Rehabilitation Corner WHAT IS AN AFO? ORTHOTICS DEMYSTIFIED The field of medicine is filled with jargon, abbreviations, and acronyms. The field of orthotics (or limb braces) is no different. Unfortunately the terms are often used without explanation and are familiar only to those who regularly use them. What follows is an attempt to demystify orthotics and the practitioners who recommend and make them. About 10 years ago, the word "orthosis" began to be used in place of the traditional word "brace." Orthosis comes from the Greek "ortho," meaning "straight." (One function of an orthosis or brace may be to keep a limb straight.) An orthosis is the same thing as an orthotic device. There are four main types of orthotic devices (or orthoses). Two of these four types may be used by people who have weakness due to ALS: 1) orthoses that stabilize and support a joint, and thereby prevent movement; and 2) orthoses that assist movement or help to compensate for loss of movement. Orthoses are named for the joints they encompass. A short leg brace (below the knee) is known as an AFO (ankle-foot orthosis) because it deals with weakness in the foot and ankle. A KAFO controls the knee, ankle, and foot, and extends above the knee. Orthoses are made of metal, plastic, or a combination of these two materials. Metal orthoses do not touch the skin and attach to the outside of a shoe. However, metal orthoses are heavier than plastic ones and are therefore not often used for people with ALS who have limb weakness. Plastic orthoses come into direct contact with the skin and fit inside a shoe. Care must be taken if there is swelling in the foot or ankle: the close contact with skin can cause pressure and discomfort. People with diabetes and those who have problems with circulation or sensation must also use plastic orthoses with cautionin order to avoid skin irritation and pressure. The type of orthosis most commonly used by people with ALS is an AFO. One type of AFO is a posterior leaf orthosis (PLO), also called a posterior leaf spring (PLS) by some orthotics professionals. The PLO or PLS is the lightest in weight of the AFOs and is used mainly when a person has "foot-drop." A foot-drop occurs when there is weakness in the muscles in the front of the lower leg that lift up the toes and foot when one takes a step. A PLO or PLS holds the foot at a right angle to the leg and prevents the foot from dragging. If a person also has weakness in the other muscles around the ankle (e.g., the muscles that turn the foot in or out, or allow one to push down with the foot), he or she may need an AFO that is more solid than a PLO/PLS. In this case, more plastic is used to hold the ankle in place and therefore prevent the ankle from being twisted or sprained. Orthoses are prescribed by a physician and fabricated by an orthotist. Orthotists are the professionals who know the latest styles and materials that are used to make orthoseis. He or she is responsible for measuring the client for the orthosis and ensuring its proper fit once it is made. The physical therapist is the clinician responsible for teaching the person with ALS how to walk using the orthosis. Both the therapist and orthotist should instruct the user in the following areas: Checking the skin for pressure areas How to apply and remove the orthosis easily The best type of shoe to use with an orthosis (sorry, no high heels) A wearing schedule; i.e., how often to wear the orthosis on the first day, the second day, etc. If a person has weakness in the foot and ankle and is having difficulty walking, a physician may prescribe an orthosis. Alternatively, the MD may prescribe a physical therapist to evaluate the person for an orthosis. The physical therapist can provide input and make recommendations to the MD and orthotist based on orthoses that have been found to be most beneficial. The ideal situation is when the orthotist and therapist work together with a person with ALS to determine which type of orthosis will best suit his or her individual needs. Usually, outpatient departments of hospitals, rehabilitation centers, and some skilled nursing facilities will have both therapists and orthotists on staff. For further information, kindly contact Sheila Hayes, MS, PT, at the Eleanor and Lou Gehrig MDA/ALS Center at (212) 305-1319.