Lumbosacral Plexuses

The lumbosacral plexuses are formed on either side by the last thoracic and the lumbar, sacral and coccygeal nerves. These networks of nerve fibers extend from the lumbar region of the lower back into the pelvic cavity, forming numerous motor and sensory fibers, which are associated with the lower abdominal wall, external genitalia, buttock, thighs, legs, and feet.