If the anterior cruciate ligament (ACL) becomes injured or torn, it may become lax or loose.  One test for this laxity is the anterior drawer test.  Your doctor will have you lay on the exam table on your back with your hips and knees bent.  He or she will sit on the edge of the table with his/her leg over the top of your foot.  The doctor grasps the lower leg (tibia) with both hands just below the knee joint.  The patient is told to relax.   The doctor attempts to pull the lower leg forward and feels the amount of motion between the lower leg (tibia) and thigh (femur).  The doctor will compare the motion from side to side.  An increase in motion or lack of a firm endpoint suggests a tear of the ACL.