The Lachman and reverse Lachman maneuvers test for ACL and PCL pathology, respectively. To perform this test, ask the patient to lie supine with the knee flexed passively to 30 degrees. Use one hand to stabilize the femur just above the knee and use the other hand to displace the tibia anteriorly to test the ACL and posteriorly to test the PCL. If unable to support the patient’s leg in this position, alternative maneuvers can be performed as shown. This includes resting the patient’s leg on your thigh while seated, or placing the patient’s leg between your knees, again while seated. These positions offer more support and rely less on arm strength. The Lachman is positive if there is increased laxity compared to the unaffected side.