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Latissimus dorsi

Musculus latissimus dorsi

The broadest muscle of the back, the latissimus dorsi extends, adducts, and medially rotates the arm at the shoulder and acts as a powerful climbing muscle; it also assists forced expiration during coughing and sneezing and helps with lateral flexion of the trunk. Forming part of the posterior axillary fold, it originates from the spinous processes of T7 to T12, the thoracolumbar fascia, the iliac crest, and the lower three ribs, and inserts on the floor of the intertubercular sulcus of the humerus. Surgeons use it in breast and thoracic wall reconstruction. As a principal muscle of swimming and rowing, it is prone to strain, and injury to the thoracodorsal nerve weakens arm adduction.

The broadest muscle of the back, forming part of the posterior axillary fold. It originates from the spinous processes of T7-T12, thoracolumbar fascia, iliac crest, and lower three ribs. It inserts on the floor of the intertubercular sulcus of the humerus.

On this page
类型 Muscle
身体系统 Muscular
身体区域 Back
拉丁名称 Musculus latissimus dorsi
FMA ID 13357

功能

Extends, adducts, and medially rotates the arm at the shoulder. A powerful climbing muscle. Also assists in forced expiration (coughing, sneezing) and trunk lateral flexion.

临床意义

The latissimus dorsi is used in breast reconstruction and thoracic wall reconstruction. It is the main muscle used in swimming and rowing, susceptible to strain injuries. Thoracodorsal nerve injury causes weakness of arm adduction.

Frequently Asked Questions

What is the latissimus dorsi?

The latissimus dorsi is the broadest muscle of the back, forming a large, flat sheet that contributes to the posterior axillary fold. It is one of the prime movers of the upper limb, particularly for adduction and medial rotation at the shoulder.

Where is the latissimus dorsi located?

The latissimus dorsi originates from the spinous processes of T7–T12, the thoracolumbar fascia, the iliac crest, and the lower three ribs. Its fibers converge to insert on the floor of the intertubercular (bicipital) sulcus of the humerus.

What is the function of the latissimus dorsi?

The latissimus dorsi extends, adducts, and medially rotates the arm at the shoulder joint. It is particularly important in pulling movements such as climbing, swimming, and rowing, and also assists in respiration during forced expiration.

What conditions may be associated with the latissimus dorsi?

The latissimus dorsi may be involved in muscle strains from overhead or pulling activities, and is occasionally a site of referred pain in shoulder and back disorders. It is also used as a donor flap in reconstructive surgeries, such as after mastectomy.

What does the latissimus dorsi look like?

The latissimus dorsi is a broad, flat, fan-shaped muscle that forms the lower part of the back and the posterior axillary wall. On imaging, it is identifiable as a wide, thin muscular sheet covering the lower thoracic and lumbar regions.

References

  1. Foundational Model of Anatomy — FMA:13357 Reference anatomy ontology (University of Washington)

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Educational Disclaimer

This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical decisions.

Data sources: Terminologia Anatomica, Foundational Model of Anatomy, Wikidata.