Mait Alexander R, Mane Adwait, Forman Jason L, Donlon John Paul, Nie Bingbing, Kent Richard W
Department of Mechanical and Aerospace Engineering University of Virginia, Center for Applied Biomechanics, 4040 Lewis and Clark Drive, Charlottesville, VA 22911, USA.
Department of Mechanical and Aerospace Engineering University of Virginia, Center for Applied Biomechanics, 4040 Lewis and Clark Drive, Charlottesville, VA 22911, USA.
J Biomech. 2017 Feb 28;53:196-200. doi: 10.1016/j.jbiomech.2017.01.006. Epub 2017 Jan 7.
The purpose of this study was to determine the long-time and transient characteristics of the moment generated by external (ER) and internal (IR) rotation of the calcaneus with respect to the tibia. Two human cadaver legs were disarticulated at the knee joint while maintaining the connective tissue between the tibia and fibula. An axial rotation of 21° was applied to the proximal tibia to generate either ER or IR while the fibula was unconstrained and the calcaneus was permitted to translate in the transverse plane. These boundary conditions were intended to allow natural motion of the fibula and for the effective applied axis of rotation to move relative to the ankle and subtalar joints based on natural articular motions among the tibia, fibula, talus, and calcaneus. A load cell at the proximal tibia measured all components of force and moment. A quasi-linear model of the moment along the tibia axis was developed to determine the transient and long-time loads generated by this ER/IR. Initially neutral, everted, inverted, dorsiflexed, and plantarflexed foot orientations were tested. For the neutral position, the transient elastic moment was 16.5N-m for one specimen and 30.3N-m for the other in ER with 26.3 and 32.1N-m in IR. The long-time moments were 5.5 and 13.2N-m (ER) and 9.0 and 9.5N-m (IR). These loads were found to be transient over time similar to previous studies on other biological structures where the moment relaxed as time progressed after the initial ramp in rotation.
本研究的目的是确定跟骨相对于胫骨进行外旋（ER）和内旋（IR）时所产生力矩的长期和瞬态特征。将两条人类尸体下肢在膝关节处离断，同时保留胫骨和腓骨之间的结缔组织。在腓骨不受约束且跟骨可在横向平面平移的情况下，对胫骨近端施加21°的轴向旋转以产生外旋或内旋。这些边界条件旨在允许腓骨自然运动，并使有效施加的旋转轴基于胫骨、腓骨、距骨和跟骨之间的自然关节运动相对于踝关节和距下关节移动。胫骨近端的一个测力传感器测量力和力矩的所有分量。建立了沿胫骨轴的力矩准线性模型，以确定这种外旋/内旋产生的瞬态和长期载荷。最初测试了中立、外翻、内翻、背屈和跖屈的足部姿势。对于中立位置，在一个标本中外旋时瞬态弹性力矩为16.5N·m，另一个标本为30.3N·m，内旋时分别为26.3和32.1N·m。长期力矩分别为5.5和13.2N·m（外旋）以及9.0和9.5N·m（内旋）。发现这些载荷随时间是瞬态的，类似于之前对其他生物结构的研究，在初始旋转斜坡后，力矩会随着时间的推移而松弛。
