Comparative Analysis of Knee-laxity Measurements by a Lefthand- and a Right-hand-dominant Physiotherapist in Patients with Anterior Cruciates Ligament Injuries and Healthy Control Group

The purpose of the study was to analyze and compare KT-1000 knee laxity as examined by a left-hand- and a righthand- dominant physiotherapist in a group of patients with an anterior cruciate ligament (ACL) injury and a group of patients, 2 years after ACL reconstruction. A cross-sectional examination of two groups of patients pre-operatively and post-operatively after ACL reconstruction and examination of healthy controls on two different occasions was performed. In the ACL-deficient group, 14 patients had a right-sided ACL injury and 08 patients a left-sided ACL injury. The corresponding figures in the post-operative group were 13 patients with a right-sided ACL injury and 07 patients with a left-sided ACL injury. 20 healthy persons without any known knee problems served as controls. One left-hand- and one right-hand-dominant experienced physiotherapist performed all the examinations. The lefthand- dominant physiotherapist measured significantly higher absolute laxity values in the left knee, both injured and non-injured ones, compared with the right-handdominant physiotherapist. This was found irrespectively of whether the patients belonged to the ACL deficient or the post-operative group. In the healthy control group, the righthand- dominant physiotherapist measured significantly higher knee-laxity values in the right knee compared with the left-hand-dominant physiotherapist. Correspondingly, the left-hand-dominant physiotherapist measured significantly higher knee laxity values in the left knee. We conclude that KT-1000 arthrometer laxity measurements can be affected by the hand dominance of the examiner. This might affect the reliability of KT-1000 arthrometer measurements.