REPEATIBILITY AND RELIABILITY OF KNEE JOINT ROTATIONAL LAXITY MEASUREMENTS WITH DOUBLE GONIOMETRY

The results of existing studies on the range of motion in the knee joint rotation are contradictory. The best method for measuring knee rotation has not yet been found. The purpose of this study was to investigate the repeatability and reliability of knee joint rotational laxity measurement using two magnetic goniometers. Thirty healthy subjects (15 males and 15 females) aged between 20 and 32 years participated in the study. Internal and external rotation of the left and right knee joints were measured with double goniometry in the sitting position with 90° flexion of the knee. There was no statistically significant difference in measurements between first and second session. The intraclass correlation coefficient (ICC) for repeatability ranged from 0.812 to 0.858 and for reliability from 0.655 to 0.837. Within-subject coefficient of variation was less than 10%, standard error of measurement was between 1.4^o and 2.0^o, minimal detectable change was between 2.5^o and 3.8^o. The measured values of internal and external rotation did not completely agree with those reported by other authors. The ICC values indicated good to very good repeatability and reliability of the double goniometry measurement of rotational knee laxity. Technical improvements will be required before translation into clinical practice.