How Do Knee Ligament Injuries Occur?
To understand the possible injuries, let’s talk anatomy. You have four main knee ligaments that connect the thigh bone (femur) to the shin bone (tibia). They are:
Anterior cruciate ligament (ACL): In the center of your knee, the ACL and PCL crisscross to form an “X”. Rotation and forward movement of the tibia under the femur is controlled by the ACL. A sudden twisting motion and abrupt stop while running, landing hard from a jump, or receiving direct contact (such as a football tackle) can cause the ACL to stretch or tear. When this happens, you’ll typically hear a loud pop and the injured leg will buckle when you attempt to stand.
For example, if a football player has a foot planted in one direction and because of a tackle, their knee twists in the other direction, the ACL could easily be injured. It can also happen due to a twisting fall while skiing if your bindings don’t release. The intense nature and frequent physical contact in sports like basketball and soccer also pose a high risk for ACL injury.
Once the injury occurs, bleeding will cause the knee to swell over the first 2-12 hours. You should ice and elevate the knee right away and see your physician for an evaluation. Full tears may even require surgical reconstruction. No matter the grade, physical therapy for knee ligament injuries help restore motion, as well as strength and agility. The worse the injury, the more intense the recovery.
Posterior cruciate ligament (PCL): Also located in the center of the knee, your PCL controls backward movement of the tibia under the femur. Stronger than the ACL, this ligament is more rarely injured. A sudden and direct blow will likely be the cause, such as a football tackle or car accident. Under most circumstances, a PCL injury does not destabilize the knee or require surgical intervention. Returning your knee to full function will, however, require physical rehabilitation.
Medial collateral ligament (MCL): This ligament is located on the inside of the knee joint and also helps with stability. A blow to the outside of the knee is often responsible for injuries to your MCL. If you’ve seen a football player land on the outside of another player’s knee while down, you might have seen this injury occur. If you experience one yourself, you’ll hear a pop instantly followed by pain on the inside of the knee. An MCL injury will also swell immediately and require full rest, ice, compression, elevation and crutches. Surgery may or may not be required depending on if the ligament fibers are torn in such a way that they’re unable to heal without medical intervention.
Lateral collateral ligament (LCL): On the outside of the knee is the LCL, which stabilizes the outer knee. The LCL is most often injured when a direct blow or sudden twisting injures one of your other three ligaments. If you hurt your LCL, your knee will most likely swell and the outside edge of the knee will be painful and tender. Follow the immediate treatment methods listed above for the MCL.
Knee Ligament Injury Prevention
To avoid injury and physical therapy for knee ligament injuries, there’s a lot you can do. Here are just a few ways to keep your knees in optimal condition.
- Stay in shape with regular exercise
- Stretch and warm up before physical activity
- Wear proper pads or protection
- Use appropriate technique for the sport
- Wear the right shoes – too much or too little traction creates risk
- Train on appropriate surfaces