The lumbar enlargement (or lumbosacral enlargement) is a widened area of the spinal cord that gives attachment to the nerves which supply the lower limbs.Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view. The lumbar enlargement (or lumbosacral enlargement) is a widened area of the spinal cord that gives attachment to the nerves which supply the lower limbs. It commences about the level of T11 and ends at S2, and reaches its maximum circumference, of about 33 mm. Inferior to the lumbar enlargement is the conus medullaris. An analogous region for the upper limbs exists at the cervical enlargement. This article incorporates text in the public domain from page 752 of the 20th edition of Gray's Anatomy (1918)