Table II.
Experimental study designs according to study design and intervention type (cardiovascular fitness, mixed intervention methods and muscle strengthening)
| Author | Study population | Diagnosis criteria used | Inclusion criteria | Study design | Intervention type and duration | Type of exercise intervention | Outcome measures | Statistical analysis | Effects of intervention |
|---|---|---|---|---|---|---|---|---|---|
| Agre et al. 1996 (44) | 12 participants (7 F and 5 M), 35-60 years | Halstead and Rossi (1985) | Excluded those with <3+/5 on manual strength testing | Longitudinal | Muscle strengthening activities (12 weeks) | Muscle strength: 4 days a week, cuffed ankle weights (~ 1 to 1.5kg = 13-14 RPE). Leg extension, hold 5 seconds. 1 rep every 30 secs, 6 reps at first then up to RPE 17/20 or 10 reps | Exercise compliance. Neuromuscular: Ankle weight lifted (kg), Isometric quads: peak torque, endurance holding time (sec), MVC (Nm) Tension time index (Nms) Isokinetic quads: quads peak torque (Nm), quads total work (Nm), hamstrings peak torque (Nm), hamstrings total work (Nm). EMG: Blocking (%), Jitter (usec), Macro EMG amplitude (mV). Serum CK | Wilcoxon matched pairs test. Friedman repeated measures ANOVA. Results in mean (SD), p < 0.05 | Positive association between strength training and ankle weight lifted |
| Agre et al. 1997 (45) | 7 participants (gender not reported), 35–65 years | Halstead and Rossi (1985) | Excluded those with <3+/5 on manual strength testing; allowed recent strength loss in 6 of 7 participants | Longitudinal | Muscle strengthening activities (12 weeks) | Muscle strength: 4 days a week ankle weights (~ 1 to 1.5kg = 13-14 RPE). Isokinetic (Tues/ Fri): Leg extension, hold 5 seconds. 3 x 12 reps rest 1 min. Isometric (Mon/ Thurs): 3 x 4 reps max. contractions 5 secs, rest 10 secs, 1 min between sets. Knee at 60 degrees from full extension | Exercise compliance. Neuromuscular: Ankle weight lifted (kg), Isometric quads: peak torque, endurance holding time (sec), tension time index (Nms), Isokinetic quads: quads peak torque (Nm), quads total work (Nm), hamstrings peak torque (Nm), hamstrings total work (Nm). EMG: Fiber density, Blocking (%), Jitter (usec), Macro EMG amplitude (mV). Serum CK | Wilcoxon matched pairs test. Friedman repeated measures ANOVA, with Holm’s post hoc comparisons. Results in mean (SD), p < 0.05 | Positive association between strength training and quad isometric (p < 0.05) and isokinetic (p < 0.05) |
| Bertelsen et al. 2009 (28) | 50 participants (30 Fand 20 M), age range 24-82 years, 4 dropped out due to illness within the follow up period. | Halstead and Rossi (1985) Informal PPS criteria; had acute polio and now have new problems | Allowed new problems related to PPS; 74% had reported recent strength decrease | Longitudinal (prospective uncontrolled intervention study) | Mixed: Aerobic fitness, muscle strengthening and functional exercises. (3 and 15 months) | Individualised physiotherapy-based approach. Physiotherapy and subsequent exercise programme including both muscle strength and aerobic fitness interventions. Consisting of a combination of exercise (included in 80% of programmes), massage (78%), stretching (72%), home training (72%), walking (26%), and/or balance training (24%) | 6MWT and timed-stands test | SF-36 and MF0-20 were converted into scales of 0 to 100. Non-parametric matchedpairs significance tests (Wilcoxon matched pair test) | Significantly improved 6MWT performance (BL: 378 m (SD 131), 3 months: 418 m (SD 122), 15 months: 419 m (SD 138); both p <0.001 to BL) and timed-stands test performance (BL: 31 sec (SD 7) , 3 months: 27 sec (SD 7), 15 months: 28 sec (SD 8); both p <0.001 to BL) |
| Brogardh et al. 2010 (46) | 5 participants (3 M and 2 F), aged 64 years (SD 6.7) , age range 55–71 years with late stages of polio | Halstead and Rossi (1985) | Excluded clinically unstable symptoms; Subjects had either PostPolio Class III clinically stable or Class IV clinically unstable polio | Case-controlled pilot study | Muscle strengthening activities (5 weeks) | Muscle strength: 2 x 30 min weekly sessions of WBV – standing knees flexed at 40–55°. Repetition duration and number was 40 sec and 4 reps (start of intervention) and increased to 60 sec and 10 reps | Isometric and isokinetic knee extensor and flexor strength - MVC (Nm) in less and more affected limbs. Gait performance – TUG, Comfortable and fast gait speeds tests, and the 6MWT | Mean relative difference = (diff pre to post/pretreatment x 100). Paired t-tests, p< 0.05 | Strength: Isokinetic KEXT (less affected limb: 125 (SD 43) to 123 Nm (SD 46), more affected limb: 54 (SD 35) to 56 Nm (SD 39), isokinetic KFLX (less affected limb: 64 (SD 32) to 66 Nm (37), more affected limb: 26 (SD 21) to 24 Nm (SD 20), Gait performance: TUG (11.0 (SD 2.0) to 10.9 sec (SD 1.9), comfortable gait speed (10.2 (SD 2.6) to 9.4 sec (SD 2.1), fast gait speed (7.2 (SD 1.9) to 7.1 sec (SD 1.7 ), and 6MWT (422 (SD 105) to 417 m (SD 92) |
| Chan et al. 2003 (33) | 10 post-polio patients (9 F and 1 M): 5 in training group (4 F and 1 M), 5 in control group (5F) | Post-polio diagnosis, affecting one or both upper limbs, moderate motor neuronal loss in median-innervated thenar muscles with MUNE 10-90 | Excluded those with MUNE <10, as increase in strength unlikely | RCT | Muscular strengthening activities (12 weeks) | 3 x 8 upper limb isometric contractions (50-70% MVC), 5 min rest between sets. 3 x weekly for 12 weeks | Thenar MVC, voluntary activation, estimated motor unit number, and surface detected motor unit action potential | One-way ANOVA. Post hoc analysis using Scheffe test. Training changes analysed using paired t-tests, between groups compared with independent t-tests | Improved thenar MVC force production and level of voluntary activation in contrast to control p < 0.05), while the estimated number of motor units and surface detected motor unit action potential remained similar (p>0.05). Compared to control MVC force increased 41%, voluntary activation improved 13%, estimated motor unit number was lower in the training group (30%), but these were greater in control at baseline (training: 45 (SD 16); control: 69 (SD 22) a.u.). Surface detected motor unit action potential increased in both groups (training: 389 (SD 53) to 370 (SD 56) and control: 215 (SD 29 to 238 (SD 31) |
| Da Silva et al. 2019 (37) | 21 with or without PPS (age: 40-85; Body weight less than 227 kgs) | National Institute of Health, 2015. PPS diagnosis not required but most participants had it; various criteria may have been used | Excluded those unable to tolerate weight bearing for 20 min | Random order, Crossover Exploratory Experimental Intervention | Muscular strengthening activities: WBV (4 week block of 8 sessions -crossover) | Two intervention groups with one group participating in low intensity WBV 4-week block of 8 sessions first (group Lo-Hi), and higher intensity WBV 4-week block of 8 sessions second | 10mWT, 2mWT, BPI Interference, Severity, PSQI, FSS | Descriptive statistics, Mann-Whitney U tests for between subject changes, Non-parametric Wilcoxon for within subject changes, Friedman's analysis of variance | Improvement in walking speed in Hi-Lo frequency group. Improvement in BPI pain severity after exposure to higher vibration. No significant change in 2mWT, PSQI or FSS |
| Davidson et al. 2009 (29) | 27 post-polio patients (17 M and 10 F), mean age of 56.4 years, age range 44-74 years | Informal PPS criteria; definite history of polio and new physical disability and symptoms typical of PPS | Allowed those with new physical disability and symptoms typical of PPS | Longitudinal | Mixed: both muscle strengthening and aerobic fitness activities (3 and 6 months) | An initial 3 per week for 3 weeks of a supervised exercise programme including a timed interval training circuit (based on CV fitness), stretching, hydrotherapy, relaxation techniques. Self-directed exercise until follow up | Muscle strength (sit to stand, grip strength of dominant hand), muscle endurance (10m shuttle walk test). Hospital anxiety and depression scale, Illness perception questionnaire | Non-parametric matched-pairs significance tests (Wilcoxon), Spearman rank correlations. Mann-Whitney test | Positive: Circuit training and shuttle test 29%), RPE, STS (20%) |
| Dean et al. 1991 (25) | 48 post-polio participants (38 F and 10 M, age ranging from 32 to 71 | Informal PPS criteria; confirmed history of poliomyelitis | Cross- sectional study | Aerobic fitness activities (6 weeks) | Two-min walking at 1.6 km/hr followed by an increase of 0.8 km/hr each min till a comfortable cadence was reached | Movement economy and cardio-respiratory conditioning based on movement economy index (MEI) and cardiorespiratory conditioning index (CRCI) based, maximum heart rate and VO2 | 2x2 ANOVA, Pearson product moment correlations and t-tests, p < 0.05 | MEIs were significantly different between the normal and reduced movement economy groups based on the manner in which the groups were categorised (p < 0.01). MEIs were not different for the conditioned and deconditioned groups (p > 0.05). CRCIs were significantly different between the normal and reduced conditioning groups based on the manner in which the groups were categorised (p <0.01). CRCIs were not significantly different for the groups with normal and reduced movement economy (p > 0.05) | |
| Einarsson 1991 (35) | 155 participants | Informal PPS criteria | Excluded those with <3+/5 on manual strength testing | Longitudinal study | Muscular strengthening activities (6 to 12 months post training) | 3 sessions/week of 12 sets of 8 isokinetic contractions, each at 180”/sec angular speed interposed with 12 sets of isolated 4-second isometric contractions at 30°, 60° | Isometric flexion and extension strength, Isokinetic flexion and extension strength, Fatigue Index and muscle biopsy | Non parametric Wilcoxon test, Spearman rank correlation test was used for analysis of correlation | Significant (p < 0.0l) increase (mean 29%) in isometric knee-extension muscle strength measured at 60° knee angle and in isokinetic knee-extension strength (mean 24%), measured as peak torques at angular velocities of 30°, 60°, 180° and 300° per second |
| Ernstoff et al. 1996 (30) | 12 (9 Fand 3 M). Aged 39 to 50 (mean 42 years), 5 lost to follow up. All but 4 had symptoms according to Halstead's criteria | Halstead (1987) | Excluded those unable to perform full knee extension or had severe weakness; those with <3/5 on quad manual strength testing | Longitudinal study | Mixed: both muscle strengthening and aerobic fitness activities (22 weeks) | 2 x week for 22 weeks. Group and home programmes. 60 min with 5 min warm up, low resistance, high rep ex for upper/lower/trunk. 5 mins cycling at 60-80% GXT | Muscle strength (highest peak torque from isokinetic concentric strength/isometric knee flexion dynamometer), Fatigue Index Evaluation, graded exercise test (GXT) bike ergo 30, 70, 100, 130 watts, muscle biopsy/CSA | Wilcoxon's signed rank test for statistical analysis. Spearman's rank correlation | Positive: 1) Less fatigue (reduction in peak torque) in weaker leg after training. 2) significant increases in strength of right elbow ext. Right wrist ext., hip abd laterally. 3) significant reduct in HR (133 vs 127 after), showing fitness |
| Fillyaw et al. 1991 (36) | 17 (6 lost to follow-up excluded from analysis) Halstead and Rossi criteria for post-polio, MMT fair +, both quads Age 51.3 (SD 12.3) | Halstead and Rossi (1985) | Excluded those with less than fair quads; <3/5 on manual strength testing | Controlled trial, randomised by muscle group (quads vs biceps) | Muscular strengthening activities (2 years) | 14 exercised quads muscle, 3 biceps. 10RM through knee ext. or elbow flex. without pain/fatigue. HEP based off 10RM 3 x 10 reps every other day. Set 1: 50% 10RM, 2: 75% 10RM, 3: 100% 10 RM. 5 mins. rest between | Maximum isometric torque (MIT), endurance integral (EI). 10 RM every 2 weeks | Analysis of variance between exercise and control group for MIT and EI using SAS General Linear Model | Positive: 1) Exercise and strength (10RM, mean increase 78%, p < 0,001). 2) Exercise and MIT: 8.4%, p = 0.04. 3) NS change in exercise and EI |
| Jones et al. 1989 (47) | 45 patients (37 completed the study) (age between 30 and 60 years) | Informal PPS criteria; hospital records | Adequate strength in at least one lower extremity to pedal an ‘exercycle’ and ’arm cycle ergometer’ | RCT | Aerobic fitness activities (16 weeks) | The training group trained at 70–75% of the heart rate plus resting heart rate on ergometer. 15–20 min exercise/session | Resting heart rate, beats per min, maximal heart rate, beats per min, Resting systolic blood pressure, mm Hg, Resting diastolic blood pressure, mm Hg, Maximum systolic blood pressure, mm Hg, Maximum diastolic blood pressure, mm Hg, Watts, Exercise times, Maximum expired volume, l/min, Maximum oxygen consumption, ml/min, Maximum carbon dioxide consumption, ml/min, Respiratory exchange ratio | Mean (SD) scores for pre and post treatment differences, multivariate analysis of variance was used to compare changes, Hotelling’s T2 for statistical test | Improvement in watts attained during testing, duration of testing, and VO2 max. Positive impa2ct of cardiorespiratory training on exercise group |
| Koopman et al. 2016 (3) | 68 participants (age between 18 and 75) | March of Dimes (2000) | Allowed those with walking ability, at least indoors, with or without a walking aid with or without a walking aid; and ability to cycle on a ergometer against a load of at least 25 W | Stratified multicentre single blinded RCT | Mixed: aerobic fitness, muscle strengthening and functional exercises. (>6 months) | Exercise Therapy: 3 sessions/week aerobic exercise on a cycle ergometer. Intensity increased from 60% to 70% heart rate reserve. Duration increased from 28 to 38 min | Submaximal heart rate during exercise, muscle strength (maximal isokinetic voluntary torque of quadriceps muscles), functional capacity (Timed-Up-and- Go test and 2-Min Walk test), and actual daily physical activity level | Primary analysis for efficacy: linear mixed models, with group and pre-treatment score of the outcome as covariates (primary analyses) | No beneficial effect of ET on fatigue, activities, or HRQoL compared with UC in patients with PPS |
| Kriz et al. 1992 (26) | 29 subjects at baseline, 20 at follow up | Informal PPS criteria | Physician screening; participants had to have adequate trunk and upper extremity strength for ergometry | RCT | Aerobic fitness activities (16 weeks) | Upper extremity aerobic exercise programme. 3 x per week for 20 min. Intensity at 70-75% HRR plus RHR | HRrest, HRmax, BP at rest, BP immediately post exercise, VO2max, RER, VEmax, RR | Change scores were compared using MANOVA. Univariate F-test was used to determine p < 0.05 | Positive: Exercise programme and fitness (VEMax - 17%, V VCO2 - 20%, VO2Max - 19%, 12% - Powe2 r, exercise time - 10%) |
| Murray et al. 2017 (4) | 55 subjects | Informal PPS criteria | Excluded those with severe weakness; those with unstable muscle groups per ACSM; severe fatigue or recent onset of weakness | Prospective, single blinded - RCT | Aerobic fitness activities (8 weeks) | Home-based arm ergometry at an intensity of 50%-70% maximum heart rate, compared with usual physiotherapy care | The 6-MAT, Fatigue Severity Scale, Physical Activity Scale for Individuals with Physical Disabilities SF-36 | Sample t-test for intergroup comparison and paired t-test for within group comparison. Linear regression modelling or Poisson regression. A significance level of p < 0.05 was set | No significant association between exercise and 6-MAT or 6MWT |
| Oncu et al. 2009 (48) | n = 15 hospitalbased programme and n = 13 in home-based exercise programme | Halstead (1991) | Allowed those with new lower limb weakness. Allowed those with ambulatory ability of 30 m in 60 sec | RCT | Aerobic fitness and stretching activities (8 weeks) | 3 session/week of 1.5 hours. Flexibility training, aerobic fitness on treadmill involving walking for 30 min with 3 rest periods at an intensity of 50–70% of pVO2 and at a level of 13–15 on the Borg Scale. Patients in group 2 performed flexibility and aerobic exercises. A walking programme was undertaken by the patients in group 2 as an aerobic exercise at 50–70% of pVO2 | FSS, FIS, Quality of life, heart rate, rhythm, Max oxygen consumption (pVO2) and carbon dioxide production (VCO2) | Mann–Whitney U test for numeric data, Fisher’s exact or chi-square tests for nominal data, nonparametric Wilcoxon test, Mann–Whitney U test for pre- vs postexercise differences | Improvement was observed in the parameters of fatigue and quality of life in both the hospital exercise group and the home exercise group. An increase in functional capacity was also found in the hospital exercise group |
| Sharma et al. 2014 (32) | 21 participants (13 F and 8 M) age between 18 and 65 | Halstead (1985) | Allowed body position change to reduce/ eliminate gravity for weaker muscle groups | Controlled trial | Aerobic fitness activities (4 weeks) | Group A: Performed exercise and lifestyle modification. Exercises were divided into 4 phases. Phase 1: warm up, gentle AROM; Phase 2: strengthening exercises, 8 muscle groups; Phase 3: aerobic exercise, 10 mins static cycling, moderate intensity (i.e. RPE of 13-15 on modified Borg's scale) Phase 4: Cool down, gentle PROM (5 reps) | FSS, 2MWD, Patient Reported Outcome Measurement Information System (PROMIS), Patient Health Questionnaire (PHQ-9) | Wilcoxon signed-rank test for within-group differences in FSS score, Kruskal-Wallis test for between groups differences, Mean difference in 2MWD within each group using paired t-test | Significant diference in FSS within group A and group B. For 2MWD, there was a statistically significant difference within group A and group B but no difference in group C. Physical function as measured by PROMIS, showed a statistically significant difference in group A and no difference in group B and group C. Statistically significant difference between groups in FSS score and PRoMiS score |
| Skough et al. 2008 (38) | 14 subjects at baseline and follow up (8 F and 6 M) | March of Dimes (2000) | Allowed those who were able to walk with or without a walking aid for 6 min | Randomized, placebocontrolled pilot study | Muscular strengthening activities (12 weeks) | Resistance training at 10-11 on the Borg Rate of Perceived Exertion scale for 30 min/session. the initial work-load was 50-60% of 1 repetition maximum (1RM) and was successively increased to an intensity of 70-80% of 1RM | Sit stand sit, timed up & go, 6-min walk, muscle strength measurement by means of dynamic dynamometer and short-form (SF)-36 questionnaire | Wilcox on signed-rank test was used to analyse differences within groups and Mann-Whitney U test for differences between groups. A p < 0.05 was taken as statistically significant | Positive: Significant associations between exercise programme and STS, 6MWT and muscle strength |
| Spector et al. 1996 (39) | 6 subjects at baseline and follow up | Informal PPS criteria | Excluded with study <3+/5 on manual strength testing; allowed limbs described ranging from asymptomatic to flaccid | Controlled those | Muscle strengthening, 10 weeks 4 to 6 weeks post training 5 months | Progressive resistance exercise of knee and elbow extensors representing both symptomatic and asymptomatic muscles | Fatigue Severity Scale, isometric and dynamic strength, MRI. Biopsies | t-tests | Positive: PRT and dynamic strength (3RM), 10 week and 5 months |
| Voorn et al. 2016 (49) | 44 participants (24 F and 20 M) | March of Dimes (2000) | Allowed those able to walk at least around their house | RCT | Mixed: aerobic fitness, muscle strengthening and functional exercises (3 x week, 4 months) | Home-based aerobic training programme on a bicycle ergometer 3 x weekly and a supervised group training 1xweek (muscle strengthening functional exercise) | Muscle endurance, Muscle strength (MVT). Resting HR, oxygen consumption at the AT, VO2 submax, RER submax, and RPE submax | Wilcoxon signed- rank test and Mann-Whitney U test were used. Linear regression model SPSS statistical software package | Training programme did not significantly improve muscle function nor CV fitness |
| Willen et al. 2001 (8) | 30 participants at baseline, 28 at follow up | Informal PPS criteria; late effects of polio | Excluded National Rehabilitation Post-Polio Limb Classification of I (no history of remote or recent weakness) | Controlled trial: Before-after tests | Mixed (Aerobic fitness, muscle strengthening and functional exercises) average of 5 months | 40 min of general fitness training session in warm water twice weekly | Peak load, Peak oxygen uptake, Peak HR, Berg balance scale, Visual analogue scale, Pain scale, Physical activity scale for the Elderly, and NHP. | Wilcoxon's signed-rank test and the Mann-Whitney U test A significance level of p = 0.05 was used throughout the study | Positive: exercise and function (lower HR and self-reported improvement in physical fitness) |
AROM: Active Range of Motion; BL: baseline; BPI: Brief Pain Inventory; CBT: Cognitive behavioural therapy; CK- Creatine Kinase; CRCI: Cardiorespiratory conditioning index; CSA : Cross-sectional area; CV: Cardiovascular; EI: Endurance integral; EMG: Electromyography; ET: Exercise therapy; Ext: Extension; F: female; FIS: Fatigue Impact Scale; Flex: Flexion; FSS: Fatigue severity scale; GLM: General linear model; GXT: Graded Exercise Test; HEP: Home exercise programme; HR: Heart rate; HRQoL: Health related quality of life; KEXT : knee extensor, KFLX : knee flexor; Kg: Kilogram; L: Litre; M: male; MAT- Min arm test; Max: Maximum; MEI: Movement economy index; MFI: Multidimensional fatigue inventory; MIT: Maximum isometric torque; mL: Millilitre; MRI: Magnetic Resonance Imaging; MUNE: Motor Unit Number Estimate; MVC: Maximal voluntary contraction; mV: millivolt; MVT: Muscle strength; MWT: Min Walk Test; Nm: Newton metre; NS: Not stated; NHP: Nottingham health profile; pVO2: Maximum oxygen consumption; PHQ: Patient health questionnaire; PPS: Post-polio syndrome; PROM: Passive Range of Motion; PROMIS: Patient reported outcome measurement information system; PSQI: Pittsburgh sleep quality index; RCT; Randomised controlled trial; RER: respiratory exchange ratio; RHR: Resting heart rate; RM: Repetition max; RPE: Rate of perceived exertion; SD: Standard deviation; Sec: Seconds; SF: short-form; SIP-68: Sickness Impact Profile; STS: Sit-to-stand; TUG: Timed up and go; usec: microsecond; UC: Usual care; VO2: Oxygen consumption; WBV: Whole body vibration.