Injuries to the upper extremities are common in sports and therefore receive considerable attention. Various studies have addressed the kinematics of the upper extremities in different motion patterns, such as throwing, a golf swing or a tennis stroke. Many studies can also be found on the diagnosis and treatment of upper extremity sports injuries as well as the corresponding rehabilitation. This is not the case with regard to injury mechanisms, however. Many questions remain unanswered and in terms of injury criteria and injury threshold levels, no conclusive literature has become available yet.