Methods for Foot Impressions

Foot impressions are taken by podiatrists and certified pedorthists to obtain the axis of the foot's subtalar joint in a neutral, prone and supine position. The subtalar joint is primarily responsible for the foot's motions during the walking process. Foot specialists can look at foot impressions and determine if foot deformities and/or abnormalities are placing undue pressure on the subtalar joint. Foot impressions are used as clinical evidence for custom-made shoe inserts, diabetic inlays and custom-molded shoes.

Wax

• The malleability of warm wax makes it a suitable material for making foot impressions. Wax molds take literal, accurate measurements of feet widths in both standing and seated positions, the distance from the heel to the ball of the foot and instep heights. In addition, wax impressions show pedorthists exactly where foot abnormalities are that prevent comfortable walking. Abnormalities may include bone deformities like bunions, skin ulcers, misshapen and/or missing toes and specific walking disorders.

Plaster Slippers

• According to certified pedorthist, Seamus Kennedy, plaster slipper casts are one of the foot orthotics industry's earliest ways of getting foot impressions. He also reports that although they are the most time-consuming methods, plaster slippers work best to capture the subtalar joint in a neutral position. Patients lie either on their backs or on their stomachs with the foot specialist controlling the subtalar joint position with his thumb placed on the fourth and fifth metatarsal heads. The plaster is allowed to harden while the subtalar joint is neutralized.

Foam Impressions

• Foam impressions do not require a heating or drying time, making them the fastest and most convenient of all foot impression techniques. The lack of commitment required to take foam impressions make them useful for people who cannot control their foot movements and active children. With the foam container placed on sturdy ground to prevent slipping, foam impressions require that patients be seated for partial weight-bearing. Kennedy recommends that foam impressions are best for creating pain-relieving orthotics. They accurately measure specific deformities such as callouses, bony protrusions or areas of tissue growth.

Advantages

• Orthotics created from foot impressions improve the function of the feet with support, cushion and ailment correction. Practitioners and patients alike expect patients to experience comfort and relief after proper impressions are taken. In addition, patients often find they do not have to buy larger shoes for custom-made inserts but sometimes regular shoe insoles have to be removed. Similar to shoes, the longevity of orthotics depends on the intensity with which they are used. Finally, some health insurance plans cover the impressions and the orthotics when they are prescribed.