- See:
Lumbar Plexus:
- Anatomy:
- lumbosacral plexus is derived from
L4,
L5,
S1,
S2,
S3 & S4 roots,
each giving rise to anterior and posterior branches;
- anterior branches supply flexor muscles of limb, & posterior branches
supply extensor and abductor muscles;
-
superior gluteal nerve (
L4
&
L5) supplies
glutei medius and
minimus &
tensor fasciae latae;
-
inferior gluteal nerve
(
L5,
S1,
S2) supplies
maximus;
- small nerves derived from
L4,
L5,
S1,
S2,
S3 supply
lateral rotators of thigh except
for obturator externus, which is supplied by
obturator nerve;
-
sciatic nerve
- largest derivative of lumbosacral plexus is
sciatic nerve, which supplies muscles
of posterior thigh & all of muscles of leg and foot;
- pudendal nerve arises from the ventral rami of S2-S4;
- Injury of Lumbrosacral Plexus:
- w/ pelvic ring trauma, the nerve which is most often injured is the
L4-
L5
portions of the lumbral sacral trunk;
-
L4-
L5 portion of trunk crosses anterior to sacral ala & sacral iliac joint;
- it exits the sciatic notch above the
piriformis, where is branches off
superior gluteal nerve and forms part of
sciatic nerve;
Anomalies
of the lumbosacral nerve roots. An anatomic investigation.
Lumbosacral nerve-root anomalies.
