Specific and non-specific upper extremity musculoskeletal disorder syndromes in automobile manufacturing workers.

Objective: A longitudinal cohort of automobile manufacturing workers (n = 1,214) was examined for: (1) prevalence and persistence of specific upper extremity musculoskeletal disorders (UEMSDs) such as lateral epicondylitis and de Quervain's disease, and non-specific disorders (NSDs) defined in symptomatic individuals without any specific disorder, and (2) disorder prognoses based on symptom characteristics and other factors.

Methods: Eight specific disorders were identified through case definitions based on upper extremity physical examinations and symptom surveys administered on three occasions over 6 years.

Results: At baseline, 41% of the cohort reported upper extremity symptoms; 18% (n = 214) of these had NSDs. In each survey, tendon-related conditions accounted for over half of the specific morbidity. Twenty-five percent had UEMSDs in multiple anatomical sites, and most with hand/wrist disorders had two or more hand/wrist UEMSDs. Persistence for all specific disorders decreased with length of follow-up. Specific UEMSDs were characterized by greater pain severity and functional impairment, and more lost work days than NSDs.

Conclusions: Upper extremity symptoms and diagnoses vary over time. NSDs may be the early stages of conditions that will eventually become more specific. NSDs and overlapping specific UEMSDs should be taken into account in UEMSD classification. Am. J. Ind. Med. 52:124-132, 2009. (c) 2008 Wiley-Liss, Inc.