"If it's got a 'P' it's a ligament injury"
Grade 1 - Some tenderness and minor pain at the point of injury. This indicates small tears in the ligament
Grade 2 - Noticeable laxity in the knee, major pain and tenderness on the inside of knee as well as swelling. Indicates larger tears in the ligament but not a complete rupture
Grade 3 - Considerable pain/tenderness, some swelling, marked laxity/instability of the joint. Ligament is completely torn/ruptured