The triceps
Triceps brachii · musculus triceps brachii
The three-headed muscle at the back of your upper arm that straightens your elbow.
What it does
The triceps covers the back of the upper arm and makes up about two-thirds of its bulk. Its three heads join into one tendon that pulls on the point of the elbow, straightening the arm when you push a door, do a push-up or reach overhead.
Surprising fact
The triceps is bigger than the biceps, so if you want a bigger-looking arm, it is the muscle that counts most.
Why it matters
Every push you make, from getting out of a chair to throwing a ball, uses your triceps. Keeping it strong helps older people stay independent, because pushing up from a seat depends on it.
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.