Corpus: Thoracolumbar fascia
1. Definition
The thoracolumbar fascia covers the autochthonous back muscles in the thoracic and lumbar regions, and also serves as an origin for several muscles.
2. Anatomy
The thoracolumbar fascia consists of two layers: a superficial and a deep leaflet.
- The superficial leaflet attaches to the iliac crest and the spinous processes of the thoracic, lumbar, and sacral vertebrae. It covers the erector spinae muscle from the dorsal side.
- The deep leaflet attaches to the iliac crest, the lower ribs, and the transverse processes of the lumbar vertebrae. It surrounds the erector spinae muscle from the ventral side and the quadratus lumborum muscle from the dorsal side.
3. Function
The thoracolumbar fascia serves as the origin of both the latissimus dorsi muscle and the serratus posterior inferior muscle. In the lumbar region, the deep leaflet forms the aponeurosis lumbalis, which acts as the origin for the obliquus internus abdominis and transversus abdominis muscles.
Together with the spinal column, the thoracolumbar fascia forms an osteofibrous canal, embedding the autochthonous muscles.