ACL is one of the four major ligaments that support the knee. ACL restricts the forward translation of the tibia over the femur.

1. After a sudden twisting motion or after you hear a sudden pop, there will be swelling and pain. Knee will start to feel unstable.


2. Lachman’s test – lying down, bend the knee 20-30 degrees, hold onto the upper bone to knee it stable and with other hand pull forward the lower bone. If there is no there then there will hardly be any movement, but if ACL tear is present then u will experience a great amount of sliding between the two bones.


3. Anterior drawer test - Lying down, knee bent to 90 degrees, sit on the person’s foot and with your hands on the lower leg try to pull it forward, if excessive translation is seen then ACL tear can be suspected.