身体上的助力提升装置对非对称自由式提升过程中腰部三维动态力矩和肌电图的影响。
The effect of on-body lift assistive device on the lumbar 3D dynamic moments and EMG during asymmetric freestyle lifting.
作者信息
Abdoli-E Mohammad, Stevenson Joan M
机构信息
School of Occupational and Public Health, Ryerson University, Toronto, Ontario, Canada M5B 2K3.
出版信息
Clin Biomech (Bristol). 2008 Mar;23(3):372-80. doi: 10.1016/j.clinbiomech.2007.10.012.
BACKGROUND
A new on-body personal lift assistive device was developed to reduce force requirements of back muscles during lifting and static holding tasks.
METHODS
Nine male subjects participated in the study. Twelve Fastrak sensors were used to record positions and rotations of the segments. Trunk muscles were normalized to maximum and integrated electromyographic amplitudes of the left and right thoracic erector spinae, lumbar erector spinae, external obliques, and rectus abdominalis were compared in asymmetrical lifting for three different loads (5 kg, 15 kg, 25 kg) using free style under two conditions: with and without a lift assistive device.
FINDINGS
The assistive device significantly reduced the required muscular effort of the lumbar and thoracic erector spinae (P=0.001) with no significant differences in the level of abdominal muscular activity. Average integrated electromyography amplitudes were reduced across all subjects by 23.9% for lumbar erector spinae, 24.4% for thoracic erector spinae, and 34.9% for the contralateral external oblique muscles. The assistive device had its greatest impact on smaller moments with 30% reduction in lateral bending, and 24% reduction in rotational moments, with only 19.5% a reduction in larger flexion-extension moments. To investigate whether the lift assistive device affected lifting kinematics, the device tensions were zeroed mathematically. No kinematic differences in lifting technique would explain this magnitude of moment reduction.
INTERPRETATION
The on-body assistive device reduced the required muscular effort of the lumbar and thoracic erector spinae without adversely affecting the level of abdominal muscle activity. These reductions were mirrored by similar 3D moment reductions.
背景
研发了一种新型的身体佩戴式个人升降辅助装置，以降低在提起和静态握持任务期间背部肌肉所需的力量。
方法
九名男性受试者参与了该研究。使用十二个Fastrak传感器记录各节段的位置和旋转情况。将躯干肌肉标准化为最大值，并比较在两种条件下（使用和不使用升降辅助装置），针对三种不同负荷（5千克、15千克、25千克）采用自由姿势进行不对称提起时，左右胸段竖脊肌、腰段竖脊肌、腹外斜肌和腹直肌的积分肌电图幅度。
研究结果
辅助装置显著降低了腰段和胸段竖脊肌所需的肌肉力量（P = 0.001），而腹部肌肉活动水平无显著差异。所有受试者的腰段竖脊肌平均积分肌电图幅度降低了23.9%，胸段竖脊肌降低了24.4%，对侧腹外斜肌降低了34.9%。辅助装置对较小力矩的影响最大，侧弯力矩降低了30%，旋转力矩降低了24%，而较大的屈伸力矩仅降低了19.5%。为了研究升降辅助装置是否影响提起运动学，通过数学方法将装置张力归零。提起技术上的运动学差异无法解释这种力矩降低幅度。
解读
身体佩戴式辅助装置降低了腰段和胸段竖脊肌所需的肌肉力量，且未对腹部肌肉活动水平产生不利影响。这些力量的降低伴随着类似的三维力矩降低。
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