Description:

 

These muscles are in the thoracic region that helps with shoulder and head movement and flexibility, as well as breathing. Muscles like the coracobrachialis and pectoralis major help the arm move forward, the scapula and vertebrae help arms pull objects, the deltoids help in flexing and extending, and the subscapularis, infraspinatus, and teres minor muscles help in rotation. The diaphragm is an external intercostal muscle that aids in lifting the ribs to help with breathing.