What is functional electrical stimulation?
Functional electrical stimulation (commonly abbreviated as FES) is a treatment that uses electrical currents to activate nerves, innervating extremities affected by paralysis resulting from incompletespinal cord injury (SCI), head injury, stroke or other neurological disorders.
FES employs small electrical impulses to excite the nerves that supply paralyzed muscles. This activates those muscles, enabling them to produce basic but useful movement. Self-adhesive patches -- or electrodes -- are placed on the skin close to the nerve that supplies the muscle and are connected by leads to a stimulator that produces the impulses.
Artificial stimulation to achieve function is not a new approach. Since the 1960s, the method has been applied in several different ways -- either on the muscle, the nerves or even directly to the brain. While there are many ongoing research projects and commercially-available products, it is important to remember not everybody can be helped by this technique.
Can FES help correct foot drop?
One of the problems most successfully treated by functional electrical stimulation (FES) is foot drop (also known as drop foot.) Foot drop is a condition caused by weakness or paralysis of the muscles involved in lifting the front part of the foot. It makes walking a challenge, causing a person to either drag the foot and toes or engage in a high-stepping walk called steppage gait.Foot drop is not a disease, but a symptom of an underlying problem. It is often caused by an interruption in the signal from the brain to the peroneal nerve (a condition commonly associated with peroneal nerve palsy). The nerve runs along the outside of the lower leg below the knee. People with multiple sclerosis, incomplete spinal cord injuries, traumatic brain injuries, cerebral palsy and stroke may experience drop foot.
Functional electrical stimulation has proven successful in correcting many instances of footdrop. FES can enable people to walk faster, further and with less effort. The improvement in the walking pattern reduces the risk of falls and leads people to become more stable and independent in their walking.
Who may benefit from using FES?
The WalkAide is an external FES system that is intended to address dropfoot in people who have sustained damage to upper motor neurons or pathways to the spinal cord. During the swing phase of walking, the WalkAide electrically stimulates the appropriate muscles that cause ankle dorsiflexion and may thus improve the person’s walking ability. Medical benefits of FES may include prevention of muscle disuse or weakness, increased local blood flow, muscle strengthening, and maintained or increased joint range of motion.
Learn more about how WalkAide can positively benefit people experiencing drop foot.
Are there any people who should not use FES?
While functional electrical stimulation delivers very beneficial results for many, there are groups of people and specific applications not indicated for use of FES devices. These include:
- Persons with implanted demand type cardiac pacemakers or defibrillators
- Do not place the electrodes in the carotid sinus region (throat). Laryngeal or pharyngeal spasms may occur when the electrodes are placed across the throat or in the mouth.
- Do not place the electrodes over malignant tumors.
- Do not place the electrodes over areas in which symptoms of existing thrombosis are present.
- Do not use if person has a history of seizure disorder.
Warnings about FES
- Monitoring equipment — The use of FES may interfere with the proper functioning of electronic monitoring equipment such as EKG machines. However the operation of the FES device will not be affected by the use of electronic monitoring equipment.
- Electrodes — Do not place electrodes over open wounds, broken skin or metal objects beneath the skin such as surgical staples.
- Pregnancy — The safety of FES for use during pregnancy has not been established.
- Hospital equipment — Do not use simultaneously with high frequency hospital equipment (e.g. diathermy equipment). It may result in burns at the site of the stimulator electrodes and possible damage to the stimulator.
- Skin irritation — Improper or prolonged use of electrodes may result in increased risk of skin irritation or burns and decreased effectiveness. Infrequently, there is an allergic response to the electrode adhesive or gel. Do not place electrodes on skin that is already irritated as this will increase the risk of discomfort with stimulation or skin burns.
- Medical supervision — FES should only be used under the medical supervision of a physician and a qualified clinician.
- Two-way radios — Care should be taken while using FES therapy in close proximity (e.g. less than one meter) to devices which emit radio frequencies such as cellular phones or two-way radios as some types of transmitters may cause undesirable stimulation to the user.
- Defibrillator — External defibrillation of a person wearing an FES device can damage the device or injure the person even when the device is turned off. Under some circumstances, there may be risk of burns under the electrode sites during defibrillation. To eliminate any risk, FES electrodes should be removed before defibrillation paddles are applied.
- Chronic stimulation — Effects of long-term chronic stimulation are unknown in this particular application.
Learn more about WalkAide at www.walkaide.com