The effects of isolation on the mechanics of the human heel pad

In previous studies on the mechanical properties of the human heel pad (Bennett & Ker, 1990; Aerts et al. 1995) the fat pad and part of the calcaneus was removed from amputated test specimens. The present study tested whether this procedure influences the mechanical behaviour of the sample. Intact amputated feet were therefore mounted on steel rods driven through the calcaneus and placed in a mechanical test situation (pendulum or servohydraulic material tester). The mechanical properties of the pad were determined for a series of experiments in which the pad was gradually freed from the foot in the way done by Bennett & Ker (1990) and Aerts et al. (1995). The results showed no observable differences in the mechanics of the pad by isolating it from the rest of the foot. Thus, in relation to human locomotion, the load-deformation relation of heel pads as described by Aerts et al. (1995) is the most appropriate to date.