Optimal modality and dose of exercise for relieving pain in patients with knee or hip osteoarthritis: Bayesian...

To compare the effects of different exercise modalities and doses on pain in patients with knee or hip osteoarthritis (OA).

A systematic search of six electronic databases was conducted, from database inception to December 2024, to identify randomized controlled trials (RCTs) on exercise interventions in patients with knee or hip OA. Bayesian pairwise, network, and dose-response meta-analyses were conducted using a random-effects model to analyze the impact of exercise on pain in knee or hip OA. Two reviewers independently assessed the quality of the literature.

A total of 92 RCTs involving 6079 participants were analyzed. Aerobic training was found to have the highest likelihood of ranking first in effectiveness (Surface Under the Cumulative Ranking curve [SUCRA]: 84.7%; Standardized Mean Difference [SMD]: -1.00; 95% CrI: -1.50, -0.62), followed by strength combined with flexibility training (SUCRA: 73.0%; SMD: -0.93; 95% CrI: -1.40, -0.50), yoga (SUCRA: 63.7%; SMD: -0.86; 95% CrI: -1.50, -0.24), and strength training (SUCRA: 55.9%; SMD: -0.78; 95% CrI: -1.00, -0.55); flexibility training (SUCRA: 39.8%; SMD: -0.65; 95% CrI: -1.10, -0.22) ranked the lowest. However, there were no significant differences in effectiveness among the exercise types. When pooling data from all exercise modalities, a 'U-shaped' dose-response relationship was observed between the overall exercise dose and pain.

Exercise effectively reduces pain in patients with knee or hip OA. Although no exercise type was found to be statistically superior to another, based on probabilistic ranking, aerobic training, strength combined with flexibility training, yoga, and strength training had the highest likelihood of being the most effective interventions. The analysis identified that the optimal dose for maximizing pain relief was 620 metabolic equivalent of task (METs)-min/week (SMD: -0.93; 95% CrI: -1.24 to -0.58) (equivalent to, for example, approximately 120 min of moderate-intensity water aerobics per week), while the minimum dose to achieve a clinically important difference was 180 METs-min/week. However, given the methodological limitations of the analysis and the overall low to moderate certainty of the evidence, these findings should be interpreted with caution.