Neuromuscular coordination of squat lifting, I: Effect of load magnitude.
Neuromuscular coordination of squat lifting, I: Effect of load magnitude.
复制标题
深蹲举重的神经肌肉协调，I：负荷大小的影响。
作者：
John P. Scholz;J. P. Millford;Amy Gross McMillan
背景和目的
在这项研究中，我们检查了深蹲举重任务的协调性（即关节运动和肌肉活动的相对时间）的运动学和肌电图 (EMG) 测量值随着举重增加的变化。
科目
十五名男性产业工人作为方便样本。
方法
受试者使用对称的深蹲举升技术举起一个包含其最大举重能力 15% 至 75% 的加重板条箱。通过摄像获得运动运动学。推导出关节运动之间的相对相位。记录股外侧肌（VL）和竖脊肌（ES）的肌电图活动，并估计它们的起始和峰值的相对时间。
结果
在举起过程中，膝关节和腰椎等关节之间的相对运动相位随着负载的增加而以准线性方式变化，但在下降过程中则不然。 ES EMG 活动开始的相对时间及其峰值活动的变化方式与关节间相对相位结果一致。 VL 事件的时间不受负载增加的影响。
结论与讨论
当增加从初始蹲姿抬起的负载时，肢体间协调性会发生相对连续的变化。肌电图相对时间的变化部分证实了与负荷缩放协调变化的运动学证据。结果表明需要进一步研究以确定观察到的协调变化对肌肉骨骼系统是有益还是有害。临床医生应评估该任务在一系列任务条件下的表现。
BACKGROUND AND PURPOSE
In this study, we examined changes in kinematic and electromyographic (EMG) measurements of the coordination (ie, the relative timing of joint movements and muscle activity) of a squat-lifting task in response to lifting increasing loads.
SUBJECTS
Fifteen male industrial workers served as a sample of convenience.
METHODS
Subjects lifted a weighted crate containing 15% to 75% of their maximum lifting capacity using a symmetrical squat-lift technique. Movement kinematics were obtained with videography. The relative phase between joint motions was derived. The EMG activity of the vastus lateralis muscle (VL) and the erector spinae muscle (ES) was recorded, and the relative timing of their onsets and peaks was estimated.
RESULTS
The relative phase of movement between joints such as the knee and lumbar spine changed in a quasi-linear fashion with increasing load during lifting but not during lowering. The relative time of onset of ES EMG activity and its peak activity changed in a manner consistent with the interjoint relative phase results. The timing of VL events were not affected by increasing the load.
CONCLUSION AND DISCUSSION
Relatively continuous changes in interlimb coordination occur when increasing the load lifted from an initial squatting posture. Changes in EMG relative timing partially corroborate the kinematic evidence for changes in coordination with load scaling. The results indicate the need for further study to determine whether the observed changes in coordination are beneficial or detrimental to the musculoskeletal system. Clinicians should evaluate performance of this task under a range of task conditions.
人类多肢协调的对称性破坏动力学。
DOI：
10.1037//0096-1523.18.3.645
发表时间：
1992
期刊：
Journal of experimental psychology. Human perception and performance
影响因子：
--
作者：
Kelso,JA;Jeka,JJ
通讯作者：
Jeka,JJ