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

Hybrid and adaptive control of functional electrical stimulation to correct hemiplegic gait for patients after stroke

Introduction: Gait, as a fundamental human movement, necessitates the coordination of muscles across swing and stance phases. Functional electrical stimulation (FES) of the tibialis anterior (TA) has been widely applied to foot drop correction for patients with post-stroke during the swing phase. Although the gastrocnemius (GAS) during the stance phase is also affected, the Functional electrical stimulation of the gastrocnemius received less attention. Methods: To address this limitation, a timing- and intensity-adaptive Functional electrical stimulation control strategy was developed for both the TA and GAS. Each channel incorporates a speed-adaptive (SA) module to control stimulation timing and an iterative learning control (ILC) module to regulate the stimulation intensity. These modules rely on real-time kinematic or kinetic data during the swing or stance phase, respectively. The orthotic effects of the system were evaluated on eight patients with post-stroke foot drop. Gait kinematics and kinetics were assessed under three conditions: no stimulation (NS), Functional electrical stimulation to the ankle dorsiflexor tibialis anterior (SA-ILC DS) and FES to the tibialis anterior and the ankle plantarflexor gastrocnemius (SA-ILC DPS). Results: The ankle plantarflexion angle, the knee flexion angle, and the anterior ground reaction force (AGRF) in the SA-ILC DPS condition were significantly larger than those in the NS and SA-ILC DS conditions (p < 0.05). The maximum dorsiflexion angle during the swing phase in the SA-ILC DPS condition was similar to that in the SA-ILC DS condition, with both being significantly larger than the angle observed in the NS condition (p < 0.05). Furthermore, the angle error and force error relative to the set targets were minimized in the SA-ILC DPS condition. Discussion: The observed improvements can be ascribed to the appropriate stimulation timing and intensity provided by the SA-ILC DPS strategy. This study demonstrates that the hybrid and adaptive control strategy of functional electrical stimulation system offers a significant orthotic effect, and has considerable potential for future clinical application.

A scoping review on recent trends in wearable sensors to analyze gait in people with stroke: From sensor placement to validation against gold-standard equipment

The purpose of the review is to evaluate wearable sensor placement, their impact and validation of wearable sensors on analyzing gait, primarily the postural instability in people with stroke. Databases, namely PubMed, Cochrane, SpringerLink, and IEEE Xplore were searched to identify related articles published since January 2005. The authors have selected the articles by considering patient characteristics, intervention details, and outcome measurements by following the priorly set inclusion and exclusion criteria. From a total of 1077 articles, 142 were included in this study and classified into functional fields, namely postural stability (PS) assessments, physical activity monitoring (PA), gait pattern classification (GPC), and foot drop correction (FDC). The review covers the types of wearable sensors, their placement, and their performance in terms of reliability and validity. When employing a single wearable sensor, the pelvis and foot were the most used locations for detecting gait asymmetry and kinetic parameters, respectively. Multiple Inertial Measurement Units placed at different body parts were effectively used to estimate postural stability and gait pattern. This review article has compared results of placement of sensors at different locations helping researchers and clinicians to identify the best possible placement for sensors to measure specific kinematic and kinetic parameters in persons with stroke.

A Sensor-Based Multichannel FES System to Control Knee Joint and Reduce Stance Phase Asymmetry in Post-Stroke Gait

Most of the studies using functional electrical stimulation (FES) in gait rehabilitation have been focused on correcting the drop foot syndrome. Using FES to control the knee joint in individuals with central nervous system (CNS) disorders could also play a key role in gait recovery: spasticity decrease, higher range of motion, positive effect on balance, limiting hyperextension and flexion in stance phase, reducing joint overload, etc. In stance phase, an accurate timing and a fine tuning of stimulation parameters are however required to provide a proper control of the knee stimulation while ensuring a safe and efficient support. In this study, 11 participants were equipped with inertial measurements units (IMU) and foot pressure insoles after supratentorial ischemic or hemorrhagic stroke, informing on knee angle and gait events used to online adapt FES during a 10 m walking protocol. Asymmetry of stance time and weight bearing were monitored as well as gait quality and physiological cost through a series of relevant markers. Vertical trunk motion has been significantly reduced during gait with FES (p-value = 0.038). Despite no significant improvement of stance phase asymmetry has been found, this preliminary work shows evidence of promising technical and rehabilitative potentials of a sensor-based multichannel FES system to control knee joint in post-stroke gait.

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).

Treadmill training augmented with real-time visualisation feedback and function electrical stimulation for gait rehabilitation after stroke: a feasibility study

Background

Stroke rehabilitation often uses the motor relearning concept that require patients to perform active practice of skill-specific training and to receive feedback. Treadmill training augmented with real-time visualisation feedback and functional electrical stimulation may have a beneficial synergistic effect on motor recovery. This study aims to determine the feasibility of this kind of enhanced treadmill training for gait rehabilitation among patients after stroke. A system for dynamic visualisation of lower-limb movement based on 3-dimentional motion capture and a computer timed functional electrical stimulation system was developed. Participants received up to 20-min enhanced treadmill training instead of their over-ground gait training once or twice a week for 6 weeks at Coathill hospital, Lanarkshire, United Kingdom. Number of training sessions attended, and training duration were used to assess feasibility. Ankle kinematics in the sagittal plane of walking with and without functional electrical stimulation support of the pre-tibial muscles were also compared and used to confirm the functional electrical stimulation was triggered at the targeted time.

Results

Six patients after stroke participated in the study. The majority of participants were male (5/6) with a age range from 30 to 84 years and 4/6 had left hemiplegia. All participants suffered from brain infarction and were at least 3 months after stroke. Number of training sessions attended ranged from 5 to 12. The duration of training sessions ranged from 11 to 20 min. No serious adverse events were reported. The computerised functional electrical stimulation to the pre-tibial muscles was able to reduce plantarflexion angle during the swing phase with statistical significance (p = 0.015 at 80%; p = 0.008 at 90 and 100% of the gait cycle).

Conclusions

It is safe and feasible to use treadmill gait training augmented with real-time visual feedback and computer-controlled functional electrical stimulation with patients after stroke in routine clinical practice.

Trial registration

NCT03348215. Registered 20 November 2017.

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.

Combined Therapy With Functional Electrical Stimulation and Standing Frame in Stroke Patients

OBJECTIVE

To investigate the effects of combination functional electrical stimulation (FES) and standing frame training on standing balance in stroke patients.

METHODS

Patients who had hemiparesis and postural instability after stroke were randomly assigned to one of the two groups; study group underwent FES on the quadriceps and tibialis anterior muscle simultaneously with standing balance training. The control group received standing frame training and FES separately. Both the groups received their respective therapies for 3 weeks. Stability index in Biodex Balance master system, Berg Balance Scale (BBS), manual muscle test, the Korean version of Modified Barthel Index, and Korean version of Mini-Mental State Examination were used to evaluate the effects of the treatment.

RESULTS

In total, 30 patients were recruited to the study group and 30 to the control group. Three weeks after treatment, both the groups showed improvement in postural stability scores and physical and cognitive functions. When changes in postural stability were compared between the groups, the study group showed more significant improvement than the control group with regards to the scores of BBS and the stability indices.

CONCLUSION

In this study, we found the therapeutic effectiveness of combined therapy of FES and standing frame in subacute stroke patients. The presented protocol is proposed as time-saving and can be applied easily in the clinical setting. Thus, the proposed combined therapy could be a useful method for improving standing balance in subacute stroke patients.

A novel hinged ankle foot orthosis for gait performance in chronic hemiplegic stroke survivors: a feasibility study

Stroke survivors with gait disturbances may use ankle foot orthoses (AFOs). However, most AFOs come in one-piece styles, which make it difficult for spasticity-affected stroke survivors to don. AFOs are also limited since they do not properly prevent ankle joint for foot drop by itself. Therefore, the present study developed a novel hinged AFO by adding a locking device to a hinged joint. We then tested its feasibility in 9 hemiplegic stroke survivors by investigating temporal-spatial gait parameters using the GAITRite in the following 3 conditions: no AFO, traditional AFO, and novel hinged AFO. There was no significant difference in spatiotemporal gait parameters among the different conditions. There were greater decreases in gait velocity, cadence, step length, and stride length in the novel hinged AFO group than in the no AFO and traditional AFO groups. This novel hinged AFO was developed to prevent foot drop. However, the AFO did not show significant differences in gait parameters because it consists of metal with extra weight and volume. Functionally, it prevented foot drop. It also improved convenience by its releasable design. Thus, further studies are needed to develop an AFO that improves gait and is convenient to use for hemiplegic stroke survivors.