Test–retest and inter-rater reliability of Clinometer for measuring range of motion in patients with hip osteoarthritis

Abstract

Objective: To evaluate the test–retest and inter-rater reliability of the application Clinometer for measuring the hip range of motion (ROM) in patients with hip osteoarthritis and its correlation with the universal goniometer. Methods: A blinded repeated measured was carried out with 35 patients with hip osteoarthritis. Hip internal rotation, external rotation, flexion and extension ROM were measured using Clinometer app by 2 independents raters. The intraclass correlation coefficient was used to calculate the test–retest reliability and inter-rater reliability. The standard error measurement and minimal detectable change were also calculated. The Pearson's correlation coefficient was used to correlate the app with the universal goniometer. Results: Clinometer application achieved excellent test–retest reliability (intraclass correlation coefficient: 0.82-0.96) and inter-rater reliability (intraclass correlation coefficient: 0.81-0.95) in all the ROMs assessed. The correlation analysis with the universal goniometer showed strong correlation values (r > 0.70) in all the ROMs assessed. Conclusion: Clinometer application presented excellent test–retest reliability and inter-rater reliability for the measurement of hip ROM in patients with hip osteoarthritis. The smartphone application showed a strong correlation compared to universal goniometer.