An ACL injury refers to damage to the anterior cruciate ligament, a key ligament in the knee that helps stabilize the joint. This type of injury often occurs during sports activities that involve sudden stops, jumps, or changes in direction, such as basketball or soccer. Symptoms typically include pain, swelling, and a feeling of instability in the knee. Treatment for an ACL injury may vary depending on the severity. Mild injuries can often be managed with rest, ice, compression, and elevation (RICE), while more severe cases may require physical therapy or surgical intervention. Rehabilitation is crucial for restoring strength and function to the knee.