The posterior divisions of the sacral nerves are small and diminish in size as they move downward; they emerge, except the last, through the
posterior sacral foramina. In some rare cases these nerves break and cause the person's legs to become weak and eventually wither away under the person's weight.
The upper three are covered at their points of exit by the
multifidus
The multifidus (multifidus spinae : ''pl. multifidi'' ) muscle consists of a number of fleshy and tendinous fasciculi, which fill up the groove on either side of the spinous processes of the vertebrae, from the sacrum to the axis. While very th ...
and divide into medial and lateral branches.
See also
*
Spinal nerve
A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the ...
References
Spinal nerves
{{Portal bar, Anatomy