What characterizes the acceleration phase in athletic movement?

The acceleration phase in athletic movement is indeed characterized by the phase that spans from maximum external rotation until ball release. This is a critical segment of actions involving throwing, swinging, or striking, where the athlete generates force and speed to propel the object.

During this phase, the body's segments work in a coordinated manner to achieve the greatest acceleration of the object being thrown or swung. The maximum external rotation position allows for optimal storage of elastic potential energy in the muscles and tendons, which is then used effectively to convert this energy into kinetic energy as the movement progresses towards the release point.

This phase is vital for achieving high velocity and power in the throw or strike, making it foundational in many sports mechanics—especially in sports like baseball, tennis, or football. Understanding this phase is crucial for athletes and trainers alike, as it is where much of the dynamic force production and technique occur.

The other described phases serve different roles in the overall motion but do not specifically capture the essence of acceleration, which is focused on the explosive force generated immediately before and during the release moment.