Popping Sound
At the time when the injury occurs, you may notice a snapping popping sound. This indicates that the ACL can be torn. Depending on the severity of the injury, the noise can be low or so loud that even people around can hear it. It is important to seek immediate medical attention to get the right diagnosis. Try to remember the precise sound as it can be helpful in diagnosing the right injury. [2]
Knee Pain
Whether it is a minor or partial ACL tear, the affected area may really hurt. This is because the pain receptors in the knee are activated. You tend to feel pain around the center of the knee after the injury. When the pain occurs on the inside, it may indicate an MCL rather than an ACL tear. In particular, gnawing or radiating pain may occur when you are doing physical activity. Unlike progressive knee issues like knee osteoarthritis, the pain caused by an ACL tear tends to be sudden. [3]