What are the important structures in the shoulder joint?
Important structures within the shoulder joint help it to move and give it strength as well as flexibility. Shoulder stability is an important part of a properly functioning shoulder joint and is achieved with the help of ligaments, tendons, muscles and cartilage. These soft tissues connect, cushion and rotate the shoulder joint and make it strong and stable through all of the shoulder’s demands.
A few important structures that make up the shoulder joint are:
Rotator Cuff – The rotator cuff’s job is to hold the head of the humerus (upper arm bone) firmly within the shallow socket of the shoulder. It is made up of a group of muscles and tendons that contribute to shoulder strength and stability. The rotator cuff is analogous to the reins on a horse. They do not power the shoulder but help to guide it and allow the major muscles around the shoulder (deltoid, pec major, trapezius, latissimus) to do their job. When the rotator cuff is injured, the shoulder does not function properly.
Labrum – The shoulder labrum is a ring of cartilage that surrounds the socket of the shoulder. Its main function is to serve as the attachment for ligaments and tendons and deepen the shallow socket. Injuries to the labrum can result in pain and/or instability
Bursa – These small, fluid-filled sacks cushion and lubricate the rotator cuff tendon. They are located between the bone and the surrounding soft tissue.
Deltoid Muscle – The strongest and largest muscle of the shoulder, provides the strength to lift the arm.
Biceps Tendon – This tendon is where the biceps muscle attaches to bone. It begins at the top of the shoulder socket and allows the elbow to bend and the forearm to rotate.