The human shoulder is a complex and interesting part of the body. Made up of three bones: the clavicle (collarbone), the scapula (shoulder-blade), and the humerus (upper arm bone) – and associated muscles, ligaments and tendons.
The clavicle is the only bony attachment between trunk and the upper limb. It forms the front portion of the shoulder girdle and is palpable along its entire length with a gentle S-shaped contour. This articulation between the end of the clavicle and the scapula forms the roof of the shoulder.
The scapula is a large, almost triangular bone. It forms the back portion of the shoulder girdle. This complex relation of muscles, bones and ligaments make up the shoulder joints. “Shoulder joint” comprises of the part of the body where the humerus attaches to the scapula, the head sitting in the glenoid fossa. It is well supplemented with two kinds of cartilage in the joint.
Know more about your shoulder joint:
- The shoulder joint itself known as the Glenohumeral joint, (is a ball and socket articulation between the head of the humerus and the glenoid cavity of the scapula)
- The acromioclavicular (AC) joint (where the clavicle meets the acromion of the scapula)
- The sternoclavicular (SC) joint (where the clavicle meets the chest bone or sternum)
- The scapulothoracic joint (where the scapula meets with the ribs at the back of the chest)
Cartilages in the Shoulder
The white cartilage on the ends of the bones (called articular cartilage) allows the bones to glide and move on each other. When this type of cartilage starts to wear out (a process called arthritis), the joint becomes painful and stiff. The labrum is a second kind of cartilage in the shoulder which is distinctly different from the articular cartilage. This cartilage is more fibrous or rigid than the cartilage on the ends of the ball and socket joint. Also, this cartilage is found only around the socket where it is attached.
Cause of Shoulder Pain
Shoulder problems including pain, are common reasons for physician visits. While the shoulder is the most movable joint, it is fairly unstable because of the allowed range of motion and has a high probability of instability and injury.
Major injuries to the shoulder include rotator cuff tear and bone fractures of one or more of the bones of the shoulder.
Shoulder pain is common among many youngsters these days because of lifestyle choices and lack of exercise. Yoga or general stretching exercises are encouraged within all age groups in order to mitigate pain.