The TuneUp Program

These two muscles share pec minor's attachment with the coracoid process at the front of the scapula. Bicep brachii is so named because it has two heads, the more lateral long head attaches on the top of the humerus while the short head and the coracobrachialis muscle originate on the scapula. Coracobrachialis lies underneath the bicep inserting onto the inside of the humerus about half way up while the bicep heads converge and insert on to the radius.

Together they will pull the shoulder forward into the familiar rounded shoulder posture as well as assisting in adduction and flexion of the arm at the shoulder joint. Bicep brachii also flexes the elbow.

These two muscles also connect the chest, via the shared attachment with pec minor, to the thumb, via the deep fascia covering the radius.

The deep shoulder flexors, along with pectoralis minor, form a functional group that is often overloaded, pulling the shoulder forward and down. They restrict the movement of the scapula and therefore the whole pectoral girdle and disrupt the balance of forces keeping the shoulder joint stable.

Along with the rotator cuff muscles they help to stabilise the joint by pulling the humerus into the scapula. Pulling it forward and down puts an extra load on the medial rotators, particularly teres major and the shoulders turn inward as well producing the classic round shouldered posture that closes off the chest even further. It also takes the load away from the rhomboids which weaken and are therefore more easily overused when you do need them.