Association Between Hip Strength and Dynamic Balance in Stroke Survivors with Coexisting Knee Osteoarthritis

Background: Stroke patients often experience impaired balance and mobility, which may be exacerbated by comorbid knee osteoarthritis (OA). Hip muscle weakness is a key contributor to reduced dynamic stability in these populations. Objective: To examine the association between hip muscle strength and dynamic balance in stroke survivors with and without knee OA. Methods: This cross-sectional study included 37 post-stroke participants (20 without OA, 17 with OA). Hip flexion and extension strength were assessed using manual muscle testing (MMT). Balance was evaluated via One-Leg Stance (OLS), Center of Pressure (COP) range and sway, and the Functional Reach Test (FRT). Results: Stroke patients with OA demonstrated significantly lower hip strength and impaired balance performance compared to those without OA. Hip flexor and extensor strength on the affected side showed moderate correlations with OLS (r = 0.52), COP sway (r = 0.49), and FRT (r = 0.45). The OA group had reduced OLS time (p < 0.05) and a smaller COP range. Conclusion: Hip muscle weakness is significantly associated with compromised dynamic balance in stroke patients with knee OA, underscoring the importance of hip-focused rehabilitation strategies in this population.