Scapula

SkeletalSkeletonThoraxLeft and right

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What it is

The shoulder blade: a thin triangular plate over ribs 2–7 with a posterior spine ending in the acromion, a hook-like coracoid process in front and the shallow glenoid cavity for the humeral head.

Function

Provides the socket of the shoulder joint and attachment for 17 muscles, gliding over the chest wall to extend the arm's reach.

Size

≈ 15–17 cm tall, 10 cm wide; glenoid ≈ 35 × 25 mm

Clinical note

Winging of the scapula signals paralysis of serratus anterior (long thoracic nerve injury).