The contribution of passive-elastic mechanisms to lower extremity joint kinetics during human walking
The contribution of passive-elastic mechanisms to lower extremity joint kinetics during human walking
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DOI：
10.1016/j.gaitpost.2007.08.005
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发表时间：
2008-05-01
期刊：
影响因子：
2.4
通讯作者：
Thelen, Darryl G.
中科院分区：
文献类型：
--
作者：
Whittington, Ben;Silder, Amy;Thelen, Darryl G.
本研究的目的是调查在慢速、舒适和快速的正常行走中被动机制对下肢关节动力学的贡献。二十名健康的年轻人参加了一项被动测试方案，其中通过全矢状髋部、膝盖和踝关节的运动范围来操纵放松的下肢，同时测量运动学和施加的力。被动关节力矩和角度之间的关系通过一组指数函数建模，该函数解释了单关节结构和双关节肌肉的拉伸。将受试者特定的步行运动学（首选速度的 80%、100% 和 120%）输入到被动模型中，以估计被动机制带来的关节力矩、功率和做功。从站立后期到挥杆早期，被动髋关节屈曲力矩很大，吸收了髋关节伸展过程中大约 40% 的净负功，并产生了髋屈肌力量爆发期间所做的净正功的一半以上 (H3)。被动踝跖屈肌力矩也在预挥杆过程中产生，但产生的净踝跖屈肌爆发力 (A2) 的百分比较小（接近 10%）。 The joint work attributed to passive structures increased significantly (p < 0.05) with walking speed.双关节股直肌和腓肠肌允许膝盖处的净被动能量吸收以及随后在臀部和脚踝处的返回（p < 0.05）。总之，这些结果表明，被动弹性机制对人类正常行走有很大贡献，并且双关节肌肉在关节之间被动传递能量方面发挥着作用。 (c) 2007 Elsevier B.V. 保留所有权利。
The purpose of this study was to investigate the contribution of passive mechanisms to lower extremity joint kinetics in normal walking at slow, comfortable, and fast speeds. Twenty healthy young adults participated in a passive testing protocol in which the relaxed lower limb was manipulated through full sagittal hip, knee, and ankle ranges of motion while kinematics and applied forces were simultaneously measured. The relationship between passive joint moments and angles was modeled by a set of exponential functions that accounted for the stretch of uniarticular structures and biarticular muscles. Subject specific walking kinematics (80%, 100%, and 120% of preferred speed) were input into the passive models to estimate joint moments, power, and work attributable to passive mechanisms. Passive hip flexion moments were substantial from late stance through early swing, absorbing approximately 40% of the net negative work done during hip extension and producing over half of the net positive work done during the hip flexor power burst (H3). Passive ankle plantarflexor moments were also produced during pre-swing, but generated a smaller percentage (similar to 10%) of the net ankle plantarflexor power burst (A2). The joint work attributed to passive structures increased significantly (p < 0.05) with walking speed. The biarticular rectus femoris and gastrocnemius allowed for net passive energy absorption at the knee and subsequent return at the hip and ankle (p < 0.05). Together, these results suggest that passive-elastic mechanisms can contribute substantially to normal human walking and that biarticular muscles play a role in passively transferring energy between joints. (c) 2007 Elsevier B.V. All rights reserved.