Technical measurements of physical workload on wrist and forearm in various types of work

摘要

Work-related musculoskeletal disorders (WMSDs) are a global problem. Physical work load, e.g., constrained postures, repetitive movements, high muscular load and lack of recovery, are known risk factors. In spite of this knowledge, preventive measures have not lead to any significant reduction of WMSDs. One reason may be that the prevailing methods for assessing physical workload - questionnaires and observer ratings - are not sufficiently valid and precise for deriving exposure-response relationships as a base for preventive work. Technical measurements, which provide quantitative and generic data, might be needed for recording the physical workload at the work places. Aim: The aim was to explore the quantitative physical workload (movements, positions and muscular activity) of relevance for work related musculoskeletal disorders (WMSDs) for the wrists and forearms in a wide range of work. Methods: Technical measurements, i.e. electrogoniometer recordings of wrist angles and movements, and electromyography (EMG) of the muscular activity of the forearm extensors, were performed in 43 types of work. Results: For all exposure measures there was a great variation due to work. Some measures were fairly uncorrelated, representing different dimensions of the exposure. Conclusion: The methods provide generic, quantitative and objective data of the main risk factors for WMSDs, appropriate for describing exposure in epidemiological studies, as well as giving priority to, and evaluating, interventions. The multidimensional character of the exposure - postures and movement, as well as muscular recover and peak load - has to be considered.