Effectiveness of diabetic insoles to reduce foot pressures.

The F-Scan system was used to measure peak plantar pressures in 11 diabetics each with a unilateral great toe amputation and an intact contralateral extremity (nonamputated), to evaluate the effectiveness of five footwear-insole strategies: 1) extra-depth shoes without an insole, 2) extra-depth shoes with a Plastizote insole, 3) extra-depth shoes with a Plastizote insole and a metatarsal pad, 4) extra-depth shoes with a Plastizote insole and a medial longitudinal arch pad, and 5) extra-depth shoes with a Plastizote insole and a combination of metatarsal pad and arch pad. When we compared extra-depth shoes with and without insoles, peak pressures were significantly reduced with insoles under the first metatarsal, the lesser metatarsals, and the heel (p < 0.001) in feet with and without an amputation, as well as under the great toe on the contralateral foot (nonamputated, p < 0.001), but not under the lesser toes (giant toe, p = 0.088; nonamputated, p = 0.763). There was no significant difference between the different insole modifications.