Identify, clean and reflect the erector spinae muscles. (G 1.26;N 172;Gl 3.10B)
- Remove the thoracolumbar fascia to reveal the three medial to lateral columns (spinalis, longissimus and iliocostalis) of the erector spinae muscles.
- Attempt to leave a flap of the thoracolumbar fascia attached adjacent to the lateral border of the iliocostalis. You may discard the small serratus posterior superior and inferior muscles.
- With a scalpel make a deep incision across the erector spinae muscles at the level of the iliac crest.
- Make a longitudinal incision along the entire extent of the exposed spinalis muscle (detaching it from the spinous processes).
- Use a chisel and blunt dissection to reflect the erector spinae muscles in the superior direction (leave the upper portion of the muscles attached to the ribs and transverse processes). This will allow you to leave the muscles attached to the body for future study.
