What is the shoulder joint?
The shoulder joint (articulatio humeri, humeroscapular joint) forms the shoulder together with the shoulder joints, clavicle, scapula, muscles, tendons, ligaments and bursae. It is the junction of the upper arm (humerus) and the shoulder blade. Strictly speaking, the head of the humerus and the elongated, concave socket of the scapula meet at this point. The glenoid cavity is covered with cartilage, which forms a bulging border on the outer edge (labrum glenoidale). This cartilage lip ensures that the relatively large condyle of the humerus can lie more stably in the much smaller and quite shallow glenoid cavity. The joint is enclosed by a relatively thin joint capsule.
Muscles
Ligaments
In addition to these muscles, several ligaments and tendons that pull from the humeral head to the scapula support the movement process. Three ligament structures at the front (ligamentum glenohumeralia superius, medial and inferius) and one ligament in the upper region (ligamentum coracohumerale) play a particularly important role here.
Bursa
A number of bursae are positioned around the shoulder joint. Acting as buffers, they prevent bone from rubbing against bone when the arms are moved. In particular, the bursa under the roof of the shoulder joint (bursa subacromialis) and that between the deltoid muscle and the shoulder joint (bursa subdeltoidea) are stressed.
What is the function of the shoulder joint?
Where is the shoulder joint located?
The shoulder joint is the junction of the upper arm bone (humerus) and the shoulder blade.
What problems can the shoulder joint cause?
When the shoulder hurts, it is often not due to the joint itself, but to one of the accessory joints, a bursa, or the ligaments and muscles involved. The joint capsule can also trigger discomfort.
For example, force (such as a fall or traffic accident) can cause bruising, straining, ligament or capsule tears in the shoulder. In addition, the shoulder joint can dislocate and involved bones can break (shoulder fracture). If the cartilage lip at the glenoid cavity tears off, physicians speak of a Bankart lesion.
Other important diseases affecting the shoulder joint include:
- Arthrosis of the shear joint (omarthrosis)
- Impingement syndrome (jammed tendon)
- Stiff shoulder (“frozen shoulder”)
- Calcific shoulder (tendinosis calcarea)
Congenital malformations (anomalies) or malpositions can have a negative effect on the function of the shoulder joint.
