The lats
Latissimus dorsi · musculus latissimus dorsi
The broadest muscle in your back, pulling your arms down and back.
What it does
The latissimus dorsi spreads across the lower and middle back from the spine and pelvis, then funnels into a narrow tendon on the front of the humerus. It pulls the arm down and back, as when you climb, swim, row or push yourself up from a chair.
Surprising fact
Its Latin name simply means "broadest muscle of the back", and surgeons sometimes move a flap of it to rebuild a breast or cover a wound elsewhere.
Why it matters
Swimmers and climbers have huge lats, which give the back its V shape. They also help when you cough hard, because they squeeze the lower ribcage.
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.