Latissimus Dorsi

Authors

Affiliations

Nathaniel Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Muscle	Origin	Insertion	Innervation	Action
Latissimus dorsi	T7-T12 SP Thoracolumbar fascia Inferior angle of scapula 9-12 ribs Posterior third of Iliac crest	Floor of the intertubercular groove of the humerus	Thoracodorsal n. C6 - C8	GHJ: IR, adduction, Extension Respiration: "cough muscle"

Origin

• Vertebral part: Spinous processes of T7–T12 vertebrae; thoracolumbar fascia¹
• Scapular part: Scapula (inferior angle)¹
• Costal part: 9th to 12th ribs¹
• Iliac part: Iliac crest (posterior one third)¹

Insertion

Floor of intertubercular groove of humerus¹

Innervation

Thoracodorsal n. (C6, C7, C8)¹

Action

• GHJ: Internal rotation, adduction, extension¹
• Respiration: “cough muscle”¹

Function

This muscle adducts and internally rotates the arm and depresses the raised arm²

Mini lat muscle

The teres major can almost be considered a “mini lat” since it has the same functions

References

1.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.

2.

Brazis PW, Masdeu JC, Biller J. Localization in Clinical Neurology. 8th ed. Wolters Kluwer Health; 2022.