Comparison of electrode positions for a multi-field FES device for compensation of foot drop

Resumen

Neurologic diseases often cause “foot drop”, a gait impairment in which the patient is not able to lift the foot due to the weakness or absence of ankle dorsiflexors. Functional electrical stimulation (FES) is one of the options for treating foot drop. Surface multi-field electrodes have emerged in the last decade, showing great potential on improving selectivity of stimulation and providing easier donning and doffing. So far, usability and clinical results of FES have been researched. This preliminary study attempts to analyse and compare the movements created using different electrode positions with a commercial multi-field technology-based FES device. 6 healthy subjects participated in the study, and one configuration was held with 2 electrode positions within 3 days. Results show that when the electrode is located more caudally, the capability of the system to produce clear dorsiflexion is increased, while when it is located more cranially, it increases the capacity to induce ankle eversion and plantar flexion. No significant differences were observed between both electrode positions. This study suggests that electrode position influences the elicited ankle movements and that therefore, it should be considered in the configuration process.