Chest · Flat bone
Scapula (Shoulder Blade)
The scapula, or shoulder blade, is the flat, triangular bone at the back of the shoulder. It forms the socket of the shoulder joint and anchors many muscles that move the arm.
What it is
The scapula is a broad, flat, triangular bone that sits over the upper ribs at the back. It links the arm to the collarbone and forms part of the shoulder joint.
Where it is
The upper back, over the ribs, on each side. It glides over the rib cage as the arm moves.
What it does
Forms the socket of the shoulder's ball-and-socket joint, provides a wide surface for muscle attachment, and lets the shoulder move through a huge range.
Connections
Joints and connections
- Shoulder joint (with the humerus)
- Acromioclavicular joint (with the clavicle)
When things go wrong
Common injuries and conditions
- Scapula fracture (uncommon; usually from major force)
- Winged scapula (from nerve or muscle problems)
Education and reference only. This explains the anatomy in plain terms; it is not a diagnosis. A severe injury, a visibly deformed limb, or the inability to move or bear weight needs urgent assessment — call 999 or go to A&E for a serious injury.
Did you know?
An interesting fact
The scapula is not fixed to the rib cage by a joint — it "floats", held and moved entirely by muscles, which gives the shoulder its remarkable mobility.
Answers
Scapula: frequently asked questions
What is the shoulder blade?
The shoulder blade (scapula) is the flat triangular bone at the back of the shoulder. It forms the shoulder socket and anchors many muscles that move the arm.
Why does my shoulder blade stick out?
A shoulder blade that sticks out ("winging") can be due to weakness or a nerve problem affecting the muscles that hold it against the ribs, and is worth having assessed.
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Related bones
Sources
Where this is drawn from
- NHS — Anatomy and body systems
- Gray's Anatomy for Students (Drake, Vogl, Mitchell)
- TeachMeAnatomy — skeletal system
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