Shafir Tal, Brown Susan H
School of Kinesiology, University of Michigan, Ann Arbor, MI 48109-0720, USA.
J Mot Behav. 2010 Jan-Feb;42(1):71-84. doi: 10.1080/00222890903397137.
Accurate timing of limb displacement is crucial for effective motor control. The authors examined the effects of movement velocity, duration, direction, added mass, and auditory cueing on timing, spatial, and trajectory variability of single- and multijoint rhythmic movements. During single-joint movements, increased velocity decreased timing and spatial variability, whereas increased movement duration increased timing variability but decreased spatial variability. For multijoint movements, regardless of condition, increasing velocity decreased joint timing, spatial, and trajectory variability, but all hand variabilities were unaffected by velocity, duration, load, or direction. Timing, spatial, and trajectory variability was greater at the shoulder compared with the elbow and minimal at the hand, supporting the notion that reaching movements are planned in hand space as opposed to joint space.
肢体位移的精确计时对于有效的运动控制至关重要。作者研究了运动速度、持续时间、方向、附加质量和听觉提示对单关节和多关节节律性运动的计时、空间和轨迹变异性的影响。在单关节运动中，速度增加会降低计时和空间变异性，而运动持续时间增加会增加计时变异性但降低空间变异性。对于多关节运动，无论何种情况，速度增加都会降低关节计时、空间和轨迹变异性，但所有手部变异性不受速度、持续时间、负荷或方向的影响。与肘部相比，肩部的计时、空间和轨迹变异性更大，而手部最小，这支持了伸手动作是在手部空间而非关节空间中规划的观点。
