Final answer:
The erector spinae muscles provide postural support and help rotate the vertebral column.
Step-by-step explanation:
The function of the erector spinae muscles is to provide postural support for the vertebral column. These muscles are located on either side of the spine and help maintain the natural curvature of the spine. They work to keep the back upright and prevent slouching or excessive curvatures of the spine. The erector spinae muscles also assist in rotating the vertebral column and play a role in maintaining proper alignment and stability.