Post-stroke Gait Research Articles

Defining characteristics of independent walking persons after stroke presenting with different arm swing coordination patterns

BackgroundPersons after stroke present with an altered arm swing during walking. Given the known influence of the arm swing on gait, it is important to identify the characteristics of persons with stroke with different arm-to-leg coordination patterns during walking. MethodsTwenty-five persons after stroke walked on a self-paced treadmill at comfortable walking speed. The frequency of shoulder movements per stride was detected by Fast Fourier transform analysis on the kinematic data for hemiplegic shoulder movements in the sagittal plane. An independent-sample t-test or Mann-Whitney U test was used to compare clinical and biomechanical parameters between identified subgroups. ResultsTwo earlier described subgroups based on the number of shoulder flexion-extension movements during one stride could be confirmed. Participants in the 1:1 ratio subgroup (one arm swing during one stride, N = 15) presented with a less upper limb impairment and less spasticity of the elbow extensors (p = 0.012) than the participants in the 2:1 ratio subgroup (two arm swings during one stride, N = 9). Although not significant, the participants in the 1:1 subgroup also seemed to have less spasticity of the shoulder internal rotators (p = 0.06) and a less walking variability based on the standard deviation of the step width. Further research on a greater sample should confirm these findings. ConclusionFast Fourier transform analysis was used to identify subgroups based on sagittal shoulder kinematics during walking. The clinical and gait related differences between the identified subgroups can be taken into account in future research investigating post-stroke gait interventions aiming to improve the arm swing.

Assessing lower limb angles from sagittal plane images captured with a smartphone for post-stroke gait

BACKGROUND: Clinical gait analysis of sagittal plane lower-limb kinematics using video images is a quantitative tool for clinicians. However, the reliability and validity of limb kinematics after stroke using video images has not been fully investigated. OBJECTIVE: This study aimed to examine the within-session inter-rater reliability and criterion-related validity of lower limb angles measured in sagittal plane images captured using a smartphone for assessing post-stroke gait and to determine which asymmetric parameters are associated with faster gait velocity. METHODS: Thirty-two patients with stroke were included; video images were recorded as they walked at their preferred pace for 1–3 cycles. Lower limb angles (contact, push-off, and excursion angles) and degree of asymmetry were determined based on video images using markers of acromion, greater trochanter, and fifth metatarsal head. Measurement reliability was calculated using the two-way random effects model of intraclass correlation coefficients and minimal detectable change. The criterion validity investigated Pearson’s correlation between lower limb angles and their asymmetry and gait velocity. RESULTS: The lower value of the 95% confidence interval of intraclass correlation coefficients (2.3) of the lower limb was 0.891, and the maximum minimal detectable change was 9.6 degrees. Push-off angle showed a moderate-to-strong correlation with gait velocity, whereas the asymmetry of the push-off angle showed a weak correlation with gait velocity. CONCLUSIONS: Assessing post-stroke gait utilizing video images using a smartphone is feasible. The push-off angle, in particular, may provide insight into the clinical assessment of post-stroke gait.

Three-phase Enriched Environment Improves Post-stroke Gait Dysfunction via Facilitating Neuronal Plasticity in the Bilateral Sensorimotor Cortex: A Multimodal MRI/PET Analysis in Rats.

The three-phase Enriched Environment (EE) paradigm has been shown to promote post-stroke functional improvement, but the neuronal mechanisms are still unclear. In this study, we applied a multimodal neuroimaging protocol combining magnetic resonance imaging (MRI) and positron emission tomography (PET) to examine the effects of post-ischemic EE treatment on structural and functional neuroplasticity in the bilateral sensorimotor cortex. Rats were subjected to permanent middle cerebral artery occlusion. The motor function of the rats was examined using the DigiGait test. MRI was applied to investigate the EE-induced structural modifications of the bilateral sensorimotor cortex. [18F]-fluorodeoxyglucose PET was used to detect glucose metabolism. Blood oxygen level-dependent (BOLD)-functional MRI (fMRI) was used to identify the regional brain activity and functional connectivity (FC). In addition, the expression of neuroplasticity-related signaling pathways including neurotrophic factors (BDNF/CREB), axonal guidance proteins (Robo1/Slit2), and axonal growth-inhibitory proteins (NogoA/NgR) as well as downstream proteins (RhoA/ROCK) in the bilateral sensorimotor cortex were measured by Western blots. Our results showed the three-phase EE improved the walking ability. Structural T2 mapping imaging and diffusion tensor imaging demonstrated that EE benefited structure integrity in the bilateral sensorimotor cortex. PET-MRI fused images showed improved glucose metabolism in the corresponding regions after EE intervention. Specifically, the BOLD-based amplitude of low-frequency fluctuations showed that EE increased spontaneous activity in the bilateral motor cortex and ipsilateral sensory cortex. In addition, FC results showed increased sensorimotor connectivity in the ipsilateral hemisphere and increased interhemispheric motor cortical connectivity and motor cortical-thalamic connectivity following EE intervention. In addition, a strong correlation was found between increased functional connectivity and improved motor performance of limbs. Specifically, EE regulated the expression of neuroplasticity-related signaling, involving BDNF/CREB, Slit2/Robo1, as well as the axonal growth-inhibitory pathways Nogo-A/Nogo receptor and RhoA/ROCK in the bilateral sensorimotor cortex. Our results indicated that the three-phase enriched environment paradigm enhances neuronal plasticity of the bilateral sensorimotor cortex and consequently ameliorates post-stroke gait deficits. These findings might provide some new clues for the development of EE and thus facilitate the clinical translation of EE.

White Matter Hyperintensities on Post-Stroke Balance and Gait Recovery: A Prospective Cohort Study Protocol

Introduction: White matter hyperintensities (WMH) are commonly associated with balance and gait disturbances. Little is known whether WMH may affect post-stroke balance and gait recovery. We aim to investigate the association of post-stroke balance and gait recovery with imaging marker of WMH on magnetic resonance imaging (MRI). Methods: This prospective cohort study will enroll consecutive patients with first-ever ischemic hemisphere stroke, between September 2023 and December 2024. Clinical data will be collected on day 30 ± 3 and at 3 months after stroke onset. WMH on FLAIR are graded according to the modified Fazekas scale. Resting-state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI) will be acquired to evaluate functional and structural connectivity. The primary endpoint is balance recovery, defined as a Postural Assessment Scale for Stroke score of 32 or higher at 3 months. The secondary endpoint is gait recovery, assessed using the modified Fugl-Meyer Gait Assessment at 3 months. We will investigate the association of post-stroke balance and gait recovery with WMH severity as well as WMH-related functional and structural connectivity. Conclusion: The study may contribute to clarify the effect of WMH on post-stroke balance and gait disorder recovery.

Effect of High-Intensity Interval Training and Moderate-Intensity Continuous Training in People With Poststroke Gait Dysfunction: ARandomized Clinical Trial.

The exercise strategy that yields the greatest improvement in both cardiorespiratory fitness () and walking capacity poststroke has not been determined. This study aimed to determine whether conventional moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT) have different effects on and 6-minute walk distance (6MWD). In this 24-week superiority trial, people with poststroke gait dysfunction were randomized to MICT (5 days/week) or HIIT (3 days/week with 2 days/week of MICT). MICT trained to target intensity at the ventilatory anaerobic threshold. HIIT trained at the maximal tolerable treadmill speed/grade using a novel program of 2 work-to-recovery protocols: 30:60 and 120:180 seconds. V̇O2 and heart rate was measured during performance of the exercise that was prescribed at 8 and 24 weeks for treatment fidelity. Main outcomes were change in and 6MWD. Assessors were blinded to the treatment group for but not 6MWD. Secondary outcomes were change in ventilatory anaerobic threshold, cognition, gait-economy, 10-meter gait-velocity, balance, stair-climb performance, strength, and quality-of-life. Among 47 participants randomized to either MICT (n=23) or HIIT (n=24) (mean age, 62±11 years; 81% men), 96% completed training. In intention-to-treat analysis, change in for MICT versus HIIT was 2.4±2.7 versus 5.7±3.1 mL·kg-1·min-1 (mean difference, 3.2 [95% CI, 1.5-4.8]; P<0.001), and change in 6MWD was 70.9±44.3 versus 83.4±53.6 m (mean difference, 12.5 [95% CI, -17 to 42]; P=0.401). HIIT had greater improvement in ventilatory anaerobic threshold (mean difference, 2.07 mL·kg-1·min-1 [95% CI, 0.59-3.6]; P=0.008). No other between-group differences were observed. During V̇O2 monitoring at 8 and 24 weeks, MICT reached 84±14% to 87±18% of while HIIT reached 101±22% to 112±14% of (during peak bouts). HIIT resulted in more than a 2-fold greater and clinically important change in than MICT. Training to target (ventilatory anaerobic threshold) during MICT resulted in ~3 times the minimal clinically important difference in 6MWD, which was similar to HIIT. These findings show proof of concept that HIIT yields greater improvements in cardiorespiratory fitness than conventional MICT in appropriately screened individuals. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03006731.

Effects of high-intensity gait training with and without soft robotic exosuits in people post-stroke: a development-of-concept pilot crossover trial

IntroductionHigh-intensity gait training is widely recognized as an effective rehabilitation approach after stroke. Soft robotic exosuits that enhance post-stroke gait mechanics have the potential to improve the rehabilitative outcomes achieved by high-intensity gait training. The objective of this development-of-concept pilot crossover study was to evaluate the outcomes achieved by high-intensity gait training with versus without soft robotic exosuits.MethodsIn this 2-arm pilot crossover study, four individuals post-stroke completed twelve visits of speed-based, high-intensity gait training: six consecutive visits of Robotic Exosuit Augmented Locomotion (REAL) gait training and six consecutive visits without the exosuit (CONTROL). The intervention arms were counterbalanced across study participants and separated by 6 + weeks of washout. Walking function was evaluated before and after each intervention using 6-minute walk test (6MWT) distance and 10-m walk test (10mWT) speed. Moreover, 10mWT speeds were evaluated before each training visit, with the time-course of change in walking speed computed for each intervention arm. For each participant, changes in each outcome were compared to minimal clinically-important difference (MCID) thresholds. Secondary analyses focused on changes in propulsion mechanics and associated biomechanical metrics.ResultsLarge between-group effects were observed for 6MWT distance (d = 1.41) and 10mWT speed (d = 1.14). REAL gait training resulted in an average pre-post change of 68 ± 27 m (p = 0.015) in 6MWT distance, compared to a pre-post change of 30 ± 16 m (p = 0.035) after CONTROL gait training. Similarly, REAL training resulted in a pre-post change of 0.08 ± 0.03 m/s (p = 0.012) in 10mWT speed, compared to a pre-post change of 0.01 ± 06 m/s (p = 0.76) after CONTROL. For both outcomes, 3 of 4 (75%) study participants surpassed MCIDs after REAL training, whereas 1 of 4 (25%) surpassed MCIDs after CONTROL training. Across the training visits, REAL training resulted in a 1.67 faster rate of improvement in walking speed. Similar patterns of improvement were observed for the secondary gait biomechanical outcomes, with REAL training resulting in significantly improved paretic propulsion for 3 of 4 study participants (p < 0.05) compared to 1 of 4 after CONTROL.ConclusionSoft robotic exosuits have the potential to enhance the rehabilitative outcomes produced by high-intensity gait training after stroke. Findings of this development-of-concept pilot crossover trial motivate continued development and study of the REAL gait training program.

A novel biomechanical indicator for impaired ankle dorsiflexion function during walking in individuals with chronic stroke

BackgroundAnkle dorsiflexion function during swing phase contributes to foot clearance and plays an important role in walking ability post-stroke. Commonly used biomechanical measures such as foot clearance and ankle joint excursion have limited ability to accurately evaluate impaired dorsiflexor function. Research questionCan ankle angular velocity and acceleration be used as reliable measurers of dorsiflexion function in post-stroke gait? MethodsUsing linear regression and Pearson’s correlation we retrospectively compared peak ankle angular velocity (AωP), peak ankle angular acceleration (AαP), peak dorsiflexion angle (DFAP) and peak foot clearance (FCLP) as direct measures for swing phase dorsiflexor function in 60 chronic stroke survivors. Intraclass correlation coefficient (ICC) analysis was used for test-retest reliability of AωP and AαP. ResultsLinear regression models revealed that AωP, AαP, DFAP, FCLP had a significant relationship (p < 0.05) with impaired dorsiflexion function. AαP and DFAP accounted for the most variance of dorsiflexion function. AωP, AαP, FCLP, correlated significantly with all clinical outcome measures of walking ability. DFAP had a positive correlation only with FMA-LE. Post-hoc William’s t-tests, used to compare the magnitude of difference between two non-independent correlations, revealed that the correlation between all clinical measures and DFAP were significantly weaker than with AωP and AαP. Correlation between FMA-LE and FCLP was weaker than with AωP and AαP. Excellent test-retest reliability for both AωP (ICC = 0.968) and AαP (ICC = 0.947) was observed. SignificanceThese results suggest that DFAP may only be associated with dorsiflexion function during non-task specific isolated movements, but not during walking. FCLP is associated with dorsiflexion function and walking ability measures but not as strongly as AωP and AαP possibly because FCLP is influenced by contribution from hip and knee joint movements. Therefore, AωP and AαP are reliable measures and represent dorsiflexion function more accurately than DFAP, and FCLP.

Effects of ankle-foot orthosis on gait pattern and spatiotemporal indices during treadmill walking in hemiparetic stroke.

Ankle-foot orthosis (AFO) is known to correct abnormal gait patterns and improve walking stability and speed in patients with hemiparesis. To quantify these benefits in post-stroke gait, a three-dimensional motion analysis of gait pattern was conducted. Forty patients with hemiparesis were enrolled. A three-dimensional motion analysis system was used to analyze patients' treadmill walking with/without an AFO. Outcome measures were 12 abnormal gait indices (forefoot contact, knee extensor thrust, retropulsion of the hip, flexed-knee gait, medial whip in the stance phase, circumduction gait, hip hiking, insufficient knee flexion during the swing phase, excessive lateral shifting of the trunk, contralateral vaulting, excessive hip external rotation, and posterior pelvic tilt), calculated using kinematic data and spatiotemporal indices, and the symmetry index of double-stance and single-stance time and step length. Forefoot contact (without AFO vs. with AFO: 71.0 vs. 65.8, P < 0.001), circumduction gait (65.0 vs. 57.9, P < 0.001), and contralateral vaulting (78.2 vs. 72.2, P = 0.003) were significantly reduced, whereas excessive hip external rotation (53.7 vs. 62.8, P = 0.003) significantly increased during walking with an AFO. Hip hiking (77.1 vs. 71.7) showed marginal reduction with the use of AFO ( P = 0.096). The absolute symmetry index of double-stance time (21.9 vs. 16.1, P = 0.014) significantly decreased during walking with an AFO. AFO effectively mitigates abnormal gait patterns typical of hemiparetic gait. A 3D motion analysis system with clinically oriented indices can help assess intervention efficacy for gait abnormalities.

Validity and reliability of a commercial wearable sensor system for measuring spatiotemporal gait parameters in a post-stroke population: the effects of walking speed and asymmetry

Objective. Commercial wearable sensor systems are a promising alternative to costly laboratory equipment for clinical gait evaluation, but their accuracy for individuals with gait impairments is not well established. Therefore, we investigated the validity and reliability of the APDM Opal wearable sensor system to measure spatiotemporal gait parameters for healthy controls and individuals with chronic stroke. Approach. Participants completed the 10 m walk test over an instrumented mat three times in different speed conditions. We compared performance of Opal sensors to the mat across different walking speeds and levels of step length asymmetry in the two populations. Main results. Gait speed and stride length measures achieved excellent reliability, though they were systematically underestimated by 0.11 m s−1 and 0.12 m, respectively. The stride and step time measures also achieved excellent reliability, with no significant errors (median absolute percentage error <6.00%, p> 0.05). Gait phase duration measures achieved moderate-to-excellent reliability, with relative errors ranging from 4.13%–21.59%. Across gait parameters, the relative error decreased by 0.57%–9.66% when walking faster than 1.30 m s−1; similar reductions occurred for step length symmetry indices lower than 0.10. Significance. This study supports the general use of Opal wearable sensors to obtain quantitative measures of post-stroke gait impairment. These measures should be interpreted cautiously for individuals with moderate-severe asymmetry or walking speeds slower than 0.80 m s−1.

Effects of Single Noninvasive Spinal Cord Stimulation in Patients with Post-Stroke Motor Disorders

Post-stroke gait disorders are often characterized by abnormal kinematic and kinetic patterns, deviations in spatiotemporal features, altered muscle activation, and increased power requirements while walking. The investigation is aimed at determining the possibility of using transcutaneous spinal cord stimulation (TSCS) to influence the kinematics of walking in stroke patients with hemiparesis in the early and late recovery periods (1–12 months) after stroke. Continuous and phasic stimulation was used during motor training on a treadmill. For stimulation of spinal neuroprosthesis including a multichannel stimulator for TSCS (Cosyma, Russia) with sensors for determining the phases of walking was used. The biomechanical study of the walking function was carried out with the Steadys system (Neurosoft, Russia). The study involved 15 patients (ages from 33 to 79 years). We analyzed the parameters of stepping movements when walking on the floor without stimulation before and after training on a treadmill using TSCS. A comparative analysis of the kinematics of walking before and after training showed an increase in walking speed, the length of the step cycle, and an increase in the range of movements in the hip, knee, and ankle joints, in 40% patients the height of the paretic foot lift increased by 1–2 cm. The results show that the training with the use of TSCS can be considered as a rehabilitation method for correcting walking after a stroke.

A VR-based Treadmill Training System for Post-stroke Gait Rehabilitation.

Virtual reality (VR) has the potential to enhance rehabilitation by creating simulated multiple training environments, thereby maximizing the implementation of motor learning principles. However, previous use of VR-based treadmill training to improve post-stroke gait function is limited by high cost and a lack of adherence to post-stroke gait rehabilitation principles in system design. This paper describes the development of a gait rehabilitation system that integrates treadmill gait training with VR technology to create a virtual rehabilitation setting with gait training tasks and real-time performance feedback. The proposed system targets post-stroke patients and integrates low-cost sensor and rehabilitation principles to allow remote training and maximize training efficacy.Clinical Relevance-This system is developed with an emphasis on rehabilitation and motor learning principles.

Effects of Single Noninvasive Spinal Cord Stimulation in Patients with Post-Stroke Motor Disorders

Post-stroke gait disorders are often characterized by abnormal kinematic and kinetic patterns, deviations in spatio-temporal features, altered muscle activation and increased power requirements during walking. The investigation is aimed at determining the possibility of using transcutaneous electrical spinal cord stimulation (scTS) to influence the kinematics of walking in stroke patients with hemiparesis in the early and late recovery periods (1–12 months) after stroke. Continuous and phasic stimulation was used during motor training on a treadmill. For stimulation a spinal neuroprosthesis including a multichannel stimulator for scTS (“Cosima”, Russia) with sensors for determining the phases of walking was used. The biomechanical study of the walking function was carried out with the complex “Stadis” (“Neurosoft”, Russia). The study involved 15 patients (age from 33 to 79 years). We analyzed the parameters of stepping movements when walking on the floor without stimulation before and after training on a treadmill using scTS. A comparative analysis of the kinematics of walking before and after training showed an increase in walking speed, the length of the step cycle, an increase in the range of movements in the hip, knee and ankle joints, in 40% patients the height of the paretic foot lift increased by 1–2 cm. The obtained results show that the training with the use of scTS can be considered as a rehabilitation method for correcting walking after a stroke.

Novel Methods of AI-Based Gait Analysis in Post-Stroke Patients

Research on gait function assessment is important not only in terms of the patient’s mobility, but also in terms of the patient’s current and future quality of life, ability to achieve health goals, family life, study and/or work, and participation in society. The main methods used herein include a literature review and an analysis of our own original research and concepts. This study used the historical data of 92 ischemic stroke patients (convenience trial) undergoing two kinds of rehabilitation. An artificial neural network, fractal analysis, and fuzzy analysis were used to analyze the results. Our findings suggest that artificial neural networks, fuzzy logic, and multifractal analysis are useful for building simple, low-cost, and efficient computational tools for gait analysis, especially in post-stroke patients. The novelty lies in the simultaneous application of the three aforementioned technologies to develop a computational model for the analysis of a patient’s post-stroke gait. The contribution of this work consists not only in its proposal of a new and useful clinical tool for gait assessment, even in the most severe post-stroke cases, but also in its attempt to offer a comprehensive computational explanation of observed gait phenomena and mechanisms. We conclude by anticipating more advanced and broader future applications of artificial intelligence (AI) in gait analysis, especially in post-stroke patients.

Self-modulation of rectus femoris reflex excitability in humans

Hyperreflexia is common after neurological injury such as stroke, yet clinical interventions have had mixed success. Our previous research has shown that hyperreflexia of the rectus femoris (RF) during pre-swing is closely associated with reduced swing phase knee flexion in those with post-stroke Stiff-Knee gait (SKG). Thus, reduction of RF hyperreflexia may improve walking function in those with post-stroke SKG. A non-pharmacological procedure for reducing hyperreflexia has emerged based on operant conditioning of H-reflex, an electrical analog of the spinal stretch reflex. It is currently unknown whether operant conditioning can be applied to the RF. This feasibility study trained 7 participants (5 neurologically intact, 2 post-stroke) to down-condition the RF H-reflex using visual feedback. We found an overall decrease in average RF H-reflex amplitude among all 7 participants (44% drop, p < 0.001, paired t-test), of which the post-stroke individuals contributed (49% drop). We observed a generalized training effect across quadriceps muscles. Post-stroke individuals exhibited improvements in peak knee-flexion velocity, reflex excitability during walking, and clinical measures of spasticity. These outcomes provide promising initial results that operant RF H-reflex conditioning is feasible, encouraging expansion to post-stroke individuals. This procedure could provide a targeted alternative in spasticity management.

Gait speed and individual characteristics are related to specific gait metrics in neurotypical adults

Gait biofeedback is a well-studied strategy to reduce gait impairments such as propulsion deficits or asymmetric step lengths. With biofeedback, participants alter their walking to reach the desired magnitude of a specific parameter (the biofeedback target) with each step. Biofeedback of anterior ground reaction force and step length is commonly used in post-stroke gait training as these variables are associated with self-selected gait speed, fall risk, and the energy cost of walking. However, biofeedback targets are often set as a function of an individual’s baseline walking pattern, which may not reflect the ideal magnitude of that gait parameter. Here we developed prediction models based on speed, leg length, mass, sex, and age to predict anterior ground reaction force and step length of neurotypical adults as a possible method for personalized biofeedback. Prediction of these values on an independent dataset demonstrated strong agreement with actual values, indicating that neurotypical anterior ground reaction forces can be estimated from an individual’s leg length, mass, and gait speed, and step lengths can be estimated from individual’s leg length, mass, age, sex, and gait speed. Unlike approaches that rely on an individual’s baseline gait, this approach provides a standardized method to personalize gait biofeedback targets based on the walking patterns exhibited by neurotypical individuals with similar characteristics walking at similar speeds without the risk of over- or underestimating the ideal values that could limit feedback-mediated reductions in gait impairments.

Hip and Knee Joint Kinematics Predict Quadriceps Hyperreflexia in People with Post-stroke Stiff-Knee Gait.

Wearable assistive technology for the lower extremities has shown great promise towards improving gait function in people with neuromuscular injuries. But common secondary impairments, such as hypersensitive stretch reflexes or hyperreflexia, have been often neglected. Incorporation of biomechanics into the control loop could improve individualization and avoid hyperreflexia. However, adding hyperreflexia prediction to the control loop would require expensive or complex measurement of muscle fiber characteristics. In this study, we explore a clinically accessible biomechanical predictor set that can accurately predict rectus femoris (RF) reaction after knee flexion assistance in pre-swing by a powered orthosis. We examined a total of 14 gait parameters based on gait kinematic, kinetic, and simulated muscle-tendon states from 8 post-stroke individuals with Stiff-Knee gait (SKG) wearing a knee exoskeleton robot. We independently performed both parametric and non-parametric variable selection approaches using machine learning regression techniques. Both models revealed the same four kinematic variables relevant to knee and hip joint motions were sufficient to effectively predict RF hyperreflexia. These results suggest that control of knee and hip kinematics may be a more practical method of incorporating quadriceps hyperreflexia into the exoskeleton control loop than the more complex acquisition of muscle fiber properties.

Autonomous Control of Music to Retrain Walking After Stroke

Background Post-stroke care guidelines highlight continued rehabilitation as essential; however, many stroke survivors cannot participate in outpatient rehabilitation. Technological advances in wearable sensing, treatment algorithms, and care delivery interfaces have created new opportunities for high-efficacy rehabilitation interventions to be delivered autonomously in any setting (ie, clinic, community, or home). Methods We developed an autonomous rehabilitation system that combines the closed-loop control of music with real-time gait analysis to fully automate patient-tailored walking rehabilitation. Specifically, the mechanism-of-action of auditory-motor entrainment is applied to induce targeted changes in the post-stroke gait pattern by way of targeted changes in music. Using speed-controlled biomechanical and physiological assessments, we evaluate in 10 individuals with chronic post-stroke hemiparesis the effects of a fully-automated gait training session on gait asymmetry and the energetic cost of walking. Results Post-treatment reductions in step time (Δ: −12 ± 26%, P = .027), stance time (Δ: −22 ± 10%, P = .004), and swing time (Δ: −15 ± 10%, P = .006) asymmetries were observed together with a 9 ± 5% reduction (P = .027) in the energetic cost of walking. Changes in the energetic cost of walking were highly dependent on the degree of baseline energetic impairment (r =− .90, P < .001). Among the 7 individuals with a baseline energetic cost of walking larger than the normative value of healthy older adults, a 13 ± 4% reduction was observed after training. Conclusions The closed-loop control of music can fully automate walking rehabilitation that markedly improves walking after stroke. Autonomous rehabilitation delivery systems that can safely provide high-efficacy rehabilitation in any setting have the potential to alleviate access-related care gaps and improve long-term outcomes after stroke.

Immediate improvements in post-stroke gait biomechanics are induced with both real-time limb position and propulsive force biofeedback

BackgroundParetic propulsion [measured as anteriorly-directed ground reaction forces (AGRF)] and trailing limb angle (TLA) show robust inter-relationships, and represent two key modifiable post-stroke gait variables that have biomechanical and clinical relevance. Our recent work demonstrated that real-time biofeedback is a feasible paradigm for modulating AGRF and TLA in able-bodied participants. However, the effects of TLA biofeedback on gait biomechanics of post-stroke individuals are poorly understood. Thus, our objective was to investigate the effects of unilateral, real-time, audiovisual TLA versus AGRF biofeedback on gait biomechanics in post-stroke individuals.MethodsNine post-stroke individuals (6 males, age 63 ± 9.8 years, 44.9 months post-stroke) participated in a single session of gait analysis comprised of three types of walking trials: no biofeedback, AGRF biofeedback, and TLA biofeedback. Biofeedback unilaterally targeted deficits on the paretic limb. Dependent variables included peak AGRF, TLA, and ankle plantarflexor moment. One-way repeated measures ANOVA with Bonferroni-corrected post-hoc comparisons were conducted to detect the effect of biofeedback on gait biomechanics variables.ResultsCompared to no-biofeedback, both AGRF and TLA biofeedback induced unilateral increases in paretic AGRF. TLA biofeedback induced significantly larger increases in paretic TLA than AGRF biofeedback. AGRF biofeedback increased ankle moment, and both feedback conditions increased non-paretic step length. Both types of biofeedback specifically targeted the paretic limb without inducing changes in the non-paretic limb.ConclusionsBy showing comparable increases in paretic limb gait biomechanics in response to both TLA and AGRF biofeedback, our novel findings provide the rationale and feasibility of paretic TLA as a gait biofeedback target for post-stroke individuals. Additionally, our results provide preliminary insights into divergent biomechanical mechanisms underlying improvements in post-stroke gait induced by these two biofeedback targets. We lay the groundwork for future investigations incorporating greater dosages and longer-term therapeutic effects of TLA biofeedback as a stroke gait rehabilitation strategy.Trial registrationNCT03466372

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

BackgroundGait 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.MethodsThis 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).DiscussionThe 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 registrationNCT03009773. Registered on January 4, 2017.

Stiff Knee Gait Disorders as Neuromechanical Consequences of Spastic Hemiplegia in Chronic Stroke

Stiff knee gait (SKG) is defined as decreased knee flexion during the swing phase. It is one of the most common gait disorders following stroke. Knee extensor spasticity is commonly accepted as the primary cause. Clinical management has focused on the reduction in knee extensor spasticity. Recent advances in understanding of post-stroke hemiplegic gait suggest that SKG can present as mechanical consequences between muscle spasticity, weakness, and their interactions with ground reactions during walking. Various underlying mechanisms are presented through sample cases in this article. They include ankle plantar flexor spasticity, knee extensor spasticity, knee flexor and extensor coactivation, and hip flexor spasticity. Careful and thorough clinical assessment is advised to determine the primary cause for each patient. Understanding of these various presentations of SKG is helpful to guide clinical assessment and select appropriate target muscles for interventions.