Variability in hip range of motion on clinical examination.
The goal of this study was to determine the interobserver and intraobserver reliability of physical examination in determining hip range of motion. Twenty normal hips, 21 hips with osteoarthritis, and 21 hips of patients more than 12 months after a total hip arthroplasty were examined for visual passive range of motion. These 62 hips were examined by 2 experienced surgeons and by 3 trainees. The 2 experienced examiners repeated their clinical examinations in 19 patients to determine the intraobserver reliability. Intraclass correlation coefficients (ICCs) indicated moderate interobserver agreement in estimates of clinical hip motion (ICC for hip flexion, 0.56 +/- 0.12; for hip abduction, 0.48 +/- 0.13). Intraclass correlation coefficients also suggest only moderate intraobserver reliability in measurements of hip motion (ICC for hip flexion, 0.62 +/- 0.14; hip abduction, 0.44 +/- 0.20). More reliable and accurate methods are needed to measure clinical hip motion before and after total hip arthroplasty.