The shoulders play a pivotal roll in the distribution of force from the upper extremities to the rest of the body so their alignment is crucial for staying pain free. When force is applied through the fingers and hands it passes through the wrist, up the forearm and humerus, and through the scapula to the spine.
From there, the force will pass down the spine to the sacrum, distribute though the ilium (hip bone) to the hip joints. Ultimately passing down the legs to the ankles and feet. As you can hopefully see, this process works best when there is no restrictions along the way. So back up to the shoulder and the shoulder girdle specifically. The shoulder girdle consists of the scapulae, the clavicles, and the humerus bones. The only attachment to the rest of the skeleton is at the point where the clavicle attaches to the sternum.
The humerus (upper arm bone) rests in the glenoid fossa of the scapula and is held there by the deltoid muscle and numerous ligaments. The muscles that control the motion of the arm form a wheel-like design, starting at the shoulder joint and expanding out to connect to the skeleton at multiple sites. Movement of the arms rely on coordinated movement in the truck and legs. When this coordination is obstructed it tends to lead to strains that ultimately lead to injury.
The scapula must be free to move along with all of the movements of the humerus while staying anchored to the thoracic cavity, through muscular action, to provide the leverage for the humeral head. A common tender point on the top of the inside edge of the scapula is commonly from a tense levator scapula muscle. This muscle can become hyperactive from holding your shoulders up from being chronically tense or work related arm positions. Another common cause for this tender spot is from a forward head position where the levator scapula is chronically elongated.
The glenoid fossa is where our humerus bone (upper arm) attaches to the frame of the body and is held in place mainly by the tendons of the rotator cuff muscles. The balance of these muscle are crucial for proper placement of the humeral head within the fossa to maximize full range of motion. One muscle that seems to be problematic to the positioning of the shoulders is the pectoralis minor. The outside bundles of nerves of the brachial plexus and the axillary artery run beneath this muscle so any dysfunction of the muscle may cause problems with these 2 structures. Chronic contraction of the pectoralis minor may interrupt blood flow and nerve supply to the arm when extended to the side and rotated outwardly. With this type of impingement it is common to feel numbness in the forearm and on the palm side of the fingers.
As you can hopefully see, with the information I presented here, that our shoulder positioning plays a big role in our overall health. If you have any problems with your shoulders now you should go to a qualified professional to have an assessment.