Three-Dimensional Innate Mobility of the Human Foot on Coronally-Wedged Surfaces Using a Biplane X-Ray Fluoroscopy

Takuo Negishi; Shuhei Nozaki; Kohta Ito; Hiroyuki Seki; Koh Hosoda; Takeo Nagura; Nobuaki Imanishi; Masahiro Jinzaki; Naomichi Ogihara

doi:10.3389/fbioe.2022.800572

Three-Dimensional Innate Mobility of the Human Foot on Coronally-Wedged Surfaces Using a Biplane X-Ray Fluoroscopy

Front Bioeng Biotechnol. 2022 Feb 4:10:800572. doi: 10.3389/fbioe.2022.800572. eCollection 2022.

Authors

Takuo Negishi¹, Shuhei Nozaki¹, Kohta Ito², Hiroyuki Seki³, Koh Hosoda⁴, Takeo Nagura⁵, Nobuaki Imanishi⁶, Masahiro Jinzaki⁷, Naomichi Ogihara¹

Affiliations

¹ Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
² Graduate School of Human Sciences, Osaka University, Suita, Japan.
³ Department of Orthopedic Surgery, Ogikubo Hospital, Tokyo, Japan.
⁴ Graduate School of Engineering Science, Osaka University, Suita, Japan.
⁵ Department of Clinical Biomechanics, Keio University School of Medicine, Tokyo, Japan.
⁶ Department of Anatomy, Keio University School of Medicine, Tokyo, Japan.
⁷ Department of Radiology, Keio University School of Medicine, Tokyo, Japan.

Abstract

Improving our understanding on how the foot and ankle joints kinematically adapt to coronally wedged surfaces is important for clarifying the pathogenetic mechanism and possible interventions for the treatment and prevention of foot and lower leg injuries. It is also crucial to interpret the basic biomechanics and functions of the human foot that evolved as an adaptation to obligatory bipedal locomotion. Therefore, we investigated the three-dimensional (3D) bone kinematics of human cadaver feet on level (0°, LS), medially wedged (-10°, MWS), and laterally wedged (+10°, LWS) surfaces under axial loading using a biplanar X-ray fluoroscopy system. Five healthy cadaver feet were axially loaded up to 60 kg (588N) and biplanar fluoroscopic images of the foot and ankle were acquired during axial loading. For the 3D visualization and quantification of detailed foot bony movements, a model-based registration method was employed. The results indicated that the human foot was more largely deformed from the natural posture when the foot was placed on the MWS than on the LWS. During the process of human evolution, the human foot may have retained the ability to more flexibly invert as in African apes to better conform to MWS, possibly because this ability was more adaptive even for terrestrial locomotion on uneven terrains. Moreover, the talus and tibia were externally rotated when the foot was placed on the MWS due to the inversion of the calcaneus, and they were internally rotated when the foot was placed on the LWS due to the eversion of the calcaneus, owing to the structurally embedded mobility of the human talocalcaneal joint. Deformation of the foot during axial loading was relatively smaller on the MWS due to restricted eversion of the calcaneus. The present study provided new insights about kinematic adaptation of the human foot to coronally wedged surfaces that is inherently embedded and prescribed in its anatomical structure. Such detailed descriptions may increase our understanding of the pathogenetic mechanism and possible interventions for the treatment and prevention of foot and lower leg injuries, as well as the evolution of the human foot.

Keywords: ankle ligamentous sprain; bipedal locomotion; foot kinematics; human evolution; insole; knee osteoarthritis; subtalar joint; tibio-calcaneal coupling.