GRAVITOINERTIAL FORCE LEVEL INFLUENCES ARM MOVEMENT CONTROL
GRAVITOINERTIAL FORCE LEVEL INFLUENCES ARM MOVEMENT CONTROL
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DOI：
10.1152/jn.1993.69.2.504
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发表时间：
1993-02-01
影响因子：
2.5
通讯作者：
DIZIO, P
中科院分区：
文献类型：
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作者：
FISK, J;LACKNER, JR;DIZIO, P
1.在背景重力惯性力（G）水平快速增加或减少后，立即测量前臂在记住的肘关节角度之间移动的能力。在高力（1.8G）和低力（0 G）环境下进行测量之前，这些动作在正常的1G环境中得到了很好的练习。前臂和上臂总是没有支撑的，以最大限度地提高改变的G负载的影响，并尽量减少有关手臂位置的外来线索。研究了水平和垂直运动平面，以测量在给定的G背景下运动平面中G载荷变化的影响。研究快速和慢速运动以评估本体感受反馈的作用. G水平不影响快速动作的幅度，表明被试能够为手臂的新G负荷计划和产生适当的运动指令;缓慢动作的幅度受G水平的影响，表明本体感受反馈受G水平的影响. G水平对水平和垂直运动的影响是相似的，这表明来自支持结构（如肩关节和肌肉）的本体感受信息在允许产生适当的运动命令中起作用。动态过冲的发生率和大小在0 G和快速运动中更大。这种与G相关的阻尼变化表明0 G时肌梭活动减少。0 G时肌梭活动的减少和1.8G时的增加与我们先前对不同力背景下的强直振动反射、运动和头部运动轨迹感知的研究结果一致。
1. The ability to move the forearm between remembered elbow joint angles immediately after rapid increases or decreases of the background gravitoinertial force (G) level was measured. The movements had been well-practiced in a normal 1G environment before the measurements in high- (1.8G) and low-force (0G) environments. The forearm and upper arm were always unsupported to maximize the influence of altered G-loading and to minimize extraneous cues about arm position.2. Horizontal and vertical movement planes were studied to measure the effects of varying the G load in the movement plane within a given G background. Rapid and slow movements were studied to assess the role of proprioceptive feedback.3. G level did not affect the amplitude of rapid movements, indicating that subjects were able to plan and to generate appropriate motor commands for the new G loading of the arm. The amplitude of slow movements was affected by G level, indicating that proprioceptive feedback is influenced by G level.4. The effects of G level were similar for horizontal and vertical movements, indicating that proprioceptive information from supporting structures, such as the shoulder joint and muscles, had a role in allowing generation of the appropriate motor commands.5. The incidence and size of dynamic overshoots were greater in 0G and for rapid movements. This G-related change in damping suggests a decrease in muscle spindle activity in 0G. A decrease in muscle spindle activity in 0G and an increase in 1.8G are consistent with the results of our prior studies on the tonic vibration reflex, locomotion, and perception of head movement trajectory in varying force backgrounds.