While one muscle is tightening the opposite is true for an opposing muscle. There is cartilage at the end of all bones in the body. It serves as a gliding surface for when the shoulder joint moves into different positions. It is made of a thick, smooth tissue that acts as a protective covering over the ends of the longs bones at the joint space. Injuries to the cartilage occur either with trauma or over long periods of time where these surfaces slowly deteriorate due to wear and tear or a disease process.
When the process is slow and gradual the damage is often worse. Eventually the cartilage is worn off and the surface of the two ends of bone are no longer gliding on a smooth surface with movement, but instead grinding together.
The labrum of the shoulder is found on the glenoid rim. Like the meniscus of the knee, the labrum of the shoulder helps deepen the contour of the glenoid so that humeral head fits better in the joint.
Injuries to the labrum occur with shoulder dislocations and repeated anterior subluxations. These can also be seen in throwers due to the long head of the biceps tendon pulling on the labrum during the acceleration phase of a pitch or throw. It is made up 4 of components:. The glenoid cavity is not even half the size of the humeral head so it does not provide the joint with much stability. When somebody dislocates their shoulder for the first time, they usually rip off this gristle, which then makes their socket shallower and predisposes them to repeat shoulder dislocations.
If this sock of tissue becomes stiff, it can result in shoulder stiffness and pain known as frozen shoulder adhesive capsulitis. The shoulder blades sit on the upper part of the back thorax , with one on each side.
Projecting from the front of the shoulder blade is a hook of bone known as the coracoid process. The coracoid process is a bone which serves as the connection point for the ligaments that connect the shoulder blade to the collarbone.
Another large hook or shelf of bone projects upwards from the shoulder blade and is known as the acromion. The acromion serves as an attachment for the strong and important deltoid muscle. The clavicle commonly known as the collar bone connects the shoulder to the rest of the body via two joints, the acromioclavicular joint and the sternoclavicular joint. The acromioclavicular joint AC joint is at the tip of the shoulder and is the site where the collarbone connects to the shoulder blade.
The collarbone serves to strut the shoulder blade out from the body, allowing the surrounding muscles to work at their most effective tensions and generate more power. The AC joint commonly wears out as we get older resulting in arthritis, which may or may not be painful.
The sternoclavicular joint is at the base of the neck and is a saddle joint which sits between the collar bone and the breast plate sternum. This joint also helps to strut the shoulder blade out from the body. Ligaments are soft tissue that holds bone to bone. Shoulder injuries can occur to any part of the shoulder.
Louis Children's Hospital St. Sprain, strain or jam? This ligament can thicken and cause Impingement Syndrome. Coraco-clavicular Ligaments CCL : These two ligaments trapezoid and conoid ligaments attach the clavicle coracoid process of the scapula.
These tiny ligaments with the acomioclavicular joint play an important role in keeping the scapula attached to the clavicle and thus keeping your shoulder 'square'. They carry a massive load and are extremely strong. A fall on the point of the shoulder can rupture these ligaments with dislocation of the AC Joint. Transverse Humeral Ligament THL :Holds the tendon of the long head of biceps brachii muscle in the groove between the greater and lesser tubercle on the humerus intertubercular sulcus.
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