AnatomyYour anterior cruciate ligament (ACL) is located in the middle of the knee joint, connecting the shin bone (tibia) to the thigh bone (femur). It crosses over diagonally with the posterior cruciate ligament (PCL) to control the backward and forward movement of the knee at the joint. It is one of four strong stabilising ligaments of the knee, along with the PCL and the medial and lateral collateral ligaments. The ACL works to stop the tibia from sliding forwards in front of the femur.
What causes an ACL injury?
Injury to the ACL is a common knee injury, and often occurs alongside injury to other knee structures, such as the cartilage and the collateral ligaments. The different levels of severity of injury include a ligament sprain, a partial tear, or a complete rupture. ACL injuries are often sustained by athletes involved in high-impact sports that involve sudden changes in direction, such as basketball or soccer. ACL injuries are more common in females, which may be attributed to by muscle strength, control and conditioning. Typically, ACL injuries are caused by:
- Direct trauma/impact such as from tackles
- Quickly changing direction
- Sudden stops, especially during fast-paced activity
- Improper landing from jumps
- Overextending the knee
What are the symptoms?Depending on the severity of your injury, symptoms may include:
- Feeling unstable, like your knee is giving out from under you
- A ‘popping’ sound on impact/injury
- Pain and tenderness in the knee, especially on walking
- Limited movement in the joint