19/07/2023
The shoulder
The shoulder is a complex joint that connects the arm to the torso. It is the most mobile joint in the human body, allowing for a wide range of movements such as flexion, extension, abduction, adduction, and rotation. The shoulder joint is formed by the articulation of three bones: the humerus (upper arm bone), the clavicle (collarbone), and the scapula (shoulder blade).
The shoulder joint itself is a ball-and-socket joint, with the rounded head of the humerus fitting into a shallow socket called the glenoid fossa of the scapula. This arrangement allows for a greater range of motion but also makes the shoulder more susceptible to instability and dislocation compared to other joints.
Several structures contribute to the stability and movement of the shoulder joint. These include the rotator cuff, a group of muscles and tendons that surround the joint and help stabilize it, as well as the labrum, a ring of cartilage that deepens the socket of the glenoid fossa. Ligaments and other soft tissues also provide additional support.
Common shoulder injuries and conditions include:
1-Rotator cuff tears: Damage or tears in the tendons of the rotator cuff muscles, often caused by repetitive overhead motions or acute trauma.
2-Shoulder impingement: Compression of the tendons and bursa within the shoulder joint, often resulting from repetitive overhead activities.
3-Shoulder dislocation: When the humerus is forced out of its socket, typically due to a traumatic injury or repetitive strain.
4-Frozen shoulder (adhesive capsulitis)
5-Shoulder arthritis: Degenerative joint disease
