Answer:
The muscles that the personal trainer would expect to be shortened are Sternocleidomastoid and pectoralis major. The right answer is Option A.
Explanation:
While assessing one's posture, if a person has protracted shoulders and a forward head, then the trainer focuses on working on the sternocleidomastoid and pectoralis major muscles. The former is one of the largest superficial cervical muscles which helps in the rotation of the head to the opposite side and flexion of the neck. The latter is responsible for shoulder joint movement. At first, it causes flexion of the humerus like lifting a child. Secondly, it adducts the humerus like when one flaps his/her arms. Working on these muscles helps to correct the posture of the concerned person.
