In sports activities, muscles must lengthen and contract with precision over very short periods of time. Muscle inherently has properties of elasticity which can compliment force production. Plyometrics take advantage of the stretch-shorten cycle of muscle.
Stretched muscle tends to immediately contract with greater force.
When training for a sport activity, muscle specificity should be adhered to. The result is a forceful contraction of the internal rotators to throw the ball. These exercises will help develop the plyometric capabilities in the throwing shoulder. Functional Plyometric Exercises for the Throwing Athlete.