Abstract: Functional electrical stimulation(FES) offers a vast potential for partial restoration of parlayzed movements. In practice,understanding on the underlying mechanism and limitations of electrical activation of nerve is essential to guide a successful deployment of FES technology to clinical utilization. Thisthree part article will review the basic concepts,system design and applications of FES. In part I,conceptssuch as activation threshold,recruitment order are discussed. Part Ⅱ introduces stimulation waveforme,safeparameters and tissue damage,as well as the design principle of stimulators for use with percutaneous electrodes. Part Ⅲ outlines clinical applications of FES,in particular,for restoration of hand grasp function forC5/C6 patients.

Key words: functional electrical stimulation, motor rehabilitation, neuroprosthesis