Stroke survivors adopt cautious or compensatory strategies for safe and successful obstacle crossing. Although knee extensor spasticity is a common independent secondary sensorimotor disorder post-stroke, few studies have examined the step adjustment and compensatory strategies used by stroke survivors with knee extensor spasticity during obstacle crossing. This study aimed to compare the differences in the kinematics and kinetics during obstacle crossing between stroke survivors with and without knee extensor spasticity, and to identify knee extensor spasticity-related differences in step adjustment and compensatory strategies. Twenty stroke subjects were divided into a spasticity group [n = 11, modified Ashworth scale (MAS) ≥ 1] and a non-spasticity group (n = 9, MAS = 0), based on the MAS score of the knee extensor. Subjects were instructed to walk at a self-selected speed on a 10-m walkway and step over a 15 cm obstacle. A ten-camera 3D motion analysis system and two force plates were used to collect the kinematic and kinetic data. During the pre-obstacle phase, stroke survivors with knee extensor spasticity adopted a short-step strategy to approach the obstacle, while the subjects without spasticity used long-step strategy. During the affected limb swing phase, the spasticity group exhibited increased values that were significantly higher than those seen in the non-spasticity group for the following measurements: pelvic lateral tilt angle, trunk lateral tilt angle, medio-lateral distance between the ankle and ipsilateral hip joint, hip work contributions, the inclination angles between center of mass and center of pressure in anterior–posterior and medio-lateral directions. These results indicate that the combined movement of the pelvic, trunk lateral tilt, and hip abduction is an important compensatory strategy for successful obstacle crossing, but it sacrifices some balance in the sideways direction. During the post-obstacle phase, short-step and increase step width strategy were adopted to reestablish the walking pattern and balance control. These results reveal the step adjustment and compensatory strategies for obstacle crossing and also provide insight into the design of rehabilitation interventions for fall prevention in stroke survivors with knee extensor spasticity.

中文翻译：

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膝伸肌痉挛的中风幸存者通过障碍物采用的短步调整和近端代偿策略

中风幸存者采取谨慎或补偿性策略以安全和成功地越过障碍物。尽管膝伸肌痉挛是中风后常见的独立继发性感觉运动障碍，但很少有研究检查过膝伸肌痉挛的中风幸存者在穿越障碍时使用的步数调整和代偿策略。本研究旨在比较有和没有膝伸肌痉挛的中风幸存者在越障过程中运动学和动力学的差异，并确定与膝伸肌痉挛相关的步长调整和补偿策略的差异。根据伸膝关节的 MAS 评分，将 20 名中风受试者分为痉挛组 [n = 11，改良 Ashworth 量表 (MAS) ≥ 1] 和非痉挛组 (n = 9，MAS = 0)。受试者被指示在 10 米长的人行道上以自行选择的速度行走，并跨过 15 厘米的障碍物。使用十个摄像头的 3D 运动分析系统和两个测力台来收集运动学和动力学数据。在障碍前阶段，膝伸肌痉挛的中风幸存者采用短步策略接近障碍，而没有痉挛的受试者采用长步策略。在受影响的肢体摆动阶段，痉挛组的以下测量值显着高于非痉挛组：骨盆侧倾角、躯干侧倾角、脚踝和同侧之间的中外侧距离髋关节，髋关节工作贡献，质心和压力中心在前后和中间横向上的倾角。这些结果表明，骨盆、躯干侧倾和髋外展的联合运动是成功越过障碍物的重要补偿策略，但它在侧身方向上牺牲了一些平衡。在后障碍阶段，采用短步和增加步宽策略来重建步行模式和平衡控制。这些结果揭示了跨越障碍的步长调整和补偿策略，并为膝伸肌痉挛的中风幸存者预防跌倒的康复干预设计提供了见解。髋关节外展是成功越过障碍的重要补偿策略，但它在侧身方向上牺牲了一些平衡。在后障碍阶段，采用短步和增加步宽策略来重建步行模式和平衡控制。这些结果揭示了跨越障碍的步长调整和补偿策略，并为膝伸肌痉挛的中风幸存者预防跌倒的康复干预设计提供了见解。髋关节外展是成功越过障碍的重要补偿策略，但它在侧身方向上牺牲了一些平衡。在后障碍阶段，采用短步和增加步宽策略来重建步行模式和平衡控制。这些结果揭示了跨越障碍的步长调整和补偿策略，并为膝伸肌痉挛的中风幸存者预防跌倒的康复干预设计提供了见解。