THE SCIENTIFIC BASIS FOR MAKING GUIDELINES AND STANDARDS TO PREVENT WORK-RELATED MUSCULOSKELETAL DISORDERS

Regulations concerning the work environment, tools, and the performanc e of work are at their best based on scientific evidence. Existing Eur opean directives, European and North American standards, and recent gu idelines with the potential to prevent musculoskeletal disorders, are either qualitative or semiquantitative. The exception is the NIOSH lif ting guide, which is highly quantitative. Of the European directives a nd standards, few have been developed with the primary goal of prevent ing musculoskeletal disorders, whereas one North American standard and another suggestion for a standard have this specific aim. In a review of epidemiological studies on low-back, neck, shoulder, and upper ext remity disorders, several physical load factors were identified as ris k factors for the disorders. Many of these factors have been repeatedl y identified, and for different types of outcomes of an anatomical are a (e.g. pain, disc herniation, disc degeneration of the low-back or ne ck). However, quantitative exposure-response relationships between phy sical load factors and disorders based on field studies are largely un known. Experimental studies have provided a multitude of potentially u seful data. It is concluded that both well-designed epidemiological st udies with quantitative assessments of physical work load and valid me asurements of musculoskeletal disorders, and experimental studies are needed for the future development of regulation. To determine the role of experimental studies in regulation, it should be known to what ext ent fatigue and other short-term responses are precursors of disorders . Regulation should be directed especially towards factors that are li kely to be causative for musculoskeletal disorders. Examples of such f actors are sudden overload in manual handling activities, heavy physic al work involving manual handling tasks, and vibration from tools. Gui delines that are acceptable and feasible can and should be developed. The effects of such guidelines on the occurrence of musculoskeletal di sorders should be investigated.