What is the Anterior Cruciate Ligament (ACL)? It’s one the four major ligaments of the knee; connecting the thigh bone (femur) to the shin bone (tibia) and plays a major role in keeping the knee stable and controlling back and forth motion, especially when cutting and pivoting.
An ACL tear is a very common knee injury, especially in sports. The majority of tears are due to non-contact injuries and women are 4-6 times more likely than men to get an ACL tear*. When ligaments are injured, it referred to as a “sprain” and is broken down into three grades:
Grade 1: The ACL is marginally stretched, but still is able to help support knee joint.
Grade 2: Also referred to as a “partial tear”, the ligament is stretched to the point it becomes loose.
Grade 3: When the ligament is split in two and the knee becomes unstable it is a “complete tear”.
Healthy ACL Torn ACL
There are several movements that may result in damage to the ACL, such as:
- Twisting your knee while keeping your foot planted on the ground
- Stopping suddenly while running
- Suddenly shifting your weight from one leg to the other
- Jumping and landing on an extended (straightened) knee
- Stretching the knee farther than you should
- Experiencing a direct hit to the knee*
When the ACL is torn, the most common report by those who are injured is that they felt or heard a “pop.” There is usually immediate pain and swelling in the knee and further participation in the activity is not possible. If this happens to you, seek medical attention. A physical therapist (PT) has several tests they are able to complete to determine if you have a tear, but it may still be necessary for you to see a sports physician for additional tests.
Unfortunately, very few ACL sprains will heal without surgery. The stresses are too great that a compromised ACL, even a grade one sprain, will notice “giving way” when they attempt to cut or pivot. Even if surgery is required, having physical therapy beforehand can help improve your outcome. Prior to surgery, your PT can work with you to help reduce swelling, strengthen your thigh and hip muscles and increase the range of motion. For an optimal and smooth recovery, the knee should fully extend before surgery.
Post-surgical physical therapy will play a very important role in getting you back to your top performance level. Your PT will set up a program specific for you and will be created to rebuild mobility and strength in the knee and the surrounding area; followed by a more functional rehabilitation tailored for your activity or sport. It will take a good six – twelve months to get back to full capacity and you should always check with your PT and doctor for the OK. Indicators that you may be ready to go back to playing include:
- You no longer have pain and swelling
- You have no feelings of instability during sport-specific activities, such as cutting, jumping, and landing
- Your quadriceps strength is 90% of that on your uninjured side
- Your performance of the 1-legged hop test is at 90% of that on the uninjured side*
Although it may be difficult to completely prevent an ACL tear; proper strength, balance, core and sport-specific training can certainly help to reduce the chance for injury. If you feel you may have a damaged ACL, contact a PT at any one of our 19 locations for a consultation.
*Move Forward PT – Physical Therapist’s Guide to Anterior Cruciate Ligament (ACL) Tear