Glenohumeral Joint

Description

The glenohumeral (GH) joint is a true synovial ball-and-socket style joint that is responsible for connecting the upper extremity to the trunk.  It is one of four joints that comprise the shoulder complex. This joint is formed from the combination of the humeral head and the glenoid fossa of the scapula. This joint is considered to have both high mobility and low stability.

Motions Available

• Abduction: elevation of the humerus on the glenoid in the frontal (coronal) plane.
• Flexion: forward and upward movement of the humerus on the glenoid in the sagittal plane.
• Extension: upward movemement of the humerus on the glenoid in the sagittal plane towards the rear of the body.
• Internal Rotation: rotation of the humerus on the glenoid in a medial direction.
• External Rotation: rotation of the humerus on the glenoid in a lateral direction.
• Scaption: elevation of the humerus on the glenoid in the scapular plane, which is midway between the coronal and sagittal planes. 
• Horizontal Adduction: movement of the humerus on the glenoid in a medial direction, usually accompanied with some degree of shoulder flexion.

Ligaments and Joint Capsule

Joint Capsule:

• The lateral attachment of the GH joint capsule attaches to the anatomical neck of the humerus.  The medial attachment of the joint capsule is the glenoid and the labrum.  According to some sources, the the overall strength of the capsule bears an inverse relationship to the patient's age; the older the patient, the weaker the joint capsule<ref name="Dutton">Dutton, M. (2008). Orthopaedic: Examination, evaluation, and intervention (2nd ed.). New York: The McGraw-Hill Companies, Inc.</ref>.

Notable Ligaments:

• Superior Glenohumeral Ligament
• Middle Glenohumeral Ligament
• Inferior Glenohumeral Ligament
• Coracohumeral Ligament
• Coracoacromial Ligament

Other Important Information

Capsular Pattern

Labrum