Gait- and Posture-Related Factors Associated With Changes in Hip Pain and Physical Function in Patients With Secondary Hip Osteoarthritis: A Prospective Cohort Study

Abstract

Objective: To identify gait- and posture-related factors associated with changes in hip pain and physical function in patients with hip osteoarthritis (OA). Design: Prospective cohort study. Setting: Clinical biomechanics laboratory of a university. Participants: Consecutive sampling of female patients with mild-to-moderate secondary hip OA (N=30). Main Outocome Measures: Hip pain (visual analog scale) and physical function (physical component summary of the Medical Outcomes Study 36-Item Short-Form Health Survey) were measured at baseline and 12 months later. With changes in hip pain and physical function as dependent variables, linear regression analyses were performed with gait- and posture-related factors as independent variables with and without adjustment for age, joint space width, and hip pain or physical function at baseline. Posture-related factors included angles of thoracic kyphosis, lumbar lordosis, sacral inclination, spinal inclination, and spinal mobility. Gait-related factors were walking speed, steps per day, joint angles, external hip joint moment impulses, and daily cumulative hip moments. Results: Multiple linear regression analyses showed that limited hip extension (adjusted standardized B coefficient [95% confidence interval]: −0.52 [−0.88 to −0.17]) and limited external rotation angles (−0.51 [−0.85 to −0.18]) during walking were associated with the worsening of hip pain. An increased thoracic kyphosis (−0.54 [−0.99 to −0.09]), less sacral anterior tilt (0.40 [0.01-0.79]), reduced thoracic spine mobility (0.59 [0.23-0.94]), less steps per day (0.53 [0.13-0.92]), and a slower walking speed (0.45 [0.04-0.86]) were associated with deterioration in physical function. Conclusions: Gait- and posture-related factors should be considered when assessing risk and designing preventive interventions for the clinical progression of secondary hip OA.