Hu Xiaoling, Tong Kaiyu, Tsang Vincent S, Song Rong
Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong.
Arch Phys Med Rehabil. 2006 May;87(5):671-9. doi: 10.1016/j.apmr.2006.02.003.
To evaluate the joint-angle-dependent neuromuscular functions at the affected wrist in hemiplegic subjects after stroke while doing isometric maximal voluntary wrist flexion and extension across different wrist angles.
We investigated torques during isometric maximal voluntary wrist flexions and extensions at 8 different wrist angles, ranging from -45 degrees to 60 degrees. We used the associated electromyographic activities of 2 agonist and antagonist muscle pairs related to wrist and elbow joints for the analysis of muscular coactivations. We compared the data obtained from poststroke subjects' affected and unaffected sides.
A research laboratory in a rehabilitation center.
Eleven subjects with hemiplegia after stroke with passive range of motion (ROM) in the wrist from -45 degrees to 60 degrees.
Not applicable.
Directly measured torques, torques after normalization during maximal isometric wrist contractions, and normalized moving average electromyographic signals of each muscle at the tested positions.
The measured torques of the affected wrists were significantly lower than those of the unaffected wrists at all tested angles during wrist flexion and extension (P<.05). The angle-dependent patterns of the normalized torque across the tested wrist angles varied from those of the unaffected wrists (2-way analysis of variance, P<.05). There were decreases in normalized torques during both flexion and extension at the extended positions in the affected group (P<.05). Abnormal cocontractions were found in agonist and antagonist muscle pairs related to wrist and elbow joints, and between the elbow flexor and wrist extensor when subjects did the wrist contractions on the paretic side, especially at the wrist extended positions.
Wrist muscle weakness was distributed unevenly across the selected wrist ROM on the affected side, as represented by the varied patterns of the normalized torque-angle relationship, compared with the unaffected wrists. There were reductions in the selective control of muscle coactivating synergies both single-jointly and cross-jointly in the impaired nervous system during wrist contractions; the extent of these reductions was also related to the wrist angle configuration.
评估中风后偏瘫患者在不同腕关节角度进行等长最大自主腕关节屈伸时，患侧腕关节的关节角度依赖性神经肌肉功能。
我们研究了在8个不同腕关节角度（从-45度到60度）进行等长最大自主腕关节屈伸时的扭矩。我们使用了与腕关节和肘关节相关的2对主动肌和拮抗肌的相关肌电图活动来分析肌肉的共同激活情况。我们比较了中风后受试者患侧和健侧获得的数据。
康复中心的一个研究实验室。
11名中风后偏瘫患者，腕关节被动活动范围（ROM）为-45度至60度。
不适用。
直接测量的扭矩、最大等长腕关节收缩时标准化后的扭矩，以及在测试位置时每块肌肉的标准化移动平均肌电图信号。
在腕关节屈伸的所有测试角度下，患侧腕关节测量的扭矩均显著低于健侧腕关节（P<0.05）。整个测试腕关节角度的标准化扭矩的角度依赖性模式与健侧腕关节不同（双向方差分析，P<0.05）。患侧组在伸展位置进行屈伸时，标准化扭矩均降低（P<0.05）。当受试者在患侧进行腕关节收缩时，尤其是在腕关节伸展位置，发现与腕关节和肘关节相关的主动肌和拮抗肌对之间，以及肘屈肌和腕伸肌之间存在异常的共同收缩。
与健侧腕关节相比，患侧腕部肌肉无力在选定的腕关节活动范围内分布不均，表现为标准化扭矩-角度关系的不同模式。在腕关节收缩过程中，受损神经系统中肌肉共同激活协同作用的单关节和跨关节选择性控制均降低；这些降低的程度也与腕关节角度配置有关。
