Roy Guylaine, Nadeau Sylvie, Gravel Denis, Piotte France, Malouin Francine, McFadyen Bradford J
Centre de Recherche Interdisciplinaire en Réadaptation (CRIR), Institut de Réadaptation de Montréal, Québec, Canada.
Clin Biomech (Bristol). 2007 Aug;22(7):795-804. doi: 10.1016/j.clinbiomech.2007.03.007. Epub 2007 May 18.
No study has reported the differences between sides in the net muscular moment of lower limbs of subjects with hemiparesis during sit-to-stand and stand-to-sit tasks in various foot positions. Moreover, the asymmetry of lower-joint moments has not yet been related to muscular weakness of the lower limbs in this population.
A convenience sample of 12 individuals (mean age (standard deviation): 49.7 (9.0) years) with chronic hemiparesis due to stroke were asked to stand up and sit down at their natural speed in four foot positions. The joint moments at the hip and knee on both sides during the tasks were estimated with an inverse dynamic approach while the dynamic concentric strength in extension at the hip and knee was assessed with a Biodex dynamometric system. Statistical analyses (paired t-tests and ANOVAs) were used to assess the effects of sides and foot position factor on the asymmetry in the hip and knee joint moments. The level of association between muscle weakness and the asymmetry in the joint moments was quantified with Pearson correlation coefficients (r).
At the knee, the extensor moments were significantly lower on the affected side (P<0.05) and were affected by the foot position. At the hip, the moments were not significantly different between sides and were slightly modified by the foot positions. There were also strong correlations (0.70<r<0.89; P<0.05, for symmetrical foot position) between the asymmetry in knee extensor moments and the asymmetry in strength. No relation was established at the hip.
The sit-to-stand and stand-to-sit tasks are characterized by a marked asymmetry in the knee extensor moments, which is associated with knee extensor weakness.
尚无研究报道偏瘫患者在不同足部位置进行坐立和站立坐任务时下肢净肌肉力矩的双侧差异。此外，该人群中下肢关节力矩的不对称性尚未与下肢肌肉无力相关联。
选取12例因中风导致慢性偏瘫的个体（平均年龄（标准差）：49.7（9.0）岁）作为便利样本，要求他们以自然速度在四种足部位置进行站立和坐下动作。在任务过程中，采用逆动力学方法估计双侧髋关节和膝关节的关节力矩，同时使用Biodex测力系统评估髋关节和膝关节伸展时的动态向心力量。采用统计分析（配对t检验和方差分析）来评估侧别和足部位置因素对髋关节和膝关节力矩不对称性的影响。肌肉无力与关节力矩不对称性之间的关联程度用Pearson相关系数（r）进行量化。
在膝关节处，患侧的伸肌力矩显著较低（P<0.05），且受足部位置影响。在髋关节处，双侧力矩无显著差异，且受足部位置的影响较小。膝关节伸肌力矩的不对称性与力量的不对称性之间也存在强相关性（对于对称足部位置，0.70<r<0.89；P<0.05）。在髋关节处未发现相关性。
坐立和站立坐任务的特点是膝关节伸肌力矩存在明显不对称，这与膝关节伸肌无力有关。
