Systematic review: occupational physical activity and low back pain.

Background: Although various occupational physical activities are suspected of contributing to low back pain (LBP), causal relationships have not been confirmed, complicating adjudication of work injuries, return to work instructions and preventive efforts.

Aims: To summarize eight systematic review (SR) reports that examined evidence supporting causal relationships between bending/twisting, awkward postures, sitting, standing/walking, carrying, pushing/pulling, lifting and manual handling/assisting patients and LBP.

Methods: A literature search was conducted to identify eligible studies. Methodological quality was assessed using a modified Newcastle-Ottawa Scale (NOS). Levels of evidence supporting factors for causation were examined using a Bradford Hill framework. Results were presented in eight SR reports, each focused on one or more related physical activities. This study summarizes findings from those reports and offers clinicians an overview.

Results: Collectively, the eight SR reports included 99 studies. None found strong evidence supporting a causal relationship between any occupational physical activity considered and LBP. Conflicting evidence was found between LBP and bending, twisting, lifting or pushing/pulling, but only for statistical association, not causation. Strong evidence against a causal relationship was found between LBP and manual handling/assisting patients, awkward postures, carrying, sitting, standing or walking.

Conclusions: Although occupational physical activities are suspected of causing LBP, findings from the eight SR reports did not support this hypothesis. This may be related to insufficient or poor quality scientific literature, as well as the difficulty of establishing causation of LBP. These population-level findings do not preclude the possibility that individuals may attribute their LBP to specific occupational physical activities.