TY - JOUR A1 - Seidler, Andreas A1 - Bolm-Audorff, Ulrich A1 - Abolmaali, Nasreddin A1 - Elsner, Gine T1 - The role of cumulative physical work load in symptomatic knee osteoarthritis : a case-control study in Germany T2 - Journal of occupational medicine and toxicology N2 - Objectives To examine the dose-response relationship between cumulative exposure to kneeling and squatting as well as to lifting and carrying of loads and symptomatic knee osteoarthritis (OA) in a population-based case-control study. Methods In five orthopedic clinics and five practices we recruited 295 male patients aged 25 to 70 with radiographically confirmed knee osteoarthritis associated with chronic complaints. A total of 327 male control subjects were recruited. Data were gathered in a structured personal interview. To calculate cumulative exposure, the self-reported duration of kneeling and squatting as well as the duration of lifting and carrying of loads were summed up over the entire working life. Results The results of our study support a dose-response relationship between kneeling/squatting and symptomatic knee osteoarthritis. For a cumulative exposure to kneeling and squatting > 10.800 hours, the risk of having radiographically confirmed knee osteoarthritis as measured by the odds ratio (adjusted for age, region, weight, jogging/athletics, and lifting or carrying of loads) is 2.4 (95% CI 1.1-5.0) compared to unexposed subjects. Lifting and carrying of loads is significantly associated with knee osteoarthritis independent of kneeling or similar activities. Conclusions As the knee osteoarthritis risk is strongly elevated in occupations that involve both kneeling/squatting and heavy lifting/carrying, preventive efforts should particularly focus on these "high-risk occupations". Y1 - 2008 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/5788 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30-56430 N1 - © 2008 Seidler et al., licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. VL - 3 IS - 14 ER -