What is “functional electrical stimulation” (FES)?
Author: SCIRE Community Team | Reviewer: Shannon Sproule | Published: 10 October 2017 | Updated: ~
Functional electrical stimulation (FES) is a type of neuromodulation where electrical stimulation is applied to the nerves located outside the spinal cord and brain. This stimulation causes the muscles to contract and can assist with purposeful or functional movement in weak or paralyzed muscles.
FES is delivered using a variety of handheld or specialized commercial electrical therapy machines connected to electrodes that are placed on the skin’s surface. Systems are also available with implanted electrodes in the muscles, although this is very specialized and not widely available.
FES electrodes are placed on the leg muscles to be used during stationary cycling.1
Muscle stimulation is used for several reasons after SCI:
To promote movement and strength in weak or paralyzed muscles: Muscle stimulation is used early in rehabilitation to promote movement in muscles that are not moving or only producing a flicker of movement. It may promote recovery of movement function by assisting with normal movements and with repetition of movements.
To improve fitness and health: When FES is used as part of a rhythmic exercise like cycling, walking, or rowing, it can help to maintain health of the heart, lungs, and circulation. It may also help to maintain healthy bones.
To assist with functional movement activities like stepping, getting up to standing, and grasping: FES can be used to assist with purposeful movements by improving muscle contractions (for weakened muscles), mobility or range of movement as well as possibly decreasing spasticity.
To maintain muscle mass below the SCI: Regular use of FES may help to prevent muscle loss that happens when the muscles that are paralyzed are not used. Unless neurological return occurs this improvement will stop if the FES is discontinued.
To control the muscles of breathing and bladder function: This includes the use of surgically implanted diaphragmatic pacers (FES systems that create muscle contractions in the diaphragm to stimulate regular breaths) and bladder control systems (FES systems that stimulate the muscles of urination). However, this page will focus on FES used for movement and strength after SCI.
Other names for FES of muscles
You may hear other names for FES such as “neuromuscular electrical stimulation” (NMES) or simply “electrical stimulation” (ES). These terms are often used to refer to electrical stimulation of the muscles during more passive activities (like lying down or sitting), while ”FES” usually describes stimulation during purposeful activities like cycling or walking. However, in practice these terms are often used interchangeably to describe similar or related treatments and the goals of all are to promote strength, movement and function and decrease pain and spasticity.
There are a number of other neuromodulation techniques that are used for various purposes in SCI, including transcutaneous electrical nerve stimulation, sacral nerve stimulation, and intrathecal Baclofen, described in other SCIRE Community articles.