Abstract: OBJECTIVE: To evaluate changes over time in a clinically based cohort of individuals with post-polio syndrome.

DESIGN: A prospective longitudinal study.

SUBJECTS: A total of 106 individuals with poliomyelitis sequelae were included in the study. They were self-referred or had been referred to the post-polio clinic. After 4 years subjects were called for a follow-up and underwent the same measurements as at the initial assessment.

METHODS: The following measurements were conducted at both the initial assessment, and the follow-up: questionnaires including Nottingham Health Profile, muscle strength and walking speed.

RESULTS: Minor changes in disability during a 4-year period were shown. A significant reduction in muscle strength was only seen for 60° flexion in the left leg and for right and left dorsal flexion. No change could be seen in the total Nottingham Health Profile score.

Conclusions: The minor changes in disability found in this study are an indication that we still do not know which subjects are at risk for deterioration. It is difficult to say whether the small changes over time shown in this study are associated with support from the polio clinic or are an expression of the natural history of the syndrome. However, it is hoped that support from the polio clinic may result in self-selected lifestyle changes, which may positively influence the development of symptoms and functional capacity.

Outcome of Research: Not applicable.

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There are currently 14 papers in this category.

Category: Muscle Strength

Title: Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.
Author: Voorn, E.L., Brehm, M.A., Beelen, A., de Haan, A., Nollet, F., Gerrits, K.H.L.


Affiliation: University of Amsterdam
Journal:
Citation: PLos One
Voorn, E.L., Brehm, M.A., Beelen, A., de Haan, A., Nollet, F., Gerrits, K.H.L. (2014) Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome. PLoS One. Jul 14;9(7):e101660. doi: 10.1371/journal.pone.0101660
Publication Year and Month: 2014 07

Abstract: Objective
To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals.

Methods
Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean).

Results
In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016).

Conclusions
In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.

Significance
This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Conclusions: Both in individuals with PPS and in healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions of the knee extensor muscles is high. The reliability of contractile speed indices is only moderate, except for RT50 in PPS, demonstrating high reliability. Considering these results, the assessment of contractile properties in PPS is sufficiently reliable to identify those patients with impaired contractile functioning of their knee extensor muscles, and, accordingly, to evaluate changes over time or following interventions in this patient group. Based on its potential in PPS, future research may also focus on the feasibility of this method in other slowly progressive neuromuscular diseases where muscle fatigue is a major problem.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Strength, endurance, and work capacity after muscle strengthening exercise in postpolio subjects
Author: Agre JC, Rodriquez AA, Franke TM
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin Medical School, Madison, USA
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1997 Jul; 78(7):681-6
Publication Year and Month: 1997 07

Abstract: OBJECTIVE: To determine whether a 12-week home quadriceps muscle strengthening exercise program would increase muscle strength, isometric endurance, and tension time index (TTI) in postpolio syndrome subjects without adversely affecting the surviving motor units or the muscle.

DESIGN: A longitudinal study to investigate the effect of a 12-week exercise program on neuromuscular function and electromyographic variables.

SETTING: Neuromuscular laboratory of a university hospital.

SUBJECTS: Seven subjects were recruited from a cohort of 12 subjects who had participated in a previous exercise study. All subjects had greater than antigravity strength of the quadriceps. Upon completion of a postpolio questionnaire, all acknowledged common postpolio syndrome symptoms such as new fatigue, pain, and weakness; 6 of the 7 acknowledged new strength decline.

INTERVENTION: On Mondays and Thursdays subjects performed three sets of four maximal isometric contractions of the quadriceps held for 5 seconds each. On Tuesdays and Fridays subjects performed three sets of 12 dynamic knee extension exercises with ankle weights.

MAIN OUTCOME MEASURES: Neuromuscular variables of the quadriceps muscles were measured at the beginning and completion of the exercise program and included: isokinetic peak torque (ISOKPT, at 60 degrees/sec angular velocity) and total work performed of four contractions (ISOKTW), isometric peak torque (MVC), endurance (EDUR, time subject could hold isometric contraction at 40% of the initial MVC), isometric tension time index (TTI, product of endurance time and torque at 40% of MVC), and initial and final ankle weight (WGT, kg) lifted. Electromyographic variables included: fiber density (FD), jitter (MCD), and blocking (BLK) from single fiber assessment and median macro amplitude (MACRO). Serum creatine kinase (CK) was also measured initially and at 4-week intervals throughout the study.

RESULTS: The following variables significantly (p < .05) increased: WGT by 47%, ISOKPT, 15%, ISOKTW, 15%; MVC, 36%; EDUR, 21%; TTI, 18%. The following variables did not significantly (p > .05) change: FD, MCD, BLK, MACRO, and CK.

Conclusions: This home exercise program significantly increased strength, endurance, and TTI without apparently adversely affecting the motor units or the muscle, as the EMG and CK variables did not change.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Neuromuscular function: comparison of symptomatic and asymptomatic polio subjects to control subjects
Author: Agre JC, Rodriquez AA
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin - Madison Medical School 53792
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1990 Jul; 71(8):545-51
Publication Year and Month: 1990 07

Abstract: The purpose of this study was to determine if there were any differences between symptomatic and asymptomatic polio survivors by history of acute poliomyelitis illness, electromyographic evidence of terminal motor unit reorganization, and neuromuscular function of the quadriceps femoris muscle. Thirty-four symptomatic postpolio subjects, 16 asymptomatic postpolio subjects, and 41 controls were studied. A questionnaire assessed polio history. Peak knee extension torque was measured isokinetically and isometrically. Endurance (time to exhaustion) was measured at 40% of maximal isometric torque. Work capacity was determined as the product of torque and duration. Recovery of isometric strength was measured at regular intervals for ten minutes after exhaustion. Quantitative electromyography was also performed on the quadriceps to determine motor unit action potential duration and amplitude. It was found that symptomatic subjects had evidence of more severe original polio involvement by history (documented electromyographically), were weaker and capable of performing less work than asymptomatic subjects, and recovered strength less readily than controls.

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Category: Muscle Strength

Title: Reduction in thigh muscle cross-sectional area and strength in a 4-year follow-up in late polio
Author: Grimby G, Kvist H, Grangård U
Affiliation: Department of Rehabilitation Medicine, University of Göteborg, Sahlgrenska University Hospital, Sweden
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1996 Oct; 77(10):1044-8
Publication Year and Month: 1996 10

Abstract: OBJECTIVE: To study changes in cross-sectional thigh muscle area and muscle strength in late polio subjects over a 4-year period.

DESIGN: Longitudinal study of a cohort of polio survivors, comparing subjects who acknowledge (unstable) with those who do not acknowledge (stable) new muscle weakness.

SETTING: University hospital.

SUBJECTS: Eighteen subjects (6 men, 12 women) with polio-myelitis sequelae (39 to 46 years of age) were studied on two occasions 4 years apart; the first examination was 37 to 44 years after onset of polio. Subjects were recruited through hospital registers, newspaper advertisement, and a patient organization.

OUTCOME MEASUREMENTS: Thigh muscle and intermuscular and intramuscular adipose tissue (AT) cross-sectional areas were measured by computed tomography. Isometric muscle strength for knee extension and flexion was measured using a Kin-Com dynamometer.

RESULTS: Cross-sectional muscle area decreased on average 1.3 +/- 3.6 cm2 (1.4%, p < .05); the intermuscular and intramuscular AT area increased 1.8 +/- 3.4 cm2 (12.1%, p < .05). When divided by legs in which subjects reported (unstable) or did not report (unstable) or did not report (stable) increased muscle weakness, unstable legs showed significant reduction (p < .05) in muscle area, whereas stable legs did not. Estimated total thigh muscle strength decreased 7.8% +/- 2.9% (p < .01), with a significant (p < .001) reduction in unstable legs (13.4% +/- 4.3%) but not in stable legs. The reduction in strength appears to be greater than the reduction in cross-sectional muscle area, but there is still a significant correlation (r = .44, p < .05).

Conclusions: The present results demonstrate not only progress of muscle weakness, but also of muscle atrophy in postpolio subjects.

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Category: Muscle Strength

Title: The course of functional status and muscle strength in patients with late-onset sequelae of poliomyelitis: a systematic review
Author: Stolwijk-Swüste JM, Beelen A, Lankhorst GJ, Nollet F; CARPA Study Group
Affiliation: Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam, The Netherlands – [email protected]
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 2005 Aug;86(8):1693-701
Publication Year and Month: 2005 08

Abstract: OBJECTIVES: To review systematically studies of late-onset polio sequelae on the course of functional status and muscle strength over time and to identify prognostic factors of change.

DATA SOURCES: We conducted a computerized literature search up to July 2004 in MEDLINE, EMBASE, CINAHL, Web of Science, PsychInfo, and the Cochrane controlled trial register using the key words: postpolio, postpoliomyelitis, postpoliomyelitis syndrome, post poliomyelitis muscular atrophy, and poliomyelitis.

STUDY SELECTION: Reports were selected by 1 reviewer if the study involved subjects with a history of poliomyelitis, the outcome measures described functional status or muscle strength, and follow-up was for at least 6 months.

DATA EXTRACTION: Studies were summarized with regard to population, design, sample size, outcome measures, results, and methodologic scores. Overlap in populations between studies was checked.

DATA SYNTHESIS: Of 71 potentially relevant studies, 19 were included (2 on functional status, 15 on muscle strength, 2 on both muscle strength and functional status). Two studies on the course of functional status had sufficient quality and reported inconsistent results. Four studies on the course of muscle strength had sufficient quality. Two studies reported a decline in strength and 2 reported no change. Decline in strength was only reported in studies with a follow-up period longer than 2 years. One study reported extent of paresis as a prognostic factor for change in perceived physical mobility.

Conclusions: Conclusions cannot be drawn from the literature with regard to the functional course or prognostic factors in late-onset polio sequelae. The rate of decline in muscle strength is slow, and prognostic factors have not yet been identified. Long-term follow-up studies with unselected study populations and age-matched controls are needed, with specific focus on prognostic factors.

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Category: Muscle Strength

Title: Disability in a 4-year follow-up study of people with post-polio syndrome
Author: Willén C, Thoren-Jönsson AL, Grimby G, Sunnerhagen KS
Affiliation: Institute of Neurosciences and Physiology-Rehabilitation Medicine, Sahlgrenska Academy, Göteborg, Sweden
Journal: Journal of Rehabilitation Medicine
Citation: J Rehabil Med. 2007 Mar;39(2):175-80.
Publication Year and Month: 2007 03

Abstract: OBJECTIVE: To evaluate changes over time in a clinically based cohort of individuals with post-polio syndrome.

DESIGN: A prospective longitudinal study.

SUBJECTS: A total of 106 individuals with poliomyelitis sequelae were included in the study. They were self-referred or had been referred to the post-polio clinic. After 4 years subjects were called for a follow-up and underwent the same measurements as at the initial assessment.

METHODS: The following measurements were conducted at both the initial assessment, and the follow-up: questionnaires including Nottingham Health Profile, muscle strength and walking speed.

RESULTS: Minor changes in disability during a 4-year period were shown. A significant reduction in muscle strength was only seen for 60° flexion in the left leg and for right and left dorsal flexion. No change could be seen in the total Nottingham Health Profile score.

Conclusions: The minor changes in disability found in this study are an indication that we still do not know which subjects are at risk for deterioration. It is difficult to say whether the small changes over time shown in this study are associated with support from the polio clinic or are an expression of the natural history of the syndrome. However, it is hoped that support from the polio clinic may result in self-selected lifestyle changes, which may positively influence the development of symptoms and functional capacity.

Outcome of Research: Not applicable.

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Category: Muscle Strength

Title: Reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio
Author: Flansbjer UB, Lexell J
Affiliation: Department of Rehabilitation, Skåne University Hospital, Orupssjukhuset, Lund, Sweden - [email protected]

Journal: Journal of Rehabilitation Medicine
Citation: J Rehabil Med. 2010 Jun;42(6):588-92. doi: 10.2340/16501977-0561
Publication Year and Month: 2010 06

Abstract: OBJECTIVE: To assess the reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio.

DESIGN: A test-retest reliability study.

SUBJECTS: Thirty men and women (mean age 63 (standard deviation 6.4) years) with verified late effects of polio.

METHODS: Knee extensor and flexor muscle strength in both lower limbs were measured twice 7 days apart using a Biodex dynamometer (isokinetic concentric contractions at 60°/s and isometric contractions with knee flexion angle 90º) and a Leg Extension/Curl Rehab exercise machine with pneumatic resistance (HUR) (isotonic contractions). Reliability was assessed with the intraclass correlation coefficient (ICC1,1), the mean difference between the test sessions (đ) together with the 95% confidence intervals for đ, the standard error of measurement (SEM and SEM%), the smallest real difference (SRD and SRD%) and Bland-Altman graphs.

RESULTS: Test-retest agreements were high, (ICC1,1 0.93–0.99) and measurement errors generally small. The SEM% was 4–14% and the SRD% 11–39%, with the highest values for the isokinetic measurements.

Conclusions: Knee muscle strength can be measured reliably and can be used to detect real changes after an intervention for a group of persons with late effects of polio, whereas the values may be too high for single individuals or to detect smaller short-term changes over time for a group of individuals.

Outcome of Research: Not applicable.

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Category: Muscle Strength

Title: An 8-year longitudinal study of muscle strength, muscle fiber size, and dynamic electromyogram in individuals with late polio
Author: Grimby G, Stålberg E, Sandberg A, Sunnerhagen KS
Affiliation: Department of Rehabilitation Medicine, Sahlgrenska University Hospital, Göteborg University, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1998 Nov; 21(11):1428-37
Publication Year and Month: 1998 11

Abstract: Twenty-one subjects with polio 24 to 51 years prior to the first examination were studied on three occasions, each 4 years apart with measurements of muscle strength and endurance for knee extension, macro EMG, and muscle biopsy from vastus lateralis. On average the muscle strength decreased during the 8-year follow-up by 9-15%. Endurance decreased during the observation period. The muscle fiber area was markedly increased in most subjects. There was a decrease in the capillarization during the follow-up. Macro EMG was increased in all subjects (range 3-42 times control) and increased in 20 legs during the 8-year follow-up, but showed a decrease in 8 of 9 legs with an approximative breakpoint when macro MUPs were around 20 times the normal size. Thus, evidence of on-going denervation/reinnervation as well as of failing capacity to maintain large motor units was demonstrated. SFEMG showed a moderate degree of disturbed neuromuscular transmission.

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Category: Muscle Strength

Title: Quantitative muscle ultrasound and quadriceps strength in patients with post-polio syndrome
Author: Bickerstaffe A (1), Beelen A, Zwarts MJ, Nollet F, van Dijk JP
Affiliation: (1) Department of Rehabilitation, Academic Medical Center, Postbus 22660, 1100 DD, Amsterdam, The Netherlands
Journal: Muscle & Nerve
Citation: Muscle Nerve. 2015 Jan;51(1):24-9. doi: 10.1002/mus.24272
Publication Year and Month: 2015 01

Abstract: INTRODUCTION: We investigated whether muscle ultrasound can distinguish muscles affected by post-polio syndrome (PPS) from healthy muscles and whether severity of ultrasound abnormalities is associated with muscle strength.

METHODS: Echo intensity, muscle thickness, and isometric strength of the quadriceps muscles were measured in 48 patients with PPS and 12 healthy controls.

RESULTS: Patients with PPS had significantly higher echo intensity and lower muscle thickness than healthy controls. In patients, both echo intensity and muscle thickness were associated independently with muscle strength. A combined measure of echo intensity and muscle thickness was more strongly related to muscle strength than either parameter alone.

Conclusions: Quantitative ultrasound distinguishes healthy muscles from those affected by PPS, and measures of muscle quality and quantity are associated with muscle strength. Hence, ultrasound could be a useful tool for assessing disease severity and monitoring changes resulting from disease progression or clinical intervention in patients with PPS.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Randomized controlled trial of strength training in post-polio patients
Author: Chan, K. M., Amirjani, N., Sumrain, M., Clarke, A. and Strohschein, F. J.
Affiliation: Funded by Alberta Heritage Foundation and Canada Foundation
Journal: Muscle & Nerve
Citation: Chan, K. M., Amirjani, N., Sumrain, M., Clarke, A. and Strohschein, F. J. (2003), Randomized controlled trial of strength training in post-polio patients. Muscle Nerve, 27: 332–338. doi:10.1002/mus.10327
Publication Year and Month: 2003 02

Abstract: Many post-polio patients develop new muscle weakness decades after the initial illness. However, its mechanism and treatment are controversial. The purpose of this study was to test the hypotheses that: (1) after strength training, post-polio patients show strength improvement comparable to that seen in the healthy elderly; (2) such training does not have a deleterious effect on motor unit (MU) survival; and (3) part of the strength improvement is due to an increase in voluntary motor drive. After baseline measures including maximum voluntary contraction force, voluntary activation index, motor unit number estimate, and the tetanic tension of the thumb muscles had been determined, 10 post-polio patients with hand involvement were randomized to either the training or control group. The progressive resistance training program consisted of three sets of eight isometric contractions, three times weekly for 12 weeks. Seven healthy elderly were also randomized and trained in a similar manner. Changes in the baseline parameters were monitored once every 4 weeks throughout the training period. The trained post-polio patients showed a significant improvement in their strength (P < 0.05). The magnitude of gain was greater than that seen in the healthy elderly (mean ± SE, 41 ± 16% vs. 29 ± 8%). The training did not adversely affect MU survival and the improvement was largely attributable to an increase in voluntary motor drive. We therefore conclude that moderate intensity strength training is safe and effective in post-polio patients.

Conclusions: This study demonstrated moderate intensity strength training of affected hand muscles is safe and effective in post-polio patients.

Outcome of Research: More research required

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Comments (if any): Strength training of more functional muscles (e.g. legs) that consider baseline strength levels, appropriate loading and rest, with regular monitoring is important to evaluate in a randomised control trial to assist with exercise recommendations.

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Category: Muscle Strength

Title: Strength gains without muscle injury after strength training in patients with postpolio muscular atrophy.
Author: Spector, S. A., Gordon, P. L., Feuerstein, I. M., Sivakumar, K., Hurley, B. F. and Dalakas, M. C.
Affiliation: Funded by Henry M. Jackson Foundation for the Advancement of Military Science
Journal: Muscle & Nerve
Citation: Spector, S. A., Gordon, P. L., Feuerstein, I. M., Sivakumar, K., Hurley, B. F. and Dalakas, M. C. (1996), Strength gains without muscle injury after strength training in patients with postpolio muscular atrophy. Muscle Nerve, 19: 1282–1290.
Publication Year and Month: 1996 10

Abstract: We evaluated changes in the dynamic and isometric strength in the newly weakened quadriceps muscles and asymptomatic triceps muscles of 6 patients with postpolio muscular atrophy (PPMA) after 10 weeks of progressive resistance strength training. Alterations in muscle size were determined with magnetic resonance imaging. Serum creatine kinase levels were measured throughout training, and histological signs of muscle injury and changes in muscle fiber size and types were assessed with muscle biopsies before and after training. Exercise training led to an increase in dynamic strength of 41% and 61% for the two knee extensor tests, and 54% and 71% for the two elbow extensor tests. Up to 20% of the improvement was maintained 5 months after cessation of training. Isometric strength, whole muscle cross-sectional areas of quadriceps and triceps muscles, and serum muscle enzymes did not change. No destructive histopathological changes were noted in the repeat muscle biopsies, and no consistent changes in muscle fiber size or fiber type percentages were observed. These results demonstrate that a supervised resistance training program can lead to significant gains in dynamic strength of both symptomatic and asymptomatic muscles of PPMA patients without serological or histological evidence of muscular damage.

Conclusions: This study of 6 patient who had postpolio muscluar atrophy (PPMA) demonstrated a supervised resistance training program can lead to significant gains in dynamic strength of both symptomatic and asymptomatic muscles of PPMA patients without serological or histological evidence of muscular damage.

Outcome of Research: More research required

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Comments (if any): A small sample size and further information regarding the baseline strength values of affected muscles makes it difficult to conclude on the significance of these results.

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Category: Muscle Strength

Title: Perceived disability, fatigue, pain and measured isometric muscle strength in patients with post-polio symptoms
Author: Hildegunn L, Jones K, Grenstad T, Dreyer V, Farbu E, Rekand T
Affiliation: Department of Physical Therapy, Haukeland University Hospital, Bergen, Norway
Journal: Physiotherapy Research International
Citation: Physiother Res Int. 2007 Mar;12(1):39-49
Publication Year and Month: 2007 07

Abstract: BACKGROUND AND PURPOSE: Several years after the acute polio illness, patients may develop new post-polio symptoms. The purpose of the present study was to evaluate patients with post-polio symptoms with regard to perceived fatigue, functional ability, muscle strength, pain and with regard to measured physical fitness and isometric muscle strength. In addition, the relationship between the results of these subjective and objective measurements was investigated.

METHOD: This was a prospective cross-sectional study in which 32 patients with post-polio symptoms were included. Main outcome measures were the Fatigue Severity Scale (FSS), the Disability Rating Index (DRI), pain intensity, pain distribution, self-reported and measured muscle strength and oxygen uptake.

RESULTS: A marked reduction in isometric muscle strength compared to normal data, high scores in fatigue, widespread pain, low oxygen uptake and difficulties in performing some daily activities were found. Self-reported general muscle strength, pain intensity and pain distribution correlated significantly with patients' perceived fatigue and function at the activity level. There was no significant correlation between self-reported and measured results except for that found between isometric muscle strength in the legs and patients' perceived general muscle strength and oxygen uptake.

Conclusions: Evaluation of pain intensity, pain distribution, perceived muscle strength, fatigue and ability to perform daily tasks reveals important aspects of health status in patients with post-polio symptoms. Reduction in isometric muscle strength was not reflected in those tests or in reported symptoms, and should be monitored independently using a sensitive assessment tool. Accurate screening of isometric muscle strength in isolated muscle groups contributes to therapeutic management in making a functional diagnosis at the level of body function and structure when designing specific training programmes and in motivating patients. An evaluation combining self-reports with sensitive muscle strength measures provide supplementary information and is appropriate for evaluating these patients in physiotherapy practice.

Outcome of Research: Not applicable

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Category: Muscle Strength

Title: Men With Late Effects of Polio Decline More Than Women in Lower Limb Muscle Strength: A 4-Year Longitudinal Study
Author: Flansbjer UB (1), Brogårdh C (2), Horstmann V (3), Lexell J (4)
Affiliation: (1) 1Department of Health Sciences, Lund University, Rehabilitation Medicine Research Group, Box 157, SE221 00 Lund, Sweden; (2) Department of Health Sciences, Lund University, Physiotherapy Research Group, Box 157, SE221 00 Lund, Sweden; Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden; (3) Department of Health Sciences, Lund University, Research Group Active and Healthy Ageing, Box 157, SE221 00 Lund, Sweden; (4) Department of Health Sciences, Lund University, Rehabilitation Medicine Research Group, Box 157, SE221 00 Lund, Sweden; Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden
Journal: PM&R: The Journal of Injury, Function, and Rehabilitation
Citation: PM R. 2015 May 12. pii: S1934-1482(15)00233-6. doi: 10.1016/j.pmrj.2015.05.005
Publication Year and Month: 2015 05

Abstract: BACKGROUND: In persons with prior paralytic poliomyelitis, progressive muscle weakness can occur after a stable period of at least 15 years. Knowledge is limited about which factors influence changes in lower limb muscle strength in these persons.

OBJECTIVE: To assess changes in lower limb muscle strength annually over 4 years in persons with late effects of polio and to identify prognostic factors for changes in muscle strength.

DESIGN: A prospective, longitudinal study.

SETTING: University hospital outpatient program.

PARTICIPANTS: Fifty-two ambulant persons (mean age ± standard deviation: 64 ± 6 years) with verified late effects of polio.

METHODS: Mixed linear models were used to analyze changes in muscle strength and to identify determinants among the following covariates: gender, age, age at acute polio infection, time with late effects of polio, body mass index, and estimated baseline muscle weakness.

MAIN OUTCOME MEASUREMENTS: Knee extensor and flexor and ankle dorsiflexor muscle strength were measured annually with a Biodex dynamometer.

RESULTS: The men (n = 28) had significant linear change over time for all knee muscle strength measurements, from -1.4% (P < .05) per year for isokinetic knee flexion in the less-affected lower limb to -4.2% (P < .001) for isokinetic knee extension in the more-affected lower limb, and for 2 ankle dorsiflexor muscle strength measurements (-3.3%-1.4% per year [P < .05]). The women (n = 24) had a significant linear change over time only for ankle dorsiflexor measurements (4.0%-5.5% per year [P < .01]). Gender was the strongest factor that predicted a change in muscle strength over time.

Conclusions: Over 4 years, men had a greater decline in muscle strength than did women, but the rate of decline did not accelerate. This finding indicates that gender could be a contributing factor to the progressive decline in muscle strength in persons with late effects of polio.

Outcome of Research: Not applicable

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Category: Muscle Strength

Title: Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.
Author: Voorn EL (1,2), Brehm MA (1), Beelen A (1), de Haan A (2), Nollet F (1), Gerrits KH (2)
Affiliation: (1) Department of Rehabilitation, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; (2) MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
Journal: Public Library of Science
Citation: PLoS One. 2014 Jul 14;9(7):e101660. doi: 10.1371/journal.pone.0101660.
Publication Year and Month: 2014 07

Abstract: OBJECTIVE: To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals.

METHODS: Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean).

RESULTS: In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016).

SIGNIFICANCE: This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Conclusions: In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.

Outcome of Research: Not applicable,

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There are currently 14 papers in this category.

Category: Muscle Strength

Title: Men With Late Effects of Polio Decline More Than Women in Lower Limb Muscle Strength: A 4-Year Longitudinal Study
Author: Flansbjer UB (1), Brogårdh C (2), Horstmann V (3), Lexell J (4)
Affiliation: (1) 1Department of Health Sciences, Lund University, Rehabilitation Medicine Research Group, Box 157, SE221 00 Lund, Sweden; (2) Department of Health Sciences, Lund University, Physiotherapy Research Group, Box 157, SE221 00 Lund, Sweden; Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden; (3) Department of Health Sciences, Lund University, Research Group Active and Healthy Ageing, Box 157, SE221 00 Lund, Sweden; (4) Department of Health Sciences, Lund University, Rehabilitation Medicine Research Group, Box 157, SE221 00 Lund, Sweden; Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden
Journal: PM&R: The Journal of Injury, Function, and Rehabilitation
Citation: PM R. 2015 May 12. pii: S1934-1482(15)00233-6. doi: 10.1016/j.pmrj.2015.05.005
Publication Year and Month: 2015 05

Abstract: BACKGROUND: In persons with prior paralytic poliomyelitis, progressive muscle weakness can occur after a stable period of at least 15 years. Knowledge is limited about which factors influence changes in lower limb muscle strength in these persons.

OBJECTIVE: To assess changes in lower limb muscle strength annually over 4 years in persons with late effects of polio and to identify prognostic factors for changes in muscle strength.

DESIGN: A prospective, longitudinal study.

SETTING: University hospital outpatient program.

PARTICIPANTS: Fifty-two ambulant persons (mean age ± standard deviation: 64 ± 6 years) with verified late effects of polio.

METHODS: Mixed linear models were used to analyze changes in muscle strength and to identify determinants among the following covariates: gender, age, age at acute polio infection, time with late effects of polio, body mass index, and estimated baseline muscle weakness.

MAIN OUTCOME MEASUREMENTS: Knee extensor and flexor and ankle dorsiflexor muscle strength were measured annually with a Biodex dynamometer.

RESULTS: The men (n = 28) had significant linear change over time for all knee muscle strength measurements, from -1.4% (P < .05) per year for isokinetic knee flexion in the less-affected lower limb to -4.2% (P < .001) for isokinetic knee extension in the more-affected lower limb, and for 2 ankle dorsiflexor muscle strength measurements (-3.3%-1.4% per year [P < .05]). The women (n = 24) had a significant linear change over time only for ankle dorsiflexor measurements (4.0%-5.5% per year [P < .01]). Gender was the strongest factor that predicted a change in muscle strength over time.

Conclusions: Over 4 years, men had a greater decline in muscle strength than did women, but the rate of decline did not accelerate. This finding indicates that gender could be a contributing factor to the progressive decline in muscle strength in persons with late effects of polio.

Outcome of Research: Not applicable

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Category: Muscle Strength

Title: Quantitative muscle ultrasound and quadriceps strength in patients with post-polio syndrome
Author: Bickerstaffe A (1), Beelen A, Zwarts MJ, Nollet F, van Dijk JP
Affiliation: (1) Department of Rehabilitation, Academic Medical Center, Postbus 22660, 1100 DD, Amsterdam, The Netherlands
Journal: Muscle & Nerve
Citation: Muscle Nerve. 2015 Jan;51(1):24-9. doi: 10.1002/mus.24272
Publication Year and Month: 2015 01

Abstract: INTRODUCTION: We investigated whether muscle ultrasound can distinguish muscles affected by post-polio syndrome (PPS) from healthy muscles and whether severity of ultrasound abnormalities is associated with muscle strength.

METHODS: Echo intensity, muscle thickness, and isometric strength of the quadriceps muscles were measured in 48 patients with PPS and 12 healthy controls.

RESULTS: Patients with PPS had significantly higher echo intensity and lower muscle thickness than healthy controls. In patients, both echo intensity and muscle thickness were associated independently with muscle strength. A combined measure of echo intensity and muscle thickness was more strongly related to muscle strength than either parameter alone.

Conclusions: Quantitative ultrasound distinguishes healthy muscles from those affected by PPS, and measures of muscle quality and quantity are associated with muscle strength. Hence, ultrasound could be a useful tool for assessing disease severity and monitoring changes resulting from disease progression or clinical intervention in patients with PPS.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.
Author: Voorn EL (1,2), Brehm MA (1), Beelen A (1), de Haan A (2), Nollet F (1), Gerrits KH (2)
Affiliation: (1) Department of Rehabilitation, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; (2) MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
Journal: Public Library of Science
Citation: PLoS One. 2014 Jul 14;9(7):e101660. doi: 10.1371/journal.pone.0101660.
Publication Year and Month: 2014 07

Abstract: OBJECTIVE: To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals.

METHODS: Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean).

RESULTS: In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016).

SIGNIFICANCE: This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Conclusions: In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.

Outcome of Research: Not applicable,

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Category: Muscle Strength

Title: Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.
Author: Voorn, E.L., Brehm, M.A., Beelen, A., de Haan, A., Nollet, F., Gerrits, K.H.L.


Affiliation: University of Amsterdam
Journal:
Citation: PLos One
Voorn, E.L., Brehm, M.A., Beelen, A., de Haan, A., Nollet, F., Gerrits, K.H.L. (2014) Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome. PLoS One. Jul 14;9(7):e101660. doi: 10.1371/journal.pone.0101660
Publication Year and Month: 2014 07

Abstract: Objective
To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS) and 18 age-matched healthy individuals.

Methods
Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD), and early and late relaxation time (RT50 and RT25), using the intraclass correlation coefficient (ICC) and standard error of measurement (SEM, expressed as % of the mean).

Results
In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90) and small SEM values (PPS: 7.1%, healthy individuals: 7.0%). Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%). We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016).

Conclusions
In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.

Significance
This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Conclusions: Both in individuals with PPS and in healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions of the knee extensor muscles is high. The reliability of contractile speed indices is only moderate, except for RT50 in PPS, demonstrating high reliability. Considering these results, the assessment of contractile properties in PPS is sufficiently reliable to identify those patients with impaired contractile functioning of their knee extensor muscles, and, accordingly, to evaluate changes over time or following interventions in this patient group. Based on its potential in PPS, future research may also focus on the feasibility of this method in other slowly progressive neuromuscular diseases where muscle fatigue is a major problem.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio
Author: Flansbjer UB, Lexell J
Affiliation: Department of Rehabilitation, Skåne University Hospital, Orupssjukhuset, Lund, Sweden - [email protected]

Journal: Journal of Rehabilitation Medicine
Citation: J Rehabil Med. 2010 Jun;42(6):588-92. doi: 10.2340/16501977-0561
Publication Year and Month: 2010 06

Abstract: OBJECTIVE: To assess the reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio.

DESIGN: A test-retest reliability study.

SUBJECTS: Thirty men and women (mean age 63 (standard deviation 6.4) years) with verified late effects of polio.

METHODS: Knee extensor and flexor muscle strength in both lower limbs were measured twice 7 days apart using a Biodex dynamometer (isokinetic concentric contractions at 60°/s and isometric contractions with knee flexion angle 90º) and a Leg Extension/Curl Rehab exercise machine with pneumatic resistance (HUR) (isotonic contractions). Reliability was assessed with the intraclass correlation coefficient (ICC1,1), the mean difference between the test sessions (đ) together with the 95% confidence intervals for đ, the standard error of measurement (SEM and SEM%), the smallest real difference (SRD and SRD%) and Bland-Altman graphs.

RESULTS: Test-retest agreements were high, (ICC1,1 0.93–0.99) and measurement errors generally small. The SEM% was 4–14% and the SRD% 11–39%, with the highest values for the isokinetic measurements.

Conclusions: Knee muscle strength can be measured reliably and can be used to detect real changes after an intervention for a group of persons with late effects of polio, whereas the values may be too high for single individuals or to detect smaller short-term changes over time for a group of individuals.

Outcome of Research: Not applicable.

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Category: Muscle Strength

Title: Perceived disability, fatigue, pain and measured isometric muscle strength in patients with post-polio symptoms
Author: Hildegunn L, Jones K, Grenstad T, Dreyer V, Farbu E, Rekand T
Affiliation: Department of Physical Therapy, Haukeland University Hospital, Bergen, Norway
Journal: Physiotherapy Research International
Citation: Physiother Res Int. 2007 Mar;12(1):39-49
Publication Year and Month: 2007 07

Abstract: BACKGROUND AND PURPOSE: Several years after the acute polio illness, patients may develop new post-polio symptoms. The purpose of the present study was to evaluate patients with post-polio symptoms with regard to perceived fatigue, functional ability, muscle strength, pain and with regard to measured physical fitness and isometric muscle strength. In addition, the relationship between the results of these subjective and objective measurements was investigated.

METHOD: This was a prospective cross-sectional study in which 32 patients with post-polio symptoms were included. Main outcome measures were the Fatigue Severity Scale (FSS), the Disability Rating Index (DRI), pain intensity, pain distribution, self-reported and measured muscle strength and oxygen uptake.

RESULTS: A marked reduction in isometric muscle strength compared to normal data, high scores in fatigue, widespread pain, low oxygen uptake and difficulties in performing some daily activities were found. Self-reported general muscle strength, pain intensity and pain distribution correlated significantly with patients' perceived fatigue and function at the activity level. There was no significant correlation between self-reported and measured results except for that found between isometric muscle strength in the legs and patients' perceived general muscle strength and oxygen uptake.

Conclusions: Evaluation of pain intensity, pain distribution, perceived muscle strength, fatigue and ability to perform daily tasks reveals important aspects of health status in patients with post-polio symptoms. Reduction in isometric muscle strength was not reflected in those tests or in reported symptoms, and should be monitored independently using a sensitive assessment tool. Accurate screening of isometric muscle strength in isolated muscle groups contributes to therapeutic management in making a functional diagnosis at the level of body function and structure when designing specific training programmes and in motivating patients. An evaluation combining self-reports with sensitive muscle strength measures provide supplementary information and is appropriate for evaluating these patients in physiotherapy practice.

Outcome of Research: Not applicable

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Category: Muscle Strength

Title: Disability in a 4-year follow-up study of people with post-polio syndrome
Author: Willén C, Thoren-Jönsson AL, Grimby G, Sunnerhagen KS
Affiliation: Institute of Neurosciences and Physiology-Rehabilitation Medicine, Sahlgrenska Academy, Göteborg, Sweden
Journal: Journal of Rehabilitation Medicine
Citation: J Rehabil Med. 2007 Mar;39(2):175-80.
Publication Year and Month: 2007 03

Abstract: OBJECTIVE: To evaluate changes over time in a clinically based cohort of individuals with post-polio syndrome.

DESIGN: A prospective longitudinal study.

SUBJECTS: A total of 106 individuals with poliomyelitis sequelae were included in the study. They were self-referred or had been referred to the post-polio clinic. After 4 years subjects were called for a follow-up and underwent the same measurements as at the initial assessment.

METHODS: The following measurements were conducted at both the initial assessment, and the follow-up: questionnaires including Nottingham Health Profile, muscle strength and walking speed.

RESULTS: Minor changes in disability during a 4-year period were shown. A significant reduction in muscle strength was only seen for 60° flexion in the left leg and for right and left dorsal flexion. No change could be seen in the total Nottingham Health Profile score.

Conclusions: The minor changes in disability found in this study are an indication that we still do not know which subjects are at risk for deterioration. It is difficult to say whether the small changes over time shown in this study are associated with support from the polio clinic or are an expression of the natural history of the syndrome. However, it is hoped that support from the polio clinic may result in self-selected lifestyle changes, which may positively influence the development of symptoms and functional capacity.

Outcome of Research: Not applicable.

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Category: Muscle Strength

Title: The course of functional status and muscle strength in patients with late-onset sequelae of poliomyelitis: a systematic review
Author: Stolwijk-Swüste JM, Beelen A, Lankhorst GJ, Nollet F; CARPA Study Group
Affiliation: Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam, The Netherlands – [email protected]
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 2005 Aug;86(8):1693-701
Publication Year and Month: 2005 08

Abstract: OBJECTIVES: To review systematically studies of late-onset polio sequelae on the course of functional status and muscle strength over time and to identify prognostic factors of change.

DATA SOURCES: We conducted a computerized literature search up to July 2004 in MEDLINE, EMBASE, CINAHL, Web of Science, PsychInfo, and the Cochrane controlled trial register using the key words: postpolio, postpoliomyelitis, postpoliomyelitis syndrome, post poliomyelitis muscular atrophy, and poliomyelitis.

STUDY SELECTION: Reports were selected by 1 reviewer if the study involved subjects with a history of poliomyelitis, the outcome measures described functional status or muscle strength, and follow-up was for at least 6 months.

DATA EXTRACTION: Studies were summarized with regard to population, design, sample size, outcome measures, results, and methodologic scores. Overlap in populations between studies was checked.

DATA SYNTHESIS: Of 71 potentially relevant studies, 19 were included (2 on functional status, 15 on muscle strength, 2 on both muscle strength and functional status). Two studies on the course of functional status had sufficient quality and reported inconsistent results. Four studies on the course of muscle strength had sufficient quality. Two studies reported a decline in strength and 2 reported no change. Decline in strength was only reported in studies with a follow-up period longer than 2 years. One study reported extent of paresis as a prognostic factor for change in perceived physical mobility.

Conclusions: Conclusions cannot be drawn from the literature with regard to the functional course or prognostic factors in late-onset polio sequelae. The rate of decline in muscle strength is slow, and prognostic factors have not yet been identified. Long-term follow-up studies with unselected study populations and age-matched controls are needed, with specific focus on prognostic factors.

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Category: Muscle Strength

Title: Randomized controlled trial of strength training in post-polio patients
Author: Chan, K. M., Amirjani, N., Sumrain, M., Clarke, A. and Strohschein, F. J.
Affiliation: Funded by Alberta Heritage Foundation and Canada Foundation
Journal: Muscle & Nerve
Citation: Chan, K. M., Amirjani, N., Sumrain, M., Clarke, A. and Strohschein, F. J. (2003), Randomized controlled trial of strength training in post-polio patients. Muscle Nerve, 27: 332–338. doi:10.1002/mus.10327
Publication Year and Month: 2003 02

Abstract: Many post-polio patients develop new muscle weakness decades after the initial illness. However, its mechanism and treatment are controversial. The purpose of this study was to test the hypotheses that: (1) after strength training, post-polio patients show strength improvement comparable to that seen in the healthy elderly; (2) such training does not have a deleterious effect on motor unit (MU) survival; and (3) part of the strength improvement is due to an increase in voluntary motor drive. After baseline measures including maximum voluntary contraction force, voluntary activation index, motor unit number estimate, and the tetanic tension of the thumb muscles had been determined, 10 post-polio patients with hand involvement were randomized to either the training or control group. The progressive resistance training program consisted of three sets of eight isometric contractions, three times weekly for 12 weeks. Seven healthy elderly were also randomized and trained in a similar manner. Changes in the baseline parameters were monitored once every 4 weeks throughout the training period. The trained post-polio patients showed a significant improvement in their strength (P < 0.05). The magnitude of gain was greater than that seen in the healthy elderly (mean ± SE, 41 ± 16% vs. 29 ± 8%). The training did not adversely affect MU survival and the improvement was largely attributable to an increase in voluntary motor drive. We therefore conclude that moderate intensity strength training is safe and effective in post-polio patients.

Conclusions: This study demonstrated moderate intensity strength training of affected hand muscles is safe and effective in post-polio patients.

Outcome of Research: More research required

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Comments (if any): Strength training of more functional muscles (e.g. legs) that consider baseline strength levels, appropriate loading and rest, with regular monitoring is important to evaluate in a randomised control trial to assist with exercise recommendations.

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Category: Muscle Strength

Title: An 8-year longitudinal study of muscle strength, muscle fiber size, and dynamic electromyogram in individuals with late polio
Author: Grimby G, Stålberg E, Sandberg A, Sunnerhagen KS
Affiliation: Department of Rehabilitation Medicine, Sahlgrenska University Hospital, Göteborg University, Sweden
Journal: Muscle & Nerve
Citation: Muscle Nerve. 1998 Nov; 21(11):1428-37
Publication Year and Month: 1998 11

Abstract: Twenty-one subjects with polio 24 to 51 years prior to the first examination were studied on three occasions, each 4 years apart with measurements of muscle strength and endurance for knee extension, macro EMG, and muscle biopsy from vastus lateralis. On average the muscle strength decreased during the 8-year follow-up by 9-15%. Endurance decreased during the observation period. The muscle fiber area was markedly increased in most subjects. There was a decrease in the capillarization during the follow-up. Macro EMG was increased in all subjects (range 3-42 times control) and increased in 20 legs during the 8-year follow-up, but showed a decrease in 8 of 9 legs with an approximative breakpoint when macro MUPs were around 20 times the normal size. Thus, evidence of on-going denervation/reinnervation as well as of failing capacity to maintain large motor units was demonstrated. SFEMG showed a moderate degree of disturbed neuromuscular transmission.

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Category: Muscle Strength

Title: Strength, endurance, and work capacity after muscle strengthening exercise in postpolio subjects
Author: Agre JC, Rodriquez AA, Franke TM
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin Medical School, Madison, USA
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1997 Jul; 78(7):681-6
Publication Year and Month: 1997 07

Abstract: OBJECTIVE: To determine whether a 12-week home quadriceps muscle strengthening exercise program would increase muscle strength, isometric endurance, and tension time index (TTI) in postpolio syndrome subjects without adversely affecting the surviving motor units or the muscle.

DESIGN: A longitudinal study to investigate the effect of a 12-week exercise program on neuromuscular function and electromyographic variables.

SETTING: Neuromuscular laboratory of a university hospital.

SUBJECTS: Seven subjects were recruited from a cohort of 12 subjects who had participated in a previous exercise study. All subjects had greater than antigravity strength of the quadriceps. Upon completion of a postpolio questionnaire, all acknowledged common postpolio syndrome symptoms such as new fatigue, pain, and weakness; 6 of the 7 acknowledged new strength decline.

INTERVENTION: On Mondays and Thursdays subjects performed three sets of four maximal isometric contractions of the quadriceps held for 5 seconds each. On Tuesdays and Fridays subjects performed three sets of 12 dynamic knee extension exercises with ankle weights.

MAIN OUTCOME MEASURES: Neuromuscular variables of the quadriceps muscles were measured at the beginning and completion of the exercise program and included: isokinetic peak torque (ISOKPT, at 60 degrees/sec angular velocity) and total work performed of four contractions (ISOKTW), isometric peak torque (MVC), endurance (EDUR, time subject could hold isometric contraction at 40% of the initial MVC), isometric tension time index (TTI, product of endurance time and torque at 40% of MVC), and initial and final ankle weight (WGT, kg) lifted. Electromyographic variables included: fiber density (FD), jitter (MCD), and blocking (BLK) from single fiber assessment and median macro amplitude (MACRO). Serum creatine kinase (CK) was also measured initially and at 4-week intervals throughout the study.

RESULTS: The following variables significantly (p < .05) increased: WGT by 47%, ISOKPT, 15%, ISOKTW, 15%; MVC, 36%; EDUR, 21%; TTI, 18%. The following variables did not significantly (p > .05) change: FD, MCD, BLK, MACRO, and CK.

Conclusions: This home exercise program significantly increased strength, endurance, and TTI without apparently adversely affecting the motor units or the muscle, as the EMG and CK variables did not change.

Outcome of Research: Effective

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Category: Muscle Strength

Title: Reduction in thigh muscle cross-sectional area and strength in a 4-year follow-up in late polio
Author: Grimby G, Kvist H, Grangård U
Affiliation: Department of Rehabilitation Medicine, University of Göteborg, Sahlgrenska University Hospital, Sweden
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1996 Oct; 77(10):1044-8
Publication Year and Month: 1996 10

Abstract: OBJECTIVE: To study changes in cross-sectional thigh muscle area and muscle strength in late polio subjects over a 4-year period.

DESIGN: Longitudinal study of a cohort of polio survivors, comparing subjects who acknowledge (unstable) with those who do not acknowledge (stable) new muscle weakness.

SETTING: University hospital.

SUBJECTS: Eighteen subjects (6 men, 12 women) with polio-myelitis sequelae (39 to 46 years of age) were studied on two occasions 4 years apart; the first examination was 37 to 44 years after onset of polio. Subjects were recruited through hospital registers, newspaper advertisement, and a patient organization.

OUTCOME MEASUREMENTS: Thigh muscle and intermuscular and intramuscular adipose tissue (AT) cross-sectional areas were measured by computed tomography. Isometric muscle strength for knee extension and flexion was measured using a Kin-Com dynamometer.

RESULTS: Cross-sectional muscle area decreased on average 1.3 +/- 3.6 cm2 (1.4%, p < .05); the intermuscular and intramuscular AT area increased 1.8 +/- 3.4 cm2 (12.1%, p < .05). When divided by legs in which subjects reported (unstable) or did not report (unstable) or did not report (stable) increased muscle weakness, unstable legs showed significant reduction (p < .05) in muscle area, whereas stable legs did not. Estimated total thigh muscle strength decreased 7.8% +/- 2.9% (p < .01), with a significant (p < .001) reduction in unstable legs (13.4% +/- 4.3%) but not in stable legs. The reduction in strength appears to be greater than the reduction in cross-sectional muscle area, but there is still a significant correlation (r = .44, p < .05).

Conclusions: The present results demonstrate not only progress of muscle weakness, but also of muscle atrophy in postpolio subjects.

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Category: Muscle Strength

Title: Strength gains without muscle injury after strength training in patients with postpolio muscular atrophy.
Author: Spector, S. A., Gordon, P. L., Feuerstein, I. M., Sivakumar, K., Hurley, B. F. and Dalakas, M. C.
Affiliation: Funded by Henry M. Jackson Foundation for the Advancement of Military Science
Journal: Muscle & Nerve
Citation: Spector, S. A., Gordon, P. L., Feuerstein, I. M., Sivakumar, K., Hurley, B. F. and Dalakas, M. C. (1996), Strength gains without muscle injury after strength training in patients with postpolio muscular atrophy. Muscle Nerve, 19: 1282–1290.
Publication Year and Month: 1996 10

Abstract: We evaluated changes in the dynamic and isometric strength in the newly weakened quadriceps muscles and asymptomatic triceps muscles of 6 patients with postpolio muscular atrophy (PPMA) after 10 weeks of progressive resistance strength training. Alterations in muscle size were determined with magnetic resonance imaging. Serum creatine kinase levels were measured throughout training, and histological signs of muscle injury and changes in muscle fiber size and types were assessed with muscle biopsies before and after training. Exercise training led to an increase in dynamic strength of 41% and 61% for the two knee extensor tests, and 54% and 71% for the two elbow extensor tests. Up to 20% of the improvement was maintained 5 months after cessation of training. Isometric strength, whole muscle cross-sectional areas of quadriceps and triceps muscles, and serum muscle enzymes did not change. No destructive histopathological changes were noted in the repeat muscle biopsies, and no consistent changes in muscle fiber size or fiber type percentages were observed. These results demonstrate that a supervised resistance training program can lead to significant gains in dynamic strength of both symptomatic and asymptomatic muscles of PPMA patients without serological or histological evidence of muscular damage.

Conclusions: This study of 6 patient who had postpolio muscluar atrophy (PPMA) demonstrated a supervised resistance training program can lead to significant gains in dynamic strength of both symptomatic and asymptomatic muscles of PPMA patients without serological or histological evidence of muscular damage.

Outcome of Research: More research required

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Comments (if any): A small sample size and further information regarding the baseline strength values of affected muscles makes it difficult to conclude on the significance of these results.

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Category: Muscle Strength

Title: Neuromuscular function: comparison of symptomatic and asymptomatic polio subjects to control subjects
Author: Agre JC, Rodriquez AA
Affiliation: Department of Rehabilitation Medicine, University of Wisconsin - Madison Medical School 53792
Journal: Archives of Physical Medicine and Rehabilitation
Citation: Arch Phys Med Rehabil. 1990 Jul; 71(8):545-51
Publication Year and Month: 1990 07

Abstract: The purpose of this study was to determine if there were any differences between symptomatic and asymptomatic polio survivors by history of acute poliomyelitis illness, electromyographic evidence of terminal motor unit reorganization, and neuromuscular function of the quadriceps femoris muscle. Thirty-four symptomatic postpolio subjects, 16 asymptomatic postpolio subjects, and 41 controls were studied. A questionnaire assessed polio history. Peak knee extension torque was measured isokinetically and isometrically. Endurance (time to exhaustion) was measured at 40% of maximal isometric torque. Work capacity was determined as the product of torque and duration. Recovery of isometric strength was measured at regular intervals for ten minutes after exhaustion. Quantitative electromyography was also performed on the quadriceps to determine motor unit action potential duration and amplitude. It was found that symptomatic subjects had evidence of more severe original polio involvement by history (documented electromyographically), were weaker and capable of performing less work than asymptomatic subjects, and recovered strength less readily than controls.

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