The boxer's muscle
Serratus anterior · musculus serratus anterior
A saw-toothed muscle on the side of your ribcage that holds the shoulder blade against your back.
What it does
The serratus anterior starts on the outer surface of the upper eight or nine ribs and wraps around to the inner edge of the shoulder blade. It slides the shoulder blade forward around the ribcage, as when you punch, and holds it flat against the chest wall.
Surprising fact
It is called the "boxer's muscle" because it powers the forward reach of a punch, and its name comes from the Latin serra, a saw, after its jagged edge.
Why it matters
If the nerve to this muscle is injured, the shoulder blade sticks out like a wing when you push against a wall, a sign doctors look for after some shoulder and chest injuries.
Nearby
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.