Which nerves primarily innervate the lower extremities?

The lumbar and sacral plexuses are the primary networks of nerves that innervate the lower extremities. These plexuses are formed by the ventral rami of the lumbar and sacral spinal nerves, specifically from L1 to L5 for the lumbar plexus and S1 to S5 for the sacral plexus. They give rise to major nerves such as the femoral nerve, which innervates the anterior thigh, and the sciatic nerve, which innervates the posterior thigh and all of the leg and foot.

These plexuses are essential because they are responsible for both motor and sensory innervation to the lower limbs. The lumbar plexus helps with movements and sensations in the thigh, while the sacral plexus extends this innervation to the lower leg and foot. Therefore, understanding these plexuses is crucial for recognizing how motor control and sensory processing occur in the lower extremities.