Background: Shoulder complex injuries are common among overhand throwing athletes. These injuries often manifest as a result of habitual sport performance and often lead to time loss injuries. The mechanisms of these injuries are often non-traumatic and theories on how shoulder injuries manifest differ. Objectives: To describe the proposed mechanisms of commonly reported shoulder injuries as they relate to the phases of the throwing motion. Major findings: Shoulder injuries commonly involve rotator cuff muscles and tendons, scapulothoracic muscles, glenohumeral joint labrum, proximal humeral epiphysis, glenohumeral joint capsule, biceps muscle and tendon, and subacromial bursa. The injuries found in these tissues and their purported mechanisms of injury during the throw vary. Conclusions: The late cocking and deceleration phases have been implicated with the largest number of associated pathologies. Multiple injuries were theorized to occur at more than one phase of the throwing motion. Consensus has not been achieved on the provocative events leading to shoulder injury during the throwing motion.