latissimus dorsi

Introduction

Superficial muscle of the back.

Origin

• spinous processes of T6 or T7 to T12 & L1-L5
• median ridge of sacrum
• outer lip of iliac crest

Insertion

• with teres major into the posterior lip of the bicipital groove of the humerus

Action

• adducts arm
• rotates arm medially
• extends arm

Innervation

• thoracodorsal nerve

More general terms

• skeletal muscle (voluntary muscle)