Improved lower extremity pedaling mechanics in individuals with stroke under maximal workloads

The effects of cycling on walking outcomes in adults with stroke: a systematic review

BACKGROUND

Stationary cycling is often prescribed for survivors of stroke as a safe means of aerobic exercise to improve cardiovascular health. While cycling is typically not prescribed to restore ambulatory function, improvements in measures of walking after cycling interventions have been reported in the literature.

OBJECTIVE

To investigate the effects of cycling on walking outcomes in adults with stroke.

METHODS

Relevant databases were searched through 15 August. Walking-related outcomes were extracted. Correlation coefficients were computed to measure the relationship between exercise protocol parameters and change in walking outcomes.

RESULTS

Eleven articles were included in the review. Eight studies representing nine cycling intervention groups reported change in walking capacity measured by the six-minute walk test with improvements ranging from 6.1 to 63.0 m. Seven studies measured gait velocity, reporting improvements ranging from 0.01 to 0.21 m/sec. Protocols that yielded the greatest improvement in walking capacity prescribed moderate- to high-intensity aerobic training. Significant positive correlations were measured between change in gait velocity and number of exercise sessions and total minutes of exercise prescribed.

CONCLUSION

Considerable heterogeneity was observed across cycling protocols with respect to intensity, frequency, exercise duration and protocol duration. However, none of the studies reported declines in walking outcomes and improvements were measured in the absence of task-specific gait training. Cycling interventions employing moderate- to high-intensity aerobic training and 24 sessions or more may be optimal in improving gait velocity and walking capacity.

The Utilization of Forced-Rate Cycling to Facilitate Motor Recovery Following Stroke: A Randomized Clinical Trial

BACKGROUND

The potential for aerobic exercise (AE) to enhance neuroplasticity post-stroke has been theorized but not systematically investigated. Our aim was to determine the effects of forced-rate AE (FE) paired with upper extremity (UE) repetitive task practice (FE + RTP) compared to time-matched UE RTP (RTP only) on motor recovery.

METHODS

A single center randomized clinical trial was conducted from April 2019 to December 2022. Sixty individuals ≥6 months post-stroke with UE hemiparesis were randomized to FE + RTP (N = 30) or RTP only (N = 30), completing 90-minute sessions, 3×/week for 8 weeks. The FE + RTP group underwent 45-minute of FE (5-minute warm-up, 35-minute main set, and 5-minute cool down) followed by 45-minute of UE RTP. The RTP only group completed 90-minute of RTP. Primary outcomes were the Fugl-Meyer Assessment (FMA) and Action Research Arm Test (ARAT). The 6-minute Walk Test (6MWT, secondary outcome) assessed walking capacity.

RESULTS

Sixty individuals enrolled and 56 completed the study. The RTP only group completed more RTP in terms of repetitions (411.8 ± 44.4 vs 222.8 ± 28.4, P < .001) and time (72.7 ± 6.7 vs 37.8 ± 2.4 minutes, P < .001) versus FE + RTP. There was no significant difference between groups on the FMA (FE + RTP, 36.2 ± 10.1-44.0 ± 11.8 and RTP only, 34.4 ± 11.0-41.2 ± 13.4, P = .43) or ARAT (FE + RTP, 32.5 ± 16.6-37.7 ± 17.9 and RTP only, 32.8 ± 18.6-36.4 ± 18.5, P = .88). The FE + RTP group demonstrated greater improvements on the 6MWT (274.9 ± 122.0-327.1 ± 141.2 m) versus RTP only (285.5 ± 160.3-316.9 ± 170.0, P = .003).

CONCLUSIONS

There was no significant difference between groups in the primary outcomes. The FE + RTP improved more on the 6MWT, a secondary outcome.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03819764.

Usability of the novel ankle training equipment with spring resistance-based plantar press exercises in the standing position: A focus on chronic stroke patients with hemiplegic gait

BACKGROUND

To improve gait disability in patients with chronic stroke, ankle muscle strengthening and calf muscle stretching exercises are required. However, currently available ankle training equipment limit ankle exercises based on the position. Recently developed ankle training equipment enables spring resistance-based plantar press exercises to be performed in the standing position with weight support.

OBJECTIVE

To conduct a usability test of the ankle training equipment in the standing position by stroke patients with hemiplegic gait and verify its effects on ankle movements.

METHODS

The ankle training equipment was applied to five patients with chronic stroke and hemiplegic gait. In the standing position, the patients performed forefoot and rearfoot press exercises in the affected side with a day's interval at 20 repetitions maximum (RM). During the exercises, surface electromyography (sEMG) was used to measure the maximum voluntary isometric contraction (%MVIC) of the leg muscles. The System Usability Scale (SUS) was used to assess the ankle training equipment. Wilcoxon signed-rank test was used to evaluate the differences in muscle activity between the two exercises.

RESULTS

Forefoot and rearfoot press exercises increased the %MVIC in the biceps femoris. Additionally, the tibialis anterior and medial gastrocnemius activity was significantly different between the two exercises. The SUS was 78.75% (SD 12.7).

CONCLUSION

The usability test of the passive-control foot press trainer (PFPT) that with improvements in the structure and functions for convenience, it could be commercialized. PFPT could be an alternative to the ankle rehabilitation robot that necessitates a sitting position.

Increased Comfortable Gait Speed Is Associated With Improved Gait Biomechanics in Persons With Chronic Stroke Completing an 8-Week Forced-Rate Aerobic Cycling Intervention: A Preliminary Study

ABSTRACT

Task-specific gait training is recommended to improve locomotor function after stroke. Our objective was to determine the effects of a forced-rate aerobic exercise intervention on gait velocity and biomechanics in the absence of task-specific gait training. Individuals with chronic stroke ( N = 14) underwent 24 sessions of forced-rate aerobic exercise, at a targeted aerobic intensity of 60%-80% of their heart rate reserve. Change in comfortable walking speed in addition to spatiotemporal, kinematic, and kinetic variables were measured using three-dimensional motion capture. Overground walking capacity was measured by the 6-min walk test. To determine gait biomechanics associated with increased walking speed, spatiotemporal, kinematic, and kinetic variables were analyzed separately for those who met the minimal clinically important difference for change in gait velocity compared with those who did not. Participants demonstrated a significant increase in gait velocity from 0.61 to 0.70 m/sec ( P = 0.004) and 6-min walk test distance from 272.1 to 325.1 meters ( P < 0.001). Those who met the minimal clinically important difference for change in gait velocity demonstrated significantly greater improvements in spatiotemporal parameters ( P = 0.041), ground reaction forces ( P = 0.047), and power generation ( P = 0.007) compared with those who did not. Improvements in gait velocity were accompanied by normalization of gait biomechanics.

Cadence Feedback and Video-Based Engagement Improves Motivation and Performance during Pedalling in Stroke Patients

Video and music as a dissociative attention stimulus during exercise is known to distract from the discomfort of physical exertion and improve exercise adherence; however, the influence of video-based feedback and engagement during pedalling on the performance and motivation of pedalling in stroke patients is poorly understood. The aim of this study was to employ a novel video-based engagement paradigm for pedalling in stroke patients and evaluate its capacity to influence the cadence control, physiological output, and perceived motivation and enjoyment. Thirteen stroke patients were recruited with low-to-moderate lower-limb disability (mean age: 64.0 yrs.). A reference group of 18 healthy young adult subjects (mean age: 27.7 yrs.) was also recruited to assess the broad applicability of the techniques to a contrasting non-pathological cohort. The participants pedalled at a slow (60 RPM) and fast (100 RPM) target speed with constant resistance in 15 min pedalling bouts that included (i) baseline pedalling with real-time visual feedback of cadence deviation from the target provided only in the first 20 s (ii) real-time visual feedback of cadence data over the entire pedalling session, and (iii) real-time engagement to maintain the playback rate of a prerecorded video by pedalling at the target speed. During low speed pedalling, stroke patients demonstrated significantly smaller absolute cadence deviation during pedalling with feedback (mean difference: 1.8 RPM, p = 0.014) and video-based engagement (mean difference: 2.4 RPM, p = 0.006) compared to the baseline pedalling. For the healthy adults, feedback and video-based engagement reduced cadence deviation significantly at all speeds (p < 0.05). All but one stroke patient either enjoyed or really enjoyed the video engagement during pedalling and felt motivated to undertake this form of exercise in therapy in the future. This proof-of-concept study showed that feedback and video-based engagement may improve the targeted pedalling performance in stroke patients, and by helping dissociate subjects from physical cues associated with fatigue, may ultimately improve exercise motivation and compliance.

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.

Functional modeling of pedaling kinematics for the Stroke patients

Understanding deficits in motor control through the analysis of pedaling biomechanics plays a key role in the treatment of stroke patients. A thorough study of the impact of different exercise patterns and workloads on the change between pre- and post-treatment movement patterns in the patients is therefore of utmost importance to the clinicians. The objective of this study was to analyze the difference between pre- and post-treatment pedaling torques when the patients are subject to different exercise groups with varying workloads. The effects of affected vs unaffected side along with the covariates age and BMI have also been accounted for in this work. Two different three-way ANOVA-based approaches have been implemented here. In the first approach, a random projection-based ANOVA technique has been performed treating the pedaling torques as functional response, whereas the second approach utilizes distance measures to summarize the difference between pre- and post-treatment torques and perform nonparametric tests on it. Bayesian bootstrap has been used here to perform tests on the median distance. A group of stroke patients have been studied in the Cleveland Clinic categorizing them into different exercise groups and workload patterns. The data obtained have been analyzed with the aforementioned techniques, and the results have been reported here. These techniques turn out to be promising and will help clinicians recommend personalized treatment to stroke patients for optimal results.

Oxygen Consumption While Walking With Multijoint Neuromuscular Electrical Stimulation After Stroke

This case study evaluated the effect of implanted multijoint neuromuscular electrical stimulation gait assistance on oxygen consumption relative to walking without neuromuscular electrical stimulation after stroke. The participant walked slowly with an asymmetric gait pattern after stroke. He completed repeated 6-min walk tests at a self-selected walking speed with and without hip, knee, and ankle stimulation assistance. His walking speed with neuromuscular electrical stimulation more than doubled from 0.28 ± 0.01 m/sec to 0.58 ± 0.04 m/sec, whereas average step length and cadence increased by 0.12 m and 24 steps/min, respectively. As a result, energy cost of walking with neuromuscular electrical stimulation decreased by 0.19 ml O2/kg per meter as compared with walking without stimulation while oxygen consumption increased by 1.1 metabolic equivalent of tasks (3.9 ml O2/kg per minute). These metabolic demands are similar to those reported for stroke survivors capable of walking at equivalent speeds without stimulation, suggesting the increase in oxygen consumption and decreased energy cost result from improved efficiency of faster walking facilitated by neuromuscular electrical stimulation. Although the effect of neuromuscular electrical stimulation on gait economy has implications for community walking within the user's metabolic reserves, this case study's results should be interpreted with caution and the hypothesis that multijoint neuromuscular electrical stimulation improves metabolic efficiency should be tested in a wide population of stroke survivors with varied deficits.

Pathway-specific modulatory effects of neuromuscular electrical stimulation during pedaling in chronic stroke survivors

Background

Neuromuscular electrical stimulation (NMES) is extensively used in stroke motor rehabilitation. How it promotes motor recovery remains only partially understood. NMES could change muscular properties, produce altered sensory inputs, and modulate fluctuations of cortical activities; but the potential contribution from cortico-muscular couplings during NMES synchronized with dynamic movement has rarely been discussed.

Method

We investigated cortico-muscular interactions during passive, active, and NMES rhythmic pedaling in healthy subjects and chronic stroke survivors. EEG (128 channels), EMG (4 unilateral lower limb muscles) and movement parameters were measured during 3 sessions of constant-speed pedaling. Sensory-level NMES (20 mA) was applied to the muscles, and cyclic stimulation patterns were synchronized with the EMG during pedaling cycles. Adaptive mixture independent component analysis was utilized to determine the movement-related electro-cortical sources and the source dipole clusters. A directed cortico-muscular coupling analysis was conducted between representative source clusters and the EMGs using generalized partial directed coherence (GPDC). The bidirectional GPDC was compared across muscles and pedaling sessions for post-stroke and healthy subjects.

Results

Directed cortico-muscular coupling of NMES cycling was more similar to that of active pedaling than to that of passive pedaling for the tested muscles. For healthy subjects, sensory-level NMES could modulate GPDC of both ascending and descending pathways. Whereas for stroke survivors, NMES could modulate GPDC of only the ascending pathways.

Conclusions

By clarifying how NMES influences neuromuscular control during pedaling in healthy and post-stroke subjects, our results indicate the potential limitation of sensory-level NMES in promoting sensorimotor recovery in chronic stroke survivors.