Background and purpose: Range of motion (ROM) measurements have been included in several hip scores evaluating the results after hip surgery. The clinical procedures of performing these measurements vary and disagreement exists about the accuracy of visual estimatess compared to goniometer measurements. The purpose of this study was to study the reliability of goniometric measurements and visual estimates of hip ROM in patients with osteoarthrosis.
Method: Hip ROM measurements (abduction, adduction, extension, flexion and internal/external rotation) were recorded by four different teams on the same day and were repeated one week later. Teams 1, 2 and 3 consisted of physiotherapists using standardized goniometric measurements. Team 4 involved an experienced orthopaedic surgeon making the assessments from visual estimates only. Twenty-five patients (6 M, 19 F; mean age 68.5 years, range 46-76 years) with osteoarthrosis of the hip, verified both clinically and radiologically, participated in the study.
Results: With the exception of abduction (p = 0.03), there were no significant differences between the measurements recorded on the first and the second occasions for the same teams. The coefficient of variance was 5.5% for flexion (lowest) and 26.1% for extension (highest). Reproducibility was best for flexion. There was also high reliability when all the arcs of motion were summed up (abuction + adduction + extension + flexion + internal/external rotation). With the exception of internal rotation, there were highly significant differences between the teams when two people performed the measurements compared to the values measured by a single individual. Concordance, expressed as the standardized agreement index, between visual estimates made by one individual (the orthopaedic surgeon) and goniometric measurements made by two experienced physiotherapists, were 0.77-0.83 which indicates good agreement.
Conclusion: The reproducibility of hip ROM measurements was highest for flexion. There was also high reliability when all the six arcs of motion were summed up. Concordance between visual estimates and goniometric measurements indicates good agreement.