Variation in occupational exposure associated with musculoskeletal complaints: a cross-sectional study among professional bassists.

Background: Variation in occupational exposure is assumed to have a protective effect against the development of musculoskeletal complaints (MSC), but this common assumption is not strongly supported by the literature. Among musicians, who have a high prevalence of MSC, many play more than one type of instrument (multi-instrumentalism) for many hours a day. Since multi-instrumentalism implies greater variation in ergonomic load of specific musculoskeletal areas than mono-instrumentalism, musicians are a suitable study population to test whether the above assumption is true.

Purpose: To investigate in a sample of professional bass players whether multi-instrumentalists are less likely to have MSC than mono-instrumentalists.

Methods: Participants were 141 professional and professional student double bassists and bass guitarists. Demographic, MSC and exposure characteristics were collected online with self-constructed and existing questionnaires. Logistic regression analysis was used to test the association between multi- versus mono-instrumentalism and MSC, adjusted for confounders.

Results: The prevalence of having MSC in the neck, back, right shoulder area and both wrist areas did not differ significantly between the two groups. Further analysis revealed that the likelihood of having MSC in the left shoulder area was higher in multi-instrumentalists compared to mono-instrumentalists (Odds ratio 0.30, 95% CI 0.119-0.753, p = 0.010).

Conclusion: In this sample of professional bass players, no protective effect of multi-instrumentalism against MSC was found. Multi-instrumentalism was associated with a higher prevalence of MSC in the left shoulder. This result challenges theoretical and clinical assumptions in occupational and pain medicine.