Origin: Spinous process
Insertion: Spinous process
Artery: Lateral sacral artery
Nerve: Posterior branch of spinal nerve
Antagonist: Rectus abdominis muscle
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).