Mechanical loading and off-loading of the plantar surface of the diabetic foot.

During weight-bearing activities, the feet are exposed to large forces, particularly when the activity is dynamic, such as walking. The pressure under the plantar surface during walking varies per foot area because of a number of factors related to the normal rollover during the stance phase of gait. Diabetes mellitus often results in loss of protective sensation and in structural changes that make the feet more susceptible to injury. Increased plantar pressure is an important factor in the development and maintenance of diabetic foot ulceration. Increased plantar pressures and associated ulcers need to be treated by off-loading of the plantar surface. Useful off-loading mechanisms include reduction of walking speed, alteration of foot rollover during gait, and transfer of load from affected areas to other areas of the foot or the lower leg. These plantar off-loading mechanisms could result in an optimization of treatment, but clinical effectiveness must be demonstrated.