Final answer:
Eccentric contraction occurs during the cocking phase of throwing a baseball when the muscles lengthen under tension. This prepares the arm for the powerful throw that follows.
Step-by-step explanation:
During the cocking phase of throwing a baseball, the muscles involved are typically undergoing an eccentric contraction. This is because during this phase, the muscle lengthens while still under tension to control the limb's movement, which is a defining characteristic of an eccentric contraction. The option b) Eccentric contraction occurs, is the correct one.
In biomechanics, this action allows the muscles, such as the rotator cuff in the shoulder, to lengthen while controlling the raising and rotation of the arm in preparation for the throw. This control is essential for both the power and the accuracy of the subsequent throwing motion. In the eccentric contraction, the muscles act as a brake to prepare for the explosive power of the throw, and although the muscle fibers are lengthening, they are still actively generating force.