The erector spinae muscle, also known as sacrospinalis and extensor spinae in some texts is from the deep muscles of the back. It lies superficial to the transversospinales muscle group and deep to the intermediate group of back muscles (serratus posterior superior and inferior).

Where are your Erectors?

The muscles and tendons of your erector spinae are located on both sides of your vertebral column (the bony points of the spine), which runs from your sacral and lumbar (lower back) to your thoracic (middle back) to your cervical region (upper back and neck).

What does Sacrospinalis mean?

: a muscle that extends the length of the back and neck, that arises from the iliac crest, the sacrum, and the lumbar and two lower thoracic vertebrae, and that splits in the upper lumbar region into three divisions of which the lateral is made up of the three iliocostalis muscles, the intermediate is made up of the ...