The medial, or inside, of the knee is the source of the most frequent knee ligament injury. While commonly referred to as the “MCL”, the medial side of the knee is actually composed of several important structures, with several components, which must be assessed to determine the best way to get back to proper functioning. These components include the superficial medial collateral ligament, the deep medial collateral ligament and the posterior oblique ligament. The proximal division of the superficial medial collateral ligament is important to valgus stability, while the distal division of the superficial medial collateral ligament is important for external rotation stability. Thus, performing a thorough assessment by palpation of the zone of injury and assessing the amount of both valgus and rotational stability is important to determine the prognosis for a medial knee injury.