Lachman’s test—the patient lies on the couch. The examiner places one hand around the distal femur and the other around the proximal tibia and then elevates the knee, producing 20° of flexion. The patient’s heel rests on the couch. The examiner’s thumb must be on the tibial tuberosity. The hand on the tibia applies a brisk anteriorly directed force. If the movement of the tibia on the femur comes to a sudden stop, it is a firm endpoint. If it does not come to a sudden stop, the endpoint is described as soft and is associated with a tear of the anterior cruciate ligament.