Study design: Back and neck pain was studied cross-sectionally in 1,449 urban transit drivers by linking medical data, self-reported ergonomic factors, and company records on job history.
Objectives: The goal was to examine the relation between physical workload, ergonomic factors, and the prevalence of back and neck pain.
Summary of background data: Researchers, to date, have not found an independent effect of ergonomic factors on back and neck pain while accounting for the effects of past and current physical workload.
Methods: Self-reported ergonomic factors, vehicle type, physical workload (measured as duration of driving), height, weight, age, and gender were analyzed in relation to back and neck pain, using multivariable logistic regression models.
Results: Physical workload showed a positive dose-response relation with back and neck pain after controlling for vehicle type, height, weight, age, and gender. The odds ratio for 10 years of driving was 3.43. Additional adjustment for ergonomic factors decreased this odds ratio to 2.55. Six out of seven ergonomic factors were significantly related to the prevalence of back and neck pain after adjustment for age, gender, height, weight, and physical workload. Problems with adjusting the seat had the largest effect (odds ratio = 3.52). Women had back and neck pain twice as frequently as men.
Conclusion: The results support the hypothesis of a causal role of physical workload for the development of back and neck pain. Ergonomic factors partially mediated the risk of back and neck pain associated with driving, suggesting a potential for prevention of back and neck pain by ergonomic redesign of transit vehicles. Elevated risks for back and neck pain for female drivers were not explained by anthropometric and ergonomic factors.