Massie Crystal L, Malcolm Matthew P, Greene David P, Browning Raymond C
Health and Exercise Science Department, Colorado State University, Fort Collins, CO 80523, USA.
J Mot Behav. 2012;44(3):213-22. doi: 10.1080/00222895.2012.681321.
Coordinated reaching requires continuous interaction between the efferent motor output and afferent feedback; this interaction may be significantly compromised following a stroke. The authors sought to characterize how survivors of stroke generate continuous, goal-directed reaching. Sixteen survivors of stroke completed functional testing of the stroke-affected side and a continuous reaching task between 2 targets with both sides. Motion analysis and electromyography data were collected to determine segmental contributions to reach (e.g., amount of compensatory trunk), spatiotemporal parameters (e.g., peak velocities), and muscle activation patterns (MAP). Repeated measures analyses of variance compared how survivors of stroke reach with the stroke-affected versus less affected sides. Correlations were determined between kinematic outcomes and functional ability. Participants used significantly more trunk movement and less shoulder flexion and elbow extension when reaching with the stroke-affected side. This corresponded with less muscle activity in the proximal musculature including the anterior, middle, and posterior deltoid on the stroke-affected side. There were significant correlations between the segmental contributions to reach, functional ability, and MAPs. Survivors of stroke generate reduced MAPs in the stroke-affected side corresponding to altered segmental kinematics and function ability. These findings suggest that impairments in the ability to generate sufficient MAPs may contribute to the difficulty in generating continuous reaching motions.
协调的伸手动作需要传出运动输出和传入反馈之间持续相互作用；中风后这种相互作用可能会受到严重损害。作者试图描述中风幸存者如何产生持续的、目标导向的伸手动作。16名中风幸存者完成了中风患侧的功能测试以及双侧在两个目标之间的持续伸手任务。收集了运动分析和肌电图数据，以确定各节段对伸手动作的贡献（例如，代偿性躯干的量）、时空参数（例如，峰值速度）和肌肉激活模式（MAP）。重复测量方差分析比较了中风幸存者患侧与患侧较轻的一侧的伸手动作情况。确定了运动学结果与功能能力之间的相关性。与中风患侧相比，参与者在伸手时使用了更多的躯干运动，更少的肩部屈曲和肘部伸展。这与中风患侧近端肌肉组织（包括三角肌前束、中束和后束）中较少的肌肉活动相对应。各节段对伸手动作的贡献、功能能力和肌肉激活模式之间存在显著相关性。中风幸存者在中风患侧产生的肌肉激活模式减少，这与节段运动学和功能能力的改变相对应。这些发现表明，产生足够肌肉激活模式的能力受损可能导致产生持续伸手动作困难。
