Occhealth Bulletin
18 June 2010
Characterizing Musculoskeletal Disorders in automotive industry
Category: Reviews
Physical work often involves repetitive movements and awkward postures (such as bending, overreaching, raised arms and twisting) that place pressure and strain on anatomical structures within the human body such as muscles, tendons, connective tissues, nerves and blood vessels. Damage to these components can cause a range of conditions such as musculoskeletal disorders (MSD). MSD conditions can occur as a result of gradual exposure to the same task over a period of time or through a single damaging event. Further, the age, stature and physical health of an employee will affect their response to a particular task.
A recent study, carried out by Michael Spallek and co-workers, aimed to discover the types of MSDs of the upper limbs suffered by blue and white collar workers in two automotive manufacturing plants in Germany. The researchers also intended to relate the MSD conditions observed with the repetitive tasks undertaken by the workers. Two cohorts were studied, one from each manufacturing plant. The first cohort comprised of 67 workers from Plant A who, over a four-month period, presented with acute or chronic MSDs in the forearm. At Plant B, a cohort of 209 white-collar workers, who typically worked at Video Display Terminals (VDT) for tasks such as data entry work, were studied.
The researchers collected information from cohort A by standardized interview. Questions were asked about the symptoms of the complaint as well as details about the individuals’ working environment. An occupational physician also examined the patients with a range of motion tests and resisted motion maneuvers. Cohort B received a regular medical check-up examination followed by information collection via a questionnaire including demographic data, employment history, current VDT working conditions, MSD complaints and relevant medical history. A visual acuity test and orthopedic-chiropractic examination of the cervical vertebrae (bone structures below the skull and in the neck region) was also performed.
The researchers determined that the majority of cohort A, presenting with forearm MSDs, were blue-collar workers (74%) and trainees rather than office workers. The most common complaint within the group was related to disorders of the flexor tendons of the forearm. Rates of MSD complaints were disproportionately higher in experienced workers undertaking new tasks and trainee workers. Spallek and co-workers also suggested that in 92.5% of the cases, they were able to accurately diagnose the cases with the functional tests undertaken in the physical examinations. In cohort B, complaints involving the neck and shoulders were more common than those observed in the forearm. A positive tendency was also observed between numbers of years worked at VDT and restricted rotation of the cervical vertebrae.
The researchers concluded that "methodological functional testing allowed the occupational physician to identify and specifically diagnose injured structures". Such tests are very useful for the design of individual rehabilitation programs and the development of specific training programs before new tasks are undertaken by workers. The results would also help to inform employers on the specific ergonomic changes that would benefit particular workers.
REFERENCE Spallek, M., Kuhn, W., Uibel, S., van Mark, A. and Quarcoo, D. (2010) Work-related musculoskeletal disorders in the automotive industry due to repetitive work - implications for rehabilitation. Journal of Occupational Medicine and Toxicology. Volume 5.