Hip osteoarthritis: influence of work with heavy lifting, climbing stairs or ladders, or combining kneeling/squatting with heavy lifting.

The aim of the study was to evaluate the evidence for an association between hip osteoarthritis (OA) and physical work demands. Systematic searches were made and epidemiological studies on hip OA and heavy lifting, including farming and construction work and climbing stairs, were reviewed for the period 1966-2007 inclusive. The quality of the studies was assessed and best-evidence syntheses of a causal relation between hip OA and physical demanding work have been made using specific criteria of the different degrees of evidence of causality. Limitations of the studies include few participants, use of different diagnostic criteria, and a poor description of the exposure. It is concluded that moderate to strong evidence was found for a relation between heavy lifting and hip OA. The burdens have to be at least 10-20 kg and the duration at least 10-20 years to give a clearly increased risk of hip OA. For farmers the risk of hip OA seems doubled after approximately 10 years of farming and the evidence is considered as moderate to strong. The evidence for a relation between hip OA for construction workers is limited and there is insufficient or no evidence that climbing stairs or ladders causes hip OA.