ABSTRACT
The nerve supply to the lower extremity is derived from the lumbar and sacral plexuses. The lumbosacral plexus arises from at least eight spinal nerve roots, each of which contains anterior and posterior divisions that innervate the original ventral and dorsal portions of the limb. With the exception of a small cutaneous portion of the buttock (which is supplied by upper lumbar and lower sacral segmental nerves), the innervation of the lower extremity is entirely through the branches of the lumbosacral plexus.
