Cardiorespiratory Responses During the 6-Minute Walk and Ramp Cycle Ergometer Tests and Their Relationship to Physical Activity in Stroke

Overground Robotic Exoskeleton Training for Patients With Stroke on Walking-Related Outcomes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This review aims to evaluate the effectiveness of solely overground robotic exoskeleton (RE) training or overground RE training with conventional rehabilitation in improving walking ability, speed, and endurance among patients with stroke.

DATA SOURCES

Nine databases, 5 trial registries, gray literature, specified journals, and reference lists from inception until December 27, 2021.

STUDY SELECTION

Randomized controlled trials adopting overground robotic exoskeleton training for patients with any phases of stroke on walking-related outcomes were included.

DATA EXTRACTION

Two independent reviewers extracted items and performed risk of bias using the Cochrane Risk of Bias tool 1 and certainty of evidence using the Grades of Recommendation Assessment, Development, and Evaluation.

DATA SYNTHESIS

Twenty trials involving 758 participants across 11 countries were included in this review. The overall effect of overground robotic exoskeletons on walking ability at postintervention (d=0.21; 95% confidence interval [CI], 0.01, 0.42; Z=2.02; P=.04) and follow-up (d=0.37; 95% CI, 0.03, 0.71; Z=2.12; P=.03) and walking speed at postintervention (d=0.23; 95% CI, 0.01, 0.46; Z=2.01; P=.04) showed significant improvement compared with conventional rehabilitation. Subgroup analyses suggested that RE training should combine with conventional rehabilitation. A preferable gait training regime is <4 times per week over ≥6 weeks for ≤30 minutes per session among patients with chronic stroke and ambulatory status of independent walkers before training. Meta-regression did not identify any effect of the covariates on the treatment effect. The majority of randomized controlled trials had small sample sizes, and the certainty of the evidence was very low.

CONCLUSION

Overground RE training may have a beneficial effect on walking ability and walking speed to complement conventional rehabilitation. Further large-scale and long-term, high-quality trials are recommended to enhance the quality of overground RE training and confirm its sustainability.

Reliability and Validity of a Wearable Sensing System and Online Gait Analysis Report in Persons after Stroke

The restoration of gait and mobility after stroke is an important and challenging therapy goal due to the complexity of the potentially impaired functions. As a result, precise and clinically feasible assessment methods are required for personalized gait rehabilitation after stroke. The aim of this study is to investigate the reliability and validity of a sensor-based gait analysis system in stroke survivors with different severities of gait deficits. For this purpose, 28 chronic stroke survivors (9 women, ages: 62.04 ± 11.68 years) with mild to moderate walking impairments performed a set of ambulatory assessments (3× 10MWT, 1× 6MWT per session) twice while being equipped with a sensor suit. The derived gait reports provided information about speed, step length, step width, swing and stance phases, as well as joint angles of the hip, knee, and ankle, which we analyzed for test-retest reliability and hypothesis testing. Further, test-retest reliability resulted in a mean ICC of 0.78 (range: 0.46-0.88) for walking 10 m and a mean ICC of 0.90 (range: 0.63-0.99) for walking 6 min. Additionally, all gait parameters showed moderate-to-strong correlations with clinical scales reflecting lower limb function. These results support the applicability of this sensor-based gait analysis system for individuals with stroke-related walking impairments.

Can functional walk tests add value to the prediction of cardiorespiratory fitness after stroke? A prospective cohort study

BACKGROUND

Cardiorespiratory fitness is often impaired following stroke, and peak oxygen consumption (VO2peak) is an important prognostic value of all-cause mortality. The primary objective was to investigate whether functional walk tests assessed in the subacute phase after stroke added value in predicting VO2peak in chronic stroke, in addition to age, sex and functional dependency. Secondary objectives were to investigate associations between daily physical activity and functional walk tests, and with VO2peak in chronic stroke.

METHODS

This prospective cohort study included eligible participants originally included in the randomized controlled trial Life After Stroke. Functional walk tests, i.e., six-minute walk test (6MWT) and maximal gait speed, were assessed at inclusion and 18 months later. VO2peak [ml/kg/min] was assessed by a cardiopulmonary exercise test on a treadmill 20 months after inclusion. Daily physical activity was measured by a uniaxial accelerometer (activPAL) at 18-month follow-up.

RESULTS

Ninety-two community-dwelling individuals, with a mean (SD) age of 69.2 (10.6) years and 33 (35.9%) women, were included 3 months after stroke onset. Eighty-three (90.2%) participants had a modified Rankin Scale (mRS) score of 1 or 2, indicating functional independence. An overall assessment of four prediction models indicated the combination of age, sex, mRS and 6MWT as predictors to be the best fitted model in predicting VO2peak (adjusted R2 = 0.612). Secondary results showed statistically significant, but not clinically significant, associations between daily physical activity and functional walk tests, and with VO2peak.

CONCLUSIONS

6MWT add significant value to the prediction of mean VO2peak in the chronic phase in mild strokes, in combination with age, sex and functional dependency. This prediction model may facilitate clinical decisions and rehabilitation strategies for mildly affected stroke survivors in risk of low levels of VO2peak. Future studies should validate the model in various stages after stroke and in patients moderately and severely affected.

Feasibility, reproducibility and validity of the 10 meter Shuttle Test in mild to moderately impaired people with stroke

Background

There currently is no field test available for measuring maximal exercise capacity in people with stroke.

Objective

To determine the feasibility, reproducibility and validity of the Shuttle Test (ST) to measure exercise capacity in people with stroke.

Design

Longitudinal study design.

Setting

Rehabilitation department, day care centres from a nursing home and private practices specialized in neuro rehabilitation.

Subjects

People with subacute or chronic stroke.

Interventions

A standardized protocol was used to determine feasibility, reproducibility and validity of the 10-meter Shuttle Test (10mST).

Main measures

Number of shuttles completed, 1^stVentilatory Threshold (1^stVT).

Results

The associations of the number of shuttles completed and cardiopulmonary capacity as measured with a portable gas analyser were r > 0.7, confirming good convergent validity in subacute and chronic people with stroke. Criterion validity, however, indicates it is not a valid test for measuring maximal cardiopulmonary capacity (VO_2max). Only 60% of participants were able to reach the 1^stVT. Higher cardiopulmonary capacity and a higher total score of the lower extremity Motricity Index contributed significantly to a higher number of shuttles walked (p = 0.001).

Conclusions

The Shuttle Test may be a safe and useful exercise test for people after stroke, but may not be appropriate for use with people who walk slower than 2 km/h or 0.56 m/s.

Forced and Voluntary Aerobic Cycling Interventions Improve Walking Capacity in Individuals With Chronic Stroke

OBJECTIVES

To determine the efficacy of high-intensity cycling to improve walking capacity in individuals with chronic stroke, identify variables that predict improvement in walking capacity, and quantify the relationship between the 6-minute walk test (6MWT) and cardiopulmonary exercise (CPX) test variables.

DESIGN

Secondary analysis of data from 2 randomized controlled trials.

SETTING

Research laboratory.

PARTICIPANTS

Individuals with chronic stroke (N=43).

INTERVENTIONS

Participants were randomized to 1 of the following time-matched interventions, occurring 3 times per week for 8 weeks: (1) forced aerobic exercise and upper extremity repetitive task practice (FE+RTP [n=16]), (2) voluntary aerobic exercise and upper extremity repetitive task practice (VE+RTP [n=14]), or (3) a non-aerobic control group (n=13).

MAIN OUTCOME MEASURE

Change in walking capacity as measured by the 6MWT from baseline to the end of treatment (EOT).

RESULTS

Significant increases were observed in distance traveled during the 6MWT at the EOT compared with baseline in the FE+RTP (P<.001) and VE+RTP (P<.001) groups, but not in the control group (P=.21). Among aerobic exercise participants, a multivariate regression analysis revealed that cycling cadence, power output, and baseline 6MWT distance were significant predictors of change in walking capacity.

CONCLUSIONS

An 8-week aerobic cycling intervention prescribed at 60% to 80% of heart rate reserve and moderate to high cadence and resistance led to significant improvements in walking capacity in our cohort of individuals with chronic stroke. Individuals with low baseline walking capacity levels may benefit most from aerobic cycling to improve over ground locomotion. Although the 6MWT did not elicit a cardiorespiratory response comparable to the maximal exertion CPX test, the 6MWT can be considered a valid and clinically relevant submaximal test of cardiorespiratory function in individuals with chronic stroke.

Guidelines for the Evaluation of Cardiorespiratory Physiotherapy in Stroke Patients

Evaluation of stroke patients is prioritized over therapeutic interventions to restore cardiorespiratory capacity. This study aimed to develop a clinically applicable guideline to evaluate cardiorespiratory physiotherapy in stroke patients based on a literature review and a modified Delphi survey. The literature search included 13,498 articles in PubMed, EMBASE, CINAHL, and Cochrane Library electronic databases. We surveyed previous articles between January 2010 and June 2019. After the option elimination process, a total of 27 documents were selected and analyzed (draft: 18, modified Delphi survey: 9). The results of this research are roughly divided into two categories. First, 31 draft items were extracted, and a modified Delphi survey questionnaire was created from a literature review. Second, an expert was asked to make two modified Delphi surveys and to modify, delete, and supplement the entries in the statistical analysis at each level to finalize the steps to 20 items. The guidelines developed in this study reflect the selective use of cardiorespiratory physiotherapy evaluation methods in the clinical setting, based on the health status of individual patients. Moreover, the guidelines may help physiotherapists make informed decisions based on expert knowledge, thereby playing a crucial role in the patient-centered treatment planning process.

Noninvasive investigation of the cardiodynamic response to 6MWT in people after stroke using impedance cardiography

This is a cross-section observational study that investigated the cardiodynamic response to a 6-minute walk test (6MWT) in patients after stroke using impedance cardiography (ICG). Patients diagnosed with stroke were invited to participate in a 6MWT on consecutive days. Heart rate (HR), cardiac output (CO), stroke volume (SV) and cardiac index (CI) were measured by ICG using the PhysioFlow^® PF07 Enduro^TM at 1-second intervals for 10 minutes prior to, during and for 10 minutes after each 6MWT. Oxygen saturation, perceived exertion score (modified Borg scale) and the distance covered at the end of each 6MWT were recorded. Twenty-nine patients (mean age 55.6±10.9 years) completed the study. The mean duration of stroke after diagnosis was 14.4±19.1 months. There were no differences in the measured data between the first and second 6MWT (mean intraclass correlation coefficient (ICC) range: 0.87–0.95). The 6 minute walk distance (6WMD) covered in the two 6MWTs was 246±126 and 255±130m respectively (p>0.05). Mean measured data for each subject at rest, and at the end of the better performed 6MWT were, respectively: HR 78±11 and 100±18 bpm; CO 5.5±1.2 and 8.9±2.6 l/min, SV 71.3±16 and 89.3±18.6 ml/beat and CI 3.0±0.6 and 4.9±1.3 l/min/m². After commencement of the 6MWT, the increase in SV took 30 sec before the rise approaching a plateau, whereas HR, CO and CI continued to rise steeply for 90 sec before leveling off to a steady rise. After completion of the 6MWT, all parameters had returned to baseline by a mean of 3.5 min. Sub-group analysis showed that the increase in cardiac output was predominantly contributed by an increase in heart rate in participants diagnosed with stroke for less than 1 year, whereas both stroke volume and heart rate contributed similarly to the increase in cardiac output in participants with diagnosis of stroke for longer than 1 year. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) both returned to baseline within 2 minutes post 6MWT. HR recorded at the end of the 6MWT was 60.8±10.6% of the predicted maximal heart rate and perceived exertion score was 5±2. Correlations between 6MWD and HR, and between 6MWD and SV were weak, with correlation coefficients Spearman’s rho (r_s) =0.46, and 0.42, respectively (p<0.05). Correlation between 6MWD and CO and CI were higher (r_s= 0.66 and 0.63, respectively (p<0.01)). This is the first study to report cardiac responses during a 6MWT in stroke patients. ICG is a reliable, non-invasive, repeatable method of measuring cardiodynamic data in stroke patients.

Addition of proprioceptive neuromuscular facilitation to cardiorespiratory training in patients poststroke: study protocol for a randomized controlled trial

BACKGROUND

Individuals affected by stroke present with changes in cardiovascular and respiratory functions. Cardiorespiratory training (CRT) is one of the classic intervention guidelines for cardiorespiratory fitness. CRT in association with the proprioceptive neuromuscular facilitation (PNF) technique for respiratory muscles could improve the quality of life, cardiorespiratory function and gait parameters of patients after stroke.

OBJECTIVE

To assess the effects of respiratory and trunk patterns of CRT associated with PNF on the quality of life, gait, oxygen consumption, respiratory muscle strength and thoracic volumes.

METHODS/DESIGN

A blind, randomized clinical trial with allocation confidentiality will be performed. Forty patients will be randomized into four groups: CRT-lower limb (LL) plus PNF; CRT-LL and respiration; CRT-upper limb (UL) plus PNF; or CRT-UL and respiration. Individuals will be evaluated at three different times (pretreatment, after 20 days of treatment and 1 month after the end of treatment). The treatment protocol consists of respiratory exercises, 30 min of CRT (cycle ergometer) and then repetition of the respiratory exercises, performed three times a week over a period of 20 days. Primary outcome measures are quality of life, gait, balance, peak oxygen uptake and rib cage compartment volumes. As secondary outcomes, respiratory function and maximal inspiratory and expiratory pressures will be measured.

DISCUSSION

The association of PNF with CRT may be a viable and accessible alternative to increase cardiorespiratory function in patients with stroke.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03171012. Registered on 6 June 2017.

Effects of protein supplementation on aerobic training-induced gains in cardiopulmonary fitness, muscle mass, and functional performance in chronic stroke: A randomized controlled pilot study

BACKGROUND & AIMS

The beneficial effects of protein supplementation on aerobic exercise-induced gains in patients with stroke are currently unknown. This study evaluated the feasibility and potential value of protein supplementation with aerobic exercise among stroke survivors.

METHODS

This double-blinded randomized controlled pilot study included 20 ambulatory persons with chronic (>6 months) stroke randomly assigned to either the protein (PRO) or carbohydrate (CHO) group. All participants received three 40-min cycling ergometric training sessions a week for 8 weeks. Training intensity at 60%-80% heart rate reserve was determined using cardiopulmonary exercise pretests. Immediately before and after each session, the PRO group received a 20-g protein-rich supplement, and the CHO group received a 20-g calorie-matched carbohydrate-rich supplement. Outcomes included changes in body composition, cardiopulmonary capacity, and clinical functional performance.

RESULTS

Those completing the protocol (n = 18) received 18-24 cycling training sessions, achieving target training intensity without major adverse effects. Of the two groups, the PRO group tended to obtain greater aerobic capacity (effect size [ES]>0.5 in every cardiopulmonary index), greater improvements in functional performance (0.25 < ES < 1.00 in various clinical tests), and greater total lean mass versus total fat mass (ES = 0.52).

CONCLUSIONS

Protein supplementation with aerobic exercise training tends to improve body composition, cardiopulmonary fitness, and function among persons with stroke. This study protocol is feasible, and future trials with larger sample sizes could confirm these results.

TRIAL REGISTRATION

NCT03244527.

Which impairments, activity limitations and personal factors at hospital discharge predict walking activity across the first 6 months poststroke?

Purpose: To determine which impairments, activity limitations and personal factors at hospital discharge poststroke predict volume, frequency, and intensity of walking activity 1, 3, and 6 months later.Materials and Methods: Prospective longitudinal observational study. Thirty-six people with stroke (71 SD 14 years, 69% male) were recruited at hospital discharge and predictors including fatigue, mood, executive function, walking speed, walking endurance, age, prestroke activity, self-efficacy, and perceived stroke recovery and health were collected. At 1, 3, and 6 months follow-up, participants wore an ActivPAL™ accelerometer to collect measures of walking activity.Results: At 1 month, walking endurance predicted all walking activity (R² > 0.29, p < 0.01). At 3 months, walking endurance and prestroke activity predicted activity volume and intensity (R² = 0.46-0.61, p < 0.001), and prestroke activity predicted activity frequency (R² = 0.31, p = 0.004). At 6 months, age-predicted activity volume and frequency (R² = 0.34-0.35, p < 0.003), while prestroke activity, discharge walking endurance, and executive function together predicted activity intensity (R² = 0.79, p < 0.001).Conclusion: Walking endurance contributes to walking activity outcomes across the first 6 months following hospital discharge poststroke. After 1 month of discharge, factors other than poststroke changes also contribute to activity outcomes, and should be considered when targeting poststroke physical activity.Implications for rehabilitationWalking endurance should be addressed during stroke rehabilitation as higher scores are linked to more walking activity in the first month after discharge.Prestroke factors such as low prestroke activity levels and older age predict reduced walking activity after stroke, so approaches to address barriers these factors may pose are needed in people with stroke.Physical activity interventions should be tailored to the individual, their environment, and context, and take into consideration prestroke factors.

Cardiopulmonary Responses During Clinical and Laboratory Gait Assessments in People With Chronic Stroke

BACKGROUND

The 6-Minute Walk Test (6MWT) is a common clinical assessment used to evaluate locomotor function in patients after stroke. Previous work suggests the 6MWT can estimate peak metabolic capacity (VO2peak) without cardiorespiratory assessments during graded exercise tests (GXTs), which may assist with exercise prescription. However, selected research also indicated increased heart rates (HRs) during 6MWTs beyond levels considered safe without GXTs.

OBJECTIVE

The goal of this study was to examine cardiorespiratory responses during 6MWTs and GXTs in individuals with chronic stroke and their associations with demographic or clinical characteristics.

DESIGN

The study used a cross-sectional observational design.

METHODS

Cardiorespiratory responses were assessed during 6MWTs at self-selected velocity (SSV) and fastest velocity (FV), and during GXTs. Secondary assessments included the lower extremity Fugl-Meyer Assessment, Functional Gait Assessment, gait speeds, and daily stepping activity. Correlation and regression analyses were used to evaluate associations between locomotor performance, cardiorespiratory responses, and clinical and demographic characteristics.

RESULTS

Average HRs during 6MWT-FV were 72% to 76% of the age-predicted maximum (HRmax), with 20% of participants exceeding 85% predicted HRmax. When normalized to HRs during GXTs, HRs during 6MWT-FV were 86% to 88% of observed HRmax. Primary predictors of increased HRs during 6MWTs were resting HR, body mass index, and daily stepping. Distance during 6MWT-FV was a significant predictor of VO2peak in combination with other variables. Electrocardiographic abnormalities were observed in >80% of participants at rest and 31% demonstrated distinct abnormalities during GXTs, which were not related to 6MWT or GXT performance.

LIMITATIONS

In addition to sample size, a primary limitation involved the ability to accurately predict or measure HRmax in patients with motor dysfunction after stroke.

CONCLUSIONS

Cardiac responses were higher than anticipated during 6MWTs and often exceeded recommended HR thresholds. Clinicians should closely monitor cardiorespiratory responses during 6MWTs.

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.

Measuring Activity Performance of Older Adults Using the activPAL: A Rapid Review

Current measures of physical activity and sedentary behaviors such as questionnaires and functional assessments are insufficient to provide comprehensive data on older adults. In response, the use of activity monitors has increased. The purpose of this review was to summarize and assess the quality of observational literature on activity measuring of older adults using the activPAL activity monitor. Seventeen databases and a bibliography, compiled by the activPAL creators, were searched. Articles were included if they were in English, were peer-reviewed, included people 65 years or older, measured activity using the activPAL and reported at least one of the following outcomes: step count, hours upright, hours sitting/lying, hours stepping, or hours standing. The search revealed 404 titles; after exclusions 24 were included in the final review. Of these studies, one examined older adults from residential aged care, six from hospital in-patient clinics, nine from outpatient clinics and eight examined community-dwellers. Mean age ranged from 66.0 to 84.2 years. Not all studies reported similar outcome variables, preventing data pooling. The review found a lack of high quality articles. There may be limitations to using the activPAL among older adults but further research is required to examine its use in this population.

Interval circuit training for cardiorespiratory fitness is feasible for people after stroke

Aims:

To determine if community-dwelling stroke survivors can achieve exercise intensities sufficient to improve cardiorespiratory fitness during a single session of circuit training using an interval training approach.

Methods:

Thirteen independently ambulant participants within 1 year of stroke were included in this observational study (females=54%; median age=65.6 years; interquartile range=23.9). Exercise intensities were assessed throughout an individually tailored circuit of up to seven 5-minute workstations from a selection of nine functional (e.g. walking, stairs, balance) and three ergometer (upright cycle, rower, treadmill) workstations. The interval durations ranged from 5–60 seconds. Oxygen consumption (VO2) was recorded continuously using a portable metabolic system. The average VO2 during each 30-second epoch was determined. VO2≥10.5 mL/kg/min was categorised as ≥moderate intensity.

Findings:

Participants exercised at VO2≥10.5 mL/kg/min for the majority of the time on the workstations [functional: 369/472 epochs (78%), ergometer: 170/204 epochs (83%)]. Most (69%) participants exercised for ≥30 minutes. No serious adverse events occurred.

Conclusions:

Applying interval training principles to a circuit of functional and ergometer workstations enabled ambulant participants to exercise at an intensity and for a duration that can improve cardiorespiratory fitness. The training approach appears feasible, safe and a promising way to incorporate both cardiorespiratory fitness and functional training into post-stroke management.

Prescribing Aerobic Exercise Intensity without a Cardiopulmonary Exercise Test Post Stroke: Utility of the Six-Minute Walk Test

BACKGROUND

The cardiopulmonary exercise test (CPET) is an established method for determining target exercise training intensity (ventilatory threshold [VAT]) and cardiovascular risk; unfortunately, CPET is not readily accessible to people post stroke. The objective of this study was to determine the utility of the 6-minute walk test (6MWT) as a less resource-intensive alternative to CPET for prescribing exercise intensity to people post stroke with motor impairments.

METHODS

Sixty participants (male, 71.7%; 13.5 ± 22.5 [mean ± standard deviation] months post stroke; age 64.5 ± 12.5 years, with a Chedoke-McMaster Stroke Assessment score of 4.9 ± .9 of the leg) underwent 6MWT, CPET, balance, strength, and cognition assessments.

RESULTS

6MWT heart rate (hr) was significantly lower than VAT-hr (92.3 ± 14.8 beats⋅min(-1) versus 99.8 ± 15.7 beats⋅min(-1), respectively, P < .001; correlation r = .7, P < .001). Bland-Altman analysis revealed that the 6MWT underestimated the VAT-hr by 7.7 ± 11.5%. The 95% confidence interval of the mean bias was large (14.8% and -30.3%), reflecting poor agreement, with 71.7% (n = 43) of the participants unable to reach a walking intensity at or above the VAT-hr. Lower oxygen uptake at the VAT (β = .655, P = .004), higher 6MWT-hr (β = 1.07, P = .01), and better balance (β = 1.128, P = .04) were associated with greater utility of the 6MWT for prescribing exercise.

CONCLUSIONS

The 6MWT-hr was not interchangeable with the target training VAT-hr determined by CPET. However, in combination with CPET, the 6MWT will indicate when deficits preclude walking alone as the primary exercise modality for optimizing cardiovascular fitness. Future studies to develop a less resource-intensive, multimodal alternative to the CPET for prescribing exercise are needed. A modality that minimizes the effect of stroke deficits, specifically poor balance, should be included.

Relationships between self-reported and performance-based measures of functional capacity in individuals with chronic stroke

[Purpose] The aim of this study was to investigate the associations between self-reported and valid performance-based measures of functional capacity in individuals with chronic stroke. [Subjects and Methods] Self-reported measures of functional capacity of 31 individuals with chronic stroke were assessed by the Duke Activity Status Index scores, whereas performance-based measures were assessed by the distance covered (in meters) and oxygen consumption (relative oxygen consumption, in ml·kg⁻¹·min⁻¹) during the six-minute walking test. [Results] The subjects had a mean age of 58.6±13 years and a mean time since the onset of stroke of 28.3±15.1 months. They had a mean Duke Activity Status Index of 27.3±14.4, mean distance covered of 325.2±140.2 m, and mean relative oxygen consumption of 9.6±2.3 ml·kg⁻¹·min⁻¹. Significant, positive, and moderate to good correlation coefficients were found between the Duke Activity Status Index scores and the distance covered during the six-minute walking test (r=0.68). Significant, positive, and fair associations were also found between the Duke Activity Status Index scores and relative oxygen consumption values obtained during the six-minute walking test (r=0.45). [Conclusion] The findings of the present study support the clinical use of the Duke Activity Status Index as a tool to assist in clinical evaluations of functional capacity of individuals with chronic stroke.

Changes in skeletal muscle perfusion and spasticity in patients with poststroke hemiparesis treated by robotic assistance (Gloreha) of the hand

[Purpose] The purpose of this case series was to determine the effects of robot-assisted hand rehabilitation with a Gloreha device on skeletal muscle perfusion, spasticity, and motor function in subjects with poststroke hemiparesis. [Subjects and Methods] Seven patients, 2 women and 5 men (mean ± SD age: 60.5 ±6.3 years), with hemiparesis (>6 months poststroke), received passive mobilization of the hand with a Gloreha (Idrogenet, Italy), device (30 min per day; 3 sessions a week for 3 weeks). The outcome measures were the total hemoglobin profiles and tissue oxygenation index (TOI) in the muscle tissue evaluated through near-infrared spectroscopy. The Motricity Index and modified Ashworth Scale for upper limb muscles were used to assess mobility of the upper extremity. [Results] Robotic assistance reduced spasticity after the intervention by 68.6% in the upper limb. The Motricity Index was unchanged in these patients after treatment. Regarding changes in muscle perfusion, significant improvements were found in total hemoglobin. There were significant differences between the pre- and posttreatment modified Ashworth scale. [Conclusion] The present work provides novel evidence that robotic assistance of the hand induced changes in local muscle blood flow and oxygen supply, diminished spasticity, and decreased subject-reported symptoms of heaviness and stiffness in subjects with post-stroke hemiparesis.

Cardiovascular Stress Induced by Whole-Body Vibration Exercise in Individuals With Chronic Stroke

BACKGROUND

Although whole-body vibration (WBV) has sparked tremendous research interest in neurorehabilitation, the cardiovascular responses to WBV in people with stroke remain unknown.

OBJECTIVE

The aim of this study was to determine the acute effects of different WBV protocols on oxygen consumption (V̇o2), heart rate (HR), rate of perceived exertion (RPE), blood pressure (BP), and rate-pressure product (RPP) during the performance of 6 different exercises among people with chronic stroke (time since onset ≥6 months).

DESIGN

A repeated-measures design was used.

METHODS

Each of the 48 participants experienced all 3 WBV protocols in separate sessions: (1) no WBV, (2) low-intensity WBV (peak acceleration=0.96 unit of gravity of Earth [g]), and (3) high-intensity WBV (1.61g). The order in which they encountered the WBV protocols was randomized, as was the order of exercises performed during each session. Oxygen consumption, HR, and RPE were measured throughout the study. Blood pressure and RPP were measured before and after each session.

RESULTS

Low-intensity and high-intensity WBV induced significantly higher V̇o2 by an average of 0.69 and 0.79 mL/kg/min, respectively, compared with the control condition. These protocols also increased HR by an average of 4 bpm. The 2 WBV protocols induced higher RPE than the control condition during static standing exercise only. Although the diastolic and systolic BP and RPP were increased at the end of each exercise session, the addition of WBV had no significant effect on these variables.

LIMITATIONS

The results are generalizable only to ambulatory and community-dwelling people with chronic stroke.

CONCLUSIONS

Addition of high- and low-intensity WBV significantly increased the V̇o2 and HR, but the increase was modest. Thus, WBV should not pose any substantial cardiovascular hazard in people with chronic 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.

Reference values for standardized tests of walking speed and distance: a systematic review

OBJECTIVE

To provide an overview of the reference values and methodology used to obtain them for time- and distance-limited walk tests.

METHODS

We performed a systematic review and searched PubMed, MEDLINE (Ovid), EMBASE, CINAHL, Scopus, PEDro, and The Cochrane Library from 1946 to May 2013. Full-text peer-reviewed articles written in English, French or Spanish were considered eligible. Two authors independently screened titles and abstracts. One author determined eligibility of full-text articles, appraised methodological quality, and extracted data. A second author independently verified the accuracy of extracted data.

RESULTS

Of the 41 eligible studies reviewed, 25 failed to describe the method used to select participants and 10 had an inadequate sample size. Twenty-five studies provided reference values for one time-limited walk test (6-min walk test (6 MWT)) and 18 studies provided reference values for 15 distance-limited walk tests. Across studies, walk test distances ranged from 3m to 40m. Descriptive values and reference equations for the 6 MWT were reported in 15 and 20 studies, respectively. Across 43 regression equations (median R(2)=0.46), age (98%) and sex (91%) were most frequently included. The equation yielding the maximum R(2) value (0.78) included age, height, weight and percentage of predicted maximum heart rate. Among six unique regression equations for distance-limited walk tests (median R(2)=0.17), sex (83%), age (67%) and weight (67%) were most frequently included. The equation yielding the maximum R(2) value (0.25) included age and sex.

CONCLUSIONS

Reference values reported for these tests provide a basis for classifying walking capacity as within normal limits, determining the magnitude of deficit, educating clients, setting rehabilitation goals, and planning studies.

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.