Low-back and shoulder complaints among workers with pushing and pulling tasks.

OBJECTIVES: Low-back and shoulder complaints were examined in relation to self-reported and objectively assessed exposure to work-related pushing and pulling.
METHODS: Workers from several companies (eg, nursing homes and flower auctions) with pushing and pulling tasks and, as reference, workers without physically demanding tasks were invited to participate. Altogether 829 workers initially received a questionnaire, of whom 459 responded both initially and after 1 year of follow-up. Initially, self-reported exposure to pushing and pulling was assessed by questionnaire. Furthermore, a representative sample of 131 workers was observed at work using TRAC (task recording and analysis on computer) to assess exposure to pushing and pulling objectively. For exposure to pushing and pulling, the workers were classified into a reference group and medium and high exposure groups. Initially and in the follow-up, the 12-month prevalence of low-back and shoulder complaints was assessed. Complaints reported in the follow-up were separately used as dependent variables to calculate prevalence rate ratios (PR) in a Cox's proportional hazard regression analysis.
RESULTS: The adjusted PR values were not significant for low-back complaints. For shoulder complaints, both the medium and high exposure groups showed significant adjusted PR values for self-reported exposure and observed duration of pushing and pulling when compared with the reference group (PR range 2.18-4.86). For the observed frequency of pushing and pulling, only the medium exposure group showed a significant PR, of 3.95.
CONCLUSIONS: The findings suggest a rather strong relationship between pushing and pulling and shoulder complaints. The evidence for a relationship between pushing and pulling and low-back complaints is limited.