A FOOT-LOADING SIMULATOR FOR BIOMECHANICAL IN-VITRO INVESTIGATIONS INLOWER LEG SPECIMENS

In this paper we describe a foot-loading simulator that permits in vit ro studies on human lower leg and foot specimens. The specimens are fi xed in a jig and loaded axially with the aid of a pneumatic cylinder. The resulting transfer of forces through the ankle joint complex and C hopart's articulation (line) can be demonstrated on a pressure-sensiti ve film. Plantar pressure measurements obtained in patients or normal subjects can be used to ensure the comparability of in vivo and in vit ro measurements. The supporting platform can be tilted in such a manne r as to provide a range of foot positions up to 20 degrees in plantar- or dorsiflexion, eversion dr inversion. The system is used for invest igating the effects on the intra-articular pressures and plantar press ure patterns of physiological muscle activity and pathological conditi ons following fracture of the calcaneum or damage to the lateral ligam ent. By way of an example, the effects of muscle forces on plantar pre ssure distribution are presented.