背景:在上肢的日常生活任务中,在不稳定的姿势情况下,我们必须用手迅速纠正。姿势和到达控制机制涉及上肢任务的准确执行。
目的:本研究旨在确定在具有非静态目标的达成任务中,不同的姿势稳定性条件对上肢运动性能的影响。
方法:19名年轻参与者在不同的姿势条件下(两足动物,双足泡沫,和单足泡沫表面)。屏幕上的性能(运动时间和空间误差),平衡(压力位移中心,CoP),在伸手任务期间记录食指运动。
结果:不稳定性影响手指运动学(位移)和CoP运动学(位移,速度,和平滑度),而不会影响屏幕上的性能(精度和持续时间)。目标更改的时间会影响屏幕上的性能,手指运动学(速度和平滑度),和CoP运动学(位移,速度,和平滑度)。
结论:姿势和伸手控制系统可以在不太稳定的情况下实现精确的手部动作,甚至在达到具有非静态目标的任务时。姿势和到达控制系统可以在不稳定条件期间保护端部执行器性能,而不是在试验期间以更少的时间来校正运动。
BACKGROUND: In daily life tasks of the upper limb, we must make quick corrections with our hands in unstable postural situations. Postural and
reaching control mechanisms are involved in the accurate execution of upper-limb tasks.
OBJECTIVE: This research aimed to determine the effect of different postural stability conditions on the motor performance of the upper limb in a
reaching task with non-static targets.
METHODS: 19 young participants performed a
reaching task toward targets that exhibited a change in position (at 200 or 600 ms) in different postural conditions (bipedal-firm, bipedal-foam, and unipedal-foam surface). Performance on the screen (motion time and spatial error), balance (center of pressure displacements, CoP), and index finger movements were recorded during the reaching task.
RESULTS: The instability affects the finger kinematic (displacements) and CoP kinematic (displacements, speed, and smoothness) without affecting the performance on the screen (precision and duration). The timing of target change affects the performance on the screen, finger kinematic (speed and smoothness), and CoP kinematic (displacements, speed, and smoothness).
CONCLUSIONS: Postural and
reaching control systems enable accurate hand motions in less stable situations, even in
reaching tasks with non-static targets. The postural and reaching control systems can protect the end-effector performance during unstable conditions but not during trials with less time to correct the motion.