A conceptual model for work-related neck and upper-limb musculoskeletal disorders.
Armstrong-TJ; Buckle-P; Fine-LJ; Hagberg-M; Jonsson-B; Kilbom-A; Kuorinka-IA; Silverstein-BA; Sjogaard-G; Viikari-Juntura-ER
Scand J Work, Environ & Health 1993 Apr; 19(2):73-84
A conceptual model was developed for work related musculoskeletal disorders (MSD) of the neck region and upper limbs. The model was developed to highlight the multifactorial nature of these problems, and to be used as a research tool. Twenty two epidemiological studies were used to support the work relatedness of these problems. Various characteristics of the work environment that led to these disorders were taken into account. The development of fatigue due to muscle energy deficiencies, and mechanical as well as physiological responses were addressed. Local changes conveyed to the central nervous system by sensory afferent nerves produced perceived fatigue. Repeated fatigue resulted in muscle disorders. The underlying metabolic events such as the accumulation of calcium ions was discussed. The special role of motor control of the working muscle and the recruitment patterns of motoneurons were addressed. The ultimate reporting of fatigue and pain depended on their effect on work capacity relative to work demands as well as socioeconomic factors. Tendon disorders were related to contact and shearing forces from adjacent anatomic surfaces, as well as tensile forces from muscle contractions. Common tendinitis sites were the wrist, forearm, elbow, and shoulder. Degenerative processes were detailed. How exertion of the body led to tendon responses was summarized. The pathogenesis of nerve disorders was discussed and included median nerve compression, the effect of pressure in vibration, and materials handling, and dose responses. The authors consider the proposed model to be useful in the design of studies on the etiology and pathomechanisms of work related MSD, as well as in the planning and evaluation of preventive programs.
NIOSH-Author; Cumulative-trauma-disorders; Ergonomics; Epidemiology; Dose-response; Injury-prevention; Mathematical-models; Muscle-stress; Musculoskeletal-system-disorders; Neuropathy;
Author Keywords: carpal tunnel syndrome; cumulative trauma disorders; dose-response; fatigue; nerve pathogenesis; repetitive strain injuries; tendinitis; tendon and muscle disorder; work-related disorders
Dr TJ Armstrong, Center for Ergonomics, University of Michigan, 1205 Beal-IOE Building, Ann Arbor, MI 48 109-2 117, USA
Scandinavian Journal of Work, Environment and Health