The glenohumeral joint is the ball-and-socket joint that forms your shoulder. It's where the head of your upper arm bone (humerus) meets the shallow socket (glenoid cavity or fossa) of your shoulder blade (scapula). This unique structure allows for an extensive range of motion, making your arm highly flexible.
Understanding the Glenohumeral Joint
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Structure: The glenohumeral joint is a complex articulation between the humeral head and the glenoid fossa. It's described as a ball-and-socket joint due to the rounded shape of the humeral head fitting into the cup-like glenoid fossa. [Reference: TeachMeAnatomy, Physiopedia, StatPearls]
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Mobility and Stability: The glenohumeral joint boasts the widest range of motion in the human body. However, this impressive mobility comes at the cost of inherent instability. The rotator cuff muscles play a crucial role in stabilizing this joint, preventing dislocation while allowing for free movement. [Reference: TeachMeAnatomy, Cleveland Clinic, StatPearls]
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Shoulder Complex: The glenohumeral joint is just one of four joints comprising the entire shoulder complex. The other joints contribute to the overall function and movement of the shoulder. [Reference: Physiopedia]
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Clinical Significance: Glenohumeral joint issues, like arthritis or instability, can significantly impact daily function. Conditions such as shoulder instability often result from stretched, torn, or detached ligaments or labrum. Intra-articular corticosteroid injections are often ineffective treatments for glenohumeral arthritis. [References: Johns Hopkins Medicine, NCBI PMC, Steadman Clinic]
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Examples of Movement: The glenohumeral joint allows for flexion, extension, abduction, adduction, internal rotation, and external rotation of the arm. In athletes like pitchers, excessive external rotation can lead to paradoxical glenohumeral joint motion. [Reference: NCBI PubMed]
