Self-reported physical activity is related to knee muscle strength on the unaffected side and walking ability in patients with knee osteoarthritis awaiting total knee arthroplasty: a cross-sectional study

Background: Additional evidence regarding the effectiveness of self-management programs for patients awaiting total knee arthroplasty is required.Objective: The study aimed to determine if self-reported physical activity was related to muscle strength and walking ability in patients with knee osteoarthritis awaiting total knee arthroplasty.Methods: The study included subjects with knee osteoarthritis awaiting total knee arthroplasty (n = 767). Walking ability and bilateral knee muscle strength were measured as dependent variables. Self-report physical activity was assessed based on the guidelines from the Japanese Ministry of Health, Labor and Welfare. Multiple regression models determined if self-reported physical activity was significantly related to dependent variables, after accounting for other related factors.Results: Physical activity was associated with both higher knee flexion (β = −0.09, p = .013) and higher extension (β = −0.09, p = .007) muscle strength on the unaffected side only. In addition, physical inactivity was associated with a lower walking ability level (TUG: β = 0.08, p = .015; 5mWT: β = 0.10, p = .005).Conclusions: These results can help health-services providers develop educational and/or self-management programs to maintain muscle strength on the unaffected side and walking ability in patients awaiting total knee arthroplasty.