MuscleBack — superficial extrinsic
Latissimus dorsi
Latin: M. latissimus dorsi sinistra
Location: Back
Paired structure: one on the left and one on the right side of the body.
View the latissimus dorsi in 3DOrigin
Spinous processes of T7–L5 (via thoracolumbar fascia), iliac crest, ribs 9–12, inferior angle of the scapula.
Insertion
Floor of the intertubercular groove of the humerus.
Action
Powerfully extends, adducts and medially rotates the arm — the climbing and swimming stroke muscle. Assists forced expiration and a vigorous cough.
Nerve supply
Thoracodorsal nerve (C6–C8).
Blood supply
Thoracodorsal artery.
Clinical relevance
Latissimus flaps are the workhorse of breast reconstruction; thoracodorsal nerve injury weakens the 'pull-up' arc. Its tendinous insertion forms the posterior wall of the axilla.
Educational anatomy reference, not medical advice. About this content.