Final answer:
The muscle in question functions to extend the vertebral column, involving both the erector spinae and multifidus muscles which support movements like extension, lateral flexion, and rotation.
Step-by-step explanation:
The function of the muscle described extends the vertebral column and includes various muscle groups such as the erector spinae and the multifidus muscle. The erector spinae is the primary extensor of the vertebral column and is comprised of three groups - the iliocostalis, the longissimus, and the spinalis. The multifidus muscle helps in the extension and lateral flexion of the vertebral column.
These muscle groups work together to allow movement and stabilization of the vertebral column, contributing to extension, flexion, lateral flexion, and rotation as well as maintaining the lumbar curve.