This article does not address injuries to the actual gleno-humeral joint cartilage or ligaments as those are beyond the scope of massage therapy and require medical or surgical intervention. This article deals with the muscles, kinesiology and massage treatment of the shoulder/arm muscles.
Let's start by listing the muscles which surround the shoulder joint then we will define what makes up the joint itself. MUSCLES AND ATTACHMENTS: On the front is the pectoralis major which stabilizes the front of the shoulder by joining the sternum with the collar-bone (clavicle) and the arm (humerus). There are two pectoralis muscles, the second being the minor. It originates from the 3-5th rib and attaches on the acromion process which is the protruding finger which is prominent on the top of the shoulder blade (scapula). The muscle which counters the pectoralis on the back is the rhomboid major and minor. These muscles originate on the spinous or vertebral edge of the scapula and attaches on the sides of the thoracic vertebrae. The minor rhomboid attaches to T1-3 while the major attaches to vertebraes T3-5.They angle downward from inside to outside of the body, medial to lateral. Also on the back is the trapezius. This is a large muscle with three components: an upper, middle, and lower. The upper attaches to the occiput of the head and proceeding down the neck does a twist at the inner corner of the scapula and then attaches to the outside edge of the scapula. Its involvement is to elevate the scapula shoulder-arm complex. The middle trapezius assists the rhomboids and is more superficial to the surface. The lower trapezius attaches across the ridge on the scapula (shoulderblade) and then proceeds downward in a diagonal inner direction to the spinous process of the vertebrae and attaches from thoracic 6-12. This part of the muscle is used to lower the scapula. The next most important muscles which are involved with the shoulder are the rotator cuff muscles. These surround the humerus (upper arm bone), are anchored on the scapula and hold the humerus in the gleno-humeral socket with ligaments assisting to provide stability. This joint is loosely-packed to allow the most range of motion, as is evident with the 360 degree rotation of the arm. The anterior rotator cuff muscle orginates beneath the scapula and is called the sub-scapularis. It attaches to the front of the humerus. The top of the humerus is maintained in its place by the supra-향남출장마사지 spinatus which originates just above the spine of the scapula and attaches at the top of the humerus bone. It passes beneath the hook on the acromion process before attaching there. This offers it some protection. The Deltoid muscle covers the shoulder joint and provides the necessary muscular strength to raise the arm fully. It is made up of three components, anterior (front), middle, and back (posterior). All three parts of the deltoid work with other muscles around the shoulder to allow for a circumferential rotation of the arm. The other posterior rotator cuff muscle is just below the spine of the scapula and is called the infra-spinatus. It covers the outside (dorsal) lower part of the scapula and attaches to the back of the humerus near the joint capsule. Another muscle which opposes the rhomboids is the serratus. It attaches to ribs 5-9 on the side of the body and attaches beneath the scapula to the vertebral edge. When it contracts it protracts the shoulder blade outward. The opposite motion of retraction is produced by the rhomboids contracting. Sometimes the serratus can get strained from excessive repetitive motion of protraction,eg: golfing, swing a bat, etc. Beneath these muscles the gleno-humeral (shoulder)joint is enclosed in a synovial joint capsule and surrounded with ligaments on the back, top, and front. However the weakest point on the joint is the front, and subsequent to tearing the front ligaments the arm can dislocate and more seriously protrude anteriorly (towards the front) with a seriously strong enough impact to the torso or arm. Ouch! Two other main muscles which surround the shoulder joint are the biceps brachii and the triceps. Both of these muscles are on the front and back respectively of the humerus or arm. The biceps brachii on the front has two attachments on the shoulder, one short, and one long. The short one attaches on the front of the scapula and the long on the top via a long tendon. The arm also has the brachio-radialis and brachialis which are on either side of the biceps brachii and which assist the arm to flex. They also attach on the front of the scapula and provide some strength to the arm-shoulder joint.
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