I blogged a couple of weeks ago about the difference between a "sprain" and a "strain." Well, during the Steelers-Titans game last night, there was a great example of a MCL sprain. The Medial Collateral Ligament is the ligament on the inside of the knee. It helps prevent the knee from "buckling" on the inside. It is frequently injured in football and injured much more frequently than the Lateral Collateral Ligament. Typically, the ligament is damaged by a valgus force, which is a force directed in the lateral to medial direction. In the above picture, the Titans player landed on the lateral aspect of the knee of Troy Polamalu, which stretched and damaged the MCL on the medial side. Football players are hit much more frequently on the lateral or outside of the knee, which causes damage to the MCL. Polamalu is reported to be out for 3-6 weeks, which would lead me to believe it is a Grade II MCL sprain. If the ligament was completely torn, as in the top picture, he would probably be out much longer, if not the entire season. With a grade II sprain, there is some tearing of the ligament, but not a complete disruption. He will likely wear a knee brace when he returns to help protect against a repeat of this injury.
