Actually, there are several laximeters for measuring anterior tibial translational in case of anterior cruciate ligament rupture. The most commonly used are telos, KT-1000, GnrB and Rolimeter. Results of these instrumented tests, which expressed in differential (millimeters values), have a bad correlation between them and so are not comparable in current literature. The aim of this study was to compare results of these tests and establish a ratio (pathologic knee laxity/ healthy knee laxity) to reduce differences between each instrumented test.