Intertester and intratester reliability of a movement control test battery for patients with knee osteoarthritis and controls

OBJECTIVES To develop a test battery of movement control (MC) tests and assess its intertester and intratester reliability. METHODS 29 subjects with knee OA with mean age of 64.7 (SD 8.7) years and 12 controls without either knee pain or previous diagnosis of OA (mean age 36.6 (SD 16.2) years) were included. Two experienced physiotherapists rated the filmed test performance of six MC tests blinded to the patients and to each other on 3-point scale as correct, incorrect or failed. Weighted kappa coefficient (wK) with 95% confidence interval (95%CI) and the percentage of agreement were calculated for each test. RESULTS One-leg stance, one-leg squat 30 degrees and step down tests showed moderate to excellent inter- and intratester reliability with wK ranging between 0.43-0.85 for intertester and 0.51-0.80 for intratester reliability. The reliability of the 90 degrees squat test, small squat and step up tests was poor (wK ranging between 0.09-0.50). CONCLUSIONS One-leg stance test, one-leg squat 30 degrees and step down test are reliable in the subjects with knee OA and controls. Further studies are needed to evaluate the discriminative validity of the reliable tests.