10/02/2023
Shoulder anatomy, I like the way this has been presented. Very nice. It is a very complex joint as it is very mobile and not totally fixed at any point. It hinges in part and rotates from another, very nice. the clavicle attaches it to the body, but still very mobile.
Essentially from my perspective, this joint is a work of art. Both complex and simple at the same time.
🔈 ANATOMY OF SCAPULA AND SCAPULAR REGION
The clavicle is the boundary demarcating the root of the neck from the thorax. It also indicates the “divide” between the deep cervical and axillary “lymph sheds” (like a mountain range dividing watershed areas): Lymph from structures superior to the clavicles drain via the deep cervical nodes, and lymph from structures inferior to the clavicles, as far inferiorly as the umbilicus, drain via the axillary lymph nodes.
The infraclavicular fossa is the depressed area just inferior to the lateral part of the clavicle. This depression overlies the clavipectoral (deltopectoral) triangle - bounded by the clavicle superiorly, the pectoralis major medially, and the deltoid laterally - which may be evident in the fossa in lean individuals. The cephalic vein, ascending from the upper limb, enters the clavipectoral triangle and pierces the clavipectoral fascia to enter the axillary vein.The coracoid process of the scapula is not subcutaneous; it is covered by the anterior border of the deltoid; however, the tip of the process can be felt on deep palpation on the lateral aspect of the clavipectoral triangle. The coracoid process is used as a bony landmark when performing a brachial plexus block, and its position is of importance in diagnosing shoulder dislocations.
While lifting a weight, palpate the anterior sloping border of the trapezius and where its superior fibers attach to the lateral third of the clavicle. When the arm is abducted and then adducted against resistance, the sternocostal part of the pectoralis major can be seen and palpated. If the anterior axillary fold bounding the axilla is grasped between the fingers and thumb, the inferior border of the sternocostal head of the pectoralis major can be felt. Several digitations of the serratus anterior are visible inferior to the anterior axillary fold. The posterior axillary fold is composed of skin and muscular tissue (latissimus dorsi and teres major) bounding the axilla posteriorly.
The lateral border of the acromion may be followed posteriorly with the fingers until it ends at the acromial angle. Clinically, the length of the arm is measured from the acromial angle to the lateral condyle of the humerus. The spine of the scapula is subcutaneous throughout and is easily palpated as it extends medially and slightly inferiorly from the acromion. The root of the scapular spine (medial end) is located opposite the tip of the T3 spinous process when the arm is adducted. The medial border of the scapula may be palpated inferior to the root of the spine as it crosses ribs 3–7. It may be visible in some people, especially thin people. The inferior angle of the scapula is easily palpated and is usually visible. Grasp the inferior scapular angle with the thumb and fingers and move the scapula up and down. When the arm is adducted, the inferior scapular angle is opposite the tip of the T7 spinous process and lies over the 7th rib or intercostal space.
