Significant Impact of Implantable Functional Electrical Stimulation on Gait Parameters: A Kinetic Analysis in Foot Drop Patients.

Abstract

Neurogenic drop foot is a common result of acquired damage of the central nervous system and can cause severe restriction of mobility. ActiGait, an implantable functional electrical stimulation device, restores ankle dorsiflexion by active peroneal nerve stimulation. The aim of our study was to evaluate its effect on foot contact pattern during normal walk. Eight patients with drop foot who used ActiGait in everyday life performed a 20-meter comfortable walk test. Gait parameters were evaluated with an insole system (Medilogic). Percentage of biped stance in a double-step, effective foot length, width of gait, and overall plantar load were measured in comparison with and without activated drop foot stimulation. Effective foot length increased in all patients on average from 46.0% to 60.2% (P = 0.038). However, percentage of biped stance in a double-step showed no significant difference (31.2% vs. 27.8% on average, P = 0.063), nor did width of gait (2.6% vs. 2.4% on average, P = 0.73) and overall plantar load (3.51 N/cm² vs. 3.39 N/cm², P = 0.25). The ActiGait implantable drop foot stimulator significantly improves effective foot length during normal walk of patients with neurogenic drop foot. Further investigation is needed to confirm whether ActiGait has no effect on the other parameters or whether it facilitates permanent gait adaptations that persist without the activated device.