While both the pectoralis major and pectoralis minor muscles control the movements of the arm, the pectoralis major is specifically responsible for its lateral, vertical and rotational movement. In addition to this primary function, both pectoral muscles also aid in the action of deep breathing.Know More
Each human has two pectoralis major muscles, one on either side of the chest. In addition, two triangular pectoralis minor muscles lie below each pectoralis major muscle and aid them in their functions. In common terms, especially in sports, all of these muscles are collectively referred to simply as the "pecs."
The pectoralis major fans across the chest, beginning at the clavicular head, sternocostal head, and anterior surface of the sternum and inserting at the lateral lip of the intertubercular groove of the the humerus. This allows the muscle, located primarily in the chest, to control the movement of the arm, its major function.
The location of the pectoralis major across the chest, however, also allows it to aid in the movements of deep breathing. In this case, the pecs pull the ribcage out, allowing the lungs room to expand.
In addition, each pectoralis major has six separate sets of muscle fibers that are capable of independent movement through the central nervous system.Learn more in Muscles
The trunk muscles involved in arm adduction are the pectoralis major and pectoralis minor. Other muscles involved in arm adduction and transverse arm adduction are latissimus dorsi, pectoralis major, pectoralis minor, teres major, coracobrachialis and triceps brachii.Full Answer >
Deltoid muscles, situated in the shoulders, are responsible for the majority of arm movements, including arm abduction, arm flexion and medial rotation, and arm extension and lateral rotation. These movements involve the deltoids working with the rotator cuff muscles, supraspinatus, pectoralis major, infraspinatus, terres minor and terres major.Full Answer >
The antagonist muscles of the pectoralis minor, a muscle that runs across the front of the chest, include the trapezius, rhomboid major and minor, and the levator scapulae, states Wellness Digest. The pectoralis minor protracts the scapula, or moves it away from the spine.Full Answer >
The biceps and triceps muscles are used to bend and extend the arm, while the deltoids are the muscles that lift the arm. When the bicep muscle contracts or flexes, it bends the forearm toward the shoulder. When the tricep flexes, it extends the forearm, straightening the arm. The bicep and tricep do not contract simultaneously. When one muscle is contracted, the other relaxes.Full Answer >