Upper limb
Latissimus dorsi
Musculus latissimus dorsi
- Origin
- Spinous processes of T7–L5, thoracolumbar fascia, iliac crest and the lower ribs
- Insertion
- Crest of the lesser tubercle of the humerus (intertubercular groove)
- Function
- Adduction, internal rotation and extension of the shoulder
- Innervation
- Thoracodorsal nerve (C6–C8)
- Movement & chain
- Adducts, retroflexes and internally rotates the arm, and powerfully pulls the raised arm down and backward: the movement of climbing, swimming and rowing. With the arm fixed, it instead lifts the trunk.
- Palpation
- The lateral border is easily felt along the posterior axillary fold during resisted adduction.
- Clinical
- Shortening limits the end-range elevation of the arm and can cause compensatory lumbar extension. The muscle is widely used as donor tissue in reconstructive surgery.
- Segmental innervation
- Thoracodorsal nerve, C6–C8.
- In clinical practice
- The lateral border and posterior axillary fold serve as landmarks for axillary lymph node palpation and for marking the muscle as a donor flap in reconstructive surgery.
- Region in the model
- Upper limb