Cocking Movement Analysis

When one is getting ready to throw a pitch, there is 5 phase to complete a proper throw. The five phases of a throw are the windup, early cocking, cocking, acceleration, and the follow-through. (Hamill & Knutzen), It should be notated that is the wind up phase there is little shoulder activity involved. In the early cocking phase, the lead off arm is in a potion of 90 degrees and in a position of abduction and introduces external rotation. As the player transitions into the cocking phase, the muscle that are involved in this motion is the supraspinatus, infraspinatus, and teres minor, these muscles will allow abduction, subsequently completing the external rotation of the shoulder as well as the position of the point of the humeral
The scapula is further conveyed into a position of retraction; the elbow is flexed; and the humerus undergoes abduction and external rotation. (Hamill & Knutzen) Though we are focusing on the muscles that eccentrically contract the shoulder, I will have to address some lower body mechanics, so that I can best explain the early cocking to cocking transition. With that being said, the lead knee begins to extend, forming a solid base for trunk flexion, in synchronization with the lower extremities, the torso will rotate, while the anterior deltoid and pectoralis major contract to bring the throwing extremity into horizontal adduction position. (Hamill & Knutzen) It should also be mentioned that during the late cocking phase, the last latissimus dorsi as well as the the pectoralis major muscles will exhibit a rapid increase in activity as these muscles will eccentrically act to slow the backward movement and concentrically act to initiate the forward progress. (Hamill & Knutzen) The biceps brachii and the brachialis are also active as the forearm flexes and the arm is abducted. When the triceps brachii becomes involved at the end of the the cocking phase, is when the arm is maximum external rotation and the elbow is in a maximally flexed. (Hamill &
Muscles encompassed during this phase are the upper trapezium, serratus anterior, anterior deltoids. These muscles will contract, therefore causing an upward rotation and elevation of the scapula and abduction of the shoulder. During the cocking phase the shoulder muscles involved are very high activity. This is due to the fact that the arm has to be in constant motion as the stabilization of the humerus. The muscles involved are the infraspinitus and teres minor muscles stabilize humerus rotation. The acceleration was extremely high, the scapular muscles, this allows the advancing motion of the arm and