Medial Collateral Ligament (MCL) Stability can be tested with the knee at 0 and 30 degrees of flexion by applying a valgus force to the knee in those positions. Laxity at 30 degrees denotes a second-degree injury to the medial collateral ligament. Laxity at 0 degrees denotes a third-degree injury to the medial collateral ligament. Tenderness to palpation over the MCL indicates at least a first-degree injury.