Thomas J S, Lavender S A, Corcos D M, Andersson G B
Ohio University, School of Physical Therapy, Athens, OH 45701, USA.
Hum Factors. 1999 Dec;41(4):670-6. doi: 10.1518/001872099779656662.
The National Institute for Occupational Safety and Health suggests there is insufficient biomechanical or epidemiological evidence to recommend the use of back belts in industry. From a biomechanical perspective, previous work suggests that lifting belts stiffen the torso, particularly in the frontal and transverse planes. To determine whether lifting belts stiffen the torso and alter the trunk muscle response during a sudden loading event, we tested the hypotheses that (a) lifting belts alter peak muscle activity recorded with electromyography (EMG) during sudden loading and (b) lifting belts have a larger impact on trunk muscle response when sudden loads are applied asymmetric to the torso's midsagittal plane. A sudden load was delivered to 10 men and 10 women without history of low back disorder via a cable attached to a thoracic harness; motion was restricted to the lumbar spine. Results indicate that gender was not a significant factor in this study. The lifting belt reduced the peak normalized EMG of the erector spinae muscles on average by 3% during asymmetric loading, though peak normalized EMG was increased by 2% during symmetric loading. Lifting belts have been shown to slightly reduce peak erector spinae activity during asymmetric sudden loading events in a constrained paradigm; however, the effects of lifting belts are too small to provide effective protection of workers. Actual or potential applications include the assessment of lifting belts as protective devices in workers based on the effects of lifting belts on the trunk muscle activity.
美国国家职业安全与健康研究所表明，目前尚无足够的生物力学或流行病学证据来推荐在工业中使用背带。从生物力学角度来看，先前的研究表明，提升带会使躯干变硬，尤其是在额面和横断面。为了确定提升带在突然加载事件中是否会使躯干变硬并改变躯干肌肉反应，我们测试了以下假设：（a）提升带会改变突然加载期间通过肌电图（EMG）记录的肌肉活动峰值；（b）当突然的负荷不对称地施加于躯干矢状面时，提升带对躯干肌肉反应的影响更大。通过连接到胸背带的电缆，对10名无腰痛病史的男性和10名女性施加突然的负荷；运动仅限于腰椎。结果表明，性别在本研究中不是一个显著因素。在不对称加载期间，提升带使竖脊肌的归一化肌电图峰值平均降低了3%，而在对称加载期间，归一化肌电图峰值增加了2%。在受限范式下，提升带已被证明在不对称突然加载事件中会略微降低竖脊肌的峰值活动；然而，提升带的效果太小，无法为工人提供有效的保护。实际或潜在的应用包括根据提升带对躯干肌肉活动的影响，将提升带评估为工人的防护装置。
