Erector Spinae

The erector spinae is a large muscle that originates near the sacrum and extends vertically up the length of the back. It lies on each side of the vertebral column and extends alongside the lumbar, thoracic and cervical sections of the spine. The erector spinae functions to straighten the back and provides for side-to-side rotation. An injury or strain to this muscle may cause back spasms and pain.