Background Despite the high prevalences of workplace physical violence and musculoskeletal symptoms among health care workers, very few studies have examined the relationship between these two phenomena.

Methods We surveyed 920 clinical nursing home workers by questionnaire regarding musculoskeletal pain in the low back, shoulders, wrists or hands, and knees. Information was also collected on exposure to physical assaults at work during the preceding 3 months, other workplace safety features, physical workload and psychosocial work environment. Log-binomial regression was used to estimate the prevalence ratios (PR) with 95% CIs.

Results Almost one-half of respondents reported being assaulted at least once during the preceding 3 months by a resident or resident's visitor. The prevalence of low back pain increased from 40% among non-assaulted workers to 70% among those assaulted three or more times. The highest risk was found for widespread pain (three or more areas), with an adjusted PR of 2.7 (95% CI 1.8 to 3.9) for workers assaulted three or more times. Good workplace safety buffered the effects, so that violence increased the risk of most pains considerably less in a work environment perceived to be safe.

Conclusions To our knowledge, this is the first study to show a dose–response association between physical assaults and musculoskeletal pain in a health care setting where violence is a frequent occurrence. This emphasises the need to address violence as a workplace hazard through practical measures for prevention as well as in future aetiological research on musculoskeletal disorders.