Background: Hip osteoarthritis (OA) is a prevalent degenerative joint disease that significantly impacts mobility and quality of life. Among individuals with unilateral hip OA, the condition often leads to reduced hip strength, compromised physical function, and impaired dynamic balance. In people with hip osteoarthritis, the association between multidirectional hip strength and physical function or balance is unknown.

Methods: Fifty- five participants (20 men and 35 women, age 40-80 years) with unilateral hip osteoarthritis were included. Hip strength was assessed with Muscle strength grading scale (oxford scale), physical function was assessed with 30-s chair-stand test (30sCST) and stair-climb test (SCT); and dynamic balance was assessed in 3 directions using the Star Excursion Balance Test. Multivariable linear regression analysis was used to determine the strength of relationships between measures. Data analysis was done by using the IBM SPSS Statistics 29.

Results: Hip strength, except for internal rotation, was positively associated with better physical function (SCT: R² = 0.5 to 0.54; 30sCST: R² = 0.39 to 0.42) and dynamic balance (anterior: R² = 0.33 to 0.45; posteromedial: R² = 0.32 to 0.45; posterolateral: R² = 0.27 to 0.35). Adjusting for knee extension strength, hip strength explained an additional 8%-12% (p < 0.05) in anterior reach and 5%-12% (p < 0.05) in posteromedial reach on the Star Excursion Balance Test.

Conclusions: Hip strength in various directions is linked to physical function and dynamic balance in individuals with unilateral hip osteoarthritis. Clinicians should incorporate multi-directional hip strength into exercise programs to address patients' functional and balance goals.

Index Terms- Hip osteoarthritis, Hip Strength, Function, Balance.