Inside each of these main layer divisions are more layers and/or muscle groups.
(The other intrinsic layers are the superficial and intermediate.)
Four muscles comprise the deep layer of the intrinsic back muscles.
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From superficial to deep: thesemispinalis, the multifidus, the rotatores and the interpinalis and intertransversii.
The multifidus and rotatores have special functions and jobs as we’ll outline below.
These triangles are located on either side of the spine, attaching on the transverse and spinous processes.
The multifidus is divided into parts that correspond with the main regions of your spine.
The job of the multifidus is to extend your spine (think about arching).
And finally, the multifidus contributes to side bending, which is called lateral flexion.
Rotatores Muscles
Just below the multifidus lies the rotatores.
Like the multifidus, the rotatores are small muscles located on either side of the spine.
They are shaped like a quadrilateral and attach on the transverse process of the vertebrae.
First, the unique function of the rotatores is not well known.
Instead, it is thought that the rotatores play a role in stiffening or stabilizing the spine.
Yes, these small muscles along the spine control flexibility and posture.
How can I strengthen the multifidus muscles?
Lumbar-stabilizing exercisescan strengthen the deep intrinsic muscles of the spine.
Training for the deep muscles of the core.
Diane Lee & Associates website.
Kendall, F., McCreary, E. Provance, P. Muscles: Testing and Function.
Moore, K., Dalley, A. Clinically Oriented Anatomy.
Lippincott, Williams & Wilkins.
