The most common mechanism of injury for posterior cruciate ligament (PCL) disruption is a force to the proximal tibia. When the foot is plantar flexed, the force vector is transmitted to the proximal tibia and a PCL injury can occur. When the foot is dorsiflexed, the force vector is transmitted through the patella. PCL injuries can also occur with hyperflexion in sports. ACL injuries typically occur with non-contact pivoting injuries. Collateral ligament injuries are a result of varus-valgus contact injuries. Knee contusion is a nonspecific diagnosis of exclusion.