SHOULDER JOINT
The shoulder is the most complex and most mobile joint group of the body. There are three joints in the shoulder:
The glenohumeral joint, (the joint between the arm and the shoulder blade)
Acromioclavicular joint, (the joint between the shoulder blade and collarbone)
Scapulothoracic joint (the joint between the scapula and the trunk)
The main shoulder joint consists of 2 bones.
The humerus (humerus) and the scapula (scapula). The term “shoulder joint” usually refers to the joint formed by these two bones. The joint faces are not compatible with each other. Although the joint is very mobile, its stability is poor. The other joint in the shoulder is between the clavicle and the scapula and is called the acromioclavicular joint. The capsule surrounding the joint is very thin-walled and loose. Its loose state increases the range of motion of the joint. The instability caused by the looseness is tried to be eliminated by the ligaments, muscles and tendons surrounding the shoulder.
There are many fluid-filled sacs (bursae) around the shoulder to prevent friction between these structures.
Structures Forming the Shoulder Joint
Bones:
Clavicle (Collarbone)
Scapula (shoulder blade)
Humerus shoulder
Soft Textures:
Rotator Cuff: It is the stabilizer of the joint capsules of the shoulder with various ligaments. It lies in the 1-1.5 cm gap between the acromion of the scapula and the head of the shoulder.
Biceps Tendon; Biceps Tendon
Bursa : It is the sac on the rotator cuff between it and the acromion. This sac is extremely soft-walled and with the lubricating fluid it produces inside, it cuts the rotator cuff from direct contact with the bone and provides a slippery-soft-safe bed.
Labrum : Labrum, a ring-shaped flexible cartilage, is the protrusion of the shoulder blade that covers the shoulder joint and articulates with the collarbone. The acromioclavicular joint is a small surface joint with very little movement. shoulder The shoulder is the most complex and most mobile joint group of the body.