What is the ACL?

The ACL stands for the anterior cruciate ligament, which is one of the stabilizing ligaments in the knee joint. It is located behind the kneecap and connects the femur to the shin bone (tibia). Importantly, this ligament prevents excess forward and backwards movements of the femur and tibia overtop each other. When people say their ACL is injured, this refers to either a sprain or tear of the ACL ligament.

How is the ACL injured?

Ligaments work as a connective, stabilizing band for two bones. The ACL, one of two ligaments that cross in the middle of the knee, connects your thighbone to your shinbone and helps stabilize your knee joint.

ACL injuries often happen during sports and fitness activities that put high shear and stress forces on the knee:

• Suddenly slowing down and changing direction (cutting)
• Pivoting with your foot firmly planted (plant and twist)
• Landing awkwardly from a jump
• Stopping suddenly from a run/sprint
• Receiving a direct blow to the knee or having a collision, such as a football tackle, dashboard injury etc

During the moment of injury, you may sometimes hear and feel a popping kind of sound inside the knee. Afterwards, the knee swells, bruises or becomes red, and is difficult to walk and put pressure on it. When the ligament is damaged, there is usually a partial or complete tear of the tissue. A mild injury may stretch the ligament but most of the tissue is still intact.

How do I know if I’ve injured my ACL?

Signs and symptoms of an ACL injury usually include:

• A loud popping sound at the time of the injury
• Severe pain and inability to continue activity
• Rapid swelling
• Loss of range of motion
• A feeling of instability or “giving way” in the knee with weight bearing

However, it is best to get checked by a healthcare professional like a physiotherapist if you suspect an ACL injury.

Can this injury be prevented?

Accidents happen and sometimes they are unavoidable such as an accidental collision of players during a game. However, proper strength and conditioning and athletic training can minimize the risk of an ACL sports injury occurring. This may include:

• Strengthening of core, glute, and knee muscles. Especially hamstring and quadriceps which are the main movers of the knee joint.
• Co-ordination, balance, proprioception, mobility training and drills
• Improving pivot shifting or other sport specific techniques

How is an ACL injury managed?

In acute injury of ACL tear or sprain, the RICE protocol will help minimize pain, swelling, inflammation, and risk of further injury.

1)The RICE protocol is as follows:

• Rest: Avoiding exercise will allow muscles to recover and allows space for healing
• Icing: Icing over top of the knee can help manage swelling, inflammation, and pain
• Compression: Compression bandages or braces will reduce the stress on the muscles, help manage swelling and minimize pain.
• Elevation: Elevating the leg on few pillows will reduce swelling from the leg

2) Modalities: TENS and ultrasound will help reduce pain and inflammation and increase the efficiency of healing

3) ACL brace: ACL braces will prevent further damage to the ACL and give more stability to your knee

An example of an ACL brace by DonJoy, they are often made to custom fit each knee

4) Orthotics: Proper footwear will improve mechanics and reduce extra stress in knee joint

5) Strengthening of knee and hip muscles: Strengthening of those muscles will support the ligament and makes knee stronger to resist the injury.

6) Balance and co-ordination training:  Oftentimes, training the specific movement is the best way to improve it. Therefore, training of cutting, pivoting, suddenly starting and stopping, landing from a high jump etc in sports that use these movements is essential to minimizing the risk of an ACL injury.

Need help with a knee injury?

If you think you may have an ACL injury or are experiencing any other type of knee pain, look for PhysioNow! We are a clinic that operates in the GTA from Burlington to Etobicoke with 9 different clinic locations. Our Registered Physiotherapists are highly experienced in sports injuries and knee injuries. Book with PhysioNow today for your first assessment and treatment!