The latissimus dorsi is the large, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region. Commonly called "lats" by bodybuilders, it's responsible for extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and (medial) internal rotation of the shoulder joint — has a synergistic role in extension and lateral flexion of the lumbar spine.
Origin (5 points):
O1 — T5-L5
O2 — Ribs
O3 — Iliac Crest
O4 — Scapula
O5 — Thoracolumbar Fascia
Intertubercular Groove of Humerus
Thoracodorsal Nerve — the middle subscapular nerve or the long subscapular nerve.
Extends | Adducts | Medially Rotates Shoulder
also known as swimmer's muscle,
helps in the strong downward strokes of the arm
Actions of Muscle Groups:
Skeletal Muscles provide