Gregory Diane E, Narula Sonia, Howarth Samuel J, Russell Caryl, Callaghan Jack P
Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada.
Ergonomics. 2008 Jul;51(7):1032-41. doi: 10.1080/00140130701813178.
The purpose of this study was to determine the effect of a fatiguing task (3 min intense stair climbing) on the adopted spinal postures and trunk muscular activation patterns during three highly physically demanding simulated firefighting tasks. Following the fatigue protocol, it was observed that individuals adopted significantly greater spinal flexion (16.3 degrees maximum prior to fatigue as compared to 20.1 degrees post fatigue) and displayed reduced abdominal muscle activation as compared to before the fatigue protocol (mean ranging from 16.6% maximum voluntary contraction (MVC) to 30.6% MVC prior to fatigue as compared to ranging from 14.6% MVC to 25.2% MVC post fatigue). The reduced abdominal activation may be due to a reduction in co-contraction during these tasks, which may compromise spinal stability. Reduced co-contraction combined with the increased spinal flexion may increase the risk of sustaining an injury to the low back.
本研究的目的是确定一项疲劳任务（3分钟高强度爬楼梯）对三项身体要求极高的模拟灭火任务中所采用的脊柱姿势和躯干肌肉激活模式的影响。按照疲劳方案进行操作后，观察到与疲劳方案实施前相比，个体采用的脊柱前屈角度显著增大（疲劳前最大为16.3度，疲劳后为20.1度），且腹部肌肉激活程度降低（疲劳前平均最大自主收缩（MVC）范围为16.6%至30.6%，疲劳后为14.6%至25.2%）。腹部激活程度降低可能是由于这些任务中协同收缩减少，这可能会损害脊柱稳定性。协同收缩减少加上脊柱前屈增加，可能会增加下背部受伤的风险。
