The middle glenohumeral ligament (MGHL) reinforces the front of your shoulder joint capsule. It helps limit excessive forward movement and external rotation in certain arm positions, but its shape varies considerably from one shoulder to another.

Location

Runs across the front of the glenohumeral joint
Commonly begins near the front-upper glenoid rim and labrum
Travels beside the subscapularis tendon
Attaches near the front of the upper humerus
Sits between the superior and inferior glenohumeral ligaments

The MGHL may be thin, cord-like, split or even absent. A variation is not automatically an injury.

Function

Helps resist forward translation of the humeral head
Contributes to control of external rotation when the arm is partly raised
Supports the front of the shoulder capsule
Works with the subscapularis, labrum and other capsular ligaments

Its contribution changes with arm position. No single ligament controls the shoulder through its entire range.

Structures It Connects To

Glenohumeral joint capsule
Glenoid labrum
Subscapularis
Superior and inferior glenohumeral ligaments
Upper humerus

Common Problems

Can be stretched or torn during a dislocation
May be involved in anterior shoulder instability
Can resemble labral tissue or normal folds on imaging
May be part of a broader capsular injury

Because normal anatomy varies so much, an imaging report must be interpreted carefully. A thin or absent-looking MGHL is not necessarily abnormal.

Clinical Relevance

Clinicians do not diagnose an MGHL injury from pain location alone. They combine the injury mechanism, apprehension or giving-way symptoms, movement, strength and imaging when needed.

Glenohumeral joint capsule — the tissue the MGHL reinforces
Subscapularis — lies directly beside it
Shoulder ligaments — the wider ligament system
Glenohumeral joint — the joint it helps stabilize

References

StatPearls. "Anatomy, Shoulder and Upper Limb, Glenohumeral Joint." https://www.ncbi.nlm.nih.gov/books/NBK537018/
StatPearls. "Shoulder Arthrogram." https://www.ncbi.nlm.nih.gov/books/NBK580562/
Lugo R, Kung P, Ma CB. Shoulder biomechanics. Eur J Radiol. 2008;68(1):16-24. https://pmc.ncbi.nlm.nih.gov/articles/PMC5039561/

Middle Glenohumeral Ligament