The inferior glenohumeral ligament complex (IGHL) is the main capsular restraint when your arm is raised. It is not one narrow cord. It forms a hammock-like system across the lower part of the shoulder joint.

Location

Reinforces the lower glenohumeral joint capsule
Includes an anterior band, a posterior band and the axillary pouch between them
Attaches around the lower glenoid rim and labrum
Extends to the lower part of the anatomical neck of the humerus
Unfolds as the arm rises

The three parts work together like a sling supporting the humeral head in different positions.

Function

Helps resist unwanted forward, backward and downward translation
Becomes especially important when the arm is raised and externally rotated
Supports the shoulder during throwing and other overhead positions
Contributes to passive stability near the end of available movement

The rotator cuff and shoulder blade muscles still provide essential active control. The IGHL is one part of the system, not a stand-alone stabilizer.

Parts of the Complex

Anterior band

The anterior band becomes important when the raised arm rotates outward. It helps resist excessive forward movement of the humeral head.

Posterior band

The posterior band contributes more when the raised arm rotates inward and helps resist backward movement.

Axillary pouch

The axillary pouch is the loose lower fold between the bands. It unfolds during elevation and helps preserve the shoulder's large range.

Structures It Connects To

Glenohumeral joint capsule
Glenoid labrum
Glenohumeral joint
Upper arm bone and shoulder blade
Axillary nerve, which passes nearby

Common Problems

Can be stretched or detached during a shoulder dislocation
May be involved in recurrent instability
Can fail near the glenoid side or humeral attachment
May become stiff as part of a broader capsular restriction

The term Bankart lesion usually describes injury near the front-lower labrum and capsuloligamentous attachment. A humeral-sided avulsion of the IGHL is often called a HAGL lesion. These labels require clinical and imaging assessment; symptoms alone cannot confirm them.

Clinical Relevance

Apprehension with the arm raised and externally rotated may make clinicians consider instability, but it does not identify one exact damaged structure. Examination and imaging findings must be interpreted together.

Glenohumeral joint capsule — contains the IGHL complex
Glenohumeral joint — the joint being stabilized
Axillary nerve — passes near the inferior capsule
Shoulder ligaments — overview of the wider ligament system

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/

Inferior Glenohumeral Ligament Complex