It emerges from the upper lateral border of the psoas major.[3]: 1148 It then crosses in front of the quadratus lumborum muscle to an area superior to the iliac crest.[4] It runs behind the kidneys. Just superior to the iliac crest, it pierces the posterior part of the transversus abdominis muscle and continues anteriorly in the abdominal wall between the transversus abdominis and internal oblique muscles.[3]: 1148
It divides into a lateral cutaneous branch and an anterior cutaneous branch between the transversus abdominis muscle and the internal oblique muscle.
Branches
Lateral cutaneous branch
The lateral cutaneous branch ("iliac branch") pierces the internal oblique muscles and the external oblique muscles immediately above the iliac crest.[4] It is distributed to the skin of the gluteal region, behind the lateral cutaneous branch of the subcostal nerve; the size of this branch bears an inverse proportion to that of the lateral cutaneous branch of the subcostal nerve.
When harvesting bone from the anterior iliac crest (AICBG), the lateral cutaneous branch of the Iliohypogastric nerve (L1) is most likely to be injured.
Area supplied by the lateral cutaneous branch can be seen in blue near the hip.
Anterior cutaneous branch
The anterior cutaneous branch ("hypogastric branch") continues onward between the abdominal internal oblique and transverse muscles.
It then pierces the internal oblique, becomes cutaneous by perforating the aponeurosis of the external oblique about 2.5 cm above the subcutaneous inguinal ring, and is distributed to the skin of the hypogastric region.
^ abSusan Standring, ed. (2021). Gray's anatomy: the anatomical basis of clinical practice (42nd ed.). New York. ISBN978-0-7020-7707-4. OCLC1201341621.{{cite book}}: CS1 maint: location missing publisher (link)
^ abcdefH. Kim, Daniel; A. Murovic, Judith (2008-01-01), Kim, Daniel H.; Midha, Rajiv; Murovic, Judith A.; Spinner, Robert J. (eds.), "11 - Lower extremity nerve injuries", Kline and Hudson's Nerve Injuries (Second Edition), Edinburgh: W.B. Saunders, pp. 209–278, ISBN978-0-7216-9537-2, retrieved 2021-01-29
^ abAasar, YH (1947). "Anatomical Anomalies". Fouad I University Press, Cairo.
^Mirjalili, S. Ali (2015-01-01), Tubbs, R. Shane; Rizk, Elias; Shoja, Mohammadali M.; Loukas, Marios (eds.), "Chapter 45 - Anatomy of the Lumbar Plexus", Nerves and Nerve Injuries, San Diego: Academic Press, pp. 609–617, ISBN978-0-12-410390-0, retrieved 2021-01-29