Scapula: Fossa, Pillar, Muscle Attachments

Scapula Anatomy: Subscapular Fossa and Associated Structures

The subscapular fossa is a significant anatomical feature of the scapula, primarily known for its excavation and muscle attachments.

Key Features of the Subscapular Fossa

• Extent: Excavated across almost its entire surface on the anterior aspect of the scapula.
• Ridges: Traversed by 3 or 4 ridges.
• Ridge Origin and Insertion: These ridges extend from the neck of the scapula to the inner edge of the bone.
• Muscle Insertion (Primary): The subscapular fossa provides the main insertion point for the subscapular muscle.

Structures Outside the Subscapular Fossa

• Pillar of the Scapula: This is an elongated projection located parallel to the outer edge of the bone.
• Pillar's Muscle Insertion: The pillar of the scapula gives insertion to the lower bundles of the subscapular muscle.

Structures Inside the Subscapular Fossa (Along Inner Edge)

• Rough Surface: Along the inner edge of the subscapular fossa, there is a distinct rough surface.
• Rough Surface's Muscle Attachment: This rough surface is where the anterior large serrated muscle (also known as the serratus anterior) attaches.

Summary of Muscle Attachments

Anatomical Feature	Muscle Attachment
Subscapular Fossa (general)	Subscapular Muscle
Pillar of the Scapula	Lower bundles of the Subscapular Muscle
Rough surface along inner edge of Subscapular Fossa	Anterior Large Serrated Muscle (Serratus Anterior)