Three-dimensional motion analysis of the hindfoot resulting from simulated contraction of individual lower leg muscles utilizing Thiel-embalmed cadavers.

BACKGROUND

Joint movement within the foot is complex involving multiple muscles. We evaluated three-dimensional movement of the hindfoot through simulated traction of extrinsic tendons of the foot.

METHODS

Six Thiel-embalmed cadavers were utilized and thread was sutured to each tendon of the lower leg muscles. Traction of the thread was prescribed and the change of calcaneal position used to quantify foot motion was measured for each increment using a magnetic tracking system.

RESULTS

As the tendon traction length advanced, the angle of the calcaneus with respect to the tibia increased linearly. Eversion and abduction angles due to extensor digitorum longus (EDL) traction were significantly greater than that due to the peroneus longus. Plantarflexion due to Achilles tendon traction was significantly greater than that of other plantarflexors.

CONCLUSIONS

Our results demonstrated three-dimensional characteristics of hindfoot motion by simulated muscle contraction and importance of EDL as an evertor. These information should be applicable for tendon transfer procedures around the ankle and physical therapy for ankle dysfunction such as chronic ankle instability.