Intrinsic Kinematics of the Tibiotalar and Subtalar Joints during Human Walking based on Dynamic Biplanar Fluoroscopy

Abstract

Accurate knowledge of the kinematics of the in vivo Ankle Joint Complex (AJC) is critical for understanding the biomechanical function of the foot and assessing postoperative rehabilitation of ankle disorders, as well as an essential guide to the design of ankle–foot assistant devices. However, detailed analysis of the continuous 3D motion of the tibiotalar and subtalar joints during normal walking throughout the stance phase is still considered to be lacking. In this study, dynamic radiographs of the hindfoot were acquired from eight subjects during normal walking. Natural motions with six Degrees of Freedom (DOF) and the coupled patterns of the two joints were analyzed. It was found that the movements of the two joints were mostly in opposite directions (including rotation and translation), mainly in the early and late stages. There were significant differences in the Range of Motion (ROM) in Dorsiflexion/Plantarflexion (D/P), Inversion/Eversion (In/Ev), and Anterior–Posterior (AP) and Medial–Lateral (ML) translation of the tibiotalar and subtalar joints (p < 0.05). Plantarflexion of the tibiotalar joint was coupled with eversion and posterior translation of the subtalar joint during the impact phase (R2 = 0.87 and 0.86, respectively), and plantarflexion of the tibiotalar joint was coupled with inversion and anterior translation of the subtalar joint during the push-off phase (R2 = 0.93 and 0.75, respectively). This coordinated coupled motion of the two joints may be a manifestation of the AJC to move flexibly while bearing weight and still have stability.

Increased subtalar rotational motion in patients with symptomatic ankle instability under load and stress conditions

“…As it has been previously reported, the tibiotalar joint is mainly responsible for dorsal and plantar flexion, while the subtalar joint is mainly responsible for inversion and eversion movement [29, 30]. From 10º dorsiflexion to 20º plantar flexion, 100% of ankle mobility occurs at the tibiotalar joint, while pronation and supination depend almost exclusively on the subtalar joint [29, 30]. Tibiotalar mobility was blocked by exerting axial load and maintaining the ankle in fixed 10º dorsiflexion, and so, being able to independently study subtalar joint motion.…”

“…To address specifically the subtalar joint biomechanics, isolating subtalar and tibiotalar mobility is key. As it has been previously reported, the tibiotalar joint is mainly responsible for dorsal and plantar flexion, while the subtalar joint is mainly responsible for inversion and eversion movement [29, 30]. From 10º dorsiflexion to 20º plantar flexion, 100% of ankle mobility occurs at the tibiotalar joint, while pronation and supination depend almost exclusively on the subtalar joint [29, 30].…”

The influence of talus size and shape onin vivotalocrural hopping kinematics

“…However, the complex changes in the size and shape of the talus have not been directly linked to changes in talocrural joint function. Fortunately, recent advancements in biplanar video radiography (BVR) can address this gap [9][10][11].…”