Sometimes the foot needs protection with a special shoe or an insert inside the shoe called a foot orthosis. The orthosis absorbs shock and cushions, supports, and controls the foot.
In this article, two shoe and orthotic specialists called pedorthists review shoes and orthoses used for a variety of foot problems. Anyone from a sports athlete to an older adult with diabetes can benefit from foot orthoses.
The insert can be modified for each person. Areas of high pressure can be off-loaded. Tender sites can be cushioned to avoid skin break down. Some deformities can be corrected to improve motion and function. Rigid deformities can be stabilized and supported. The end result is to relieve pain and prevent the condition from getting worse.
Shoes that have many modifications already built-in may be enough support for some problems without using an orthosis. Flares, a strip of firm material, along the inside or outside of the main body of the shoe can help stabilize the foot. There are also different kinds of soles. For example, a steel or graphite shank may be used between the layers of the sole to provide a firm support.
The authors provide drawings and descriptions of half-a-dozen other soles available. These include a mild rocker sole as well as a heel-to-toe, toe only, severe angle, negative heel rocker and double rocker sole. Modifications to shoe soles are made to reduce bending stresses through the midfoot and forefoot.
The second half of the article is a review of foot orthoses. These shoe inserts can be purchased off-the-shelf and used as is. Or they can be custom-made by a pedorthist. Custom-made means a mold or model of the patient’s foot is used to construct the device. A three-dimensional (3-D) scan of the foot can be used to make a computer-generated model.
Orthotics come in a wide range of materials and densities. Most people can use a prefab orthotic. Patients with severe deformities, loss of sensation, and/or pressure ulcers often need a custom foot orthosis.
Selection is based on the desired function of the insert. For example, soft, less dense materials can be used with preventive padding for the active patient who is not too large or overweight. This type of insert is called an accomodative foot orthoses.
A semi-rigid orthosis has a soft, top layer of cushion over a firm, supportive base. This design distributes support across the foot without compressing the tissues. Patients with pressure over areas of bone can use this type of orthosis to off-load the weight-bearing surfaces. The semi-rigid orthosis is also good for reducing shear needed to get rid of blisters and prevent calluses from forming.
More involved custom foot orthotics are needed for patients with foot amputations. The rigid foot orthosis provides good arch support but does not mold or conform to bony prominences on the bottom of the foot. They are made of rigid plastics and are not easy to adjust. Rigid orthoses give excellent support but they do not cushion, protect, or absorb shock. However, they hold up well and last a long time.
Each type of shoe and/or foot orthotic has a special purpose. The pedorthist properly modifies and fits the shoe to each patient. As a member of the foot care team, the pedorthist finds the best solution for each individual patient. Goals are identified and the shoe or foot orthoses is designed, manufactured, fit, and modified as needed. Patients are followed closely to ensure success and avoid further foot problems from developing.