Dept. of Physical Therapy, Marquette University, PO Box 1881, Milwaukee, WI 53201-1881, USA.
J Neurophysiol. 2010 Mar;103(3):1557-68. doi: 10.1152/jn.00528.2009. Epub 2010 Jan 20.
The purpose of this study was to quantify how volitional control of hip torque relates to walking function poststroke. Volitional phasing of hip flexion and extension torques was assessed using a load-cell-instrumented servomotor drive system in 11 chronic stroke subjects and 5 age-matched controls. Hips were oscillated from approximately 40 degrees of hip flexion to 10 degrees of hip extension at a frequency of 0.50 Hz during three movement conditions [hips in phase (IP), 180 degrees out of phase (OP), and unilateral hip movement (UN)] while the knees and ankles were held stationary. The magnitude and phasing of hip, knee, and ankle torques were measured during each movement condition. Surface electromyography was measured throughout the legs. Over ground gait analysis was done for all stroke subjects. During robotic-assisted movement conditions, the paretic limb produced peak hip torques when agonist hip musculature was stretched instead of midway through the movement as seen in the nonparetic and control limbs (P < 0.012). However, mean torque magnitudes of the paretic and nonparetic limbs were not significantly different. Abnormalities of paretic hip torque phasing were more pronounced during bilateral movement conditions and were associated with quadriceps overactivity. The magnitude of flexion torque produced during maximal hip extension was correlated with the Fugl Meyer Score, self-selected walking speed, and maximal hip extension during over ground walking. These results suggest that hyperexcitable stretch reflexes in the paretic limb impair coordinated hip torque phasing and likely interfere with walking function post stroke.
本研究旨在量化脑卒中后髋关节力矩的随意控制与步行功能的关系。通过使用装有测力传感器的伺服电机驱动系统，在 11 名慢性脑卒中患者和 5 名年龄匹配的对照者中评估髋关节屈伸力矩的随意相位。在三种运动条件下（髋关节同相 (IP)、180 度异相 (OP) 和单侧髋关节运动 (UN)），髋关节从大约 40 度的髋关节屈曲到 10 度的髋关节伸展以 0.50 Hz 的频率摆动，同时膝关节和踝关节保持静止。在每个运动条件下测量髋关节、膝关节和踝关节的转矩幅度和相位。在整个腿部测量表面肌电图。对所有脑卒中患者进行地面步行分析。在机器人辅助运动条件下，瘫痪侧肢体在伸展拮抗肌时产生峰值髋关节力矩，而不是在非瘫痪侧和对照组肢体的运动中途（P < 0.012）。然而，瘫痪侧和非瘫痪侧肢体的平均扭矩幅度没有显著差异。双侧运动条件下，瘫痪侧髋关节力矩相位异常更为明显，与股四头肌过度活跃有关。最大髋关节伸展时产生的伸展扭矩幅度与 Fugl Meyer 评分、自我选择的步行速度和地面行走时的最大髋关节伸展幅度相关。这些结果表明，瘫痪侧肢体过度兴奋的牵张反射会损害协调的髋关节力矩相位，并可能干扰脑卒中后的步行功能。
