Functional Electrical Stimulation - FES

Functional Electrical Stimulation (FES)

FES is a physiotherapy procedure whereby a computer generated electrical signal is initiated which is similar to one that may be released from the brain to a muscle that causes it to contract. The functional aspect of the electrical stimulation relates to its ability to initiate the contraction then as the signal cycles off the muscle relaxes and this can continue with controlled repeated contraction-relaxation for a set period of time. These are benefits to muscles that may be in a state of contraction or splinted as well as ones that have become dysfunctional, weak and may have atrophied.

This therapy was developed on the human medicine side and was utilized for patients with spinal cord injury and stroke victims. Stimulation of the motor nerves or neurons were critical to get affected muscles to contract. A heart pacemaker would be an example of FES with a specific function of regulating contraction of heart muscles. In human medicine early work began in 1967, on the equine side, the development of this technology and application to conditions affecting horses was developed by Dr. Sheila Schils. Dr. Schils has training in Biomechanics and Kinesiology and has been able to extrapolate and apply principles from that to horse physiotherapy. In addition to those therapies the FES became a way to work with muscles and other tissues that were not functioning properly.

FES is a newer procedure offered by Burlington Equine Veterinary Services which we started in 2018. The modality utilizes a small control unit that generates a low voltage electronic signal to treat typically muscles or other soft tissue structures that may be in a state of dysfunction.

The unit itself that generates the signal is below:

The electrical box that generates a low voltage signal is attached to a surcingle that the horse has on during the treatment then the electrodes that are on the surface of the skin may be taped in place or simply laid across a horse’s pelvis or back with a pad. The signal can be modified during the treatment to enact the muscle response that we are interested in treating. Because the voltage is low, actually lower than typical Electrical Stimulation (E Stim) devices or TENS units, which are reported to initiate muscle contractions. FES can produce a more normal electrical conduction signal without the stinging or irritation caused by those modalities. There is no pain involved and horses are not stressed by the procedure. It’s been described as a warm feeling through the muscle or a massage. Having tried it on myself using typical horse settings and higher I can attest to the fact that there is no pain or unpleasantness experienced.

The pad itself is embedded with the electrodes that conduct the signal onto the horse's hips or sacro-iliac area as seen in the following picture. This was taken of a horse I was treating with tightness through the saco-iliac area that was impacting how the horse was using not just that area but his lower-mid back as well. Following the SI treatment the pad was placed anterior to this and I treated that area.

Movement of soft tissues (muscles, tendons, ligaments, joint capsules) as well as bones (when not associated with a fracture) is integral to an early and integrated rehabilitation. Failure to move or keep areas from mobilizing will potentially lead to scar formation, shortened muscles and/or loss of muscle conditioning. Naturally rehabbing a relatively recent and minor trauma may proceed rather quickly, but in conditions such as ongoing back problems - lack of topline and accompanying back pain that may be associated with Kissing Spine Disease for example, that becomes more of a long term condition and FES can positively affect those tight, spasming muscles. In addition. bowed tendons (tendonitis) can be helped by working on the muscles that may be in contraction thus “pulling” on that affected tendon. The following is a list of conditions that could be considered appropriate for FES:

  • Muscle spasms - could be back or muscles located elsewhere, such as thigh area, neck, shoulder or lower limbs.
  • Myofascial syndrome - pain associated with the connective tissue or fascia that overlies affected muscles
  • Treatment of tendons or ligaments - similar to work with muscles allowing for contraction and relaxation movement.
  • Reduction of swelling and edema.
  • Improved blood flow through an affected area.

There are numerous benefits with the use of FES and fortunately since starting to use this therapy 12 months ago we have seen the improvement:

  • Pain relief - especially associated with muscles in spasm
  • Improved Range of Motion (ROM) - muscles that are tight or spasming are shortened and this therapy will allow for relaxation thus allowing more normal ROM in restricted areas.
  • Re-education of muscle function - essentially returning that muscle to more normal function and “training” it so that it maintains that functional state
  • Strengthening of muscles and tendons - useful in conditions with atrophying or weakening of muscles along with decreased use of the tendons.
  • As an adjust therapy for conditions elsewhere in body that may have altered muscle strength thus helping with overall rehabilitation.

Treatments may vary between 30 minutes up to 90 minutes if treating multiple areas. Horses can be on cross ties or even in their stalls eating hay. On the day of treatment there will be no exercise other than turnout then, depending on the problem being treated, there may be riding or ground work done the following day.

In the picture below, you can see the electrodes that were taped on this side of the neck and the same was on the opposite. In this horse I was him for tight neck muscles and a decreased range of motion with lateral flexion.

In addition to its therapeutic applications for the issues described above, it also has benefits pre-competition. That is, if a horse has a history of tight muscles, chronic back or sacro-iliac soreness this would be an effective non-medication way to mobilize and relax these areas prior to a competition. Ideally it may be done 24-48 hours before departing for a show.

We treated numerous horses last year for a variety of issues ranging from upper body - back, hips and neck as well as muscle-tendon issues on the lower legs. It's an exciting technology as it offers so many benefits especially when we are treating or rehabilitating an injury.