For decades, practitioners have used electrotherapy devices for rehabilitation purposes in human medicine. Now veterinarians are using them with increasing frequency as well. Not to be confused with electroshock therapy, electrotherapy devices are a group of instruments, including functional electrical stimulators, that are used to stimulate sensory nerves and muscles following injury or dysfunction.

Following a horse’s injury, surgery, or some other type of dysfunction, the electrical pathway can become disrupted, causing abnormal muscle contractions (spasm) and relaxations (atrophy) that can manifest as tight or locked muscles, pain, muscle wasting, and poor performance. When used appropriately, FES can cause muscle contractions that result in coordinated limb movements of tendons, ligaments, and even joints.