The part of the spinal cord that is situated at the bony segmental level of L1 contains most of the spinal cord that represent the L1-S4 spinal segments. These segments innervate the pelvic area and the legs.

 Collections of neurons in these segments control a variety of functions. These include walking (locomotion), the series of reflexes leading to urination (micturation), sexual function, etc. The neurons of course also mediate the reflexes that control and coordinate movements in the legs. Finally, many of the neurons that innervate the muscles of the pelvic area and legs are situated in these segments. If these motoneurons are killed, the muscles that they innervate will undergo atrophy. Electrical stimulation may not be able to activate atrophied muscles.