Lachman test

A Lachman test is a medical test used for examining the ACL (anterior cruciate ligament) in the knee for patients where there is a suspicion of a torn ACL.

To do this, lie the patient supine on a bed. Put the patient's knee in about 20-30 degrees flexion . The examiner should place one hand behind the tibia and the other on the patient's thigh. On pulling anteriorly on the tibia, an intact ACL should prevent forward translational movement of the tibia on the femur. More than about 2mm of give suggests a torn ACL.