It’s all about the talus - In vivo tarsal joint complex kinematics during walking, running, and hopping

Abstract

The interaction among joints of the tarsal complex (talus, navicular, calcaneus, and cuboid) plays an essential role in locomotor function; however, its anatomical and functional complexity poses substantial challenges in quantifying its motion. We determine the mobility of these joints across locomotion tasks and investigate whether the individual kinematic tarsal joint axes align with the talus morphology.

We use highly accurate biplanar videoradiography to obtain three-dimensional bone kinematics. We calculate each tarsal bone’s rotation axis and compare these axes to each other and to a coordinate system embedded in the talus capturing the morphological subtalar joint axis. We measure the total rotation about and the orientation of the rotation axes in the subtalar joint direction for the landing and propulsion phases, respectively.

The rotation axes of all three bones relative to the talus closely align with each other and with the morphological subtalar joint axis. This suggests that the tarsal complex’s motion might be described by one common axis in the non-pathological population. The ranges of motion about this axis differed among the bones.

Our results provide a novel perspective of healthy foot function across different locomotion tasks underscoring the importance of understanding tarsal motion with respect to subject-specific morphology.