[Characteristics of anatomical structures and clinical significance of lumbar Jiaji (EX-B 2) points].

Objective: To observe the anatomical structure of Jiaji (EX-B 2) points at the level of lower lumbar region so as to provide evidence for the insertion angle and depth.

Methods: Thirty spine samples of male adults were adopted, and perpendicular insertion of the needle was applied at 3 locations including 1 cun, 0.5 cun and 0.3 cun lateral to the lower border of the spinous process of the lumbar vertebra. The needles were fixed at the local region. Structures and the adjacent major blood vessels and nerves were observed during the anatomy.

Results: When the needle was inserted perpendicularly at the point 1 cun lateral to the lower border of the spinous process of the lumber vertebra with the insertion depth of (35.77 +/- 5.86) mm, the zygapophyseal joints, the adjacent osteo-fibrous canal and osteo-fibrous aperture were touched by the tip of the needle, and the medial ramus of dorsal primary ramus of spinal nerve and concomitant vessels were stimulated. Then, needles were inserted perpendicularly 0.5 cun and 0.3 cun lateral to the lower border of the spinous process of the lumber vertebra with the insertion depth of (32.89 +/- 4.79)mm for both. When needle was inserted 0.5 cun lateral, the medial ramus of dorsal primary ramus of spinal nerve and the concomitant vessels were touched by the tip of the needle at where they across the lamina periosteum and erector spinae. When needle was inserted 0.3 cun lateral, the body of the needle reached the terminal branches of the medial ramus of dorsal primary ramus of spinal nerve and the concomitant vessels through the deep paraspinal muscles and the thoracolumbar fascia.

Conclusion: The medial ramus of dorsal primary ramus of lumbar spinal nerve and concomitant vessels distributed at the region 1 cun, 0.5 cun and 0.3 cun beside the lower border of each lumbar spinous process. Therefore, the location of Jiaji (EX-B 2) points can be considered in the region from 0.3 cun to 1 cun beside the lower border of each spinous process.