Walking speed affects instrumental activities of daily living in patients with hip osteoarthritis

BACKGROUND: The symptoms of hip osteoarthritis (OA) influence instrumental activities of daily living (IADL). Evidence form previous studies suggest that body functions and walking speed are important etiological factors for IADL. However, no studies have investigated which factors that have the greatest influence on IADL. OBJECTIVE: The aims of this study were (1) to analyze factors related to IADL in patients with hip OA, including 10 m walking speed (10 mWS), and (2) to establish cut-off values for factors that predict maintenance of IADL. METHODS: Forty-eight patients participated in this study. IADL was treated as dependent variable. Range of motion (ROM), muscle strength of the hips and knees, and 10 mWS were measured as independent variables. Other potential confounding factors were also measured. Data were analyzed using hierarchical multiple regression and Receiver Operating Characteristic curve analysis. RESULTS: The hip flexion ROM on the affected side and 10 mWS were selected as significant variables in this study. The cut-off values obtained were 92.5 degrees for the hip flexion ROM on the affected side and 42.3 m/min for 10 mWS. CONCLUSIONS: The suggested target associated with maintaining IADL in patients with hip OA is the cut-off value of 42.3 m/min for 10 mWS found in this study.