Description
The intrinsic muscles are one of two subgroups of muscles of the back, the other being the extrinsic muscles. These muscles lie deep to the thoracolumbar fascia and the extrinsic muscles of back. Overall, the intrinsic muscles of back are involved in movements of the vertebral column and help maintain posture.
For classification purposes, the intrinsic muscles of the back are divided into three distinct layers:
- a superficial layer, which consists of the spinotransversales muscles;
- an intermediate layer, which consists of the erector spinae muscles;
- a deep layer, which consists of the transversospinal, interspinales, and intertransversarii muscles.
