1 Axial pain. 2  Also called mechanical pain, axial pain is the most common cause of back pain and may present in a number of different ways (sharp or dull, constant, comes and goes, etc.). 3  A muscle strain is a common cause of axial pain.ommon anatomical causes of back pain include: 1  The large nerve roots that go to the legs and arms may be irritated. 2  The smaller nerves that innervate the spine may be irritated. 3  The large paired back muscles (erector spinae) may be strained. 4  The bones, ligaments, or joints themselves may be injured.
Merge this question into. Split and merge into it. Answer by Puhlaa. Confidence votes 4.9K. The spinal cord enlarges at the cervical and lumbosacral areas in order to accomodate the extra neurons involved with the motor control going to, and sensations coming from, the upper and lower limbs.
Lumbar Spine Anatomy Video. The base of the spine is made up of the intricate L5-S1 vertebral segment, also called the lumbosacral joint. This spinal segment has several interconnected components, any of which can cause lower back and/or leg pain (sciatica):ciatica Animated Video. 1  There is a nerve that passes from the spinal canal through an opening in the back of the L5-S1 segment and runs down the back of each leg (as part of the large sciatic nerve).