Latissimus Dorsi (“Lat”)

Joe Muscolino

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Latissimus-Dorsi_HR

Posterior view of the right latissimus dorsi. Permission Joseph E. Muscolino.

ATTACHMENTS:

  • The latissimus dorsi attaches from the spinous processes of T7-L5, posterior sacrum, and the posterior iliac crest to the medial lip of the bicipital groove of the humerus.

 

ACTIONS:

  • Medially rotates the arm at the glenohumeral joint
  • Adducts the arm at the glenohumeral joint
  • Extends the arm at the glenohumeral joint
  • Elevates the same-side (ipsilateral) pelvis at the lumbosacral joint.
  • Anteriorly tilts the pelvis at the lumbosacral joint.

 

TRIVIA NOTE:

  • The latissimus dorsi is the principal muscle involved in swimming the freestyle/crawl stroke. For this reason, it is sometimes referred to as “the swimmer’s muscle” and is usually very well developed in swimmers.
  • The latissimus dorsi has the same glenohumeral joint actions as the teres major (medial rotation, adduction, and extension).
  • The latissimus dorsi and teres major comprise the posterior axillary fold of tissue.