Functional Electrical Stimulation to Dorsiflexors and Plantar Flexors During Gait to Improve Walking in Adults With Chronic Hemiplegia

The effect of electromyographic feedback functional electrical stimulation on the plantar pressure in stroke patients with foot drop

Purpose

The purpose of this study was to observe, using Footscan analysis, the effect of electromyographic feedback functional electrical stimulation (FES) on the changes in the plantar pressure of drop foot patients.

Methods

This case-control study enrolled 34 stroke patients with foot drop. There were 17 cases received FES for 20 min per day, 5 days per week for 4 weeks (the FES group) and the other 17 cases only received basic rehabilitations (the control group). Before and after 4 weeks, the walking speed, spatiotemporal parameters and plantar pressure were measured.

Results

After 4 weeks treatments, Both the FES and control groups had increased walking speed and single stance phase percentage, decreased step length symmetry index (SI), double stance phase percentage and start time of the heel after 4 weeks (p < 0.05). The increase in walking speed and decrease in step length SI in the FES group were more significant than the control group after 4 weeks (p < 0.05). The FES group had an increased initial contact phase, decreased SI of the maximal force (Max F) and impulse in the medial heel after 4 weeks (p < 0.05).

Conclusion

The advantages of FES were: the improvement of gait speed, step length SI, and the enhancement of propulsion force were more significant. The initial contact phase was closer to the normal range, which implies that the control of ankle dorsiflexion was improved. The plantar dynamic parameters between the two sides of the foot were more balanced than the control group. FES is more effective than basic rehabilitations for stroke patients with foot drop based on current spatiotemporal parameters and plantar pressure results.

Fused ultrasound and electromyography-driven neuromuscular model to improve plantarflexion moment prediction across walking speeds

Background

Improving the prediction ability of a human-machine interface (HMI) is critical to accomplish a bio-inspired or model-based control strategy for rehabilitation interventions, which are of increased interest to assist limb function post neurological injuries. A fundamental role of the HMI is to accurately predict human intent by mapping signals from a mechanical sensor or surface electromyography (sEMG) sensor. These sensors are limited to measuring the resulting limb force or movement or the neural signal evoking the force. As the intermediate mapping in the HMI also depends on muscle contractility, a motivation exists to include architectural features of the muscle as surrogates of dynamic muscle movement, thus further improving the HMI’s prediction accuracy.

Objective

The purpose of this study is to investigate a non-invasive sEMG and ultrasound (US) imaging-driven Hill-type neuromuscular model (HNM) for net ankle joint plantarflexion moment prediction. We hypothesize that the fusion of signals from sEMG and US imaging results in a more accurate net plantarflexion moment prediction than sole sEMG or US imaging.

Methods

Ten young non-disabled participants walked on a treadmill at speeds of 0.50, 0.75, 1.00, 1.25, and 1.50 m/s. The proposed HNM consists of two muscle-tendon units. The muscle activation for each unit was calculated as a weighted summation of the normalized sEMG signal and normalized muscle thickness signal from US imaging. The HNM calibration was performed under both single-speed mode and inter-speed mode, and then the calibrated HNM was validated across all walking speeds.

Results

On average, the normalized moment prediction root mean square error was reduced by 14.58 % (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p=0.012$$\end{document}p=0.012) and 36.79 % (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p<0.001$$\end{document}p<0.001) with the proposed HNM when compared to sEMG-driven and US imaging-driven HNMs, respectively. Also, the calibrated models with data from the inter-speed mode were more robust than those from single-speed modes for the moment prediction.

Conclusions

The proposed sEMG-US imaging-driven HNM can significantly improve the net plantarflexion moment prediction accuracy across multiple walking speeds. The findings imply that the proposed HNM can be potentially used in bio-inspired control strategies for rehabilitative devices due to its superior prediction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-022-01061-z.

Concurrent impact of bilateral multiple joint functional electrical stimulation and treadmill walking on gait and spasticity in post-stroke survivors: a pilot study

Background: Stroke causes multi-joint gait deficits, so a major objective of post-stroke rehabilitation is to regain normal gait function. Design and Setting: A case series completed at a neuroscience institute. Aim: The aim of the study was to determine the concurrent impact of functional electrical stimulation (FES) during treadmill walking on gait speed, knee extensors spasticity and ankle plantar flexors spasticity in post-stroke survivors. Participants: Six post-stroke survivors with altered gait patterns and ankle plantar flexors spasticity (4 = male; age 56.8 ± 4.8 years; Body Mass Index (BMI) 26.2 ± 4.3; since onset of stroke: 30.8 ± 10.4 months; side of hemiplegia [L/R]: 3:3) were recruited. Intervention: Nine treatment sessions using FES bilaterally while walking on a treadmill. Main Outcome Measures: Primary outcome measures included the Modified Modified Ashworth Scale (MMAS), Timed Up and Go test (TUG), 10-m walking test, gait speed, and Functional ambulation category (FAC). Secondary outcome measures included the Step Length Test (SLT), and active range of motion (ROM) of the affected ankle and the knee. Measurements were taken at baseline (T0), at the end of last treatment (T1), and 1 month after the final treatment session (T2). Results: The TUG, 10-m walking test, gait speed, FAC, active ROM, and SLT all significantly improved following treatment (P< .05), while ankle plantar flexors spasticity (P = .135), and knee extensors spasticity (P = .368) did not show any significant decrease. Conclusions: A short duration of bilateral FES in conjugation with treadmill walking contributed to significant improvement in gait speed, functional mobility, functional ambulation, range of motion and step length in post-stroke survivors. In contrast, no significant decreases were identified in the spasticity of the ankle plantar flexors and knee extensors muscles.

DNN-Based FES Control for Gait Rehabilitation of Hemiplegic Patients

In this study, we proposed a novel machine-learning-based functional electrical stimulation (FES) control algorithm to enhance gait rehabilitation in post-stroke hemiplegic patients. The electrical stimulation of the muscles on the paretic side was controlled via deep neural networks, which were trained using muscle activity data from healthy people during gait. The performance of the developed system in comparison with that of a conventional FES control method was tested with healthy human subjects.

Clinical outcome measures to evaluate the effects of orthotic management post-stroke: a systematic review

PURPOSE

To identify, and classify, according to International Classification of Functioning, Disability and Health (ICF), clinically applicable outcome measures that have been used to evaluate lower limb orthotic management post-stroke and to investigate which outcome measures recorded the largest effect sizes.

MATERIALS AND METHODS

Electronic searches were performed in Pubmed, Cochrane, Web of Science, Cinahl, Scopus and Embase databases from inception to May 2020. Articles were included if they investigated clinical outcomes in people post-stroke who had received a lower-limb orthotic intervention.

RESULTS

88 articles underwent full-text review and 54 were included in the review, which was performed in accordance with the Preferred Reporting Items for Systematic Review (PRISMA) principles. 48 different outcome measures were identified; effect sizes were able to be calculated from 39 studies. The most frequently applied outcome measures were the 10-metre Walk Test and the timed-up-and-go test. Outcome measures that recorded large effect sizes in two or more studies were the 10-metre Walk Test, Functional Reach Test, and Physiological Cost Index. When coded according to the ICF, the most frequently represented codes were d450 (Walking) and d455 (moving around).

CONCLUSIONS

Results suggest that outcome measures related to mobility (ICF chapter d4) are most often applied to evaluate orthotic management post-stroke. Effect sizes appear to be greatest in outcome measures related to velocity, balance, and energy expenditure.IMPLICATIONS FOR REHABILITATIONThe 10-meter Walk Test appears to have the greatest effect size when evaluating orthotic management post-stroke.While outcome measures related to mobility are commonly applied when evaluating orthotic management post-stroke, rehabilitation professionals should consider complementing these with measures representing the participation domain of the ICF.

Effect of a HIIT protocol on the lower limb muscle power, ankle dorsiflexion and dynamic balance in a sedentary type 1 diabetes mellitus population: a pilot study

Background

Type 1 diabetes mellitus (T1DM) is commonly associated with premature loss of muscle function, ankle dorsiflexion and dynamic balance. Those impairments, usually, lead to physical functionality deterioration. High-intensity interval training is an efficient and safety methodology since it prevents hypoglycemia and not requires much time, which are the main barriers for this population to practice exercise and increase physical conditioning. We hypothesized that a 6-week HIIT program performed on a cycle ergometer would increase lower limb muscle power, ankle dorsiflexion range of motion and dynamic balance without hypoglycemic situations.

Methods

A total of 19 diagnosed T1DM subjects were randomly assigned to HIIT group (n = 11; 6-week HIIT protocol) or Control group (n = 8; no treatment). Lower limb strength was evaluated through velocity execution in squat with three different overloads. Weight bearing lunge test (WBLT) was performed to test ankle dorsiflexion range of motion and Y-Balance test (YBT) was the test conducted to analyze dynamic balance performance.

Results

Velocity in squat improved a 11.3%, 9.4% and 10.1% (p < 0.05) with the 50%, 60% and 70% of their own body mass overload respectively, WBLT performance increased a 10.43% in the right limb and 15.45% in the left limb. YBT showed improvements in all directions (right limb-left limb): Anterior (4.3–6.1%), Posteromedial (1.8–5.2%) and Posterolateral (3.4–4.5%) in HIIT group (p < 0.05), unlike control group that did not experience any significant change in any of the variables (p > 0.05).

Conclusion

A 6-week HIIT program is safe and effective to improve execution velocity in squat movement, a fundamental skill in daily living activities, as well as ankle dorsiflexion range of motion and dynamic balance to reduce foot ulcers, risk falls and functional impairments. HIIT seems an efficient and safety training methodology not only for overcome T1DM barriers for exercising but also for improving functional capacities in T1DM people.

Modeling Ankle Torque and Stiffness Induced by Functional Electrical Stimulation

Functional electrical stimulation (FES) is commonly used for individuals with neuromuscular impairments to generate muscle contractions. Both joint torque and stiffness play important roles in maintaining stable posture and resisting external disturbance. However, most previous studies only focused on the modulation of joint torque using FES while ignoring the joint stiffness. A model that can simultaneously modulate both ankle torque and stiffness induced by FES was investigated in this study. This model was composed of four subparts including an FES-to-activation model, a musculoskeletal geometry model, a Hill-based muscle-tendon model, and a joint stiffness model. The model was calibrated by the maximum voluntary contraction test of the tibialis anterior (TA) and gastrocnemius medial (GAS) muscles. To validate the model, the estimated torque and stiffness by the model were compared with the measured torque and stiffness induced by FES, respectively. The results showed that the proposed model can estimate torque and stiffness with electrically stimulated TA or/and GAS, which was significantly correlated to the measured torque and stiffness. The proposed model can modulate both joint torque and stiffness induced by FES in the isometric condition, which can be potentially extended to modulate the joint torque and stiffness during FES-assisted walking.

Ankle-foot orthoses and continuous functional electrical stimulation improve walking speed after stroke: a systematic review and meta-analyses of randomized controlled trials

BACKGROUND

Foot-drop is a common impairment after stroke, which reduces walking ability.

OBJECTIVE

To examine the efficacy of interventions aimed at reducing foot-drop, i.e., ankle-foot orthoses and functional electrical stimulation, on walking speed and balance after stroke.

DATA SOURCES

MEDLINE, EMBASE, Cochrane, PsycINFO, and PEDro databases.

ELIGIBILITY CRITERIA

The review included only parallel, randomized trials. Participants were ambulatory adults after stroke. The experimental interventions were the use of an ankle-foot orthosis or functional electrical stimulation.

DATA SYNTHESIS

Outcome data related to walking speed and balance were extracted from the eligible trials and combined in random-effects meta-analyses. The quality of trials was assessed by the PEDro scores and the quality of evidence was determined according the Grading of Recommendations Assessment, Development, and Evaluation system.

RESULTS

Eleven trials involving 1135 participants were included. The mean PEDro score of the trials was 5.8 (ranging from 4 to 7). Ankle-foot orthoses (MD 0.24m/s; 95% CI 0.06 to 0.41) and functional electrical stimulation (MD 0.09m/s; 95% CI 0.03 to 0.14) significantly increased walking speed, compared with no intervention/placebo. Results regarding balance were inconclusive. Ankle-foot orthoses were not superior to functional electrical stimulation for improving walking speed (MD 0.00m/s; 95% CI -0.06 to 0.05) or balance (MD 0.27 points on the Berg Balance Scale; 95% CI -0.85 to 1.39) after stroke.

CONCLUSIONS

This systematic review provided moderate-quality evidence that both ankle-foot orthoses and functional electrical stimulation improve walking speed after stroke, but the effects on balance remain unclear.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019130988.

Pragmatic Solutions for Stroke Recovery and Improved Quality of Life in Low- and Middle-Income Countries-A Systematic Review

Background: Given the limited healthcare resources in low and middle income countries (LMICs), effective rehabilitation strategies that can be realistically adopted in such settings are required. Objective: A systematic review of literature was conducted to identify pragmatic solutions and outcomes capable of enhancing stroke recovery and quality of life of stroke survivors for low- and middle- income countries. Methods: PubMed, HINARI, and Directory of Open Access Journals databases were searched for published Randomized Controlled Trials (RCTs) till November 2018. Only completed trials published in English with non-pharmacological interventions on adult stroke survivors were included in the review while published protocols, pilot studies and feasibility analysis of trials were excluded. Obtained data were synthesized thematically and descriptively analyzed. Results: One thousand nine hundred and ninety six studies were identified while 347 (65.22% high quality) RCTs were found to be eligible for the review. The most commonly assessed variables (and outcome measure utility) were activities of daily living [75.79% of the studies, with Barthel Index (37.02%)], motor function [66.57%; with Fugl Meyer scale (71.88%)], and gait [31.12%; with 6 min walk test (38.67%)]. Majority of the innovatively high technology interventions such as robot therapy (95.24%), virtual reality (94.44%), transcranial direct current stimulation (78.95%), transcranial magnetic stimulation (88.0%) and functional electrical stimulation (85.00%) were conducted in high income countries. Several traditional and low-cost interventions such as constraint-induced movement therapy (CIMT), resistant and aerobic exercises (R&AE), task oriented therapy (TOT), body weight supported treadmill training (BWSTT) were reported to significantly contribute to the recovery of motor function, activity, participation, and improvement of quality of life after stroke. Conclusion: Several pragmatic, in terms of affordability, accessibility and utility, stroke rehabilitation solutions, and outcome measures that can be used in resource-limited settings were found to be effective in facilitating and enhancing post-stroke recovery and quality of life.

Effects of EMG-triggered FES during trunk pattern in PNF on balance and gait performance in persons with stroke

BACKGROUND

EMG-triggered functional electrical stimulation (EMG-triggered FES) is one of the effective method for improving task performance and providing movement re-learning of central nervous system. Proprioceptive neuromuscular facilitation (PNF) is a traditional manual therapy that is used as a method to regain normal movement by providing specific training methods.

OBJECTIVE

The purpose of this study was to investigate the effect of EMG-triggered FES during trunk pattern in PNF on trunk control, balance, and gait of stroke patients.

METHODS

Forty participants were randomly allocated to EMG-triggered FES during PNF trunk pattern group (n = 20) and PNF trunk pattern group (n = 20). This study was a pretest-posttest with a control group design for duration of 4weeks (30 min/5 times/1 week). Outcome measures involved trunk impairment scale (TIS), Berg balance scale (BBS), and dynamic gait index (DGI).

RESULTS

In the experimental group and control group, TIS, BBS, and DGI score was significantly increased after intervention. However, there was no significant difference between the two groups in the comparison of the experimental group and the control group according to the amount of change before and after the training.

CONCLUSIONS

The results of this study showed that PNF trunk pattern affected the trunk control for stroke patients, and increased trunk control ability was effective in improving balance and walking. In addition, it was found that the EMG-triggered FES applied to the PNF trunk pattern affected the trunk control.

Advances in neuroprosthetic management of foot drop: a review

This paper reviews the technological advances and clinical results obtained in the neuroprosthetic management of foot drop. Functional electrical stimulation has been widely applied owing to its corrective abilities in patients suffering from a stroke, multiple sclerosis, or spinal cord injury among other pathologies. This review aims at identifying the progress made in this area over the last two decades, addressing two main questions: What is the status of neuroprosthetic technology in terms of architecture, sensorization, and control algorithms?. What is the current evidence on its functional and clinical efficacy? The results reveal the importance of systems capable of self-adjustment and the need for closed-loop control systems to adequately modulate assistance in individual conditions. Other advanced strategies, such as combining variable and constant frequency pulses, could also play an important role in reducing fatigue and obtaining better therapeutic results. The field not only would benefit from a deeper understanding of the kinematic, kinetic and neuromuscular implications and effects of more promising assistance strategies, but also there is a clear lack of long-term clinical studies addressing the therapeutic potential of these systems. This review paper provides an overview of current system design and control architectures choices with regard to their clinical effectiveness. Shortcomings and recommendations for future directions are identified.

Effect of unstable surface sitting on paretic anterior tibial muscle following stroke

INTRODUCTION

Postural reactions have been used to facilitate dorsiflexor activity following stroke. However, the effectiveness of this method is not clear in the literature. This study is designed to test the effect of postural reactions provoked by sitting in an unstable surface on dorsiflexor activity in acute stroke.

METHODS

Fifteen first-time acute hemispheric cerebral infarct patients with hemiplegia and 15 age-matched healthy adults participated in the study. Subjects performed static sitting, forward reach and lateral reach on a stool and Swiss ball. The anterior tibial activity was recorded in the normal and affected lower limbs in hemiplegic patients and both lower limbs of healthy adults. Non-parametric testing was used with alpha less than 0.05.

RESULTS

All the subjects showed an increase in anterior tibial activity in Swiss ball sitting compared to stool sitting. Lateral reaching resulted in higher levels of anterior tibial activity among the participants. In hemiplegic patients, anterior tibial activity in the affected side was lesser than in the normal side on stable and unstable surfaces. In healthy adults there was no inter-limb difference. The normal side activity in stroke patients was greater than that recorded in healthy individuals (p < 0.05). The anterior tibial activity in the affected side reached values equal to those of healthy adults when using the Swiss ball.

CONCLUSION

Postural reactions provoked from sitting on a unstable surface is effective in facilitating dorsiflexor activity in acute stroke.

Motor neuroprosthesis for promoting recovery of function after stroke

BACKGROUND

Motor neuroprosthesis (MN) involves electrical stimulation of neural structures by miniaturized devices to allow the performance of tasks in the natural environment in which people live (home and community context), as an orthosis. In this way, daily use of these devices could act as an environmental facilitator for increasing the activities and participation of people with stroke.

OBJECTIVES

To assess the effects of MN for improving independence in activities of daily living (ADL), activities involving limbs, participation scales of health-related quality of life (HRQoL), exercise capacity, balance, and adverse events in people after stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (searched 19 August 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (August 2019), MEDLINE (1946 to 16 August 2019), Embase (1980 to 19 August 2019), and five additional databases. We also searched trial registries, databases, and websites to identify additional relevant published, unpublished, and ongoing trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and randomized controlled cross-over trials comparing MN for improving activities and participation versus other assistive technology device or MN without electrical stimulus (stimulator is turned off), or no treatment, for people after stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted data, and assessed risk of bias of the included studies. Any disagreements were resolved through discussion with a third review author. We contacted trialists for additional information when necessary and performed all analyses using Review Manager 5. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included four RCTs involving a total of 831 participants who were more than three months poststroke. All RCTs were of MN that applied electrical stimuli to the peroneal nerve. All studies included conditioning protocols to adapt participants to MN use, after which participants used MN from up to eight hours per day to all-day use for ambulation in daily activities performed in the home or community context. All studies compared the use of MN versus another assistive device (ankle-foot orthosis [AFO]). There was a high risk of bias for at least one assessed domain in three of the four included studies. No studies reported outcomes related to independence in ADL. There was low-certainty evidence that AFO was more beneficial than MN on activities involving limbs such as walking speed until six months of device use (mean difference (MD) -0.05 m/s, 95% confidence interval (CI) -0.10 to -0.00; P = 0.03; 605 participants; 2 studies; I² = 0%; low-certainty evidence); however, this difference was no longer present in our sensitivity analysis (MD -0.07 m/s, 95% CI -0.16 to 0.02; P = 0.13; 110 participants; 1 study; I² = 0%). There was low to moderate certainty that MN was no more beneficial than AFO on activities involving limbs such as walking speed between 6 and 12 months of device use (MD 0.00 m/s, 95% CI -0.05 to 0.05; P = 0.93; 713 participants; 3 studies; I² = 17%; low-certainty evidence), Timed Up and Go (MD 0.51 s, 95% CI -4.41 to 5.43; P = 0.84; 692 participants; 2 studies; I² = 0%; moderate-certainty evidence), and modified Emory Functional Ambulation Profile (MD 14.77 s, 95% CI -12.52 to 42.06; P = 0.29; 605 participants; 2 studies; I² = 0%; low-certainty evidence). There was no significant difference in walking speed when MN was delivered with surface or implantable electrodes (test for subgroup differences P = 0.09; I² = 65.1%). For our secondary outcomes, there was very low to moderate certainty that MN was no more beneficial than another assistive device for participation scales of HRQoL (standardized mean difference 0.26, 95% CI -0.22 to 0.74; P = 0.28; 632 participants; 3 studies; I² = 77%; very low-certainty evidence), exercise capacity (MD -9.03 m, 95% CI -26.87 to 8.81; P = 0.32; 692 participants; 2 studies; I² = 0%; low-certainty evidence), and balance (MD -0.34, 95% CI -1.96 to 1.28; P = 0.68; 692 participants; 2 studies; I² = 0%; moderate-certainty evidence). Although there was low- to moderate-certainty evidence that the use of MN did not increase the number of serious adverse events related to intervention (risk ratio (RR) 0.35, 95% CI 0.04 to 3.33; P = 0.36; 692 participants; 2 studies; I² = 0%; low-certainty evidence) or number of falls (RR 1.20, 95% CI 0.92 to 1.55; P = 0.08; 802 participants; 3 studies; I² = 33%; moderate-certainty evidence), there was low-certainty evidence that the use of MN in people after stroke may increase the risk of participants dropping out during the intervention (RR 1.48, 95% CI 1.11 to 1.97; P = 0.007; 829 participants; 4 studies; I² = 0%).

AUTHORS' CONCLUSIONS

Current evidence indicates that MN is no more beneficial than another assistive technology device for improving activities involving limbs measured by Timed Up and Go, balance (moderate-certainty evidence), activities involving limbs measured by walking speed and modified Emory Functional Ambulation Profile, exercise capacity (low-certainty evidence), and participation scale of HRQoL (very low-certainty evidence). Evidence was insufficient to estimate the effect of MN on independence in ADL. In comparison to other assistive devices, MN does not appear to increase the number of falls (moderate-certainty evidence) or serious adverse events (low-certainty evidence), but may result in a higher number of dropouts during intervention period (low-certainty evidence).

Effectiveness of the Combined Treatment of Functional Electrical Stimulation and Deambulation in Diabetic Arteriopathy

OBJECTIVE

To determine whether functional electrical stimulation (FES) is able to improve ischemic pain and quality of life of patients with diabetic arteriopathy (DA) in grade-IIa Leriche-Le Fontaine.

MATERIAL AND METHODS

This is a single-blinded, randomized, prospective cohort study. We included patients diagnosed with grade-IIa Leriche-Le Fontaine peripheral arterial disease in both lower extremities with and without diabetes mellitus (DM). The ankle-brachial index was 0.4-0.9. Patients were randomized into two experimental groups: nondiabetic (non-DM) (n = 71) and diabetic (DM) (n = 71). The patients received FES while walking for 1 hr on a supervised treadmill. Three months of follow-up were conducted after treatment.

RESULTS

A total of 168 patients were randomized; 142 completed the study, with 71 in each group. Both groups reported an improvement after the treatment, but the improvement was statistically significant in the DM group, in which all the parameters studied improved. Greater benefits were observed in all the parameters in the DM group after the follow-up, except for the test of the meters walked in 6 min.

CONCLUSIONS

The use of FES during daily walking is effective in patients with DA, reducing intermittent claudication and improving the quality of life of these patients.

Effect of afferent electrical stimulation with mirror therapy on motor function, balance, and gait in chronic stroke survivors: a randomized controlled trial

BACKGROUND

When solely mirror therapy is applied for a long period of time, spatial perception and attention to the damaged side may decrease, and the effect of mirror therapy may be limited. To overcome this limitation, it has recently been suggested that the combination of mirror therapy with mirror treatment is effective.

AIM

The aim of this study was to investigate the effects of afferent electrical stimulation with mirror therapy on motor function, balance, and gait in chronic stroke survivors.

DESIGN

A randomized controlled trial.

SETTING

Rehabilitation center.

POPULATION

Thirty stroke survivors were randomly assigned to two groups: the experimental group (N.=15) and the control group (N.=15).

METHODS

Participants of the experimental group received afferent electrical stimulation with mirror therapy, and participants of the control group received sham afferent electrical stimulation with sham mirror therapy for 60 minutes per day, 5 days per week, for 4 weeks. Motor function was measured using a handheld dynamometer and the Modified Ashworth Scale, balance was measured using the Berg Balance Scale, and gait was assessed using the GAITRite® (GAITRite, CIR System Inc., Franklin, NJ, USA) pressure-sensitive walkway at baseline and after 4 weeks.

RESULTS

The experimental group showed significant differences in muscle strength, Modified Ashworth Scale, and Berg Balance Scale results, and velocity, cadence, step length, stride length, and double support time of their gait (P<0.05) in the pre-post intervention comparison. Significant differences between the two groups in muscle strength, Berg Balance Scale, gait velocity, step length, and stride length (P<0.05) were found.

CONLCUSIONS

Mirror therapy with afferent electrical stimulation may effectively improve muscle strength and gait and balance abilities in hemiplegic stroke survivors.

CLINICAL REHABILITATION IMPACT

Afferent electrical stimulation combined with mirror therapy can be used as an effective intervention to improve lower limb motor function, balance, and gait in chronic stroke survivors in clinical settings.

Effects of neuromuscular electrical stimulation on gait performance in chronic stroke with inadequate ankle control - A randomized controlled trial

Neuromuscular electrical stimulation (NMES) has been used to improve muscle strength and decrease spasticity of the ankle joint in stroke patients. However, it is unclear how NMES could influence dynamic spasticity of ankle plantarflexors and gait asymmetry during walking. The study aimed to evaluate the effects of applying NMES over ankle dorsiflexors or plantarflexors on ankle control during walking and gait performance in chronic stroke patients. Twenty-five stroke participants with inadequate ankle control were recruited and randomly assigned to an experimental or a control group. The experimental group received 20 minutes of NMES on either the tibialis anterior muscle (NMES-TA) or the medial gastrocnemius muscle (NMES-MG). The control group received 20 minutes of range of motion and stretching exercises. After the 20 minutes of NMES or exercises, all participants received ambulation training for 15 minutes. Training sessions occurred 3 times per week for 7 weeks. The pre- and post-training assessments included spatio-temporal parameters, ankle range of motion, and dynamic spasticity of ankle plantarflexors during walking. Muscle strength of ankle dorsiflexors and plantarflexors as well as static spasticity of ankle plantarflexors were also examined. The results showed that the static and dynamic spasticity of ankle plantarflexors of the NMES-TA group were significantly decreased after training. Reduction in dynamic spasticity of ankle plantarflexors of the NMES-TA group was significantly greater than that of the NMES-MG group. When compared to the control group, the NMES-TA group had greater improvements in spatial asymmetry, ankle plantarflexion during push off, and muscle strength of ankle dorsiflexors, and the NMES-MG group showed a significant decrease in temporal asymmetry. In summary, NMES on ankle dorsiflexors could be an effective management to enhance gait performance and ankle control during walking in chronic stroke patients. NMES on ankle plantarflexors may improve gait symmetry.

Effects of biofeedback versus switch-triggered functional electrical stimulation on sciatica-related foot drop

BACKGROUND

Sciatica-related Foot Drop is a peripheral nervous condition that produces a loss of power in the ankle dorsiflexion muscles. Functional electrical stimulation is a modality of electrical stimulation that produces muscle contraction in a functional movement of the limb. This technique was utilized with positive effects in central nervous afflictions but it is not known whether or not it has any influence in motor recovery following peripheral nervous system problems. This study aims to clarify the effects of functional electrical stimulation on foot drop caused by peripheral nerve compression resulting from lumbar disc herniation.

METHODS

Fifty patients were enrolled in our study; of whom 25 were treated with EMG triggered electrical stimulation (EMG-FES) and 25 with heel-floor sensor triggered electrical stimulation (SWITCH-FES) during normal gait cycle. Patients received functional electrical stimulation (with a pulse of 60 Hz and phase duration of 200 ms) once a day, for 30 minutes during 5 consecutive days, over a period of 4 weeks. Electrical diagnostic tests (nerve conduction velocity/NCV and the amplitude of compound muscle action potential/CMAP), dynamometry and Osvestry Disability Index scores were measured at baseline and after treatment.

RESULTS

We found that axonal loss was lower in the EMG-FES group than in the SWITCH-FES group (p< 0.004). The motor functional recovery was higher in terms of muscle force and overall functional status for the EMG-FES group compared to the SWITCH-FES group. This was underlined by Dynamometry test with a p value of < 0.0001 and ODI score with a statistical significant p value of < 0.0001.

CONCLUSIONS

The overall results showed that there was a significant increase in all the parameters studied for both types of FES applications. However we found that the EMG triggered electrical stimulation technique had a higher influence on the quality of the muscle action control. For patients who cannot yet produce minimal muscle active contraction we recommend switch triggered stimulation first and then, immediately after the recovery of the motor control, to change to EMG triggered functional electrical stimulation.

Can somatosensory electrical stimulation relieve spasticity in post-stroke patients? A TMS pilot study

Evidence suggests that somatosensory electrical stimulation (SES) may decrease the degree of spasticity from neural drives, although there is no agreement between corticospinal modulation and the level of spasticity. Thus, stroke patients and healthy subjects were submitted to SES (3 Hz) for 30' on the impaired and dominant forearms, respectively. Motor evoked potentials induced by single-pulse transcranial magnetic stimulation were collected from two forearm muscles before and after SES. The passive resistance of the wrist joint was measured with an isokinetic system. We found no evidence of an acute carry-over effect of SES on the degree of spasticity.

Novel multi-pad functional electrical stimulation in stroke patients: A single-blind randomized study

BACKGROUND

Foot drop is common gait impairment after stroke. Functional electrical stimulation (FES) of the ankle dorsiflexor muscles during the swing phase of gait can help correcting foot drop.

OBJECTIVE

To evaluate efficacy of additional novel FES system to conventional therapy in facilitating motor recovery in the lower extremities and improving walking ability after stroke.

METHODS

Sixteen stroke patients were randomly allocated to the FES group (FES therapy plus conventional rehabilitation program) (n = 8), and control group (conventional rehabilitation program) n = 8. FES was delivered for 30 min during gait to induce ankle plantar and dorsiflexion.

MAIN OUTCOME MEASURES

gait speed using 10 Meter Walk Test (10 MWT), Fugl-Meyer Assessment (FMA), Berg Balance Scale (BBS) and modified Barthel Index (MBI).

RESULTS

Results showed a significant increase in gait speed in FES group (p < 0.001), higher than the minimal detected change. The FES group showed improvement in functional independence in the activities of daily living, motor recovery and gait performance.

CONCLUSIONS

The findings suggest that novel FES therapy combined with conventional rehabilitation is more effective on walking speed, mobility of the lower extremity, balance disability and activities of daily living compared to a conventional rehabilitation program only.

Supplemental Stimulation Improves Swing Phase Kinematics During Exoskeleton Assisted Gait of SCI Subjects With Severe Muscle Spasticity

Spasticity is a common comorbidity associated with spinal cord injury (SCI). Robotic exoskeletons have recently emerged to facilitate legged mobility in people with motor complete SCI. Involuntary muscle activity attributed to spasticity, however, can prevent such individuals from using an exoskeleton. Specifically, although most exoskeleton technologies can accommodate low to moderate spasticity, the presence of moderate to severe spasticity can significantly impair gait kinematics when using an exoskeleton. In an effort to potentially enable individuals with moderate to severe spasticity to use exoskeletons more effectively, this study investigates the use of common peroneal stimulation in conjunction with exoskeleton gait assistance. The electrical stimulation is timed with the exoskeleton swing phase, and is intended to acutely suppress extensor spasticity through recruitment of the flexion withdrawal reflex (i.e., while the stimulation is activated) to enable improved exoskeletal walking. In order to examine the potential efficacy of this approach, two SCI subjects with severe extensor spasticity (i.e., modified Ashworth ratings of three to four) walked in an exoskeleton with and without supplemental stimulation while knee and hip motion was measured during swing phase. Stimulation was alternated on and off every ten steps to eliminate transient therapeutic effects, enabling the acute effects of stimulation to be isolated. These experiments indicated that common peroneal stimulation on average increased peak hip flexion during the swing phase of walking by 21.1° (236%) and peak knee flexion by 14.4° (56%). Additionally, use of the stimulation decreased the swing phase RMS motor current by 228 mA (15%) at the hip motors and 734 mA (38%) at the knee motors, indicating improved kinematics were achieved with reduced effort from the exoskeleton. Walking with the exoskeleton did not have a significant effect on modified Ashworth scores, indicating the common peroneal stimulation has only acute effects on suppressing extensor tone and aiding flexion. This preliminary data indicates that such supplemental stimulation may be used to improve the quality of movement provided by exoskeletons for persons with severe extensor spasticity in the lower limb.

Influence of peripheral magnetic stimulation of soleus muscle on H and M waves

[Purpose] This study evaluated the effects of repetitive peripheral magnetic stimulation of the soleus muscle on spinal cord and peripheral motor nerve excitability. [Subjects and Methods] Twelve healthy adults (mean age 22 years) who provided written informed consent were administered repetitive peripheral magnetic stimulation for 10 min. Pre-and post-stimulation latencies and amplitudes of H- and M-waves of the soleus muscle were measured using electromyography and compared using paired t-tests. [Results] Pre- and post-stimulation latencies (28.3 ± 3.3 vs. 29.1 ± 1.3 ms, respectively) and amplitudes (35.8 ± 1.3 vs. 35.8 ± 1.1 mV, respectively) of H-waves were similar. Pre-stimulation latencies of M-waves were significantly higher than post-stimulation latencies (6.1 ± 2.2 vs. 5.0 ± 0.9 ms, respectively), although pre- and post-stimulation amplitudes were similar (12.2 ± 1.4 vs. 12.2 ± 1.3 mV, respectively). Motor neuron excitability, based on the excitability of motor nerves and peripheral nerve action, was increased by M-waves following magnetic stimulation. [Conclusion] The lack of effect of magnetic stimulation on the amplitude and latency of the H-reflex suggests that magnetic stimulation did not activate sensory nerve synapses of α motor neurons in the spinal cord. However, because motor nerves were stimulated together with sensory nerves, the increased H-wave amplitude may have reflected changes in peripheral rather than in α motor nerves.

Accuracy to detection timing for assisting repetitive facilitation exercise system using MRCP and SVM

This paper presents a feasibility study of a brain–machine interface system to assist repetitive facilitation exercise. Repetitive facilitation exercise is an effective rehabilitation method for patients with hemiplegia. In repetitive facilitation exercise, a therapist stimulates the paralyzed part of the patient while motor commands run along the nerve pathway. However, successful repetitive facilitation exercise is difficult to achieve and even a skilled practitioner cannot detect when a motor command occurs in patient’s brain. We proposed a brain–machine interface system for automatically detecting motor commands and stimulating the paralyzed part of a patient. To determine motor commands from patient electroencephalogram (EEG) data, we measured the movement-related cortical potential (MRCP) and constructed a support vector machine system. In this paper, we validated the prediction timing of the system at the highest accuracy by the system using EEG and MRCP. In the experiments, we measured the EEG when the participant bent their elbow when prompted to do so. We analyzed the EEG data using a cross-validation method. We found that the average accuracy was 72.9% and the highest at the prediction timing 280 ms. We conclude that 280 ms is the most suitable to predict the judgment that a patient intends to exercise or not.

Functional electrical stimulation improves quality of life by reducing intermittent claudication

OBJECTIVE

To determine if Functional Electrical Stimulation (FES) would improve ischemic pain, walking distance, and quality of life of patients with intermittent claudication.

DESIGN

Single blind, randomized block, two factorial design.

PATIENTS

Patients diagnosed with Peripheral Artery Disease (PAD) and intermittent claudication (IC). Ankle Brachial Index ranged 0.4-0.9 on at least one leg. Patients were randomly assigned to experimental (FES+Walk, N=13) or control (WALK, N=14) groups.

INTERVENTION

Experimental group patients received FES to the dorsiflexor and plantarflexor muscles while walking for 1h/day, six days/week for eight weeks. Control group patients received similar intervention without FES. A Follow-up period of both groups lasted eight weeks.

OUTCOME MEASURES

Outcome measures were taken at baseline (T₀), after intervention (T₁), and after follow-up (T₂). Primary measures included Perceived Pain Intensity (PPI), Six minute walk (6MW), and Peripheral Arterial Disease Quality of Life (PADQOL). Secondary measures included Intermittent Claudication Questionnaire (ICQ) and Timed Up and Go (TUG).

RESULTS

Group by time interactions in PPI were significant (P<0.001) with differences of 27.9 points at T₁ and 36.9 points at T₂ favoring the FES+Walk group. Groups difference in Symptoms and Limitations in Physical Function of the PADQOL reached significance (T₁=8.9, and T₂=8.3 improvements; P=0.007). ICQ was significant (T₁=9.3 and T₂=13.1 improvements; P=0.003). Improvement in 6MW and TUG tests were similar between groups.

CONCLUSIONS AND RELEVANCE

Walking with FES markedly reduced ischemic pain and enhanced QOL compared to just walking. FES while walking may offer an effective treatment option for the elderly with PAD and Intermittent Claudication.

TRIAL REGISTRATION

NIH-NIA 1R21AG048001 https://projectreporter.nih.gov/project_info_description.cfm?aid=8748641&icde=30695377&ddparam=&ddvalue=&ddsub=&cr=1&csb=default&cs=ASC. https://clinicaltrials.gov/ct2/show/NCT02384980?term=David+Embrey&rank=1.

Review of devices used in neuromuscular electrical stimulation for stroke rehabilitation

Neuromuscular electrical stimulation (NMES), specifically functional electrical stimulation (FES) that compensates for voluntary motion, and therapeutic electrical stimulation (TES) aimed at muscle strengthening and recovery from paralysis are widely used in stroke rehabilitation. The electrical stimulation of muscle contraction should be synchronized with intended motion to restore paralysis. Therefore, NMES devices, which monitor electromyogram (EMG) or electroencephalogram (EEG) changes with motor intention and use them as a trigger, have been developed. Devices that modify the current intensity of NMES, based on EMG or EEG, have also been proposed. Given the diversity in devices and stimulation methods of NMES, the aim of the current review was to introduce some commercial FES and TES devices and application methods, which depend on the condition of the patient with stroke, including the degree of paralysis.

Mirror Therapy with Neuromuscular Electrical Stimulation for improving motor function of stroke survivors: A pilot randomized clinical study

OBJECTIVE

This study was to investigate the effects of Mirror Therapy (MT) combined with Neuromuscular Electrical Stimulation (NMES) on muscle strength and tone, motor function, balance, and gait ability in stroke survivors with hemiplegia.

METHODS

This study was a randomized controlled trial. Twenty-seven hemiplegic stroke survivors from a rehabilitation center participated in the study. The participants were randomly assigned to either an experimental or a control group. The experimental group (n = 14) underwent MT combined with NMES and conventional physical therapy, and the control group (n = 13) underwent conventional physical therapy alone. Muscle strength and tone, balance, and gait ability were examined at baseline and after 4 weeks of intervention. A hand-held dynamometer was used to assess muscle strength, the Modified Ashworth Scale (MAS) was used to assess muscle tone, the Berg Balance Scale (BBS) and Timed Up and Go test (TUG) were used to ascertain balance, and the 6-m Walk Test (6mWT) was used to examine gait ability.

RESULTS

After the intervention, compared to baseline values, there were significant improvements in muscle strength and MAS, BBS, TUG, and 6mWT values in the experimental group (P< 0.05). In addition, at post-intervention, there were significant differences between the two groups in muscle strength and BBS (P< 0.05).

CONCLUSION

MT combined with NMES may effectively improve muscle strength and balance in hemiplegic stroke survivors. However, further studies are necessary to demonstrate brain reorganization after MT combined with NMES.

A Personalized Multi-Channel FES Controller Based on Muscle Synergies to Support Gait Rehabilitation after Stroke

It has been largely suggested in neuroscience literature that to generate a vast variety of movements, the Central Nervous System (CNS) recruits a reduced set of coordinated patterns of muscle activities, defined as muscle synergies. Recent neurophysiological studies have recommended the analysis of muscle synergies to finely assess the patient's impairment, to design personalized interventions based on the specific nature of the impairment, and to evaluate the treatment outcomes. In this scope, the aim of this study was to design a personalized multi-channel functional electrical stimulation (FES) controller for gait training, integrating three novel aspects: (1) the FES strategy was based on healthy muscle synergies in order to mimic the neural solutions adopted by the CNS to generate locomotion; (2) the FES strategy was personalized according to an initial locomotion assessment of the patient and was designed to specifically activate the impaired biomechanical functions; (3) the FES strategy was mapped accurately on the altered gait kinematics providing a maximal synchronization between patient's volitional gait and stimulation patterns. The novel intervention was tested on two chronic stroke patients. They underwent a 4-week intervention consisting of 30-min sessions of FES-supported treadmill walking three times per week. The two patients were characterized by a mild gait disability (walking speed > 0.8 m/s) at baseline. However, before treatment both patients presented only three independent muscle synergies during locomotion, resembling two different gait abnormalities. After treatment, the number of extracted synergies became four and they increased their resemblance with the physiological muscle synergies, which indicated a general improvement in muscle coordination. The originally merged synergies seemed to regain their distinct role in locomotion control. The treatment benefits were more evident for one patient, who achieved a clinically important change in dynamic balance (Mini-Best Test increased from 17 to 22) coupled with a very positive perceived treatment effect (GRC = 4). The treatment had started the neuro-motor relearning process also on the second subject, but twelve sessions were not enough to achieve clinically relevant improvements. This attempt to apply the novel theories of neuroscience research in stroke rehabilitation has provided promising results, and deserves to be further investigated in a larger clinical study.

Effects of a multichannel dynamic functional electrical stimulation system on hemiplegic gait and muscle forces

[Purpose] The purpose of the study was to design and implement a multichannel dynamic functional electrical stimulation system and investigate acute effects of functional electrical stimulation of the tibialis anterior and rectus femoris on ankle and knee sagittal-plane kinematics and related muscle forces of hemiplegic gait. [Subjects and Methods] A multichannel dynamic electrical stimulation system was developed with 8-channel low frequency current generators. Eight male hemiplegic patients were trained for 4 weeks with electric stimulation of the tibia anterior and rectus femoris muscles during walking, which was coupled with active contraction. Kinematic data were collected, and muscle forces of the tibialis anterior and rectus femoris of the affected limbs were analyzed using a musculoskelatal modeling approach before and after training. A paired sample t-test was used to detect the differences between before and after training. [Results] The step length of the affected limb significantly increased after the stimulation was applied. The maximum dorsiflexion angle and maximum knee flexion angle of the affected limb were both increased significantly during stimulation. The maximum muscle forces of both the tibia anterior and rectus femoris increased significantly during stimulation compared with before functional electrical stimulation was applied. [Conclusion] This study established a functional electrical stimulation strategy based on hemiplegic gait analysis and musculoskeletal modeling. The multichannel functional electrical stimulation system successfully corrected foot drop and altered circumduction hemiplegic gait pattern.

Effect of Rhythmic Auditory Stimulation on Hemiplegic Gait Patterns

PURPOSE

The purpose of our study was to investigate the effect of gait training with rhythmic auditory stimulation (RAS) on both kinematic and temporospatial gait patterns in patients with hemiplegia.

MATERIALS AND METHODS

Eighteen hemiplegic patients diagnosed with either cerebral palsy or stroke participated in this study. All participants underwent the 4-week gait training with RAS. The treatment was performed for 30 minutes per each session, three sessions per week. RAS was provided with rhythmic beats using a chord progression on a keyboard. Kinematic and temporospatial data were collected and analyzed using a three-dimensional motion analysis system.

RESULTS

Gait training with RAS significantly improved both proximal and distal joint kinematic patterns in hip adduction, knee flexion, and ankle plantar flexion, enhancing the gait deviation index (GDI) as well as ameliorating temporal asymmetry of the stance and swing phases in patients with hemiplegia. Stroke patients with previous walking experience demonstrated significant kinematic improvement in knee flexion in mid-swing and ankle dorsiflexion in terminal stance. Among stroke patients, subacute patients showed a significantly increased GDI score compared with chronic patients. In addition, household ambulators showed a significant effect on reducing anterior tilt of the pelvis with an enhanced GDI score, while community ambulators significantly increased knee flexion in mid-swing phase and ankle dorsiflexion in terminal stance phase.

CONCLUSION

Gait training with RAS has beneficial effects on both kinematic and temporospatial patterns in patients with hemiplegia, providing not only clinical implications of locomotor rehabilitation with goal-oriented external feedback using RAS but also differential effects according to ambulatory function.

Effects of Electrical Stimulation in Spastic Muscles After Stroke

Background and Purpose—

Neuromuscular electric stimulation (NMES) has been used to reduce spasticity and improve range of motion in patients with stroke. However, contradictory results have been reported by clinical trials. A systematic review of randomized clinical trials was conducted to assess the effect of treatment with NMES with or without association to another therapy on spastic muscles after stroke compared with placebo or another intervention.

Methods—

We searched the following electronic databases (from inception to February 2015): Medline (PubMed), EMBASE, Cochrane Central Register of Controlled Trials and Physiotherapy Evidence Database (PEDro). Two independent reviewers assessed the eligibility of studies based on predefined inclusion criteria (application of electric stimulation on the lower or upper extremities, regardless of NMES dosage, and comparison with a control group which was not exposed to electric stimulation), excluding studies with <3 days of intervention. The primary outcome extracted was spasticity, assessed by the Modified Ashworth Scale, and the secondary outcome extracted was range of motion, assessed by Goniometer.

Results—

Of the total of 5066 titles, 29 randomized clinical trials were included with 940 subjects. NMES provided reductions in spasticity (−0.30 [95% confidence interval, −0.58 to −0.03], n=14 randomized clinical trials) and increase in range of motion when compared with control group (2.87 [95% confidence interval, 1.18–4.56], n=13 randomized clinical trials) after stroke.

Conclusions—

NMES combined with other intervention modalities can be considered as a treatment option that provides improvements in spasticity and range of motion in patients after stroke.

Clinical Trial Registration Information—

URL: http://www.crd.york.ac.uk/PROSPERO . Unique identifier: CRD42014008946.

A microcontroller platform for the rapid prototyping of functional electrical stimulation-based gait neuroprostheses

Functional electrical stimulation (FES) has been used over the last decades as a method to rehabilitate lost motor functions of individuals with spinal cord injury, multiple sclerosis, and post-stroke hemiparesis. Within this field, researchers in need of developing FES-based control solutions for specific disabilities often have to choose between either the acquisition and integration of high-performance industry-level systems, which are rather expensive and hardly portable, or develop custom-made portable solutions, which despite their lower cost, usually require expert-level electronic skills. Here, a flexible low-cost microcontroller-based platform for rapid prototyping of FES neuroprostheses is presented, designed for reduced execution complexity, development time, and production cost. For this reason, the Arduino open-source microcontroller platform was used, together with off-the-shelf components whenever possible. The developed system enables the rapid deployment of portable FES-based gait neuroprostheses, being flexible enough to allow simple open-loop strategies but also more complex closed-loop solutions. The system is based on a modular architecture that allows the development of optimized solutions depending on the desired FES applications, even though the design and testing of the platform were focused toward drop foot correction. The flexibility of the system was demonstrated using two algorithms targeting drop foot condition within different experimental setups. Successful bench testing of the device in healthy subjects demonstrated these neuroprosthesis platform capabilities to correct drop foot.

Effect of pneumatic compressing powered orthosis in stroke patients: preliminary study

OBJECTIVE

To evaluate the feasibility and effectiveness of a knee-ankle-foot orthosis powered by artificial pneumatic muscles (PKAFO).

METHODS

Twenty-three hemiplegic patients (age, 59.6±13.7 years) were assessed 19.7±36.6 months after brain lesion. The 10-m walking time was measured as a gait parameter while the individual walked on a treadmill. Walking speed (m/s), step cycle (cycle/s), and step length (m) were also measured on a treadmill with and without PKAFO, and before and after gait training. Clinical parameters measured before and after gait training included Korean version of Modified Bathel Index (K-MBI), manual muscle test (MMT), and Modified Ashworth Scale (MAS) of hemiplegic ankle. Gait training comprised treadmill walking for 20 minutes, 5 days a week for 3 weeks at a comfortable speed.

RESULTS

The 10-m walking time, walking speed, step length, and step cycle were significantly greater with PKAFO than without PKAFO, and after gait training (both p<0.05). K-MBI was improved after gait training (p<0.05), but MMT and MAS were not.

CONCLUSION

PKAFO may improve gait function in hemiplegic patients. It can be a useful orthosis for gait training in hemiplegic patients.

Therapeutic effects of functional electrical stimulation on gait in individuals post-stroke

Functional electrical stimulation (FES) to lower extremity (LE) muscles is used by individuals post-stroke as an alternative to mechanical orthotic devices during gait or as a training modality during rehabilitation. Technological developments which improve the feasibility, accessibility and effectiveness of FES systems as orthotic and training devices, highlight the potential of FES for rehabilitating LE function in individuals post-stroke. This study presents a systematic review of the carryover effects of LE FES to motor performance when stimulation is not applied (therapeutic effects) in subjects post-stroke. A description of advances in FES technologies, with an emphasis on systems designed to promote LE function is included, and mechanisms that may be associated with the observed therapeutic effects are discussed. Eligible studies were reviewed for methodological quality, population, intervention and outcome characteristics. Therapeutic effects of FES were consistently demonstrated at the body function and activity levels when it was used as a training modality. Compared to matched treatments that did not incorporate FES, no definite conclusions can be drawn regarding the superiority of FES. When FES was used as an alternative to an orthotic device, it had no superior therapeutic effects at the activity level, yet patients still seemed to prefer it.

Poststroke muscle architectural parameters of the tibialis anterior and the potential implications for rehabilitation of foot drop

Poststroke dorsiflexor weakness and paretic limb foot drop increase the risk of stumbling and falling and decrease overall functional mobility. It is of interest whether dorsiflexor muscle weakness is primarily neurological in origin or whether morphological differences also contribute to the impairment. Ten poststroke hemiparetic individuals were imaged bilaterally using noninvasive medical imaging techniques. Magnetic resonance imaging was used to identify changes in tibialis anterior muscle volume and muscle belly length. Ultrasonography was used to measure fascicle length and pennation angle in a neutral position. We found no clinically meaningful bilateral differences in any architectural parameter across all subjects, which indicates that these subjects have the muscular capacity to dorsiflex their foot. Therefore, poststroke dorsiflexor weakness is primarily neural in origin and likely due to muscle activation failure or increased spasticity of the plantar flexors. The current finding suggests that electrical stimulation methods or additional neuromuscular retraining may be more beneficial than targeting muscle strength (i.e., increasing muscle mass).

The effectiveness of functional electrical stimulation based on a normal gait pattern on subjects with early stroke: a randomized controlled trial

Objective. To investigate the effectiveness of four-channel FES based on a normal gait pattern on improving functional ability in subjects early after ischemic stroke. Methods. Forty-five subjects were randomly assigned into a four-channel FES group (n = 16), a placebo group (n = 15), or a dual-channel group (n = 14). Stimulation lasted for 30 min in each session with 1 session/day, 5 days a week for 3 weeks. All subjects were assessed at baseline, at 3 weeks of treatment, and at 3 months after the treatment had finished. The assessments included Fugl-Meyer Assessment (FMA), the Postural Assessment Scale for Stroke Patients (PASS), Berg Balance Scale (BBS), Functional Ambulation Category (FAC), and the Modified Barthel Index (MBI). Results. All 3 groups demonstrated significant improvements in all outcome measurements from pre- to posttreatment and further gains at followup. The score of FMA and MBI improved significantly in the four-channel group at the end of the 3 weeks of training. And the scores of PASS, BBS, MBI, and FAC in the four-channel group were significantly higher than those of the placebo group. Conclusions. This study indicated that four-channel FES can improve motor function, balance, walking ability, and performance of activities of daily living in subjects with early ischemic stroke.

Time course of functional and biomechanical improvements during a gait training intervention in persons with chronic stroke

BACKGROUND AND PURPOSE

In rehabilitation, examining how variables change over time can help define the minimal number of training sessions required to produce a desired change. The purpose of this study was to identify the time course of changes in gait biomechanics and walking function in persons with chronic stroke.

METHODS

Thirteen persons who were more than 6 months poststroke participated in 12 weeks of fast treadmill training combined with plantar- and dorsiflexor muscle functional electrical stimulation (FastFES). All participants completed testing before the start of intervention, after 4, 8, and 12 weeks of FastFES locomotor training.

RESULTS

Peak limb paretic propulsion, paretic limb propulsive integral, peak paretic limb knee flexion (P < 0.05 for all), and peak paretic trailing limb angle (P < 0.01) improved from pretraining to 4 weeks but not between 4 and 12 weeks. Self-selected walking speed and 6-minute walk test distance improved from pretraining to 4 weeks and from 4 to 12 weeks (P < 0.01 and P < 0.05, respectively for both). Timed Up & Go test time did not improve between pretraining and 4 weeks, but improved by 12 weeks (P = 0.24 and P < 0.01, respectively).

DISCUSSION AND CONCLUSIONS

The results demonstrate that walking function improves with a different time course compared with gait biomechanics in response to a locomotor training intervention in persons with chronic stroke. Thirty-six training sessions were necessary to achieve an increase in walking speed that exceeded the minimally clinically important difference. These findings should be considered when designing locomotor training interventions after stroke.Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A63) for more insights from the authors.

Functional electrical stimulation to ankle dorsiflexor and plantarflexor using single foot switch in patients with hemiplegia from hemorrhagic stroke

Objective

To evaluate the effects of functional electrical stimulation (FES) to ankle dorsiflexor (DF) and ankle plantarflexor (PF) on kinematic and kinetic parameters of hemiplegic gait.

Methods

Fourteen post-stroke hemiplegic patients were considered in this study. Electrical stimulation was delivered to ankle DF during the swing phase and ankle PF during the stance phase via single foot switch. Kinematic and kinetic data were collected using a computerized motion analysis system with force plate. Data of no stimulation (NS), DF stimulation only (DS), DF and PF stimulation (DPS) group were compared among each other.

Results

Peak ankle dorsiflexion angle during swing phase is significantly greater in DS group (-1.55°±9.10°) and DPS group (-2.23°±9.64°), compared with NS group (-6.71°±11.73°) (p<0.05), although there was no statistically significant difference between DS and DPS groups. Ankle plantarflexion angle at toe-off did not show significant differences among NS, DS, and DPS groups. Peak knee flexion in DPS group (34.12°±13.77°) during swing phase was significantly greater than that of NS group (30.78°±13.64°), or DS group (32.83°±13.07°) (p<0.05).

Conclusion

In addition to the usual FES application stimulating ankle DF during the swing phase, stimulation of ankle PF during stance phase can help to increase peak knee flexion during the swing phase. This study shows the advantages of stimulating the ankle DF and PF using single foot switch for post-stroke gait.

Effects on foot external rotation of the modified ankle-foot orthosis on post-stroke hemiparetic gait

Objective

To evaluate the effects of heel-opened ankle foot orthosis (HOAFO) on hemiparetic gait after stroke, especially on external foot rotation, and to compare the effects of HOAFO with conventional plastic-AFO (pAFO) and barefoot during gait.

Methods

This cross-over observational study involved 15 hemiparetic patients with external rotation of the affected foot. All subjects were able to walk independently, regardless of their usual use of a single cane, and had a less than fair-grade in ankle dorsiflexion power. Each patient was asked to walk in three conditions with randomized sequences: 1) barefoot, 2) with a pAFO, and 3) with an HOAFO. Their gait patterns were analyzed using a motion analysis system.

Results

Fifteen patients consisted of nine males and six females. On gait analysis, hip and foot external rotation were significantly greater in pAFO (-3.35° and -23.68°) than in barefoot and HOAFO conditions (p<0.05). Wearing an HOAFO resulted in significant decreases in hip (0.78°, p=0.04) and foot (-17.99°, p<0.01) external rotation compared with pAFO; although there was no significant difference between HOAFO and barefoot walking. Walking speed and percentage of single limb support were significantly greater for HOAFO than in barefoot walking.

Conclusion

HOAFO was superior to pAFO in reducing hip and foot external rotation during the stance phase in patients with post-stroke hemiparesis. HOAFO may, therefore, be useful in patients with excessive external rotation of the foot during conventional pAFO.

The effect of electrical stimulation on corticospinal excitability is dependent on application duration: a same subject pre-post test design

BACKGROUND

In humans, corticospinal excitability is known to increase following motor electrical stimulation (ES) designed to mimic a voluntary contraction. However, whether the effect is equivalent with different application durations and whether similar effects are apparent for short and long applications is unknown. The aim of this study was to investigate whether the duration of peripheral motor ES influenced its effect on corticospinal excitability.

METHODS

The excitability of the corticomotor pathway to abductor pollicis brevis (APB) was measured in fourteen health subjects using transcranial magnetic stimulation before, immediately after and 10 minutes after three different durations (20-, 40-, 60-min) of motor ES (30Hz, ramped). This intervention was designed to mimic a voluntary contraction in APB. To control for effects of motor ES on the peripheral elements (muscle fibre, membrane, neuromuscular junction), maximum compound muscle actions potentials (M-waves) were also recorded at each time point. Results were analysed using a repeated measures analysis of variance.

RESULTS

Peripheral excitability was reduced following all three motor ES interventions. Conversely, corticospinal excitability was increased immediately following 20- and 40-min applications of motor ES and this increase was maintained at least 20-min following the intervention. A 60-min application of motor ES did not alter corticospinal excitability.

CONCLUSIONS

A 20-min application of motor ES that is designed to mimic voluntary muscle contraction is as effective as that applied for 40-min when the aim of the intervention is to increase corticospinal excitability. Longer motor ES durations of 60-min do not influence corticospinal excitability, possibly as a result of homeostatic plasticity mechanisms.

Dual-channel functional electrical stimulation improvements in speed-based gait classifications

Background

Functional electrical stimulation (FES) is becoming an accepted treatment method for enhancing gait performance in patients who present with gait difficulties resulting from hemiparesis. The purpose of this study was to test whether individuals with hemiparesis who have varied gait speeds, which place them in different functional categories, benefit to the same extent from the application of FES.

Methods

Thirty-six subjects with chronic hemiparesis demonstrating foot-drop and deficits in knee and/or hip control were fitted with a dual-channel FES system activating the dorsiflexors and hamstring muscles. Gait was assessed during a 2-minute walk test with and without stimulation. A second assessment was conducted after 6 weeks of daily use. Analysis was performed with the subjects stratified into three functional ambulation classes according to their initial gait categories.

Results

The dual-channel FES improved the gait velocity of all three subgroups. No minimal gait velocity was required in order to gain benefits from FES. For example, subjects with limited household ambulation capabilities improved their gait speed by 63.3% (from 0.30 ± 0.09 m/sec to 0.49 ± 0.20 m/sec; P < 0.01), while subjects with functional community ambulation capabilities improved their gait speed by 25.5% (from 0.90 ± 0.11 m/sec to 1.13 ± 0.22 m/sec; P < 0.01).

Conclusion

Dual-channel FES positively affects gait velocity in patients with chronic hemiparesis, regardless of their initial gait velocity. Furthermore, gait velocity gains may be large enough to change an individual’s ambulation status to a higher functional category.