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

Stroke Rehabilitation: Synopsis of the 2024 U.S. Department of Veterans Affairs and U.S. Department of Defense Clinical Practice Guidelines

DESCRIPTION

In July 2024, the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DOD) released a joint update of their 2019 clinical practice guideline (CPG) for the management of stroke rehabilitation. This synopsis is a condensed version of the 2024 CPG, highlighting the key aspects of the guideline development process and describing the major recommendations.

METHODS

The VA/DOD Evidence-Based Practice Work Group convened a joint VA/DOD guideline development work group (WG) that included clinical stakeholders and conformed to the Institute of Medicine's tenets for trustworthy CPGs. The guideline WG conducted a patient focus group, developed key questions, and systematically searched and evaluated the literature (English-language publications from 1 July 2018 to 2 May 2023). The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to evaluate the evidence. The WG developed 47 recommendations along with algorithms for stroke rehabilitation in the inpatient and outpatient settings. Stakeholders outside the WG reviewed the CPG before approval by the VA/DOD Evidence-Based Practice Work Group.

RECOMMENDATIONS

This synopsis summarizes where evidence is strongest to support guidelines in crucial areas relevant to primary care physicians: transition to community (case management, psychosocial or behavioral interventions); motor therapy (task-specific practice, mirror therapy, rhythmic auditory stimulation, electrical stimulation, botulinum toxin for spasticity); dysphagia, aphasia, and cognition (chin tuck against resistance, respiratory muscle strength training); and mental health (selective serotonin reuptake inhibitor use, psychotherapy, mindfulness-based therapies for treatment but not prevention of depression).

Peripheral electrical stimulation on neuroplasticity and motor function in stroke patients: a systematic review and meta-analysis

INTRODUCTION

The use of electrotherapy has been presented as a great resource for the professional physiotherapist in the most diverse pathologies. Stroke is a neurological condition responsible for sequelae such as hemiplegia that directly impair the quality of life of patients.

OBJECTIVE

This study aimed to review the literature on the effects of electrotherapeutic resources on motor function and neuroplasticity in individuals with post-stroke sequelae.

MATERIALS AND METHODS

2427 articles were found in databases according to search criteria for each base according to the included descriptors (EndNote Web). After exclusion of duplicate articles, automatically and manually, Phase 1 was performed - reading of titles and abstracts of 1626 articles according to eligibility criteria by two blinded reviewers using the programme Rayyan QCRI (Qatar Computing Research Institute), conflicts were resolved in consensus between the two reviewers. Thus, 13 articles were selected for Phase 2-13 articles were selected for reading in full, leaving 8 articles in this review. To assess the quality of bias of the selected studies, the PEDro Scale was used.

RESULTS

In the assessment of neuroplasticity, statistically significant results were found in two studies (p < 0.05). However, the effects of electrostimulation stood out significantly in the motor function of these individuals (p < 0.05). It can be considered with neuroplasticity, since improved functionality can be related to electrostimulation-induced neuroplasticity. Conclusions Electrostimulation is able to promote neuroplasticity and increase motor function, generating positive effects in the treatment of individuals with post-stroke sequelae.

Asymmetric cortical activation in healthy and hemiplegic individuals during walking: A functional near-infrared spectroscopy neuroimaging study

Background

This study investigated the cortical activation mechanism underlying locomotor control during healthy and hemiplegic walking.

Methods

A total of eight healthy individuals with right leg dominance (male patients, 75%; mean age, 40.06 ± 4.53 years) and six post-stroke patients with right hemiplegia (male patients, 86%; mean age, 44.41 ± 7.23 years; disease course, 5.21 ± 2.63 months) completed a walking task at a treadmill speed of 2 km/h and a functional electrical stimulation (FES)-assisted walking task, respectively. Functional near-infrared spectroscopy (fNIRS) was used to detect hemodynamic changes in neuronal activity in the bilateral sensorimotor cortex (SMC), supplementary motor area (SMA), and premotor cortex (PMC).

Results

fNIRS cortical mapping showed more SMC-PMC-SMA locomotor network activation during hemiplegic walking than during healthy gait. Furthermore, more SMA and PMC activation in the affected hemisphere was observed during the FES-assisted hemiplegic walking task than during the non-FES-assisted task. The laterality index indicated asymmetric cortical activation during hemiplegic gait, with relatively greater activation in the unaffected (right) hemisphere during hemiplegic gait than during healthy walking. During hemiplegic walking, the SMC and SMA were predominantly activated in the unaffected hemisphere, whereas the PMC was predominantly activated in the affected hemisphere. No significant differences in the laterality index were noted between the other groups and regions (p > 0.05).

Conclusion

An important feature of asymmetric cortical activation was found in patients with post-stroke during the walking process, which was the recruitment of more SMC-SMA-PMC activation than in healthy individuals. Interestingly, there was no significant lateralized activation during hemiplegic walking with FES assistance, which would seem to indicate that FES may help hemiplegic walking recover the balance in cortical activation. These results, which are worth verifying through additional research, suggest that FES used as a potential therapeutic strategy may play an important role in motor recovery after stroke.

Effectiveness of Repetitive Facilitative Exercise Combined with Electrical Stimulation Therapy to Improve Very Severe Paretic Upper Limbs in with Stroke Patients: A Randomized Controlled Trial

Background

The difference in the effects of combined therapy with repetitive facilitative exercise (RFE) and neuromuscular electrical stimulation (NMES) on stroke upper limb paralysis was only reported by a pilot study; it has not been investigated in many patients.

Objective

We investigated the effect of combined therapy with RFE and NMES on stroke patients with severe upper paresis.

Methods

This study included 99 of the very severe paresis stroke patients with scores of zero or 1a in the Finger-Function test of the Stroke Impairment Assessment Set (SIAS). We randomly divided the patients into four groups, namely, NMES, RFE, RFE under NMES, and conventional training (CT) groups. A total of 20 min of group-specific training in addition to 40 min of conventional exercise per day, seven times a week for 4 weeks after admission, was performed. The upper extremity items of the Fugl-Meyer Assessment (FMA) were evaluated before and after the training period.

Results

The total score gains of the FMA, FMA wrist item, and FMA finger item were significantly larger in the RFE under NMES group than those in the CT group (p < 0.05).

Conclusion

The combination of voluntary movement and electrical stimulation may promote the activation of paralyzed muscles and improve distal function for very severe paralyzed upper limbs.

Effects of Tai Chi Exercise on Balance Function in Stroke Patients: An Overview of Systematic Review

Background

Tai chi (TC) has received increased attention in stroke rehabilitation, yet services are greatly underutilized. An increasing number of systematic reviews and meta-analyses (SRs/MAs) have begun to investigate the effects of TC on balance function in stroke patients. The aim of this current study was to systematically collate, appraise, and synthesize the results of these SRs/MAs using a systematic overview.

Methods

Eight databases were searched: PubMed, Cochrane Library, Embase, Web of Science, CNKI, SinoMed, Chongqing VIP, and Wanfang Data. SRs/MAs of TC on balance function in stroke patients were included. Literature selection, data extraction, and assessment of the review quality were performed by two independent reviewers. Methodological quality was assessed by the Assessing the Methodological Quality of Systematic Reviews 2 (AMSTAR-2), reporting quality by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and evidence quality by Grading of Recommendations, Assessment, Development, and Evaluation (GRADE).

Results

Nine SRs/MAs were included in this study. For methodological quality, what resulted in unsatisfactory methodological quality was noncompliance with critical item 4 (using a comprehensive literature search strategy) and critical item 7 (providing the list of excluded research literature). For reporting quality, what resulted in unsatisfactory reporting quality was inadequate reporting of Q1 (protocol and registration), Q8 (search), Q15 (risk of bias across studies), Q16 (additional analyses), Q22 (risk of bias across studies), Q23 (additional analysis), and Q27 (funding). For GRADE, the evidence quality was high in 0, moderate in 3, low in 11, and very low in 6. Risk of bias was the most common factor leading to downgrading of evidence, followed by inconsistency, imprecision, publication bias, and indirectness.

Conclusions

TC may have beneficial effects on balance function in stroke survivors; however, this finding is limited by the generally low methodology, reporting quality, and evidence quality for published SRs/MAs.

Whole-Body Adaptive Functional Electrical Stimulation Kinesitherapy Can Promote the Restoring of Physiological Muscle Synergies for Neurological Patients

Background: Neurological diseases and traumas are major factors that may reduce motor functionality. Functional electrical stimulation is a technique that helps regain motor function, assisting patients in daily life activities and in rehabilitation practices. In this study, we evaluated the efficacy of a treatment based on whole-body Adaptive Functional Electrical Stimulation Kinesitherapy (AFESK™) with the use of muscle synergies, a well-established method for evaluation of motor coordination. The evaluation is performed on retrospectively gathered data of neurological patients executing whole-body movements before and after AFESK-based treatments. Methods: Twenty-four chronic neurologic patients and 9 healthy subjects were recruited in this study. The patient group was further subdivided in 3 subgroups: hemiplegic, tetraplegic and paraplegic. All patients underwent two acquisition sessions: before treatment and after a FES based rehabilitation treatment at the VIKTOR Physio Lab. Patients followed whole-body exercise protocols tailored to their needs. The control group of healthy subjects performed all movements in a single session and provided reference data for evaluating patients’ performance. sEMG was recorded on relevant muscles and muscle synergies were extracted for each patient’s EMG data and then compared to the ones extracted from the healthy volunteers. To evaluate the effect of the treatment, the motricity index was measured and patients’ extracted synergies were compared to the control group before and after treatment. Results: After the treatment, patients’ motricity index increased for many of the screened body segments. Muscle synergies were more similar to those of healthy people. Globally, the normalized synergy similarity in respect to the control group was 0.50 before the treatment and 0.60 after (p < 0.001), with improvements for each subgroup of patients. Conclusions: AFESK treatment induced favorable changes in muscle activation patterns in chronic neurologic patients, partially restoring muscular patterns similar to healthy people. The evaluation of the synergic relationships of muscle activity when performing test exercises allows to assess the results of rehabilitation measures in patients with impaired locomotor functions.

Neuromuscular Electric Stimulation in Addition to Exercise Therapy in Patients with Lower Extremity Paresis Due to Acute Ischemic Stroke. A proof-of-concept randomised controlled trial

INTRODUCTION

Exercise therapy and neuromuscular electrical stimulation (NMES) during the initial 14 days after stroke may benefit recovery of gait. We aimed to determine whether poststroke NMES of vastus medial and tibial muscles during exercise therapy is more effective than exercise therapy alone.

MATERIALS AND METHODS

In this proof-of-concept randomised trial patients with first-ever acute ischemic stroke and a leg paresis (40-85 years of age) were randomised (1:1) to 10 min of daily NMES + exercise therapy or exercise therapy alone. Primary outcome was the between-group difference in change in 6 min Walk Test (6MWT) at 90 days post stroke estimated with a mixed regression model. Secondary outcomes included 10 m Walk Test, Fugl-Meyer Motor Assessment, Guralnik Timed Standing Balance, Sit to Stand, Timed Up and Go, EQ-5D-5L, Montreal Cognitive Assessment and Becks Depression Inventory.

RESULTS

50 stroke survivors (25 in each group) with a mean age of 67 years (range 43-83) were included. An insignificant between-group difference in change of 28.3 m (95%CI -16.0 to 72.6, p = 0.23, adjusted for baseline) in 6MWT at 90-days follow-up was found, in favour of the NMES group. All secondary outcomes showed no statistically significant between-group difference. The conclusion was that adding NMES to exercise therapy had no effect on poststroke walking distance measured by the 6 MWT or any of the secondary outcomes.

CONCLUSIONS

In this proof-of-concept RCT, we demonstrated that NMES in addition to exercise therapy during the first 14 days after onset of ischemic stroke did not improve walking distance or any of the secondary outcomes. Future studies with a longer trial period, stratifying patients into subgroups with comparable patterns of expected spontaneous recovery - if possible within 48 h post stroke, and greater sample size, than in this study are suggestions of how rehabilitation research could go on exploring the potential for NMES as an amplifier in stroke recovery.

The Effects of Electrical Stimulation of Lower Extremity Muscles on Balance in Stroke Patients: A Systematic Review of Literatures

OBJECTIVE

Stroke is one of the main causes of disability and the second common cause of mortality in the world. Stroke causes relatively permanent motor defects, including balance disorder, and thus affects an individual's functional capacity and independence. Many clinical types of research have been conducted to evaluate the effect of functional electrical stimulation (FES) on balance in post-stroke patients. The objective of this study was to systematically review the effect of functional electrical stimulation (FES) on balance as compared to conventional therapy alone in post-stroke.

METHODS

The databases of Google Scholar, PubMed, Scopus, ScienceDirect and ProQuest were searched using selected keywords. The randomized controlled trials were searched for published original articles before February 2019 in English language and included if they assessed the effect of FES on balance ability compared to conventional therapy alone in adult post-stroke. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality.

RESULTS

Nine papers were included in this review (median PEDro scale =7/11). The total number of participants in this review study was 255. The age of participants ranged from 20 to 80 years. Stroke patients were in chronic phase (n = 5) and in subacute phase (n = 4). various parameters, including the target muscles, the treatment time per session (20 min-2 h), number of treatment sessions (12-48) and FES frequency (25-40 Hz), were assessed. Among the studies, significant between-group improvement favoring FES in combination with conventional therapy was found on the Berg Balance Scale (n = 7) and Timed Up and Go Scale (n = 4) when compared to conventional therapy alone. There was no adverse effect reported by any studies.

CONCLUSION

FES was reported to be more beneficial in balance improvement among stroke patients when combined with conventional balance therapy. The studies were limited by low-powered, small sample sizes ranging from 9 to 48, and lack of blinding, and reporting of missing data.

Smart Protocols for Physical Therapy of Foot Drop Based on Functional Electrical Stimulation: A Case Study

Functional electrical stimulation (FES) is used for treating foot drop by delivering electrical pulses to the anterior tibialis muscle during the swing phase of gait. This treatment requires that a patient can walk, which is mostly possible in the later phases of rehabilitation. In the early phase of recovery, the therapy conventionally consists of stretching exercises, and less commonly of FES delivered cyclically. Nevertheless, both approaches minimize patient engagement, which is inconsistent with recent findings that the full rehabilitation potential could be achieved by an active psycho-physical engagement of the patient during physical therapy. Following this notion, we proposed smart protocols whereby the patient sits and ankle movements are FES-induced by self-control. In six smart protocols, movements of the paretic ankle were governed by the non-paretic ankle with different control strategies, while in the seventh voluntary movements of the paretic ankle were used for stimulation triggering. One stroke survivor in the acute phase of recovery participated in the study. During the therapy, the patient’s voluntary ankle range of motion increased and reached the value of normal gait after 15 sessions. Statistical analysis did not reveal the differences between the protocols in FES-induced movements.

Feasibility and Preliminary Efficacy of Gait Training Assisted by Multichannel Functional Electrical Stimulation in Early Stroke Rehabilitation: A Pilot Randomized Controlled Trial

Background. Many stroke survivors suffer from leg muscle paresis, resulting in asymmetrical gait patterns, negatively affecting balance control and energy cost. Interventions targeting asymmetry early after stroke may enhance recovery of walking. Objective. To determine the feasibility and preliminary efficacy of up to 10 weeks of gait training assisted by multichannel functional electrical stimulation (MFES gait training) applied to the peroneal nerve and knee flexor or extensor muscle on the recovery of gait symmetry and walking capacity in patients starting in the subacute phase after stroke. Methods. Forty inpatient participants (≤31 days after stroke) were randomized to MFES gait training (experimental group) or conventional gait training (control group). Gait training was delivered in 30-minute sessions each workday. Feasibility was determined by adherence (≥75% sessions) and satisfaction with gait training (score ≥7 out of 10). Primary outcome for efficacy was step length symmetry. Secondary outcomes included other spatiotemporal gait parameters and walking capacity (Functional Gait Assessment and 10-Meter Walk Test). Linear mixed models estimated treatment effect postintervention and at 3-month follow-up. Results. Thirty-seven participants completed the study protocol (19 experimental group participants). Feasibility was confirmed by good adherence (90% of the participants) and participant satisfaction (median score 8). Both groups improved on all outcomes over time. No significant group differences in recovery were found for any outcome. Conclusions. MFES gait training is feasible early after stroke, but MFES efficacy for improving step length symmetry, other spatiotemporal gait parameters, or walking capacity could not be demonstrated. Trial Registration. Netherlands Trial Register (NTR4762).

Effect of aquatic therapy on balance and gait in stroke survivors: A systematic review and meta-analysis

BACKGROUND

The evidence on aquatic therapy (AT) for improving balance and gait deficits post-stroke is unclear. Therefore, this study aimed to determine the effect of AT on balance and gait in stroke survivors.

METHODS

We searched CINAHL, PubMed, Web of Science, Aqua4balance, Ewac, Cochrane, and EMBASE databases from inception to 1^st November 2019.

RESULTS

Eleven studies with 455 participants were included for the review. Meta-analysis showed that AT was effective for improving balance (MD 3.23, 95% CI 1.06, 5.39; p = 0.004; I² = 61%) and gait speed (MD 0.77, 95% CI 0.25, 1.29; p = 0.004; I² = 0%) when delivered alone. AT was effective in improving cadence (MD 4.41, 95% CI 0.82, 8.00; p = 0.02; I² = 68%) when delivered as an adjunct to land-based therapy.

CONCLUSION

AT may be used to improve balance and gait after stroke; however, the evidence to support its use is still low.

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.

Adaptive multichannel FES neuroprosthesis with learning control and automatic gait assessment

Background

FES (Functional Electrical Stimulation) neuroprostheses have long been a permanent feature in the rehabilitation and gait support of people who had a stroke or have a Spinal Cord Injury (SCI). Over time the well-known foot switch triggered drop foot neuroprosthesis, was extended to a multichannel full-leg support neuroprosthesis enabling improved support and rehabilitation. However, these neuroprostheses had to be manually tuned and could not adapt to the persons’ individual needs. In recent research, a learning controller was added to the drop foot neuroprosthesis, so that the full stimulation pattern during the swing phase could be adapted by measuring the joint angles of previous steps.

Methods

The aim of this research is to begin developing a learning full-leg supporting neuroprosthesis, which controls the antagonistic muscle pairs for knee flexion and extension, as well as for ankle joint dorsi- and plantarflexion during all gait phases. A method was established that allows a continuous assessment of knee and foot joint angles with every step. This method can warp the physiological joint angles of healthy subjects to match the individual pathological gait of the subject and thus allows a direct comparison of the two. A new kind of Iterative Learning Controller (ILC) is proposed which works independent of the step duration of the individual and uses physiological joint angle reference bands.

Results

In a first test with four people with an incomplete SCI, the results showed that the proposed neuroprosthesis was able to generate individually fitted stimulation patterns for three of the participants. The other participant was more severely affected and had to be excluded due to the resulting false triggering of the gait phase detection. For two of the three remaining participants, a slight improvement in the average foot angles could be observed, for one participant slight improvements in the averaged knee angles. These improvements where in the range of 4^circat the times of peak dorsiflexion, peak plantarflexion, or peak knee flexion.

Conclusions

Direct adaptation to the current gait of the participants could be achieved with the proposed method. The preliminary first test with people with a SCI showed that the neuroprosthesis can generate individual stimulation patterns. The sensitivity to the knee angle reset, timing problems in participants with significant gait fluctuations, and the automatic ILC gain tuning are remaining issues that need be addressed. Subsequently, future studies should compare the improved, long-term rehabilitation effects of the here presented neuroprosthesis, with conventional multichannel FES neuroprostheses.

A Neuro-Prosthetic Device for Substituting Sensory Functions during Stance Phase of the Gait

In this study, we present the experimental results demonstrating the functionality of our recently developed “balancing device” for walking restoration in patients with spinal cord injuries. Since we are preparing this device for testing on dogs, we program the analytical core of the device to recognize both stance and swing phases of the dog gait, the direction that the dog is falling, as well as selecting a suitable balancing strategy to prevent falling. The analytical core of the device is a commercial microcontroller, the Teensy, which is able to provide suitable stimulation commands and intensities as a voltage for delivery to the stimulation circuit and target muscles. We show the functional schematic of the device along with experimental results obtained by testing the device in a simulated robotic dog. Results show that the sensory system of the animal lost by spinal cord injury can be replaced by the sensing core of the device and the analytical core can provide appropriate stimulation control to balance the body of a dog. All test results are obtained using our robot test-bed and living animals are not involved in this study.

Effects of hydrokinesitherapy on balance and walking ability in stroke survivors: a systematic review and meta-analysis of randomized controlled studies

BACKGROUND

Balance and walking impairment are common dysfunctions after stroke. Emerging data has demonstrated that hydrokinesitherapy may have a positive influence on improvement of balance and walking ability. However, there is no firm evidence to support these results. Therefore, the aim of this review is to evaluate the effects of hydrokinesitherapy in stroke survivors systematically.

METHODS

Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, CINAHL and SPORTDiscus were systemic searched from their inception to Septemter 30, 2018. RevMan 5.3 software was used to perform data synthesis. The fixed-effect model or random-effect model was employed according to the results of heterogeneity test. The mean differences (MD) or standardized mean difference (SMD) was used to evaluate the pooled effect of hydrokinesitherapy on balance function, walking ability and activty of daily life (ADL).

RESULTS

A total of 13 studies were included involving 381 stroke survivors. Meta-analysis results indicated that hydrokinesitherapy could improve balance ability based on three test: Berg balance scale (BBS: MD = 3.84, 95% confidence interval (95% CI) 2.84 to 4.86, P < 0.001), Time Up To Go Test (TUGT: MD = - 1.22, 95% CI - 2.25 to - 0.18, P = 0.02, fixed-effect model), Functional Reach Test (FRT: MD = 2.41, 95% CI 1.49 to 3.33, P < 0.001). Additionally, we found a weakly positive effect on walking speed (SMD = 0.75, 95% CI 0.26 to 1.25, P = 0.003) and walking ability test (SMD = 0.36, 95% CI 0.04 to 0.68, P = 0.03). There was no significant difference between experimental group and control group in terms of ADL.

SHORT CONCLUSION

Hydrokinesitherapy can improve balance function and had a weakly positive effect on walking ability in stroke survivors. We did not find sufficient evidence to indicate that hydrokinesitherapy could improve the ADL of stroke survivors. However, due to the methodological shortcoming and small number of included studies, caution is needed when interpreting these results. Due to imprecision and publication bias, the quality of the evidence was downgraded to "low-quality" for the primary outcomes of balance and walking ability.

TRIAL REGISTRATION

CRD42018110787.

Evaluation of Gait Phase Detection Delay Compensation Strategies to Control a Gyroscope-Controlled Functional Electrical Stimulation System During Walking

Functional electrical stimulation systems are used as neuroprosthetic devices in rehabilitative interventions such as gait training. Stimulator triggers, implemented to control stimulation delivery, range from open- to closed-loop controllers. Finite-state controllers trigger stimulators when specific conditions are met and utilize preset sequences of stimulation. Wearable sensors provide the necessary input to differentiate gait phases during walking and trigger stimulation. However, gait phase detection is associated with inherent system delays. In this study, five stimulator triggers designed to compensate for gait phase detection delays were tested to determine which trigger most accurately delivered stimulation at the desired times of the gait cycle. Motion capture data were collected on seven typically-developing children while walking on an instrumented treadmill. Participants wore one inertial measurement unit on each ankle and gyroscope data were streamed into the gait phase detection algorithm. Five triggers, based on gait phase detection, were used to simulate stimulation to five muscle groups, bilaterally. For each condition, stimulation signals were collected in the motion capture software via analog channels and compared to the desired timing determined by kinematic and kinetic data. Results illustrate that gait phase detection is a viable finite-state control, and appropriate system delay compensations, on average, reduce stimulation delivery delays by 6.7% of the gait cycle.

A Randomized Clinical Trial of a Functional Electrical Stimulation Mimic to Gait Promotes Motor Recovery and Brain Remodeling in Acute Stroke

Functional electrical stimulation can improve motor function after stroke. The mechanism may involve activity-dependent plasticity and brain remodeling. The aim of our study was to investigate the effectiveness of a patterned electrical stimulation FES mimic to gait in motor recovery among stroke survivors and to investigate possible mechanisms through brain fMRI. Forty-eight subjects were recruited and randomly assigned to a four-channel FES group (n = 18), a placebo group (n = 15), or a dual-channel FES group (n = 15). Stimulation lasted for 30 minutes in each session for 3 weeks. All of the subjects were assessed at baseline and after weeks 1, 2, and 3. The assessments included the Fugl-Meyer Assessment, the Postural Assessment Scale for Stroke Patients, Brunel's Balance Assessment, the Berg Balance Scale, and the modified Barthel Index. Brain fMRI were acquired before and after the intervention. All of the motor assessment scores significantly increased week by week in all the three groups. The four-channel group showed significantly better improvement than the dual-channel group and placebo groups. fMRI showed that fractional anisotropy was significantly increased in both the four-channel and dual-channel groups compared with the placebo group and fiber bundles had increased significantly on the ipsilateral side, but not on the contralateral side in the group given four-channel stimulation. In conclusion, when four-channel FES induces cycling movement of the lower extremities based on a gait pattern, it may be more effective in promoting motor recovery and induce more plastic changes and brain remodeling than two-channel stimulation. This trial is registered with clinical trial registration unique identifier ChiCTR-TRC-11001615.

A decision support system for electrode shaping in multi-pad FES foot drop correction

BACKGROUND

Functional electrical stimulation (FES) can be applied as an assistive and therapeutic aid in the rehabilitation of foot drop. Transcutaneous multi-pad electrodes can increase the selectivity of stimulation; however, shaping the stimulation electrode becomes increasingly complex with an increasing number of possible stimulation sites. We described and tested a novel decision support system (DSS) to facilitate the process of multi-pad stimulation electrode shaping. The DSS is part of a system for drop foot treatment that comprises a custom-designed multi-pad electrode, an electrical stimulator, and an inertial measurement unit.

METHODS

The system was tested in ten stroke survivors (3-96 months post stroke) with foot drop over 20 daily sessions. The DSS output suggested stimulation pads and parameters based on muscle twitch responses to short stimulus trains. The DSS ranked combinations of pads and current amplitudes based on a novel measurement of the quality of the induced movement and classified them based on the movement direction (dorsiflexion, plantar flexion, eversion and inversion) of the paretic foot. The efficacy of the DSS in providing satisfactory pad-current amplitude choices for shaping the stimulation electrode was evaluated by trained clinicians. The range of paretic foot motion was used as a quality indicator for the chosen patterns.

RESULTS

The results suggest that the DSS output was highly effective in creating optimized FES patterns. The position and number of pads included showed pronounced inter-patient and inter-session variability; however, zones for inducing dorsiflexion and plantar flexion within the multi-pad electrode were clearly separated. The range of motion achieved with FES was significantly greater than the corresponding active range of motion (p < 0.05) during the first three weeks of therapy.

CONCLUSIONS

The proposed DSS in combination with a custom multi-pad electrode design covering the branches of peroneal and tibial nerves proved to be an effective tool for producing both the dorsiflexion and plantar flexion of a paretic foot. The results support the use of multi-pad electrode technology in combination with automatic electrode shaping algorithms for the rehabilitation of foot drop.

TRIAL REGISTRATION

This study was registered at the Current Controlled Trials website with ClinicalTrials.gov ID NCT02729636 on March 29, 2016.

Gait training assisted by multi-channel functional electrical stimulation early after stroke: study protocol for a randomized controlled trial

Background

Many stroke survivors suffer from paresis of lower limb muscles, resulting in compensatory gait patterns characterised by asymmetries in spatial and temporal parameters and reduced walking capacity. Functional electrical stimulation has been used to improve walking capacity, but evidence is mostly limited to the orthotic effects of peroneal functional electrical stimulation in the chronic phase after stroke. The aim of this study is to investigate the therapeutic effects of up to 10 weeks of multi-channel functional electrical stimulation (MFES)-assisted gait training on the restoration of spatiotemporal gait symmetry and walking capacity in subacute stroke patients.

Methods

In a proof-of-principle study with a randomised controlled design, 40 adult patients with walking deficits who are admitted for inpatient rehabilitation within 31 days since the onset of stroke are randomised to either MFES-assisted gait training or conventional gait training. Gait training is delivered in 30-minute sessions each workday for up to 10 weeks. The step length symmetry ratio is the primary outcome. Blinded assessors conduct outcome assessments at baseline, every 2 weeks during the intervention period, immediately post intervention and at 3-month follow-up.

Discussion

This study aims to provide preliminary evidence for the feasibility and effectiveness of MFES-assisted gait rehabilitation early after stroke. Results will inform the design of a larger multi-centre trial.

Trial registration

This trial is registered at the Netherlands Trial Register (number NTR4762, registered 28 August 2014)

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1604-x) contains supplementary material, which is available to authorized users.

A Virtual Reality-Cycling Training System for Lower Limb Balance Improvement

Stroke survivors might lose their walking and balancing abilities, but many studies pointed out that cycling is an effective means for lower limb rehabilitation. However, during cycle training, the unaffected limb tends to compensate for the affected one, which resulted in suboptimal rehabilitation. To address this issue, we present a Virtual Reality-Cycling Training System (VRCTS), which senses the cycling force and speed in real-time, analyzes the acquired data to produce feedback to patients with a controllable VR car in a VR rehabilitation program, and thus specifically trains the affected side. The aim of the study was to verify the functionality of the VRCTS and to verify the results from the ten stroke patients participants and to compare the result of Asymmetry Ratio Index (ARI) between the experimental group and the control group, after their training, by using the bilateral pedal force and force plate to determine any training effect. The results showed that after the VRCTS training in bilateral pedal force it had improved by 0.22 (p = 0.046) and in force plate the stand balance has also improved by 0.29 (p = 0.031); thus both methods show the significant difference.

Electrical Stimulation and Motor Recovery

In recent years, several investigators have successfully regenerated axons in animal spinal cords without locomotor recovery. One explanation is that the animals were not trained to use the regenerated connections. Intensive locomotor training improves walking recovery after spinal cord injury (SCI) in people, and >90% of people with incomplete SCI recover walking with training. Although the optimal timing, duration, intensity, and type of locomotor training are still controversial, many investigators have reported beneficial effects of training on locomotor function. The mechanisms by which training improves recovery are not clear, but an attractive theory is available. In 1949, Donald Hebb proposed a famous rule that has been paraphrased as “neurons that fire together, wire together.” This rule provided a theoretical basis for a widely accepted theory that homosynaptic and heterosynaptic activity facilitate synaptic formation and consolidation. In addition, the lumbar spinal cord has a locomotor center, called the central pattern generator (CPG), which can be activated nonspecifically with electrical stimulation or neurotransmitters to produce walking. The CPG is an obvious target to reconnect after SCI. Stimulating motor cortex, spinal cord, or peripheral nerves can modulate lumbar spinal cord excitability. Motor cortex stimulation causes long-term changes in spinal reflexes and synapses, increases sprouting of the corticospinal tract, and restores skilled forelimb function in rats. Long used to treat chronic pain, motor cortex stimuli modify lumbar spinal network excitability and improve lower extremity motor scores in humans. Similarly, epidural spinal cord stimulation has long been used to treat pain and spasticity. Subthreshold epidural stimulation reduces the threshold for locomotor activity. In 2011, Harkema et al. reported lumbosacral epidural stimulation restores motor control in chronic motor complete patients. Peripheral nerve or functional electrical stimulation (FES) has long been used to activate sacral nerves to treat bladder and pelvic dysfunction and to augment motor function. In theory, FES should facilitate synaptic formation and motor recovery after regenerative therapies. Upcoming clinical trials provide unique opportunities to test the theory.