Infraspinatus

A posterior member of the cuff

Infraspinatus is one of the four rotator-cuff muscles.

The list contains a separate supraspinatus entry. Keep the full selected name in view: similar names do not mean that the two meshes are parts of the same muscle.

Sources: Arm anatomy tables

From the infraspinous fossa toward the greater tubercle

The muscle arises in the infraspinous fossa. Its distal attachment includes the middle facet of the greater tubercle and the shoulder capsule.

Compare Scapula and Humerus in the same scene; their whole-bone surfaces do not provide separately selectable attachment footprints.

Sources: Loyola anatomy

External rotation at the shoulder

Infraspinatus laterally rotates the arm and contributes to shoulder stability. Lateral and external rotation describe the same direction here.

The source pose is fixed. Turning the camera does not raise the arm or rotate the humerus within the socket; the viewer does not simulate muscle contraction or shoulder mechanics.

Comparing it with teres minor helps organize the study, but the model cannot tell you their relative strength or activation in a particular movement.

Sources: Loyola anatomy

A shared named nerve

Infraspinatus receives suprascapular-nerve supply, as does supraspinatus.

Nerves and vessels are not loaded in this subset, so the text describes connections you cannot select in the viewer.

Sources: Loyola anatomy · Arm anatomy tables

Read the model

Explore infraspinatus in 3D

1. Begin from behind. Use Back to inspect the isolated surface, then Oblique to compare its depth. The camera presets do not alter muscle shape.
2. Add the bony context. Choose Show context, keep Infraspinatus selected and enable Fade others. Alternate with Scapula to locate the model against the bone.
3. Compare its neighbors. Choose Supraspinatus and Teres minor in turn. Open a selected title for its individual guide; Show context restores the surrounding scene.

Sources and editorial status

This guide uses independently written explanations with links to the evidence behind them. Source checking and specialist anatomical review are separate steps; the latter is still pending.

1. Loyola University Chicago — LUMEN, Infraspinatus

   Named muscle: attachments, principal action and nerve. Original educational summary; no source illustration reproduced.

2. Texas Tech University Health Sciences Center El Paso — Axilla, Posterior Shoulder, & Arm

   Four rotator-cuff rows: group membership and comparison of named attachments, actions and nerve supply. No source illustrations reproduced.

3D geometry and its separate license are credited beneath the viewer. References do not imply endorsement of this site.