Siegel Karen Lohmann, Kepple Thomas M, Stanhope Steven J
Physical Disabilities Branch, National Institutes of Health, Department of Health and Human Services, Building 10, CRC, Room 1-1469, 10 Center Drive, MSC 1604, Bethesda, MD 20892, USA.
Gait Posture. 2006 Jun;23(4):435-40. doi: 10.1016/j.gaitpost.2005.05.007. Epub 2005 Aug 10.
The purpose of this case series was to quantify the effectiveness of different compensatory strategies used by individuals with muscle weakness to produce knee extension during the stance phase gait. Subjects were three males with less than anti-gravity strength in the quadriceps femoris and a variable pattern of weakness elsewhere in the lower extremity. They walked independently at a self-selected speed without assistive devices. Gait analysis of the pelvis and bilateral lower extremity segments was performed with a six-camera, two force platform motion capture system. Joint angles and net internal moments were computed from the motion data. Induced acceleration analysis was performed to quantify the relative ability of each lower extremity joint moment and gravity to produce knee angular acceleration. Results showed that a variety of adaptive strategies both within and across limbs can control knee position during gait. One subject generated knee extension almost exclusively via the hip extensor moment. Another relied less on the hip extensor moment (39%) and more on the ankle plantar flexor moment (61%) to create knee extension. The third subject used the ipsilateral hip extensor moment (24%) and the contralateral ankle plantar flexor moment (67%) to assist knee extension. The strategy selected by each subject likely was influenced by both their total pattern of impairments and the effectiveness of the available compensations. This case series demonstrates how an induced acceleration analysis can augment a traditional gait analysis to expand and enhance our understanding of compensatory movement control strategies.
本病例系列的目的是量化肌肉无力个体在步态站立期产生膝关节伸展时使用的不同代偿策略的有效性。受试者为三名男性，股四头肌抗重力力量不足，下肢其他部位存在不同程度的无力。他们在无辅助装置的情况下以自行选择的速度独立行走。使用六台摄像机、两个测力平台的运动捕捉系统对骨盆和双侧下肢节段进行步态分析。根据运动数据计算关节角度和净内力矩。进行诱导加速度分析以量化每个下肢关节力矩和重力产生膝关节角加速度的相对能力。结果表明，肢体内部和肢体之间的多种适应性策略可在步态期间控制膝关节位置。一名受试者几乎完全通过髋关节伸肌力矩产生膝关节伸展。另一名受试者较少依赖髋关节伸肌力矩（39%），更多地依赖踝关节跖屈肌力矩（61%）来产生膝关节伸展。第三名受试者使用同侧髋关节伸肌力矩（24%）和对侧踝关节跖屈肌力矩（67%）来辅助膝关节伸展。每个受试者选择的策略可能受到其整体损伤模式和可用代偿有效性的影响。本病例系列展示了诱导加速度分析如何增强传统步态分析，以扩展和加深我们对代偿性运动控制策略的理解。
