The posterior inferior dentate muscle originates from the posterior leaflet of the lumbodorsal fascia (at the level of the spinous processes of T11-T12 and L1-L3). It is placed deeper than the large dorsal muscle, it covers the iliocostal, the very long of the back, the ribs and the intercostal muscles.
It is inserted with four digits at the lower edge and the outer face of the last 4 ribs (9th-12th coast).
With its action it lowers the ribs, intervening in forced expiration (action contrary to the upper posterior toothed muscle). Extends and inclines the trunk (lower dorsal section) laterally.
It is innervated by a branch of the thoracodorsal nerve (C6-C8) and by branches of the intercostal nerves (T9-T11).
| ORIGIN Posterior leaflet of the lumbodorsal fascia (or thoracolumbar fascia) at the level of the spinous processes of T11-T12 and L1-L3 |  |
| INSERTION With 4 digits at the lower edge and the outer face of the last 4 ribs | |
| ACTION Contracting lowers the ribs (expiratory muscle); extends and inclines the trunk laterally (lower dorsal section) | |
| INNERVATION Thoracodorsal nerve branch (C6-C8) and intercostal nerve branches (T9-T12) |
| Upper limb | Lower limb | Trunk | Abdomen | Articles |
