Position-dependent torque coupling and associated muscle activation in the hemiparetic upper extremity
Position-dependent torque coupling and associated muscle activation in the hemiparetic upper extremity
复制标题
DOI：
10.1007/s00221-006-0637-x
复制
发表时间：
2007-02-01
影响因子：
2
通讯作者：
Dewald, Julius P. A.
中科院分区：
文献类型：
--
作者：
Ellis, Michael D.;Acosta, Ana Maria;Dewald, Julius P. A.
先前的研究已经证实了单侧中风患者上肢的异常关节扭矩耦合和相关的肌肉协同激活。我们研究了上肢构型对肩外展/肘屈曲和肩内收/肘伸展模式表达的影响。在四种不同的手臂配置中测量中风受试者的最大等长肩和肘扭矩。此外，还完成了等长组合扭矩任务，要求受试者保持不同水平的肩关节外展/内收扭矩，同时尝试最大化肘关节屈曲或伸展扭矩。显性外展/肘屈曲模式对肢体构型的变化不敏感，而内收/伸展模式手肘伸展组件在较小的肩外展角下变为肘屈曲。这种效应在没有中风的对照组中不存在。扭矩耦合模式的逆转不能用机械因素来解释，如手肘关节的肌肉长度变化或肌肉力量不平衡。潜在的神经机制的敏感性内收/肘伸展模式，以不同的躯体感觉输入所产生的肢体结构的变化进行了讨论沿着与未来的研究的影响。
Previous studies have demonstrated abnormal joint torque coupling and associated muscle coactivations of the upper extremity in individuals with unilateral stroke. We investigated the effect of upper limb configuration on the expression of the well-documented patterns of shoulder abduction/elbow flexion and shoulder adduction/elbow extension. Maximal isometric shoulder and elbow torques were measured in stroke subjects in four different arm configurations. Additionally, an isometric combined torque task was completed where subjects were required to maintain various levels of shoulder abduction/adduction torque while attempting to maximize elbow flexion or extension torque. The dominant abduction/elbow flexion pattern was insensitive to changes in limb configuration while the elbow extension component of the adduction/extension pattern changed to elbow flexion at smaller shoulder abduction angles. This effect was not present in control subjects without stroke. The reversal of the torque-coupling pattern could not be explained by mechanical factors such as muscle length changes or muscle strength imbalances across the elbow joint. Potential neural mechanisms underlying the sensitivity of the adduction/elbow extension pattern to different somatosensory input resultant from changes in limb configuration are discussed along with the implications for future research.