It is inserted on the crest of the lesser tubercle of the humerus along with the large round muscle, which surrounds with its fibers.
At the top it is covered by the trapezius muscle. The deep face is related to part of the sacrospinal, with the inferior posterior dentate, with the external intercostal muscles and with the oblique of the abdomen.
With its action (with a fixed origin), it adds, extends and rotates the humerus inside; if the humerus is taken as a fixed point it raises the trunk and raises the ribs (inspiratory muscle). Acting bilaterally, it extends the rachis (lower back and lower back) and brings the pelvis into anteversion.
It is innervated by the thoracodorsal nerve of the brachial plexus (C6-C8).
DESCRIPTION Triangular shaped muscle |  |
ORIGIN Vertebral part: from the lumbodorsal fascia and from the spinous processes of the last 6 thoracic vertebrae Coastal side: 10th to 12th coast Scapular part: from the lower corner of the lateral margin of the scapula. | |
| INSERTION Crest of the small humeral tuberosity (medial lip) also called bicipital groove; | |
| ACTION Adduce, extend and internally rotate the humerus. It intervenes in the forced inspiration, extends the trunk (lower back and lower back) and tilts it laterally (unilateral contraction); intervenes in the rearward position of the shoulder | |
| INNERVATION Thoracodorsal nerve of the brachial plexus (C6-C8) |
| Upper limb | Lower limb | Trunk | Abdomen | Articles |
