Functional electrical stimulation (FES) is a form of neuromuscular electrical stimulation (NMES) (see NMES section). Similar to NMES, FES involves the application of peripheral electrical stimulation to the nerves to activate muscles and induce movement of an impaired limb (Hodkin et al., 2018). However, FES simultaneously stimulates a number of muscle groups to coordinate movement of a functional activity such as cycling, standing or walking, unlike NMES (Bekhet et al., 2019). In a recent meta analysis, FES interventions improved activity in stroke patients when compared to no intervention and training alone (Howlett et al., 2015). The beneficial effects of FES are thought to arise from neuroplastic changes in motor circuits (Hodkin et al., 2018). These changes may be induced through the pairing of cortical and peripheral activity, whereby “cells that fire together, wire together” (Hebb’s principle) (Hodkin et al., 2018).
A total of seven studies investigating FES to enhance upper extremity rehabilitation were found. The methodological details and results of these studies are presented in Table 14.