The capsule of the glenohumeral (shoulder) joint is the

articular capsule In anatomy, a joint capsule or articular capsule is an envelope surrounding a synovial joint.shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder mak ...

. It completely surrounds the joint. It is attached above to the circumference of the

glenoid cavity The glenoid fossa of the scapula or the glenoid cavity is a bone part of the shoulder. The word ''glenoid'' is pronounced or (both are common) and is from el, gléne, "socket", reflecting the shoulder joint's ball-and-socket form. It is a sha ...

beyond the

glenoidal labrum The glenoid labrum (glenoid ligament) is a fibrocartilaginous structure (not a fibrocartilage as previously thought) rim attached around the margin of the glenoid cavity in the shoulder blade. The shoulder joint is considered a ball and socket j ...

, and below to the

anatomical neck of the humerus The anatomical neck of the humerus is obliquely directed, forming an obtuse angle with the body of the humerus. It represents the fused epiphyseal plate. Structure The anatomical neck divides the head of the humerus from the greater and less ...

, approaching nearer to the articular cartilage above than in the rest of its extent. It is thicker above and below than elsewhere, and is so remarkably loose and lax, that it has no action in keeping the bones in contact, but allows them to be separated from each other more than 2.5 cm, an evident provision for that extreme freedom of movement which is peculiar to this articulation. It is strengthened, above, by the

Supraspinatus The supraspinatus (plural ''supraspinati'') is a relatively small muscle of the upper back that runs from the supraspinous fossa superior portion of the scapula (shoulder blade) to the greater tubercle of the humerus. It is one of the four rotator ...

; below, by the long head of the

Triceps brachii The triceps, or triceps brachii (Latin for "three-headed muscle of the arm"), is a large muscle on the back of the upper limb of many vertebrates Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with ba ...

; behind, by the tendons of the

Infraspinatus In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa.''Gray's Anatomy'', see infobox. As one of the four muscles of the rotator cuff, the main function of the infraspina ...

and

Teres minor The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the ...

; and in front, by the tendon of the

Subscapularis The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint. Structure It arises from its medial two-thirds and Som ...

Structure

There are usually three openings in the capsule. * One anteriorly, below the coracoid process, establishes a communication between the joint and a bursa beneath the tendon of the Subscapularis. * The second, which is not constant, is at the posterior part, where an opening sometimes exists between the joint and a bursal sac under the tendon of the Infraspinatus. * The third is between the tubercles of the humerus, for the passage of the long tendon of the Biceps brachii.

Clinical significance

Adhesive capsulitis Adhesive capsulitis, also known as frozen shoulder, is a condition associated with shoulder pain and stiffness. It is a common shoulder ailment that is marked by pain and a loss of range of motion, particularly in external rotation. There is a l ...

or ''frozen shoulder syndrome'' is a common shoulder capsule pathology that results when injury, surgery, or other chronic health conditions such as

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

and

arthritis Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In som ...

damage or loosen the

shoulder joint The shoulder joint (or glenohumeral joint from Greek ''glene'', eyeball, + -''oid'', 'form of', + Latin ''humerus'', shoulder) is structurally classified as a synovial ball-and-socket joint and functionally as a diarthrosis and multiaxial joint. ...

. As a result of the damage, the shoulder capsule becomes

inflamed Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecu ...

and taut, leading to stiffness, pain, and limited range of motion in the shoulder area. Range of motion can usually be restored by treating the affected area with heat and non-steroidal anti-inflammatory drugs (NSAIDs) in addition to light stretching and or a disciplined

physical therapy Physical therapy (PT), also known as physiotherapy, is one of the allied health professions. It is provided by physical therapists who promote, maintain, or restore health through physical examination, diagnosis, management, prognosis, patient ...

program. In extreme cases where medication and physical therapy prove to be ineffective in treating the condition,

arthroscopic surgery Arthroscopy (also called arthroscopic or keyhole surgery) is a minimally invasive surgical procedure on a joint in which an examination and sometimes treatment of damage is performed using an arthroscope, an endoscope that is inserted into the jo ...

(known as Arthroscopic Capsular Release) can be performed to loosen the capsule by removing regions of thickened

scar tissue Scar tissue may refer to: Medicine * Scar, an area of fibrous tissue that replaces normal skin after injury * Granulation tissue, a product of healing in major wounds Film and television * ''Scar Tissue'' (1975 film), or ''Wanted: Babysitter'' ...

within and around the shoulder joint.

References

Upper limb anatomy {{Portal bar, Anatomy