Knee osteoarthritis: influence of work involving heavy lifting, kneeling, climbing stairs or ladders, or kneeling/squatting combined with heavy lifting

Abstract

The purpose of the study was to evaluate the evidence for an association between knee osteoarthritis (kneeOA) and physical work demands. Systematic searches were made, and epidemiological studies on kneeOA and heavy lifting, kneeling and climbing stairs published in 1966 to 2007 inclusive were reviewed. The quality of the studies was assessed and an overall evaluation of the degree of evidence of a causal relationship between kneeOA and physically demanding work was 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 evidence was found for a relationship between kneeling, heavy lifting and kneeOA. For the combination of kneeling/squatting and heavy lifting the association seemed stronger than for kneeling/squatting or heavy lifting alone, but only a few studies were found concerning this relationship. Therefore the degree of evidence for a causal relationship was considered to be moderate. In the studies on the association between kneeOA and climbing stairs or ladders, there was an increased risk for kneeOA, but only a few studies were found and no dose-response relationship has been investigated. The evidence of a causal relationship is therefore considered to be limited.

Occupational Physical Loading Tasks and Knee Osteoarthritis: A Review of the Evidence

“…We chose to use this quality-assessment method so that our findings could be directly compared with those of the previous review. 6 …”

“…7,9 Some occupations that involve repetitive performance of tasks such as heavy lifting, kneeling, and stair climbing have been hypothesized to play a role in knee OA. 6,10 Denmark and Germany have accepted knee OA as an occupational disease, although a clear dose-response relationship has not been quantified. 11 In British Columbia, Canada, WorkSafeBC currently defines occupational disease as one ''peculiar to or characteristic of a particular process, trade, or occupation''; 12 at present, however, only one type of osteoarthritis-that affecting the first carpometacarpal joint of both thumbs, which can affect physiotherapists who perform deep friction massage-is recognized as an occupational disease.…”

“…6,7 Both reviews reported evidence that heavy lifting, kneeling, and combined heavy lifting and kneeling are associated with knee OA in men but not in women. The authors explained that this might be because (1) very few women work in physically demanding jobs or (2) most studies did not recognize homemaking as an occupation.…”

“…The authors explained that this might be because (1) very few women work in physically demanding jobs or (2) most studies did not recognize homemaking as an occupation. 6,7 More recently, some authors have recognized that homemakers should be considered when exploring occupational physical loading, since kneeling and lifting are central components of performing household chores. 13,14 This conclusion accords with a broader definition of occupation, such as that suggested by the Canadian Occupational Therapy Association: occupation is what people do to occupy themselves with some regularity or consistency by contributing to the productivity of their communities through engagement in the workforce or at home.…”

Conceptual heuristic models of the interrelationships between obesity and the occupational environment

“…In addition to biomechanical factors, studies of animal MSD models suggest multiple biochemical and molecular mechanisms that may interact with obesity to influence MSD development (61). The association of knee osteoarthritis with occupational kneeling and squatting has been shown to increase 7-fold between the lowest and highest categories of BMI (69,70). The impact of heavy workload, obesity, and traumatic knee injuries on the development of osteoarthritis have been reported from a prospective study of a Finnish cohort with ≥20 years of follow-up (71).…”