Reliability and Agreement of Hip Range of Motion and Provocative Physical Examination Tests in Asymptomatic Volunteers

Objective: To: (1) report passive hip range of motion (ROM) in asymptomatic young adults, (2) report the intratester and intertester reliability of hip ROM measurements among testers of multiple disciplines, and (3) report the results of provocative hip tests and tester agreement.

Design: Descriptive epidemiology study.

Setting: Tertiary university.

Participants: Twenty-eight young adult volunteers without musculoskeletal symptoms, history of disorder, or surgery involving the lumbar spine or lower extremities were enrolled and completed the study.

Methods: Asymptomatic young adult volunteers completed questionnaires and were examined by 2 blinded examiners during a single session. The testers were physical therapists and physicians. Hip ROM and provocative tests were completed by both examiners on each hip.

Main Outcome Measurements: Inter-rater and intrarater reliability for ROM and agreement for provocative tests were determined.

Results: Twenty-eight asymptomatic adults, mean age 31 years (range, 18-51 years), with a mean modified Harris Hip Score of 99.5 ± 1.5 and UCLA activity score of 8.8 ± 1.2 completed the study. Intrarater agreement was excellent for all hip ROM measurements, with intraclass correlation coefficients (ICCs) ranging from 0.76 to 0.97, with similar agreement if the examiner was a physical therapist or a physician. Excellent inter-rater reliability was found for hip flexion ICC 0.87 (95% confidence interval [95% CI] 0.78-0.92), supine internal rotation ICC 0.75 (95% CI 0.60-0.84), and prone internal rotation ICC 0.79 (95% CI 0.66-0.87). The least reliable measurements were supine hip abduction (ICC 0.34) and supine external rotation (ICC 0.18). Agreement between examiners ranged from 96% to 100% for provocative hip tests, which included the hip impingement, resisted straight leg raise, Flexion Abduction External Rotation/Patrick, and log roll tests.

Conclusions: Specific hip ROM measures show excellent inter-rater reliability, and provocative hip tests show good agreement among multiple examiners and medical disciplines. Further studies are needed to assess the use of these measurements and tests as a part of a hip screening examination to assess for young adults at risk for intra-articular hip disorders before the onset of degenerative changes.