Characteristics of the kinematic coupling behavior of the calcaneus and shank

Abstract

[Purpose] The purpose of this study was to clarify the characteristics of the kinematic coupling behavior of the calcaneus and the shank. [Subject] Sixteen young healthy subjects participated in this study. [Method] Motion of the calcaneus and the shank during active inversion-eversion of the foot in the standing position was recorded using a 3-dimensional motion analysis system. In addition, the relationships between the kinematics and the physical findings of the leg were investigated. [Results] The calcaneus inversion-eversion and the shank external-internal rotation were linked to each other in constant ratios. The ratio showed individual differences of 4 times or more, and a right-left difference in nine of the 16 subjects. The range of motion of the subtalar joint was related to the ratio. [Conclusion] The ratio of kinematic coupling behavior of the calcaneus inversion-eversion and the shank external-internal rotation was constant in the same limb, but showed variance between individuals and right and left limbs of the same subject. © 2012, The Society of Physical Therapy Science. All rights reserved.