MODEL RELEASED. Lachman knee ligament test. Physiotherapist performing a Lachman test on a patient's knee ligaments. This test is designed as an assessment of the knee's anterior cruciate ligament, one of the major ligaments holding the knee joint together. The knee is bent slightly (about 20-30 degrees of flexion), and the physiotherapist holds down the patient's thigh with one hand. The other hand is placed behind the calf near the knee and used to pull the lower leg forward. If the tibia (the main lower leg bone) moves forward while the femur (thigh bone) stays in place, this suggests a torn anterior cruciate ligament. The physiotherapist will also carry out the Drawer test to confirm the diagnosis.