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

An adaptive reflexive control strategy for walking assistance system based on functional electrical stimulation

Functional electrical stimulation (FES) neuroprostheses have been regarded as an effective approach for gait rehabilitation and assisting patients with stroke or spinal cord injuries. A multiple-channel FES system was developed to improve the assistance and restoration of lower limbs. However, most neuroprostheses need to be manually adjusted and cannot adapt to individual needs. This study aimed to integrate the purely reflexive FES controller with an iterative learning algorithm while a multiple-channel FES walking assistance system based on an adaptive reflexive control strategy has been established. A real-time gait phase detection system was developed for accurate gait phase detection and stimulation feedback. The reflexive controller generated stimulation sequences induced by the gait events. These stimulation sequences were updated for the next gait cycle through the difference between the current and previous five gait cycles. Ten healthy young adults were enrolled to validate the multiple-channel FES system by comparing participants' gait performance to those with no FES controller and purely reflexive controller. The results showed that the proposed adaptive FES controller enabled the adaption to generate fitted stimulation sequences for each participant during various treadmill walking speeds. The maximum, minimum, and range of motion (ROM) of the hip, knee, and ankle joints were furtherly improved for most participants, especially for the hip and knee flexion and ankle dorsiflexion compared with the purely reflexive FES control strategy. The presented system has the potential to enhance motor relearning and promote neural plasticity.

The influence of surface EMG-triggered multichannel electrical stimulation on sensomotoric recovery in patients with lumbar disc herniation: study protocol for a randomized controlled trial (RECO)

Background

Intervertebral disc degeneration is one of the most common reasons for chronic low back pain and sensomotoric deficits, often treated by lumbar sequestrectomy. Nevertheless, the prognostic factors relevant for time and quality of recovery, of the surgical procedure, relative to conservative treatment, remain controversial and require further investigation. Surface electrical stimulation (SES) may be an influential intervention, already showing positive impact on motor and sensory recovery in different patient groups. Since mechanisms of SES still remain unclear, further inquiry is needed.

Methods/Design

This is a prospective, monocentric, randomized, controlled clinical trial. A total of 80 adult patients suffering from a lumbar disc herniation (LDH; 40 treated surgically, 40 conservatively) are allocated in a ratio of 1:1. Patients in the treatment group will receive surface electromyography (EMG)-triggered electrical stimulation for eight weeks, whereas patients in the control group will not obtain any additional treatment. The primary outcome parameter is defined as the cold detection threshold (CDT), determined by quantitative sensory testing (QST), 24 months after intervention. Secondary outcome parameters include the inquiry of sensory nerve function by two-point discrimination and QST, the assessment of motor nerve function by manual muscle testing, and validated scales and scores. These include: the Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI) assessing the domains pain, back-specific function, work disability, and patient satisfaction; the EQ-5D investigating the patient’s generic health status; the painDETECT questionnaire (PD-Q) to identify neuropathic pain components; and the Beck Depression Inventory (BDI) to assess severity of depression. Moreover, neurological status, pain medication usage, and blood samples (CRP, TNFα, IL-1β, IL-6) will be evaluated. Study data generation (study site) and data storage, processing, and statistical analysis are clearly separated.

Discussion

The results of the RECO study will detect the effect of EMG-triggered multichannel SES on the improvement of mechanical and thermal sensitivity and the effect on motor recovery and pain, associated with clinical and laboratory parameters. Furthermore, data comparing surgical and conservative treatment can be collected. This will hopefully allow treatment recommendations for patients with LDH accompanied by a sensomotoric deficit.

Trial registration

ISRCTN, ISRCTN12741173. Registered on 15 January 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2310-z) contains supplementary material, which is available to authorized users.

Improving Walking with an Implanted Neuroprosthesis for Hip, Knee, and Ankle Control After Stroke

OBJECTIVE

The objective of this work was to quantify the effects of a fully implanted pulse generator to activate or augment actions of hip, knee, and ankle muscles after stroke.

DESIGN

The subject was a 64-year-old man with left hemiparesis resulting from hemorrhagic stroke 21 months before participation. He received an 8-channel implanted pulse generator and intramuscular stimulating electrodes targeting unilateral hip, knee, and ankle muscles on the paretic side. After implantation, a stimulation pattern was customized to assist with hip, knee, and ankle movement during gait.The subject served as his own concurrent and longitudinal control with and without stimulation. Outcome measures included 10-m walk and 6-minute timed walk to assess gait speed, maximum walk time, and distance to measure endurance, and quantitative motion analysis to evaluate spatial-temporal characteristics. Assessments were repeated under 3 conditions: (1) volitional walking at baseline, (2) volitional walking after training, and (3) walking with stimulation after training.

RESULTS

Volitional gait speed improved with training from 0.29 m/s to 0.35 m/s and further increased to 0.72 m/s with stimulation. Most spatial-temporal characteristics improved and represented more symmetrical and dynamic gait.

CONCLUSIONS

These data suggest that a multijoint approach to implanted neuroprostheses can provide clinically relevant improvements in gait after stroke.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES:: Upon completion of this article, the reader should be able to do the following: (1) Describe the rationale for evaluating a multijoint implanted neuroprosthesis to improvewalkingafter stroke; (2)Understand the study design and conclusions that can be inferred as a result of the design; and (3) Discuss the statistical significance and clinical relevance of changes between (a) volitional walking at baseline, (b) volitional walking after training, and (c) walking with stimulation after training.

LEVEL

Advanced ACCREDITATION:: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Effects of functional electrical stimulation on gait in people with multiple sclerosis - A systematic review

BACKGROUND

Functional electrical stimulation (FES) is commonly used to ameliorate gait deficits in patients with multiple sclerosis (PwMS). This review critically evaluates the literature describing the orthotic and therapeutic effects of FES on gait in PwMS.

METHODS

The PubMed, CINAHL, and ProQuest databases were searched. Included were studies that evaluated therapeutic and/or orthotic effects of FES in PwMS with at least one outcome measure related to gait. Methodology was assessed using the Downs and Black checklist.

RESULTS

Twelve relevant studies were reviewed. Their methodological quality ranged from 14 to 21 of 28. Eleven studies reported the effects of peroneal stimulation. Most found a significant orthotic effect (measured during stimulation), mainly on walking speed. Only three assessed the therapeutic effect (carry-over), which was not significant.

CONCLUSIONS

The evidence presented in this review suggests that FES has a positive orthotic effect on walking in PwMS. Yet, more robust trials are needed to substantiate this finding. Therapeutic efficacy of FES was not demonstrated, and almost all studies tested a single channel peroneal stimulator. Future studies involving FES technological innovations with advanced clinical approaches might contribute to a carry-over effect from FES and increase the percentage of PwMS who benefit from this technology.

Examination of the use of a dual-channel functional electrical stimulation system on gait, balance and balance confidence of an adult with spastic diplegic cerebral palsy

The purpose of this case report is to determine the effects of a dual-channel functional electrical stimulation (FES) system on gait and balance of a 57-year-old male diagnosed with spastic diplegic cerebral palsy (CP). Outcome measures included the: Activities-specific Balance Confidence Scale (ABC); Dynamic Gait Index (DGI); Observational Gait Scale (OGS) and Tinetti Performance Oriented Mobility Assessment (POMA). Assessments were completed with and without use of FES during the initial examination and after two, four and six weeks of intervention with FES. ABC Scale scores improved from 32.8 to 48.1% during the 6-week intervention. Scores on the DGI improved from 6/24 to 9/24 without FES and from 9/24 to 14/24 with FES. OGS scores improved on both legs with and without FES. Tinetti POMA scores improved from 12/28 to 15/28 without FES and decreased from 16/28 to 15/28 with FES. The patient demonstrated improvement in both objective and subjective measures. The use of FES facilitated improved gait and balance; however, the patient was still at increased risk for falls after the 6-week intervention despite improved scores on the ABC Scale, DGI, OGS and Tinetti POMA.