Comparison of Configuration Postures for a Foot Drop Multi-field FES Device

Functional electrical stimulation (FES) is a popular technique to treat foot drop, a common gait impairment caused by inadequate dorsiflexion of the ankle. Multi-field surface electrodes provide easier and faster electrode donning and doffing and higher selectivity of stimulation, solving the problems of traditional FES devices. It also allows an automatic configuration of the device. This pilot study analyses the effectivity of different postures for the automatic configuration of the Fesia Walk system, a commercial multifield technology-based FES device. 5 healthy subjects participated in the study, and 5 configurations where held at 3 body postures within 5 days. The analysis focused on the ability of the system to classify the movements (dorsiflexion, plantarflexion, eversion and inversion) of the ankle in the 3 configuration postures. Results show that sitting on top of a table with both knees extended and ankle and foot hanging freely is the most appropriate posture for configuration as it only presents limitations to generate inversion.