Functional electrical stimulation on improving foot drop gait in poststroke rehabilitation: a review of its technology and clinical efficacy.

This article presents technical developments in and clinical applications of functional electrical stimulation (FES) in the recovery of gait and motor function in poststroke rehabilitation. We review stroke incidence, stimulator design, brain-computer interface-based FES systems, and clinical applications of FES. Developments in different types of foot drop stimulators are reviewed, including hard-wired and microprocessor-based surface stimulator systems. The replacement of the foot switch by using artificial and "natural" sensors as the primary control in foot drop stimulators is reviewed. In addition, this review evaluates the clinical effects of FES applications in gait, motor control, and functional ability compared to conventional therapy alone during poststroke rehabilitation. The literature suggests the combination of FES and a conventional rehabilitation program has a positive therapeutic effect on the recovery of gait, motor function, energy expenditure, and functional ability in stroke patients. On the basis of our review, we recommend using FES therapy along with a conventional rehabilitation program in the poststroke rehabilitation process. In summary, this article describes the need for rigorous technological development, clinical studies, and collaboration between clinicians and engineers for FES systems. Future research would facilitate the design of costeffective FES systems as well as analysis of FES applications in stroke patients to optimize the rehabilitation process.

Functional electrical stimulation of dorsiflexor muscle: effects on dorsiflexor strength, plantarflexor spasticity, and motor recovery in stroke patients.

OBJECTIVE: To evaluate the therapeutic effects of Functional Electrical Stimulation (FES) of the tibialis anterior muscle on plantarflexor spasticity, dorsiflexor strength, voluntary ankle dorsiflexion, and lower extremity motor recovery with stroke survivors. DESIGN: We conducted a prospective interventional study. SETTING: Rehabilitation ward, physiotherapy unit and gait analysis laboratory. PARTICIPANTS: Fifty-one patients with foot drop resulting from stroke. INTERVENTION: The functional electrical stimulation (FES) group (n=27) received 20-30 minutes of electrical stimulation to the peroneal nerve and anterior tibial muscle of the paretic limb along with conventional rehabilitation program (CRP). The control group (n=24) treated with CRP only. The subjects were treated 1 hr per day, 5 days a week, for 12 weeks. MAIN OUTCOME MEASURES: Plantarflexor spasticity measured by modified ashworth scale (MAS), dorsiflexion strength measured by manual muscle test (MMT), active/passive ankle joint dorsiflexion range of motion, and lower-extremity motor recovery by Fugl-Meyer assessment (FMA) scale. RESULTS: After 12 weeks of treatment, there was a significant reduction in a plantarflexor spasticity by 38.3% in the FES group and 21.2% in control group (P< 0.05), between the beginning and end of the trial. Dorsiflexor muscle strength was increased significantly by 56.6% and 27.7% in the FES group and control group, respectively. Similarly, voluntary ankle dorsiflexion and lower-extremity motor function improved significantly in both the groups. No significant differences were found in the baseline measurements among groups. When compared with control group, a significant improvement (p< 0.05) was measured in all assessed parameters in the FES group at post-treatment assessment, thus FES therapy has better effect on recovery process in post-stroke rehabilitation. CONCLUSIONS: Therapy combining FES and conventional rehabilitation program was superior to a conventional rehabilitation program alone, in terms of reducing spasticity, improving dorsiflexor strength and lower extremity motor recovery in stroke patients.

Effect of functional electrical stimulation on the effort and walking speed, surface electromyography activity, and metabolic responses in stroke subjects.

OBJECTIVE: To investigate the effects of functional electrical stimulation (FES) combined with conventional rehabilitation program on the effort and speed of walking, the surface electromyographic (sEMG) activity and metabolic responses in the management of drop foot in stroke subjects. METHODS: Fifteen patients with a drop foot resulting from stroke at least 3 months prior to the start of the trial took part in this study. All subjects were treated 1h a day, 5 days a week, for 12 weeks, including conventional stroke rehabilitation program and received 30 min of FES to the tibialis anterior (TA) muscle of the paretic leg in clinical settings. Baseline and post-treatment measurements were made for temporal and spectral EMG parameters of TA muscle, walking speed, the effort of walking as measured by physiological cost index (PCI) and metabolic responses. RESULTS: The experimental results showed a significant improvement in mean-absolute-value (21.7%), root-mean-square (66.3%) and median frequency (10.6%) of TA muscle EMG signal, which reflects increased muscle strength. Mean increase in walking speed was 38.7%, and a reduction in PCI of 34.6% between the beginning and at end of the trial. Improvements were also found in cardiorespiratory responses with reduction in oxygen consumption (24.3%), carbon dioxide production (19.9%), heart rate (7.8%) and energy cost (22.5%) while walking with FES device. CONCLUSIONS: The results indicate that the FES may be a useful therapeutic tool combined with conventional rehabilitation program to improve the muscle strength, walking ability and metabolic responses in the management of drop foot with stroke patients.

Restoration of gait and motor recovery by functional electrical stimulation therapy in persons with stroke.

PURPOSE: To evaluate the clinical efficacy of functional electrical stimulation (FES) therapy of the tibialis anterior (TA) muscle on gait restoration and enhancing motor recovery with stroke patients. METHOD: Thirty hemiparetic participants with spastic foot-drop impairments who were at least 3 months post-stroke were recruited from a rehabilitation institute and were assigned either to a control group or a FES group. Both the groups participated in a conventional stroke rehabilitation program for 60 min per day, 5 days a week, for 12-weeks. The FES group received the electrical stimulation to the TA muscle for correction of foot-drop. RESULTS: Functional electric stimulation (FES) resulted in a 26.3% (p < 0.001) improvement of walking speed measured with 10-m walkway, whereas the improvement in the control group was only 11.5% (p < 0.01). The FES group also showed significantly greater improvements compared to control group in other gait parameters (e.g. cadence, step length), physiological cost index (PCI), ankle range of motion, spasticity of calf muscle, Fugl-Meyer scores, and the maximum value of the root mean square (RMS(max)), which reflects the capacity of the muscle output. CONCLUSIONS: These findings suggest that, the FES therapy combined with conventional therapy treatment more effectively improves the walking ability and enhances the motor recovery when compared with conventional therapy alone in stroke survivors.