Normalized Muscle Strength, Aerobic Capacity, and Walking Performance in Chronic Stroke: A Population-Based Study on the Potential for Endurance and Resistance Training

Ten Meter Walk Test for motor function assessment with technological devices based on lower members' movements: A systematic review

OBJECTIVE

The Ten Meter Walk Test (10MWT) is a vital diagnostic tool for identifying neuromuscular and neurodegenerative conditions. This systematic review explores the potential of wearables, mobile devices, and sensors to enhance the 10MWT's use in medical gait analysis based on lower limb movements.

METHODS

This systematic review explores the use of wearables, mobile devices, and sensors to improve the 10MWT in medical gait analysis based on lower limb movements. The study uses the PRISMA approach to assess literature from January 2010 to October 2023, highlighting the importance of new technologies like machine learning and artificial intelligence in improving the accuracy and efficiency of the 10MWT.

RESULTS

The findings demonstrate how technology-enabled 10MWT can help develop specialized treatment strategies and provide a more accurate understanding of disease pathophysiology.

CONCLUSIONS

The paper reviews 17 studies on lower limb movements during the 10MWT, highlighting their importance in assessing medical diseases and gait analysis as a diagnostic tool. It emphasizes the role of technology in rehabilitation and physical therapy, where some studies combine Transcranial Direct Current Stimulation with robotic or wearable technologies.

SIGNIFICANCE

The review comprehensively explains these technologies' advantages and current use in therapeutic contexts.

Establishment of regression-based isometric strength reference values for the upper limb in persons with multiple sclerosis

BACKGROUND

Muscle weakness is common and significantly affects persons with multiple sclerosis (PwMS), with dysfunction in upper limb (UL) muscle groups occurring in approximately 60% of PwMS.

OBJECTIVE

To develop gender-specific regression-based prediction equations, with 95% confidence intervals for maximal bilateral UL isometric strength (shoulder abduction and adduction, wrist flexion and extension) and hand grip strength in PwMS.

DESIGN

Cross-sectional study.

SETTING

Comprehensive MS center.

PARTICIPANTS

256 PwMS.

INTERVENTIONS

Not Applicable.

MAIN OUTCOME MEASURES

Shoulder abduction and adduction and wrist flexion and extension isometric strength (Biodex System 4 Pro Dynamometer) and hand grip strength (Jamar handheld dynamometer) were measured. Disease characteristics (disability and disease duration) and demographics (age, height, and weight) were collected. Regression-based predictive equations were generated for the UL muscle groups for each gender and limb, using age, height, weight, disability, and disease duration as covariates. Variables were compared between genders using the Mann-Whitney U test. Maximal voluntary contraction (MVC) reference values (mean ± SD) were reported based on age (<30, 30-39, 40-49, 50-59, 60-69 years) and disability (mild, moderate, severe ambulant, and severe nonambulant) for each gender and limb.

RESULTS

Regression-based equations were developed for both genders' strongest and weakest limb, accounting for age, height, weight, disability, and disease duration. MVC was higher in men than women (p < .001) in all muscle groups. Overall, MVC was significantly related to age in 14, height in 5, weight in 6, disability in 14, and disease duration in none of the 20 models.

CONCLUSION

This is the first study to provide regression-based prediction equations for strongest and weakest MVC of UL muscle groups and demonstrated an inverse relationship between MVC with disability and age. Regression-based reference strength values can help clinicians understand muscular strength along a spectrum of PwMS and can aid in goal setting and education for realistic outcomes.

Effect of a Multicomponent Exercise Intervention on Recovery of Walking Ability in Stroke Survivors: A Systematic Review With Meta-analysis

OBJECTIVE

To evaluate whether multicomponent exercise (MCE) is more effective than single exercise in improving walking ability in patients with stroke.

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

A systematic search of PubMed, Embase, Web of Science, Cochrane Library, and CINAHL from the establishment of each database to February 2024 was performed. A combination of medical subject headings and free-text terms relating to stroke and exercise were searched.

STUDY SELECTION

Randomized controlled trials treating stroke survivors with MCE were included. The control groups received conventional treatments such as conventional treatment or no intervention or sham training; the experimental groups received MCE. The outcome measures were walking endurance, gait speed, and balance ability.

DATA EXTRACTION

The data extraction form was completed by 2 independent reviewers. The risk of bias was assessed using the Cochrane Risk of Bias Tool for randomized controlled trials. Review manager 5.4 software was used for data analysis. Subgroup analysis and sensitivity analysis were used to supplement the results with higher heterogeneity. The preferred reporting project for systematic reviews and meta-analyses 2020 guidelines were followed.

DATA SYNTHESIS

Twelve studies were included. Meta-analyses found that compared with the control group, the MCE significantly affected gait speed (mean difference=0.11; 95% CI, 0.06-0.16; I2=0%), but the effect on balance ability was not statistically significant. Subgroup analysis showed that MCE (≥60min) was effective in improving walking endurance. These results suggest that MCE improves walking endurance and walking speed in patients with stroke.

CONCLUSIONS

MCE helps improve the gait speed of stroke survivors. Prolonging the MCE time may have a better effect on improving the walking endurance of patients with stroke.

Cardiorespiratory Fitness Benefits of High-Intensity Interval Training After Stroke: A Randomized Controlled Trial

BACKGROUND

Limited evidence supports the effects of short-interval high-intensity interval training (HIIT) for improving cardiorespiratory fitness (V̇O2peak) after stroke. We aimed to compare the effects of 12 weeks of short-interval HIIT versus moderate-intensity continuous training (MICT) on V̇O2peak, cardiovascular risk factors, and mobility outcomes among individuals ≥6 months poststroke.

METHODS

This study was a multi-site, 12-week randomized controlled trial (NCT03614585) with an 8-week follow-up. Participants were randomized into 3 d/wk of HIIT (10×1 minute 80%-100% heart rate reserve interspersed with 1 minute 30% heart rate reserve [19 minutes]) or MICT (20-30 minutes 40%-60% heart rate reserve). Secondary outcomes of the trial, including V̇O2peak, cardiovascular risk factors (carotid-femoral pulse wave velocity, blood pressure, and waist-hip ratio), and mobility (6-minute walk test, 10 m gait speed), were reported. Linear mixed model analyses with a group×study time point interaction evaluated between-group differences.

RESULTS

Of the 305 potential participants, 82 consented (mean [SD] age 64.9 [9.3] years, 32 females [39%], 1.8 [1.2] years poststroke) and were randomized to HIIT (n=42, mean [SD] baseline V̇O2peak 17.3 [5.9] mL/kg·min) or MICT (n=40, mean [SD] baseline V̇O2peak 17.2 [6.0] mL/kg·min). Participants attended 82% of visits (n=2417/2952). No adverse events occurred during the study period. A significant group×study time point interaction was found (χ2=8.46; P=0.015) for V̇O2peak at 12 weeks (mean difference, 1.81 [95% CI, 0.58-3.04]; P=0.004) whereby the HIIT group had greater gains in V̇O2peak (∆3.52 mL/kg·min [95% CI, 2.47-4.57]; P<0.001) compared with the MICT group (∆1.71 mL/kg·min [95% CI, 0.55-2.86]; P=0.001). There was no between-group difference in V̇O2peak (mean difference, 1.08 [95% CI, -0.26 to 2.42]; P=0.11) at 8-week follow-up. No group×study time point interactions were found for cardiovascular risk factors or mobility outcomes.

CONCLUSIONS

Short-interval HIIT may be an effective alternative to MICT for improving V̇O2peak at 12 weeks postintervention.

REGISTRATION

URL: https://clinicaltrials.gov; Unique identifier: NCT03614585.

The effect of robot-assisted versus standard training on motor function following subacute rehabilitation after ischemic stroke - protocol for a randomised controlled trial nested in a prospective cohort (RoboRehab)

BACKGROUND

Body weight unloaded treadmill training has shown limited efficacy in further improving functional capacity after subacute rehabilitation of ischemic stroke patients. Dynamic robot assisted bodyweight unloading is a novel technology that may provide superior training stimuli and continued functional improvements in individuals with residual impairments in the chronic phase after the ischemic insult. The aim of the present study is to investigate the effect of dynamic robot-assisted versus standard training, initiated 6 months post-stroke, on motor function, physical function, fatigue, and quality of life in stroke-affected individuals still suffering from moderate-to-severe disabilities after subacute rehabilitation.

METHODS

Stroke-affected individuals with moderate to severe disabilities will be recruited into a prospective cohort with measurements at 3-, 6-, 12- and 18-months post-stroke. A randomised controlled trial (RCT) will be nested in the prospective cohort with measurements pre-intervention (Pre), post-intervention (Post) and at follow-up 6 months following post-intervention testing. The present RCT will be conducted as a multicentre parallel-group superiority of intervention study with assessor-blinding and a stratified block randomisation design. Following pre-intervention testing, participants in the RCT study will be randomised into robot-assisted training (intervention) or standard training (active control). Participants in both groups will train 1:1 with a physiotherapist two times a week for 6 months (groups are matched for time allocated to training). The primary outcome is the between-group difference in change score of Fugl-Meyer Lower Extremity Assessment from pre-post intervention on the intention-to-treat population. A per-protocol analysis will be conducted analysing the differences in change scores of the participants demonstrating acceptable adherence. A priori sample size calculation allowing the detection of the minimally clinically important between-group difference of 6 points in the primary outcome (standard deviation 6 point, α = 5% and β = 80%) resulted in 34 study participants. Allowing for dropout the study will include 40 participants in total.

DISCUSSION

For stroke-affected individuals still suffering from moderate to severe disabilities following subacute standard rehabilitation, training interventions based on dynamic robot-assisted body weight unloading may facilitate an appropriate intensity, volume and task-specificity in training leading to superior functional recovery compared to training without the use of body weight unloading.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT06273475.

TRIAL STATUS

Recruiting. Trial identifier: NCT06273475. Registry name: ClinicalTrials.gov. Date of registration on ClinicalTrials.gov: 22/02/2024.

Effect of robot-assisted gait training on improving cardiopulmonary function in stroke patients: a meta-analysis

OBJECTIVE

Understanding the characteristics related to cardiorespiratory fitness after stroke can provide reference values for patients in clinical rehabilitation exercise. This meta- analysis aimed to investigate the effect of robot-assisted gait training in improving cardiorespiratory fitness in post-stroke patients, compared to conventional rehabilitation training.

METHODS

PubMed, EMBASE, Web of Science, Cochrane Database of Systematic Reviews, CBM, CNKI and Wanfang databases were searched until March 18th, 2024. Randomized controlled trials (RCTs) comparing the effectiveness of robot-assisted gait training versus control group were included. The main outcome variable was peak oxygen uptake. 6-minute walking test, peak heart rate, peak inspiratory expiratory ratio as our secondary indicators. RevMan 5.3 software was used for statistical analysis.

RESULTS

A total of 17 articles were included, involving 689 subjects. The results showed a significant effect for robot-assisted gait training to improve VO2peak (MD = 1.85; 95% CI: -0.13 to 3.57; p = 0.04) and 6WMT (MD = 19.26; 95% CI: 10.43 to 28.08; p < 0.0001). However, no significant difference favouring robot-assisted gait training were found in HRpeak (MD = 3.56; 95% CI: -1.90 to 9.02; p = 0.20) and RERpeak (MD = -0.01; 95% CI: -0.04 to 0.01; p = 0.34).

CONCLUSION

These results showed that robot-assisted gait training may have a beneficial effect in improving VO2peak and 6WMT, with a moderate recommendation level according to the GRADE guidelines.

Spinal Cord Stimulation for Poststroke Hemiparesis: A Scoping Review

IMPORTANCE

Spinal cord stimulation (SCS) is a neuromodulation technique that can improve paresis in individuals with spinal cord injury. SCS is emerging as a technique that can address upper and lower limb hemiparesis. Little is understood about its effectiveness with the poststroke population.

OBJECTIVE

To summarize the evidence for SCS after stroke and any changes in upper extremity and lower extremity motor function.

DATA SOURCES

PubMed, Web of Science, Embase, and CINAHL. The reviewers used hand searches and reference searches of retrieved articles. There were no limitations regarding publication year.

STUDY SELECTION AND DATA COLLECTION

This review followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. The inclusion and exclusion criteria included a broad range of study characteristics. Studies were excluded if the intervention did not meet the definition of SCS intervention, used only animals or healthy participants, did not address upper or lower limb motor function, or examined neurological conditions other than stroke.

FINDINGS

Fourteen articles met the criteria for this review. Seven studies found a significant improvement in motor function in groups receiving SCS.

CONCLUSIONS AND RELEVANCE

Results indicate that SCS may provide an alternative means to improve motor function in the poststroke population. Plain-Language Summary: The results of this study show that spinal cord stimulation may provide an alternative way to improve motor function after stroke. Previous neuromodulation methods have targeted the impaired supraspinal circuitry after stroke. Although downregulated, spinal cord circuitry is largely intact and offers new possibilities for motor recovery.

Multi-Modal versus Uni-Modal Treatment for the Recovery of Lower Limb Motor Function in Patients after Stroke: A Systematic Review with Meta-Analysis

The aim of this study is to evaluate whether the multimodal treatment based on both resistance and endurance training for the recovery of lower limb function in post-stroke patients is more effective than unimodal treatment. Six electronic databases were searched. The included articles were firstly analysed for methodological quality and then quantitatively analysed for the following outcomes: endurance, knee-extensor muscle strength, gait speed, and aerobic capacity. The treatment effect was analysed with the mean difference (MD) or standardised mean difference (SMD). From a total of 4439 records, 10 studies met the inclusion criteria for the qualitative analysis, whereas 7 studies were included in the quantitative analysis. There is a significant difference favourable to the group with multimodal treatment for knee-extensor muscle strength (SMD = 1.25; 95% CI 0.97, 1.53, I2 = 42%), both for the affected and the unaffected side. Multimodal treatments are a valid choice in the field of post-stroke rehabilitation. In particular, the combination of resistance and endurance training is useful to maximise the recovery of knee-extensor muscle strength, which in turn could be beneficial for achieving upright position and walking, allowing patients to improve independence levels in their activities of daily life.

Dual-task versus single-task gait rehabilitation after stroke: the protocol of the cognitive-motor synergy multicenter, randomized, controlled superiority trial (SYNCOMOT)

BACKGROUND

Gait disorders and cognitive impairments are prime causes of disability and institutionalization after stroke. We hypothesized that relative to single-task gait rehabilitation (ST GR), cognitive-motor dual-task (DT) GR initiated at the subacute stage would be associated with greater improvements in ST and DT gait, balance, and cognitive performance, personal autonomy, disability, and quality of life in the short, medium and long terms after stroke.

METHODS

This multicenter (n=12), two-arm, parallel-group, randomized (1:1), controlled clinical study is a superiority trial. With p<0.05, a power of 80%, and an expected loss to follow-up rate of 10%, the inclusion of 300 patients will be required to evidence a 0.1-m.s-1 gain in gait speed. Trial will include adult patients (18-90 years) in the subacute phase (0 to 6 months after a hemispheric stroke) and who are able to walk for 10 m (with or without a technical aid). Registered physiotherapists will deliver a standardized GR program (30 min three times a week, for 4 weeks). The GR program will comprise various DTs (phasic, executive function, praxis, memory, and spatial cognition tasks during gait) in the DT (experimental) group and gait exercises only in the ST (control) group. The primary outcome measure is gait speed 6 months after inclusion. The secondary outcomes are post-stroke impairments (National Institutes of Health Stroke Scale and the motor part of the Fugl-Meyer Assessment of the lower extremity), gait speed (10-m walking test), mobility and dynamic balance (timed up-and-go test), ST and DT cognitive function (the French adaptation of the harmonization standards neuropsychological battery, and eight cognitive-motor DTs), personal autonomy (functional independence measure), restrictions in participation (structured interview and the modified Rankin score), and health-related quality of life (on a visual analog scale). These variables will be assessed immediately after the end of the protocol (probing the short-term effect), 1 month thereafter (the medium-term effect), and 5 months thereafter (the long-term effect).

DISCUSSION

The main study limitation is the open design. The trial will focus on a new GR program applicable at various stages after stroke and during neurological disease.

TRIAL REGISTRATION

NCT03009773 . Registered on January 4, 2017.

Effect of Lower Extremity Muscle Strength on Aerobic Capacity in Adults with Cerebral Palsy

The purpose of this study is to analyze the effect of lower extremity muscle strength of HIP joint and KNEE joint on the aerobic capacity to provide the basic data for developing an exercise program that can effectively improve the aerobic capacity of adults with cerebral palsy (CP) by identifying the part of the lower extremity muscle. A total of 18 ambulant adults with CP were recruited for this study. Seven ambulant adults with CP were excluded because they did not achieve the criteria of maximal exercise. The data from 11 subjects (11 men) with CP were used for the analysis. The mean (±SD) age, height, weight, and BMI of the subjects were 37.00 ± 12.72 years, 170.45 ± 6.37 cm, 67.02 ± 8.62 kg, and 23.09 ± 2.78 kg/m2, respectively. To measure the muscle strength of HIP joint and KNEE joint in lower extremities, the variables of the isokinetic muscle strength and the muscular endurance were performed using the isokinetic equipment (Biodex Co., Shirley, NY, USA). For the isokinetic muscle strength measurement of HIP joint, the 45°/sprotocol indicating the muscle power and the 300°/s protocol indicating the muscle endurance were used. Additionally, the measurement of KNEE joint was performed once on the left and right side, using the protocol of 60°/s indicating the muscle power and 300°/s indicating the muscular endurance. Progressive exercise tests were conducted on the treadmill (Quinton model—4500) using previously developed protocols targeting CP. The initial protocol speeds were 5 km/h−1 and 2 km/h−1 for the subjects who have been classified as Gross Motor Function Classification System (GMFCS) level I and II, respectively. Using a portable cardiopulmonary indirect breath-by-breath calorimetry system (MetaMax 3B; Cortex Biophysik, Leipzig, Germany), pulmonary ventilation (VE), respiratory exchange ratio (RER), and oxygen uptake (VO2) have been persistently measured. HR monitor (Polar Electro, Kempele, Finland polar Co. RS-800) was used to measure heart rate (HR). A correlation analysis was conducted to find out how the lower extremity muscle strength and aerobic capacity with cerebral palsy are related. Therefore, as a result, VO2peak among aerobic capacity displayed a significant positive correlation in 45° and 300°/s peak torque/BW of HIP joint, and with 60° and 300°/s peak torque/BW of KNEE joint. It was the same with 60°/s Agon/Antag ratio of KNEE Joint (p < 0.05). VEpeak showed a significant positive correlation with 45° and 300°/s peak torque/BW of HIP joint, as well as correlation with 60° and 300°/s peak torque/BW and 60°/s Agon/Antag ratio of KNEE joint (p < 0.05). However, HRpeak showed a significant positive correlation only in 45°/s peak torque/BW of HIP joint (p < 0.05). The result of step-wise analysis was to find out which muscle strength significantly affects VO2peak and HRpeak among aerobic abilities in the lower extremity muscles of those disabled with cerebral palsy. Among the muscle functions of lower extremity muscle strength, 300°/s peak torque/BW of KNEE Joint was found to have the greatest effect on VO2peak (p < 0.001). As a result, 300°/s peak torque/BW of KNEE Joint was found to be the predictable factor that could explain the VO2peak in the disabled people with cerebral palsy at 67% (R2 = 0.661). In particular, among the muscle functions of lower extremity muscle strength at 45°/s peak, torque/BW of HIP Joint was found to have the greatest effect on HRpeak (p < 0.001). As a result, this factor was found to be the predictable factor that could explain the HRpeak in disabled people with cerebral palsy at 39% (R2 = 0.392). In this study, the muscle strength of the lower extremity of CP was closely related to the aerobic capacity, and the muscle endurance of KNEE Joint and the muscle power of HIP Joint were found to be important factors to predict the aerobic capacity of CP.

The Relationship Between Strength of the Affected Leg and Walking Speed After Stroke Varies According to the Level of Walking Disability: A Systematic Review

OBJECTIVE

The objectives of this review were to determine the relationship between muscle strength of the affected leg and walking speed after stroke and whether this relationship varied according to muscle group or level of walking disability.

METHODS

This systematic review with meta-analysis focused on observational studies of adult survivors of stroke. Muscle strength had to be measured as maximum voluntary force production during an isometric contraction of the affected leg. Walking had to be measured as walking speed. Studies had to report correlations between muscle strength and walking speed.

RESULTS

Thirty studies involving 1001 participants were included. Pooled mean correlations between muscle strength of the affected leg and walking speed was 0.51 (95% CI = 0.45 to 0.57). Pooled correlations between the strength of individual muscle groups and walking speed ranged from 0.42 (for the hip abductors) to 0.57 (for the ankle dorsiflexors). The correlation between level of walking disability and the mean correlation between muscle strength and walking speed was -0.70 (95% CI = -0.42 to -0.86).

CONCLUSION

After stroke, there is a strong relationship between strength of the affected leg and walking speed, with little variability across individual muscle groups. However, the level of walking disability of people with stroke does make a difference such that the more disabled people are, the stronger the relationship is between strength of the affected leg and walking speed.

IMPACT

This study suggests that the strength of all muscles of the affected leg is important for walking after stroke. It appears that increasing strength in the affected leg could be most important in people who are more disabled.

LAY SUMMARY

After stroke, the speed at which a person can walk is highly associated with the muscle strength of their affected leg. In people whose walking speed is severely affected, this association is stronger, and the physical therapist might focus on strengthening that leg so the individual can walk faster.

Comparison of training effects between underwater treadmill gait training and overground gait training on the walking ability and respiratory function in patients with chronic severe hemiplegic stroke: A randomized, controlled, preliminary trial

Background: The need to develop a more effective intervention to obtain a functional recovery of stroke patients who are unable to perform land-based treadmill gait training has been widely reported. Thus, this pilot study aimed to identify a gait training type that could lead to improved gait and respiratory functioning in adult patients with chronic severe hemiplegic stroke.Objectives: To examine whether underwater treadmill or/and overground gait training could be more effective in stroke patients.Methods: In this single-blinded, randomized, controlled, comparative study, 22 patients with severe hemiplegic stroke in a rehabilitation hospital were randomly assigned to the experimental (underwater treadmill gait training) or control group (overground gait training). All participants performed a 60-min neurodevelopmental treatment (five times/week for 12 weeks). Each group performed 30-min underwater or overground gait training (two times/week for 12 weeks). Gait and respiratory function were measured before and after the 12-week training.Results: For the walking variables, step-time difference changes post-training showed significant differences between the groups (-.06 vs. +.04 s, p < .05). Both groups showed significant increases in the maximal voluntary volume (MVV) at post compared to pre training (p < .05). The post-training MVV values were significantly different between the two groups (+23.35 vs. +4.76 L, p < .05).Conclusions: In severe stroke patients, underwater treadmill gait training can be more effective in improving gait and respiratory function than overground gait training and could be an effective clinical intervention tool for the training of such patients.

Integrating Survivors of Stroke Into Exercise-Based Cardiac Rehabilitation Improves Endurance and Functional Strength

Background

Cardiac rehabilitation (CR) is a structured exercise program prevalent in the United States for people with cardiovascular disease that has been shown to increase cardiovascular endurance and improve quality of life. Despite similar cardiovascular risk factors, stroke is not among the covered diagnoses for CR. The purpose of this study was to examine the participant impact of integrating survivors of stroke into the exercise portion of an existing hospital‐based CR program through measures of physical function and other health impacts and through qualitative evaluation of participant perception.

Methods and Results

Subacute and chronic survivors of stroke were integrated into a standard 12‐week, 3 sessions per week, exercise‐based CR program. A total of 29 began the program, 24 completed the program, and 18 were available for 6‐month follow‐up. Quantitative measures were compared preprogram with postprogram with t‐test or equivalent, and preprogram with postprogram to 6‐month follow‐up with ANOVA or equivalent. Semistructured interviews were completed with 11 participants postprogram. Exercise‐based CR had significant impacts on cardiovascular endurance preprogram to postprogram, with maintenance at 6‐month follow‐up. The participants improved on the 6‐minute walk test on average by 61.92 m(95% CI, 33.99–89.84 m), and maximum metabolic equivalents improved by a median of 3.6 (interquartile range, 2.35). Five times sit to stand (functional strength) improved preprogram to postprogram by a median of 2.85 s (interquartile range, 4.03 s). Qualitative findings highlight additional health improvements. Most participants (83% [15/18]) reported continued exercise at follow‐up.

Conclusions

Exercise‐based CR has the potential to improve cardiovascular endurance, health status, and quality of life for survivors of stroke.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03706105.

Effects of different vibration frequencies on muscle strength, bone turnover and walking endurance in chronic stroke

This randomized controlled trial aimed to evaluate the effects of different whole body vibration (WBV) frequencies on concentric and eccentric leg muscle strength, bone turnover and walking endurance after stroke. The study involved eighty-four individuals with chronic stroke (mean age = 59.7 years, SD = 6.5) with mild to moderate motor impairment (Fugl-Meyer Assessment lower limb motor score: mean = 24.0, SD = 3.5) randomly assigned to either a 20 Hz or 30 Hz WBV intervention program. Both programs involved 3 training sessions per week for 8 weeks. Isokinetic knee concentric and eccentric extension strength, serum level of cross-linked N-telopeptides of type I collagen (NTx), and walking endurance (6-min walk test; 6MWT) were assessed at baseline and post-intervention. An intention-to-treat analysis revealed a significant time effect for all muscle strength outcomes and NTx, but not for 6MWT. The time-by-group interaction was only significant for the paretic eccentric knee extensor work, with a medium effect size (0.44; 95% CI: 0.01, 0.87). Both WBV protocols were effective in improving leg muscle strength and reducing bone resorption. Comparatively greater improvement in paretic eccentric leg strength was observed for the 30 Hz protocol.

Distance-limited walk tests post-stroke: A systematic review of measurement properties

BACKGROUND

Improving walking capacity is a key objective of post-stroke rehabilitation. Evidence describing the quality and protocols of standardized tools for assessing walking capacity can facilitate their implementation.

OBJECTIVE

To synthesize existing literature describing test protocols and measurement properties of distance-limited walk tests in people post-stroke.

METHODS

Electronic database searches were completed in 2017. Records were screened and appraised for quality.

RESULTS

Data were extracted from 43 eligible articles. Among the 12 walk tests identified, the 10-metre walk test (10mWT) at a comfortable pace was most commonly evaluated. Sixty-three unique protocols at comfortable and fast paces were identified. Walking pace and walkway surface, but not walkway length, influenced walking speed. Intraclass correlation coefficients for test-retest reliability ranged from 0.80-0.99 across walk tests. Measurement error values ranged from 0.04-0.40 and 0.06 to 0.20 for the 10mWT at comfortable and fast and paces, respectively. Across walk tests, performance was most frequently correlated with measures of strength, balance, and physical activity (r = 0.26-0.8, p < 0.05).

CONCLUSIONS

The 10mWT has the most evidence of reliability and validity. Findings indicate that studies that include people with severe walking deficits, in acute and subacute phases of recovery, with improved quality of reporting, are needed.

Residual Deficits of Knee Flexors and Plantar Flexors Predict Normalized Walking Performance in Patients with Poststroke Hemiplegia

OBJECTIVES

The aim of the study was to investigate the relation of lower limb muscle strength with normalized walking value, gait speed, and balance in patients with poststroke hemiplegia.

METHODS

Functional ambulatory unilateral hemiplegic patients were included in the study. Functionality of the lower limb was tested by Fugl-Meyer lower extremity motor subscale. Six-minute walk test (6MWT), 10-meter walk test, and Berg Balance Scale were performed to evaluate functional walking capacity, gait speed, and balance, respectively. Normalized 6MWT value was calculated by using a formula. Maximum isometric strengths of 8 muscle groups of both limbs were measured using a handheld dynamometry and residual deficits of the paretic side muscles were calculated.

RESULTS

The study population was comprised of 61 hemiplegic patients (mean age: 54.6 ± 11.7 years and mean duration after stroke: 23.4 ± 18.1 months). Mean normalized walking distance on 6MWT was 44.4% of expected. The residual deficits of the affected lower extremity muscles were negatively correlated with normalized 6MWT: hip flexors (r = -.651), hip extensors (r = -.621), hip abductors (r = -.657), hip adductors (r = -.630), knee flexors (r = -.738), knee extensors (r = -.659), ankle dorsiflexors (r = -.776), and ankle plantar flexors (r = -.773). Lower extremity residual deficits also showed moderate-strong negative correlations with Berg Balance Scores and gait speed. Multiple linear regression analyses showed that the residual deficits of the ankle plantar flexors and knee flexors are the major independent determinants of normalized 6MWT results (R: .791 R²: 625).

CONCLUSIONS

Residual deficits of lower extremity muscles-particularly of ankle dorsiflexors, plantar flexors, and knee flexors-are related to walking performance, gait speed and balance. Besides, knee flexors and plantar flexors are predictors of normalized 6MWT.

Analyzing walking speeds with ankle and wrist worn accelerometers in a cohort with myotonic dystrophy

Background: Accelerometers are accurate tools to assess movement and physical activity. However, interpreting standardly used outputs is not straightforward for populations with impaired mobility.

Methods: The applicability of GENEActiv was explored in a group of 30 participants with myotonic dystrophy and compared to a group of 14 healthy-controls. All participants performed a set of tests while wearing four different accelerometers (wrists and ankles): [1] standing still; [2] ten-meters walk test; [3] six-minutes walking test; and, [4] ten-meters walk/run test.

Results: Relevant findings were: [1] high intra-accelerometer reliability (i.e. 0.97 to 0.99; p < 0.001); [2] each test acceleration values differ significantly between each other; [3] no inter-accelerometer reliability between wrist-worn devices and ankle-worn; and [4] a significant difference between the myotonic dystrophy group and the healthy-controls detectable at each test (i.e. Left-ankle values at six-minutes walking test: 48±17 for the myotonic dystrophy group, vs, 74±16 for the healthy-controls; p < 0.001).

Conclusions: GENEActiv demonstrated to be valid and reliable, capable of detecting walking periods and discriminating different speeds. However, inter-accelerometer reliability only applied when comparing opposite sides of the same limb. Specific movement characteristics of the myotonic dystrophy group were identified and muscle strength showed not to be a full determinant of limb acceleration.

Implications for rehabilitation

Rehabilitation professionals in the field of neuromuscular disorders should be aware of the potential use of objective monitoring tools such as accelerometers whilst acknowledging the implications of assessing populations with altered movement patterns.

Researchers should be cautious when translating accelerometry outputs previously validated in healthy populations to functionally impaired cohorts like myotonic dystrophy.

Accelerometers can objectively expose movement disturbances allowing further investigations for the source of these disturbances.

Validity of the total body centre of gravity during gait using a markerless motion capture system

PURPOSE

The purpose of this study was to examine the validity of total body centre of gravity (COG) measurement during gait with markerless motion capture system (MLS) on the basis of values acquired with a marker-based motion capture system (MBS).

MATERIALS AND METHODS

Thirty young healthy subjects walked on a flat surface as coordinate data from their bodies were acquired using the Kinect v2 (as a MLS) and Vicon systems (as a MBS). COG was calculated using coordinate data of the total body. Comparisons of COG ensemble curves in the mediolateral and vertical directions were performed between MLS and MBS throughout the gait cycle. The relative consistency between these systems was assessed using Pearson correlation coefficients.

RESULTS

The COG trajectory made by using MLS data followed the trend of the COG trajectory with MBS in the mediolateral direction. In the vertical direction, however, the COG trajectories did not match between two systems. High correlation coefficients (r  > 0.79) were observed from 30% to 80% of the gait cycle. The greatest difference of COG between MLS and MBS in the mediolateral direction was 1.1 mm. Differences in the vertical direction appeared to be proportional to the distance between the participant and the Kinect v2 sensor.

CONCLUSION

In the mediolateral direction, COG calculated with MLS data during gait was validated with COG calculated on the basis of a MBS. Further correction of systematic error is necessary to improve the validity of COG calculations in the vertical direction.

The prevalence, distribution, and functional importance of lower limb somatosensory impairments in chronic stroke survivors: a cross sectional observational study

Purpose: To investigate the prevalence and distribution of lower limb somatosensory impairments in community dwelling chronic stroke survivors and examine the association between somatosensory impairments and walking, balance, and falls. Methods: Using a cross sectional observational design, measures of somatosensation (Erasmus MC modifications to the (revised) Nottingham Sensory Assessment), walking ability (10 m walk test, Walking Impact Scale, Timed "Get up and go"), balance (Functional Reach Test and Centre of Force velocity), and falls (reported incidence and Falls Efficacy Scale-International), were obtained. Results: Complete somatosensory data was obtained for 163 ambulatory chronic stroke survivors with a mean (SD) age 67(12) years and mean (SD) time since stroke 29 (46) months. Overall, 56% (n = 92/163) were impaired in the most affected lower limb in one or more sensory modality; 18% (n = 30/163) had impairment of exteroceptive sensation (light touch, pressure, and pin-prick), 55% (n = 90/163) had impairment of sharp-blunt discrimination, and 19% (n = 31/163) proprioceptive impairment. Distal regions of toes and foot were more frequently impaired than proximal regions (shin and thigh). Distal proprioception was significantly correlated with falls incidence (r = 0.25; p < 0.01), and centre of force velocity (r = 0.22, p < 0.01). The Walking Impact Scale was the only variable that significantly contributed to a predictive model of falls accounting for 15-20% of the variance. Conclusion: Lower limb somatosensory impairments are present in the majority of chronic stroke survivors and differ widely across modalities. Deficits of foot and ankle proprioception are most strongly associated with, but not predictive, of reported falls. The relative contribution of lower limb somatosensory impairments to mobility in chronic stroke survivors appears limited. Further investigation, particularly with regard to community mobility and falls, is warranted. Implications for Rehabilitation Somatosensory impairments in the lower limb were present in approximately half of this cohort of chronic stroke survivors. Tactile discrimination is commonly impaired; clinicians should include an assessment of discriminative ability. Deficits of foot and ankle proprioception are most strongly associated with reported falls. Understanding post-stroke lower limb somatosensory impairments may help inform therapeutic strategies that aim to maximise long-term participation, minimise disability, and reduce falls.

Safety and Feasibility of the 6-Minute Walk Test in Patients with Acute Stroke

BACKGROUND

Our objective was to investigate the safety and feasibility of the 6-minute walk test in patients with acute stroke.

MATERIALS AND METHODS

Consecutive patients with acute stroke, admitted to the Itami Kosei Neurosurgical Hospital from September 2016 to April 2017 were enrolled. Walking capacity was assessed by a physical therapist using the 6-minute walk test in 94 patients with acute stroke within 14 days of hospital admission. The primary outcomes were safety (i.e., the prevalence of new adverse events during and after the test) and feasibility (i.e., test completion rate) of the 6-minute walk test.

RESULTS

The 6-minute walk test was performed for a mean duration of 5.1 days (standard deviation, 2.6 days) after hospital admission. Seventy patients (74.5%) could walk without standby assistance or a walking aid, and 24 patients (25.5%) could walk without standby assistance but with a walking aid. The average distance walked by patients during the 6-minute walk test was 331 m (standard deviation, 107.2 m). Adverse events following the 6-minute walk test occurred in 6 patients (6.4%) and included stroke progression, stroke recurrence, seizures, and neurological deterioration. Heart rate increase (>120 beats/min) occurred in 3 patients (3.2%) during the test. Lastly, 6 patients (6.4%) were unable to complete the 6-minute walk test.

CONCLUSIONS

Although performance in the 6-minute walk test was decreased in patients with acute stroke, the test itself appears to be safe and feasible in this patient population.

Ten Meters Walking Speed in Spinal Cord-Injured Patients: Does Speed Predict Who Walks and Who Rolls?

BACKGROUND

Walking speed is assumed to be a key factor in regaining ambulation after spinal cord injury (SCI). However, from the literature it remains unclear which walking speed usually results in independent community ambulation.

OBJECTIVE

The primary aim of this study was to determine at which walking speed SCI patients tend to walk in the community instead of using a wheelchair. The secondary aim was to investigate clinical conditions that favor independent ambulation in the community.

METHODS

Data from SCI patients were collected retrospectively from the European Multicenter Study about Spinal Cord Injury database. We determined a cutoff walking speed at which the patients tend to walk in the community by plotting a receiver operating characteristics curve, using the Spinal Cord Independence Measure for outdoor mobility. Univariate analyses investigated which factors influence independent community ambulation.

RESULTS

A walking speed of 0.59 m/s is the cutoff between patients who do and do not ambulate independently in the community, with a sensitivity of 91.6% and a specificity of 80.3%. Age, injury severity, and lower limb muscle strength have a significant influence on independent community ambulation.

CONCLUSIONS

Patients with an SCI who regain a walking speed of 0.59 m/s tend to achieve a level of walking effectiveness that allows for independent community walking. Although such patients tend to be younger and less severely injured, this walking speed can be a target for locomotor training in rehabilitation and clinical trials that lead to a meaningful outcome level of community walking.

Reliability and Validity of the Timed Up and Go Test With a Motor Task in People With Chronic Stroke

OBJECTIVES

To examine (1) the intra-rater, interrater, and test-retest reliabilities of the timed Up and Go test with a motor task (TUG_motor) in terms of the number of steps taken in the test and completion time in a population with chronic stroke; (2) the relation between stroke-specific impairments and the number of steps taken in the test and the completion time; (3) the minimum detectable change in TUG_motor times; and (4) the cutoff time that best discriminates the performance of people with stroke from that of older adults without stroke.

DESIGN

Cross-sectional study.

SETTING

University-based rehabilitation center.

PARTICIPANTS

A sample (N=65) of chronic stroke survivors (n=33) and healthy older adults (n=32).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

TUG_motor times and number of steps taken; Fugl-Meyer Assessment for the Lower Extremities score; handheld dynamometer measurements of hip abductor, knee flexor and extensor, and ankle dorsiflexor and plantar flexor muscle strength; 5-times sit-to-stand test time, Berg Balance Scale score; conventional timed Up and Go test time, and Activities-specific Balance Confidence scale and Community Integration Measure questionnaire scores.

RESULTS

The TUG_motor completion times and number of steps demonstrated excellent intra-rater, interrater, and test-retest reliabilities. The TUG_motor times correlated significantly with the Fugl-Meyer Assessment for the Lower Extremities and Berg Balance Scale scores, with hip abductor, knee flexor, ankle dorsiflexor and plantar flexor strength on the paretic side, with 5-times sit-to-stand test times, and with times on the conventional timed Up and Go test. The minimum detectable change in TUG_motor time was 3.53 seconds in stroke survivors. A TUG_motor cutoff time of 13.49 seconds was found to best discriminate the performance of stroke survivors from that of older adults without stroke.

CONCLUSIONS

The TUG_motor is a reliable, valid, and easy-to-administer clinical tool for assessing advanced functional mobility after a stroke.

Considerations for the Selection of Time-Limited Walk Tests Poststroke: A Systematic Review of Test Protocols and Measurement Properties

BACKGROUND AND PURPOSE

Systematic reviews of research evidence describing the quality and methods for administering standardized outcome measures are essential to developing recommendations for their clinical application. The purpose of this systematic review was to synthesize the research literature describing test protocols and measurement properties of time-limited walk tests in people poststroke.

METHODS

Following an electronic search of 7 bibliographic data-bases, 2 authors independently screened titles and abstracts. One author identified eligible articles, and performed quality appraisal and data extraction.

RESULTS

Of 12 180 records identified, 43 articles were included. Among 5 walk tests described, the 6-minute walk test (6MWT) was most frequently evaluated (n = 36). Only 5 articles included participants in the acute phase (<1 month) poststroke. Within tests, protocols varied. Walkway length and walking aid, but not turning direction, influenced 6MWT performance. Intraclass correlation coefficients for reliability were 0.68 to 0.71 (12MWT) and 0.80 to 1.00 (2-, 3-, 5- and 6MWT). Minimal detectable change values at the 90% confidence level were 11.4 m (2MWT), 24.4 m (5MWT), and 27.7 to 52.1 m (6MWT; n = 6). Moderate-to-strong correlations (≥0.5) between 6MWT distance and balance, motor function, walking speed, mobility, and stair capacity were consistently observed (n = 33). Moderate-to-strong correlations between 5MWT performance and walking speed/independence (n = 1), and between 12MWT performance and balance, motor function, and walking speed (n = 1) were reported.

DISCUSSION AND CONCLUSIONS

Strong evidence of the reliability and construct validity of using the 6MWT poststroke exists; studies in the acute phase are lacking. Because protocol variations influence performance, a standardized 6MWT protocol poststroke for use across the care continuum is needed.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A150).

Factors Influencing the Efficacy of Aerobic Exercise for Improving Fitness and Walking Capacity After Stroke: A Meta-Analysis With Meta-Regression

OBJECTIVE

To assess the influence of dosing parameters and patient characteristics on the efficacy of aerobic exercise (AEX) poststroke.

DATA SOURCES

A systematic review was conducted using PubMed, MEDLINE, Cumulative Index of Nursing and Allied Health Literature, Physiotherapy Evidence Database, and Academic Search Complete.

STUDY SELECTION

Studies were selected that compared an AEX group with a nonaerobic control group among ambulatory persons with stroke.

DATA EXTRACTION

Extracted outcome data included peak oxygen consumption (V˙o₂peak) during exercise testing, walking speed, and walking endurance (6-min walk test). Independent variables of interest were AEX mode (seated or walking), AEX intensity (moderate or vigorous), AEX volume (total hours), stroke chronicity, and baseline outcome scores.

DATA SYNTHESIS

Significant between-study heterogeneity was confirmed for all outcomes. Pooled AEX effect size estimates (AEX group change minus control group change) from random effects models were V˙o₂peak, 2.2mL⋅kg^-1⋅min^-1 (95% confidence interval [CI], 1.3-3.1mL⋅kg^-1⋅min^-1); walking speed, .06m/s (95% CI, .01-.11m/s); and 6-minute walk test distance, 29m (95% CI, 15-42m). In meta-regression, larger V˙o₂peak effect sizes were significantly associated with higher AEX intensity and higher baseline V˙o₂peak. Larger effect sizes for walking speed and the 6-minute walk test were significantly associated with a walking AEX mode. In contrast, seated AEX did not have a significant effect on walking outcomes.

CONCLUSIONS

AEX significantly improves aerobic capacity poststroke, but may need to be task specific to affect walking speed and endurance. Higher AEX intensity is associated with better outcomes. Future randomized studies are needed to confirm these results.

The correlation between muscle activity of the quadriceps and balance and gait in stroke patients

[Purpose] The purpose of this study was to examine the correlation between quadriceps muscle activity and balance and gait in stroke patients. [Subjects and Methods] Fifty-five stroke patients (30 males 25 females; mean age 58.7 years; stroke duration 4.82 months; Korean mini-mental state examination score 26.4) participated in this study. MP100 surface electromyography, BioRescue, and LUKOtronic were used to measure the quadriceps muscle activity, balance, and gait, respectively. [Results] There was a significant correlation between quadriceps muscle activity (vastus lateralis % reference voluntary contraction, vastus medialis % reference voluntary contraction) and balance (limits of stability) and gait (gait velocity) but there was none between vastus lateralis % reference voluntary contraction, vastus medialis % reference voluntary contraction. [Conclusion] An increase in quadriceps muscle activity will improve balance and gait ability. To improve function in stroke patients, training is needed to strengthen the quadriceps muscles.

Balance impairment limits ability to increase walking speed in individuals with chronic stroke

Purpose Determine the relationship between balance impairments and the ability to increase walking speed (WS) on demand in individuals with chronic stroke. Methods WS and Berg Balance Scale (BBS) data were collected on 124 individuals with chronic stroke (>6 months). The ability to increase WS on demand (walking speed reserve, WSR) was quantified as the difference between participants' self-selected (SSWS) and maximal (MWS) walking speeds. Correlation, regression and receiver operating characteristic (ROC) analyses were performed to investigate the relationship between balance and the ability to increase WS. Results Of sample, 58.9% were unable to increase WS on demand (WSR < 0.2 m/s). BBS scores were associated with WSR values (r_s=0.74, 0.65-0.81) and were predictive of 'able/unable' to increase WS [odds ratio (OR) = 0.75, 0.67-0.84]. The AUC for the ROC curve constructed to assess the accuracy of BBS to discriminate between able/unable to increase WS was 0.85 (0.78-0.92). A BBS cutscore of 47 points was identified [sensitivity: 72.6%, specificity: 90.2%, +likelihood ratio (LR): 7.41, -LR: 0.30]. Conclusions The inability to increase WS on demand is common in individuals with chronic stroke, and balance appears to be a significant contributor to this difficulty. A BBS cutscore of 47 points can identify individuals who may benefit from balance interventions to improve the ability to increase their WS. Implications for Rehabilitation A majority of individuals with chronic stroke may be unable to increase their walking speed beyond their self-selected speed on demand. This may limit functional ambulation, as these individuals are walking "at capacity". Balance impairments contribute to the inability to increase walking speed. A Berg Balance Scale score <47 points can be used to identify individuals with chronic stroke walking "at capacity" due to balance impairments.

Effects of aerobic exercise training on fitness and walking-related outcomes in ambulatory individuals with chronic incomplete spinal cord injury

Study Design

Single group, pretest-posttest study.

Objectives

To determine the effects of a non-task-specific, voluntary, progressive aerobic exercise training (AET) intervention on fitness and walking-related outcomes in ambulatory adults with chronic motor-incomplete SCI.

Setting

Rehabilitation research center.

Methods

Ten ambulatory individuals (50% female; 57.94 ± 9.33 years old; 11.11 ± 9.66 years post injury) completed voluntary, progressive moderate-to-vigorous intensity AET on a recumbent stepper three days per week for six weeks. The primary outcome measures were aerobic capacity (VO_2peak) and self-selected overground walking speed (OGWS). Secondary outcome measures included: walking economy, six-minute walk test (6MWT), daily step counts, Walking Index for Spinal Cord Injury (WISCI-II), Dynamic Gait Index (DGI), and Berg Balance Scale (BBS).

Results

Nine participants completed all testing and training. Significant improvements in aerobic capacity (P=0.011), OGWS (P=0.023), the percentage of VO_2peak utilized while walking at self-selected speed (P=0.03), and daily step counts (P=0.025) resulted following training.

Conclusions

The results indicate that total-body, voluntary, progressive AET is safe, feasible, and effective for improving aerobic capacity, walking speed, and select walking-related outcomes in an exclusively ambulatory SCI sample. This study suggests the potential for non-task-specific aerobic exercise to improve walking following incomplete SCI and builds a foundation for further investigation aimed at the development of exercise based rehabilitation strategies to target functionally limiting impairments in ambulatory individuals with chronic SCI.

Brain-controlled functional electrical stimulation therapy for gait rehabilitation after stroke: a safety study

BACKGROUND

Many stroke survivors have significant long-term gait impairment, often involving foot drop. Current physiotherapies provide limited recovery. Orthoses substitute for ankle strength, but they provide no lasting therapeutic effect. Brain-computer interface (BCI)-controlled functional electrical stimulation (FES) is a novel rehabilitative approach that may generate permanent neurological improvements. This study explores the safety and feasibility of a foot-drop-targeted BCI-FES physiotherapy in chronic stroke survivors.

METHODS

Subjects (n = 9) operated an electroencephalogram-based BCI-FES system for foot dorsiflexion in 12 one-hour sessions over four weeks. Gait speed, dorsiflexion active range of motion (AROM), six-minute walk distance (6MWD), and Fugl-Meyer leg motor (FM-LM) scores were assessed before, during, and after therapy. The primary safety outcome measure was the proportion of subjects that deteriorated in gait speed by ≥0.16 m/s at one week or four weeks post-therapy. The secondary outcome measures were the proportion of subjects that experienced a clinically relevant decrease in dorsiflexion AROM (≥2.5°), 6MWD (≥20 %), and FM-LM score (≥10 %) at either post-therapy assessment.

RESULTS

No subjects (0/9) experienced a clinically significant deterioration in gait speed, dorsiflexion AROM, 6MWT distance, or FM-LM score at either post-therapy assessment. Five subjects demonstrated a detectable increase (≥0.06 m/s) in gait speed, three subjects demonstrated a detectable increase (≥2.5°) in dorsiflexion AROM, five subjects demonstrated a detectable increase (≥10 %) in 6MWD, and three subjects demonstrated a detectable increase (≥10 %) in FM-LM. Five of the six subjects that exhibited a detectable increase in either post-therapy gait speed or 6MWD also exhibited significant (p < 0.01 using a Mann-Whitney U test) increases in electroencephalogram event-related synchronization/desynchronization. Additionally, two subjects experienced a clinically important increase (≥0.16 m/s) in gait speed, and four subjects experienced a clinically important increase (≥20 %) in 6MWD. Linear mixed models of gait speed, dorsiflexion AROM, 6MWD, and FM-LM scores suggest that BCI-FES therapy is associated with an increase in lower motor performance at a statistically, yet not clinically, significant level.

CONCLUSION

BCI-FES therapy is safe. If it is shown to improve post-stroke gait function in future studies, it could provide a new gait rehabilitation option for severely impaired patients. Formal clinical trials are warranted.

Exercise stress testing after stroke or transient ischemic attack: a scoping review

OBJECTIVE

To provide insight into exercise stress testing after stroke or transient ischemic attack (TIA) in terms of feasibility, safety, and protocols used.

DATA SOURCES

PubMed, Embase, CINAHL, and Web of Science were searched for relevant studies published from inception to March 2014, and reference lists were hand searched.

STUDY SELECTION

To be included in the review, the articles needed to include participants diagnosed with stroke or TIA and have any form of test to assess exercise capacity.

DATA EXTRACTION

The scoping review methodology does not include critical appraisal of the literature but was chosen to reflect all aspects of exercise stress testing after stroke or TIA. Two reviewers performed screening for eligible studies independently, and 1 reviewer extracted the data.

DATA SYNTHESIS

We found a total of 112 studies involving 5008 participants describing symptom-limited (n=103), submaximal (n=9), and field (n=6) exercise stress test protocols. Some of the studies reported on data from >1 protocol. Metabolic analysis was included in 87% of the studies involving symptom-limited tests, 40% of submaximal studies, and 29% of field tests. Monitoring of blood pressure, perceived exertion, and electrocardiographic responses was done in 54%, 42%, and 95% of all studies, respectively. A mere 10% of all studies reported on electrocardiographic abnormalities detected during testing. No serious adverse events were reported.

CONCLUSIONS

Symptom-limited exercise stress testing appears to be safe in patients with stroke or TIA and provides a more valid measure of exercise capacity than submaximal and field tests. The level of disability may compromise feasibility, and test modality should be chosen carefully to optimize test results.

How strongly is aerobic capacity correlated with walking speed and distance after stroke? Systematic review and meta-analysis

BACKGROUND

Restoration of walking capacity, as reflected by walking speed and walking distance, is a primary goal after stroke. Peak aerobic capacity (peak oxygen consumption [V̇o₂peak]) is suggested to be correlated with walking capacity after stroke. Although the strength of this correlation is unclear, physical therapy programs often target walking capacity by means of aerobic training.

PURPOSE

The purpose of this systematic review was to summarize the available evidence on the correlation between V̇o₂peak and walking capacity.

DATA SOURCES

The databases MEDLINE, CINAHL, EMBASE, Cochrane Library, and SPORTDiscus were searched up to May 2014.

STUDY SELECTION

Cross-sectional studies reporting correlation coefficients between V̇o₂peak and walking capacity in stroke were included, along with longitudinal studies reporting these correlation coefficients at baseline.

DATA EXTRACTION

The methodological quality of the studies was assessed using a checklist of 27 items for observational research. Information on study design, stroke severity and recovery, and assessments and outcome of V̇o₂peak and walking capacity, as well as the reported correlation coefficients, were extracted.

DATA SYNTHESIS

Thirteen studies involving 454 participants were included. Meta-analyses showed combined correlation coefficients (rɱ) for V̇o₂peak and walking speed and for V̇o₂peak and walking distance of .42 (95% credibility interval=.31, .54) and .52 (95% credibility interval=.42, .62), respectively.

LIMITATIONS

The studies included in the present review had small sample sizes and low methodological quality. Clinical and methodological diversity challenged the comparability of the included studies, despite statistical homogeneity. Relevant data of 3 studies could not be retrieved.

CONCLUSIONS

The strength of the correlation of V̇o₂peak with walking speed was low and moderate for V̇o₂peak and walking distance, respectively, indicating that other factors, besides V̇o₂peak, determine walking capacity after stroke.

Classifying physical activity research following stroke using the behavioral epidemiologic framework

BACKGROUND

Stroke is a significant public health issue in the USA and a need emerges to better understand how to reduce an individual's co-morbidity risk. Physical activity is one approach to improving the health of individuals and comprehensive literature supports increased activity as a means to reduce risk of morbidity and mortality. One approach to examining whether research in a field is addressing a public health issue is through application of the behavioral epidemiological framework.

OBJECTIVE

To classify physical activity research for individuals following stroke into distinct phases so that efforts can be made to systematically address gaps and disseminate evidence-based practice.

METHODS

Specific key words were identified and then searched through EBSCO host, PubMed, and Google Scholar. Physical activity and stroke literature from 2000-2014 was categorized into one of five discrete phases. Research in Phase 1 identified associations between activity and health; Phase 2 established valid measures of activity; Phase 3 examined determinants of behavior; Phase 4 evaluated activity interventions; and Phase 5 disseminated evidence-based practice.

RESULTS

A comprehensive review of literature identified 202 articles with 70% categorized in Phase 1 (n = 141), 11% in Phase 2 (n = 23), 10% in Phase 3 (n = 20), 8% in Phase 4 (n = 15), and 1% in Phase 5 (n = 3).

CONCLUSION

Findings suggest that physical activity research for individuals following stroke is in the early stages of development with less than 10% of research evaluating or disseminating interventions.

Protocol variations and six-minute walk test performance in stroke survivors: a systematic review with meta-analysis

Objective. To investigate the use of the six-minute walk test (6MWT) for stroke survivors, including adherence to 6MWT protocol guidelines and distances achieved. Methods. A systematic search was conducted from inception to March 2014. Included studies reported a baseline (intervention studies) or first instance (observational studies) measure for the 6MWT performed by stroke survivors regardless of time after stroke.  Results. Of 127 studies (participants n = 6,012) that met the inclusion criteria, 64 were also suitable for meta-analysis. Only 25 studies made reference to the American Thoracic Society (ATS) standards for the 6MWT, and 28 reported using the protocol standard 30 m walkway. Thirty-nine studies modified the protocol walkway, while 60 studies did not specify the walkway used. On average, stroke survivors walked 284 ± 107 m during the 6MWT, which is substantially less than healthy age-matched individuals. The meta-analysis identified that changes to the ATS protocol walkway are associated with reductions in walking distances achieved. Conclusion. The 6MWT is now widely used in stroke studies. The distances achieved by stroke patients indicate substantially compromised walking ability. Variations to the standard 30 m walkway for the 6MWT are common and caution should be used when comparing the values achieved from studies using different walkway lengths.

Chronic stroke patients show early and robust improvements in muscle and functional performance in response to eccentric-overload flywheel resistance training: a pilot study

BACKGROUND

Resistance exercise comprising eccentric (ECC) muscle actions enhances muscle strength and function to aid stroke patients in conducting daily tasks. The purpose of this study was to assess the efficacy of a novel ECC-overload flywheel resistance exercise paradigm to induce muscle and functional performance adaptations in chronic stroke patients.

METHODS

Twelve patients (~8 years after stroke onset) performed 4 sets of 7 coupled concentric (CON) and ECC actions using the affected limb on a flywheel leg press (LP) device twice weekly for 8 weeks. Maximal CON and ECC isokinetic torque at 30, 60 and 90°/s, isometric knee extension and LP force, and CON and ECC peak power in LP were measured before and after training. Balance (Berg Balance Scale, BBS), gait (6-Min Walk test, 6MWT; Timed-Up-and-Go, TUG), functional performance (30-s Chair-Stand Test, 30CST), spasticity (Modified Ashworth Scale) and perceived participation (Stroke Impact Scale, SIS) were also determined.

RESULTS

CON and ECC peak power increased in both the trained affected (34 and 44%; P < 0.01), and the untrained, non-affected leg (25 and 34%; P < 0.02). Power gains were greater (P = 0.008) for ECC than CON actions. ECC isokinetic torque at 60 and 90°/s increased in the affected leg (P < 0.04). The increase in isometric LP force for the trained, affected leg across tests ranged 10-20% (P < 0.05). BBS (P = 0.004), TUG (P = 0.018), 30CST (P = 0.024) and SIS (P = 0.058) scores improved after training. 6MWT and spasticity remained unchanged.

CONCLUSIONS

This novel, short-term ECC-overload flywheel RE training regime emerges as a valid, safe and viable method to improve muscle function, balance, gait and functional performance in men and women suffering from chronic stroke.

Energy cost of obstacle crossing in stroke patients

OBJECTIVE

The purpose of this study was to analyze the effects of clearing and skirting obstacles during the gait on the energetic cost of walking (ECW) of patients with chronic hemiplegia. The hypothesis was that hemiplegia would have a greatest increase in the ECW than in the healthy group.

DESIGN

Fifteen healthy subjects and 17 patients with chronic hemiplegia completed two 6-min walking sessions: one with obstacles and the other without obstacles. During both sessions, the patients were equipped with a portable gas analyzer to measure oxygen uptake (V˙o2). Gait velocity and ECW were calculated.

RESULTS

In both groups, gait velocity was lower in the with-obstacles condition and the ECW was significantly higher. V˙o2 was greater in the with-obstacles condition for the healthy group, whereas it remained unchanged for the group with hemiplegia.

CONCLUSIONS

Results demonstrated that the addition of obstacles during gait increased the ECW and decreased mean walking speed in both the healthy subjects and the patients with hemiplegia. More interestingly, the authors found differences in adaptation strategies between the healthy subjects and the patients with hemiplegia. During the with-obstacles condition, the oxygen uptakes of the healthy subjects increased and mean walking speed decreased, whereas, in the subjects with hemiplegia, only mean walking speed decreased.

Variability, frequency composition, and complexity of submaximal isometric knee extension force from subacute to chronic stroke

We examined changes in the variability, frequency composition, and complexity of force signal from subacute to chronic stage of stroke during maintenance of isometric knee extension and compared these parameters between chronic stroke and healthy subjects. The sample included 15 healthy (65±8 years) and 23 chronic stroke subjects (65±14 years, 6-112 months post-stroke) of whom 10 (64±15 years) were also examined 11-22 days post-stroke (subacute stage). The subjects performed isometric knee extension at 10%, 20%, 30%, and 50% of peak torque for 10s (two trials each). Coefficient of variation (CV) was used as a measure of force variability. The median frequency and relative power in the 0-3, 4-6, and 8-12 Hz bands were obtained through a power spectrum analysis of the force signal. The signal complexity was quantified using the sample entropy (SampEn). The longitudinal analysis revealed a significant decrease in CV from subacute to chronic stage across all contraction levels (P<0.001) but no significant changes in the frequency and entropy parameters. Comparison between the chronic stroke and control subjects revealed no significant difference in CV across the force levels (P>0.05) but significantly decreased median frequency (P<0.01), with the relative power increased in 0-3 Hz band and decreased in 4-6 and 8-12 Hz bands in both paretic and non-paretic legs (P<0.001). SampEn was also significantly decreased in chronic stroke, bilaterally (P<0.001). These results indicate a shift toward lower frequencies and a less complex physiological process underlying force control in chronic stroke. The overall results suggest the improvement in force variability from subacute to chronic stroke but without normalization in the frequency composition and complexity of the force signal. Thus, disordered structure of the force signal remains a marker of impaired motor control long after stroke occurrence despite apparent recovery in force variability.

Feasibility of virtual reality augmented cycling for health promotion of people poststroke

BACKGROUND AND PURPOSE

A virtual reality (VR) augmented cycling kit (VRACK) was developed to address motor control and fitness deficits of individuals with chronic stroke. In this article, we report on the safety, feasibility, and efficacy of using the VR augmented cycling kit to improve cardiorespiratory (CR) fitness of individuals in the chronic phase poststroke.

METHODS

Four individuals with chronic stroke (47-65 years old and ≥3 years poststroke), with residual lower extremity impairments (Fugl-Meyer 24-26/34), who were limited community ambulators (gait speed range 0.56-1.1 m/s) participated in this study. Safety was defined as the absence of adverse events. Feasibility was measured using attendance, total exercise time, and "involvement" measured with the presence questionnaire (PQ). Efficacy of CR fitness was evaluated using a submaximal bicycle ergometer test before and after an 8-week training program.

RESULTS

The intervention was safe and feasible with participants having 1 adverse event, 100% adherence, achieving between 90 and 125 minutes of cycling each week, and a mean PQ score of 39 (SD 3.3). There was a statistically significant (13%; P = 0.035) improvement in peak VO(2), with a range of 6% to 24.5%.

DISCUSSION AND CONCLUSION

For these individuals, poststroke, VR augmented cycling, using their heart rate to set their avatar's speed, fostered training of sufficient duration and intensity to promote CR fitness. In addition, there was a transfer of training from the bicycle to walking endurance. VR augmented cycling may be an addition to the therapist's tools for concurrent training of mobility and health promotion of individuals poststroke.

Eccentric Versus Concentric Resistance Training to Enhance Neuromuscular Activation and Walking Speed Following Stroke

Background. Impaired voluntary neuromuscular activation of agonist muscles is a primary determinant of weakness and motor dysfunction following stroke. Objective. To determine whether eccentric resistance training (ECC) resistance training is superior to concentric resistance training (CON) resistance training to enhance neuromuscular activation, strength, and walking speed after stroke. Methods. A total of 34 adults poststroke participated in a staged intervention comprising (1) either CON-only or ECC-only resistance training of the paretic leg followed by (2) gait training. Changes in voluntary neuromuscular activation and power were assessed for both the trained paretic and untrained nonparetic legs. Self-selected and fast walking speeds were also assessed. Results. In response to resistance training, the ECC group experienced larger improvements in neuromuscular activation of paretic leg muscles, rectus femoris and vastus medialis ( P < .005), and the largest gains in paretic leg power (+74% for ECC contractions, P < .0001). ECC also had greater cross-education of increased power to the untrained nonparetic leg (12%-14%, P = .006). Over the course of gait training, much of the gain in paretic leg activation in the ECC group was lost, such that the net change in agonist activation was comparable between the CON and ECC groups when the full intervention was completed. Nevertheless, improvement in walking speed postintervention was more prevalent in the ECC than CON group. Conclusion. ECC resistance training was more effective for improving bilateral neuromuscular activation, strength, and walking speed following stroke. Future research should assess whether a longer duration ECC training program can provide further benefit.