- Subscapular spaces (intermuscular spaces of the scapular region): one quadrangular and two triangular gaps between the muscles around the scapula.
- Clearly seen from behind after reflecting the posterior part of the deltoid.
Quadrangular Space
Boundaries of the quadrangular space
Boundary
Superior
- Structure
- Teres minor (posteriorly), subscapularis (anteriorly), shoulder joint capsule between them
Inferior
- Structure
- Teres major
Medial
- Structure
- Long head of triceps
Lateral
- Structure
- Surgical neck of humerus
- Structures traversing the quadrangular space: axillary nerve and posterior circumflex humeral vessels (artery and vein).