During which phase does maximum shoulder internal rotation occur?

Maximum shoulder internal rotation occurs during the deceleration phase of throwing or overhead athletic movements. This phase follows the acceleration phase and is critical for managing the forces that are generated during the throw.

As the athlete transitions into the deceleration phase, the arm slows down its forward motion after ball release, and the shoulder rotates internally to help decelerate the arm and protect the shoulder joint from excessive strain. This internal rotation helps stabilize the shoulder and prevent injuries by dissipating the forces acting on the joint. The other phases of the motion align with different functions; for instance, the acceleration phase is focused on generating power and speed, while the follow-through phase aids in completing the motion but does not reach maximum internal rotation as seen in deceleration.