by Dr. Hoy
Orthotics are like eyeglasses and meant to be worn indefinitely. Eyeglasses change the shape of light to allow one to see better. Orthotics change the way ground reactive forces hit the feet, to allow one to walk better. They work to support certain muscles and ligaments, so that there is not excess strain on them. They can relieve pain in the feet, ankles, legs, knees, hip and back. They also work to prevent certain disease processes from advancing, such as bunions, osteoarthritis, posterior tibial dysfunction.
If glasses are not worn, one no longer gets the benefit from them. Orthotics are the same way. They help to reduce pain and avoid the progression of deformities. But as soon as they are not used, the pain may come back and the condition for which the orthotics were initially prescribed may advance.
Orthotics do not change the structures of the feet like braces do to correct teeth position. When the custom prescription orthotic is worn, the feet are automatically at their optimal biomechanical position. As soon as they are taken off, they are not. They return to the original position.
Custom functional orthotics usually last about 3-5 years, depending on activity. The shell of the orthotic is like the lens of the eyeglasses. However, the shell is subject to the patient’s weight and activity. They are made of either polypropylene or graphite, and will flatten out over time, and the correction is lost. Our lab stores orthotics cast scans and can produce new pairs of orthotics. Unless there is rearfoot or ankle surgery, first ray fusion surgery, advancing arthritis in the mid- or rearfoot, or other factors that affect the subtalar or midtarsal joints, a new mold usually is not needed.
There are other health professions which advocate that foot problems are due to not walking right and will advocate months or years of expensive therapy or gait training exercises instead of simple orthotics. Exercises for the feet to replicate optimal foot position without orthotics is like squinting, exercising muscles of the eye to see. It is not sustainable or accurate. It may take many sessions of training to barely come close to the correction a custom prescription functional orthotic can give. Muscles may not be able to bear the extra strain, especially if they are pathologic or dysfunctional to begin with. It is much easier to put on a pair of glasses instead of squint, so it is much easier to wear an orthotic than to try to shift one’s foot to walk more normally. Therapy can be used to adapt to better foot position due to orthotics, but not to replace orthotics with exercises.
