Metabolic and Mechanical Energy Costs of Reducing Vertical Center of Mass Movement During Gait
Metabolic and Mechanical Energy Costs of Reducing Vertical Center of Mass Movement During Gait
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DOI：
10.1016/j.apmr.2008.07.014
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发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Kuo, Arthur D.
中科院分区：
文献类型：
--
作者：
Gordon, Keith E.;Ferris, Daniel P.;Kuo, Arthur D.
目的：验证减少垂直重心(COM)移位将降低人类步行代谢成本的假设。研究步态中关节活动与垂直运动增减相关的变化。设计：随机重复测量。地点：密歇根大学人类神经力学实验室。参与者：健康受试者(N=10)。干预：受试者在跑步机上以1.2m/S的速度超圈行走。受试者通过调整步长或使用视觉反馈来减少关节运动来操纵垂直COM位移。主要观察指标：我们测量运动学和运动学数据以计算垂直和横向COM位移、关节扭矩和功。此外，我们还收集了耗氧量来计算代谢力。结果：增加和减少超出受试者偏好范围的垂直COM位移会导致步行代谢成本的增加。当COM垂直位移减少时，相应地增加了踝关节和髋关节的正功和负的膝关节功。结论：人类能够以一种能够减少正常COM位移的方式行走。减少垂直COM运动会导致代谢能量成本的增加，因为髋关节、膝盖和脚踝关节需要做更多的机械工作。因此。对于身体健全的受试者来说，在正常步行过程中，减少垂直COM运动并不是改善代谢或机械能量经济性的成功策略。
Objectives: To test the hypothesis that reducing vertical center of mass (COM) displacement will lower the metabolic cost of human walking. To examine changes in joint work associated with increasing and decreasing vertical COM movement during gait.Design: Randomized repeated measures.Setting: Human Neuromechanics Laboratory, University of Michigan.Participants: Able-bodied subjects (N=10).Interventions: Subjects walked at 1.2m/s on a treadmill and over-round. Subjects manipulated vertical COM displacement either by adjusting stride length or by using visual feedback to reduce COM movement.Main Outcome Measures: We measured kinematic and kinetic data to calculate vertical and lateral COM displacements, joint torques, and work. In addition, we collected oxygen consumption to calculated metabolic power. CResults: Increasing and decreasing vertical COM displacement beyond subjects' preferred range resulted in increases in the metabolic cost of walking. When vertical COM displacement was reduced, corresponding increases in positive ankle and hip work and negative knee work were observed.Conclusions: Humans are capable of walking in a manner that will reduce COM displacement from normal. Decreasing vertical COM movement results in increases in metabolic energy costs because of greater mechanical work performed at the hip, knee, and ankle joints. Thus. reducing vertical COM movement is not a successful strategy for improving either metabolic or mechanical energy economy during normal walking by able-bodied subjects.