Throwing Injuries of the Shoulder Wheeless

Description: Phases of Throwing:
- wind up
- early cocking: deltoid and rotator cuff are active;
- late cocking phase:
- muscle activity:
- shoulder is placed in hyper-external rotation;
- pectoralis major and the subscapularis (shoulder adductors) and the latissimus and teres major (internal rotators) are placed under eccentric stress;
- supraspinatus is also active during this stage (by EMG analysis);
- biceps contracts (for elbow flexion)
Wheeless' Textbook of Orthopaedics