10 Common Symptoms of ACL Injuries


An ACL injury is when you tear the anterior cruciate ligament (ACL), which is basically a major ligament in your knee. Athletes are often those who suffer ACL injuries due to changing directions, making sudden stops, and jumping around.

You may need rest and rehabilitation to regain strength and stability. If the injury is more serious, surgery is required. An estimated 200,000 ACL injuries occur each year, and 100,000 ACL surgeries are performed annually, according to the American Academy of Orthopaedic Surgeons (AAOS). There are several symptoms that indicate you have an ACL injury.

Symptom 1: Pop Sound

Did you hear or feel a loud "pop" sound in your knee? That is one indication that you inured your ACL.

The sound and/or feeling is very distinct. Most people know instantly that it is from their ACL. Check out this video!

Symptom 2: Limited Range of Motion

Is there a limited range of motion for your knee? You may not be able to move your knee much because of the pain and swelling associated with the ACL injury.

After a few days or weeks, you should be able to move your knee like normal, but you may still experience some instability.

Symptom 3: Unstable Knee

Does your knee seem unstable and unable to bear any weight? Does it feel like your knee just gives out?

Any type of injury to your ACL can make it difficult or impossible to walk or run, at least for a while.

Symptom 4: Severe Pain

Is there severe pain and inability to continue with your physical activity? Is it painful to stand? With an ACL injury, you feel severe pain, especially on the front and back of your knee.

The pain decreases in a few weeks or sooner if you use anti-inflammatory medications, icepacks, and other treatments.

Symptom 5: Swelling

With an ACL injury, your knee may swell immediately or within a few hours of the ACL being injured. The sooner the swelling occurs, the more serious the injury.

Swelling diminishes in a few weeks or sooner if you use anti-inflammatory medications, icepacks, and other treatments.

Symptom 6: Stiffness

An ACL injury involves stiffness and swelling of the knee, making it hard to walk of perform actions. Your range of motion is limited due to the stiffness.

Surgery and/or rehabilitation may be required to reduce the stiffness and let you be able to properly use your knee again.

Symptom 7: Bruising

Bruising typically occurs hours after the ACL injury. It happens when bleeding reaches the top of the knee joint.

To reduce the bruising, use icepacks and elevate your knee.

Symptom 8: Limping

It is often difficult to walk after injuring your ACL. You may limp and feel unstable for a while. Use crutches or a cane for assistance.

There are exercised you can do to improve your strength and stability to minimize or eliminate limping.

Symptom 9: Warm to Touch
Does your knee feel warm when you touch it? If it does, it could be because of the knee joint bleeding.

Put ice on your knee to reduce swelling and inflammation, but do not use heat on the injury.

Symptom 10: Hyperextension

You may feel a brief hyperextension of the knee joint, like it is bent backward, with an ACL injury. This is uncomfortable and not within the normal range of motion.

You should rest, ice, compress, and elevate your knee to try and avoid surgery.