What are the subscapular spaces?

The subscapular spaces are three intermuscular spaces in the posterior scapular region, visible after reflecting the posterior deltoid. They include one quadrangular and two triangular spaces, serving as important surgical landmarks.

What are the boundaries and contents of the quadrangular space?

The quadrangular space is bounded superiorly by teres minor, subscapularis, and shoulder joint capsule; inferiorly by teres major; medially by the long head of triceps brachii; and laterally by the surgical neck of the humerus. It contains the axillary nerve and posterior circumflex humeral artery and vein.

What structures pass through the upper triangular space?

The upper triangular space is bounded by teres minor superiorly, the long head of triceps laterally, and teres major inferiorly. Its only content is the circumflex scapular artery.

What are the boundaries and contents of the lower triangular space?

The lower triangular space is bounded superiorly by teres major, medially by the long head of triceps, and laterally by the shaft of the humerus. It contains the radial nerve and profunda brachii artery and vein.

Why are the subscapular spaces important in anatomy?

These spaces are crucial as surgical landmarks for accessing nerves and vessels in the shoulder region, such as the axillary and radial nerves, which are vital for arm function.

How many subscapular spaces are there, and what are their types?

There are three subscapular spaces: one quadrangular space and two triangular spaces (upper and lower), each with distinct boundaries and contents.

Subscapular Spaces – Quadrangular & Triangular Anatomy