Abstract
Patients with osteoarthritis of the hip (hip OA) often present an abnormal gait. To assess an abnormal gait objectively in patients with hip OA, gait parameters were developed by means of power-spectrum (PS), root mean square (RMS), auto-correlation (AC), and cross-correlation (CC) of trunk acceleration measured using a tri-axial accelerometer during free walking. The validity of parameters was examined by comparing those of 55 patients with unilateral hip OA and 31 normal control subjects and by analyzing correlations between parameters and clinical scores (Harris hip score, radiographic stage, walking score, and 10m maximum walking speed) in the OA group. There were significant differences in all parameters of three axes (p < 0.05) between patients and control subjects. PS and AC correlated significantly with all clinical scores (0.36 < r < 0.76 and 0.30 < r < 0.74, respectively). RMS and CC of anterior-posterior and vertical axes correlated with the majority of clinical scores (0.32 < r < 0.62 and 0.31 < r < 0.51, respectively). Among clinical scores, gait parameters had relatively strong correlations with walking-related indices (walking score and speed). These results suggest that trunk acceleration is useful to develop gait parameters for the objective assessment of an abnormal gait in patients with hip OA.
