Question: At the ER, the nurse practitioner performed a Lachman test to assess damage to the ACL. In the Lachman test, the knee is flexed at 15 degrees with the patient supine. The places one hand behind the tibia and the other grasping the patient's thigh. The tibia is pulled forward to assess the amount of anterior motion of the tibia in comparison to the femur (see image in the introduction to the case). An intact ACL should prevent this forward movement.