Ferguson S A, Marras W S, Waters T R
Department of Industrial and Systems Engineering, Ohio State University, Columbus 43210.
Ergonomics. 1992 Jul-Aug;35(7-8):845-59. doi: 10.1080/00140139208967366.
The objective of this study was to determine how trunk motion characteristics (in all three planes of the trunk) change as a free dynamic lifting task becomes more asymmetric. Trunk motion characteristics included range of motion, velocity (peak and average), and acceleration. Previous studies have shown that trunk motion characteristics affect trunk strength as well as the action of the trunk musculature. These trunk motion characteristics were quantified as a function of seven task asymmetries and three task weights. The experimental task required the subject to lift materials in positions commonly seen in the workplace. The range of motion, peak velocity, average velocity, and peak acceleration in each plane of the body were documented during the tasks. Generally, trunk motion characteristics in all three planes increased with an increase in task asymmetry. However, with an increase in task weight all the sagittal plane parameters and one transverse plane parameter decreased. Models were constructed to predict trunk motion characteristics given a task asymmetry and weight. When these motion components were compared to dynamic strength estimates from previous studies it was found that dynamic asymmetric lifts could reduce available strength up to 21% of maximum static strength. The results provide new insight into factors associated with the risk of developing low back disorders.
本研究的目的是确定随着自由动态举重任务变得更加不对称，躯干运动特征（在躯干的所有三个平面中）如何变化。躯干运动特征包括运动范围、速度（峰值和平均值）以及加速度。先前的研究表明，躯干运动特征会影响躯干力量以及躯干肌肉组织的活动。这些躯干运动特征被量化为七个任务不对称性和三个任务重量的函数。实验任务要求受试者在工作场所常见的位置举起材料。在任务过程中记录了身体每个平面的运动范围、峰值速度、平均速度和峰值加速度。一般来说，所有三个平面的躯干运动特征都随着任务不对称性的增加而增加。然而，随着任务重量的增加，所有矢状面参数和一个横断面参数都下降了。构建了模型以根据任务不对称性和重量预测躯干运动特征。当将这些运动成分与先前研究中的动态力量估计值进行比较时，发现动态不对称举重可使可用力量降低至最大静态力量的21%。这些结果为与下背部疾病发生风险相关的因素提供了新的见解。
