Latissimus dorsi
Musculus latissimus dorsi
MuscularSuperficial musclesWhole bodyLeft and right
View left in 3D View right in 3D
- What it is
- The broadest muscle of the back: a thin triangular sheet arising via the thoracolumbar fascia from the spinous processes of T7–L5 and the sacrum, the posterior iliac crest and the lower ribs. It sweeps up round the side of the chest, forming the posterior axillary fold, to a flat tendon in the floor of the intertubercular groove of the humerus.
- Function
- Extends, adducts and medially rotates the arm; pulls the trunk up towards the arms in climbing and helps in forced expiration and coughing.
- Size
- Up to ~40 cm across, 2–5 mm thick; tendon about 3 cm wide.
- Clinical note
- A workhorse flap for breast reconstruction; supplied by the thoracodorsal nerve.