The Anterior Cruciate Ligament (ACL) is a major ligament located inside the knee and provides a large amount of stability to the joint. A sprain of the ACL can be caused by hyper extending the knee, a twisting motion, landing awkwardly from jumping or it can come from a direct blow. Many experience a “pop” in the knee at the time of injury, causing the knee to buckle and give way when walking. This is often followed by rapid knee swelling within the next few hours. Initial treatment for an ACL sprain is Rest, Ice for 15-20 minutes at a time, a Compression wrap to control swelling, and Elevation of the leg (R.I.C.E.). This type of injury can be significant and needs to be evaluated by your primary care provider, orthopedist or you can contact Children’s Sports Medicine for more specialized care.