- 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

Lumbosacral nerve-root anomalies.