[Location] Localized in the prone position. On the back, 1.5 cun lateral to the lower border of the spinous process of the twelfth thoracic vertebra. (Fig.61)
 
[Regional Anatomy] Skin→subcutaneous tissue→the superficial layer of the thoracolumbar fascia and the aponeurosis of the latissimus dorsi→the erector spinae. Superficial layer, the distribution of the cutaneous branches of the posterior rami of the twelfth thoracic nerve and the first lumbar nerve, and the artery and vein along with them; deep layer, the muscular branch of the posterior rami of the twelfth thoracic nerve and the first lumbar nerve and the branches or the subordiantial ramus of the relevant artery and vein.