9. Latissimus Dorsi

Origin: SP of lower 6 thoracic vertebrae and related interspinous ligaments, inferior 3-4 ribs, thoracolumbar fascia, and iliac crest

Insertion: Floor of the intertubercular groove of the humerus

Action:

• Shoulder extension
• Shoulder medial rotation
• Shoulder adduction
• Raises the torso during climbing
• Role in lumbar stabilization

Innervation: Thoracodorsal nerve (C6/7/8)

Needling

Position: Prone or supine

Palpation: Palpate the bulk of this muscle in the subaxilla space when the arm is abducted

Technique: Pick up the bulk of this muscle and pull it away from the rib cage – Needle in an anterolateral direction when in prone and a posterior lateral direction when in supine

Caution: Moderate – never needle in a medial direction due to the position of the lung field