Functional Electrical Stimulation- hemiplegic shoulder
Functional electrical stimulation (FES), also called functional neuromuscular stimulation (FNS), is a technique used to replace or assist a voluntary muscle contraction during a functional task by applying low-level electrical current to the nerves that control muscles or directly over the motor end-plate of the muscle (just like a pacemaker makes a heart beat).
The term "FES" is commonly used to describe electrical stimulation used as a treatment modality for loss of shoulder function, pain, spasticity and subluxation following stroke. The U.S. AHCPR Post Stroke Rehabilitation Guidelines defines FES as "bursts of electrical stimulation applied to the nerves or muscles affected by the stroke, with the goal of strengthening muscle contraction and improving motor control."
Neuromuscular electrical stimulation, or simply "electrical stimulation" (ES), is a modality used for strengthening muscles. ES may be considered a FES when a muscle contraction is facilitated during a functional task. Despite the use of all three terms in the literature (FES, FNS and ES) the applications to the hemiplegic shoulder all focus on the stimulation of the supraspinatus and deltoid muscles. Therefore, this module includes the modalities that elicit muscular contraction of the rotator cuff muscles. TENS and other therapeutic electrical stimulation that do not elicit muscular contraction are reviewed in other modules.
Theoretically, FES should help to compensate or facilitate flaccid shoulder muscles, which in turn should reduce the risk of shoulder subluxation, by involuntary muscle contractions. The effectiveness of FES in improving function, tone, EMG activity and in reducing pain and subluxation has been reported.
Authors*: Marc-André Roy, MSc; Nicol Korner-Bitensky, PhD; Robert Teasell, MD; Norine Foley, BASc; Sanjit Bhogal, MSc; Jamie Bitensky, MScOT; and Mark Speechley, MD.