Westgaard R H
National Institute of Occupational Health, Department of Physiology, Oslo, Norway.
Eur J Appl Physiol Occup Physiol. 1988;57(3):291-304. doi: 10.1007/BF00635987.
This paper describes methodological considerations and problems experienced when quantifying muscle load in occupational work situations. A system for the quantification of the health effect of prolonged muscle load on the shoulder muscles is also described. Combined measurements of postural load and health effects can be used in a quantitative evaluation of postural load as a risk factor for the development of musculo-skeletal injury. Postural muscle load may be quantified by electromyography or by biomechanical methods. Problems associated with quantitative electromyography are described, including selective inhibition of functional compartments in a muscle. This phenomenon results in other compartments coming under proportionally higher strain, disturbing the force-EMG calibration curves. It is suggested that fatigue measurements, indicated by a shift in the centre frequency of the EMG frequency spectrum, are not easily used for evaluation of vocational EMG recordings if the purpose is to indicate the risk of occupational muscle injury. Load measurements using biomechanical methods may provide an acceptable alternative to electromyography, but more work is required before these methods can be used on a routine basis.
本文描述了在职业工作场景中量化肌肉负荷时所考虑的方法及遇到的问题。还介绍了一种用于量化肩部肌肉长期承受肌肉负荷对健康影响的系统。姿势负荷与健康影响的综合测量可用于对姿势负荷作为肌肉骨骼损伤发展风险因素进行定量评估。姿势肌肉负荷可通过肌电图或生物力学方法进行量化。文中描述了与定量肌电图相关的问题，包括肌肉中功能区的选择性抑制。这种现象会导致其他区域承受比例更高的应变，从而干扰力 - 肌电图校准曲线。研究表明，如果目的是指示职业性肌肉损伤风险，那么由肌电图频谱中心频率偏移所指示的疲劳测量不易用于评估职业性肌电图记录。使用生物力学方法进行负荷测量可能为肌电图提供一种可接受的替代方法，但在这些方法能够常规使用之前，还需要开展更多工作。
