Answer:
The pectoralis major is the muscle responsible for pulling the arm forward (felxion) and across chest (adduction) and rotating medially.
Step-by-step explanation:
A fan-shaped muscle this muscle, present under the breast and in the chest of human body is known as the pectoralis major. The term pectoralis is derived from a Latin word pectus, meaning- breast.
The main function of the muscle pectoralis major is the flexion (pull arm forward) , adduction (pull arm across chest) and internal rotation of the humerus.