In Vitro Simulation of Stance Phase Gait Part II: Simulated Anterior Tibial Tendon Dysfunction and Potential Compensation

The diagnosis of anterior tibial tendon tear is often missed. The ability of the remaining ankle extensor muscles to compensate for lost anterior tibial force was thus investigated. The effect of tibialis anterior deficiency on tarsal bone motion and plantar pressure was measured during in vitro simulated stance phase gait on eight cadaver specimens. Increased internal rotation, plantarflexion, and inversion of the talus and calcaneus (p ≤ .001), as well as significant reductions of plantar pressure on the heel (p ≤ .04) were observed during the first half of the stance phase. The observed drop foot was partly compensated by increased extensor muscle force.