To review within a prescribed evidence-based framework (1) the relationship between intermittent or lifelong physical activity and the subsequent onset or progression of osteoarthritis (OA) in later life and (2) the effect of structured exercise routines on the management of OA in the elderly.
A systematic literature search of MEDLINE (1950 to April Week 2, 2008) and EMBASE (1980 to 2008 Week 16) was carried out using the Ovid interface. Relevant mapped terms addressing the identified objectives were combined and exploded according to a defined protocol.
Studies that met relevancy criteria and were of high methodologic quality (prospective cohort studies for the risk factor component and systematic reviews and randomized controlled trials for the therapy component) were extracted and then hand searched for any additional studies. Final inclusion was based on agreement between two independent assessors, according to prescribed criteria. Any studies that were not in the English language, did not address the questions of interest in humans, or did not include a population that had at least a mean age of 55 years at the time of study termination, were excluded. Only land-based regimens were included in the therapy component of the review.
Pertinent information on subjects, risks, and outcomes (when assessing physical activity as a risk factor for OA in the elderly) and subjects, interventions, and outcomes (when evaluating the application of exercise in the management of OA in older persons) was extracted from the selected studies.
Ten studies met entry criteria for examining the relationship between physical activity and the development or progression of OA. Likely because of study variations and differences in the nature, duration and intensities of exercise regimens, no clearcut consensus was apparent on whether or not physical activity was a risk factor for OA. Six scientific reviews and ten single blinded randomized controlled trials were included when evaluating the effect of exercise on OA management. Regardless of wide variability in the included studies, a majority demonstrated that structured exercise programs were effective in the management of older subjects with OA.
Nuances of study design, differences in age and type of target populations, variability in the intensity, duration, and nature of physical activity in the respective studies, and lack of standardization in the way radiographic data are interpreted are among the factors that prevent consensus regarding the effect of physical activity on later development of OA. Similarly, there is considerable heterogeneity in the studies that assessed exercise in the treatment of OA. Nonetheless, there is substantive evidence in support of the benefits of one or another strength training or aerobic exercise regimen in the management of OA in middle-aged and elderly subjects.