Text Size: A A A

Spinal Muscles: A Comprehensive Guide

Peer Reviewed

Muscles are named according to their shape, location, or a combination. They are further categorized according function such as flexion, extension, or rotation. Muscles and ligaments work together to support the spine, hold it upright, and control movement during rest and activity.

 

Types of Vertebral Muscles General Location
Forward flexors Anterior
Lateral flexors Lateral
Rotators Lateral
Extensors Posterior

Skeletal muscle is striated (striped) in appearance. It is innervated, under voluntary control, and has the fastest contraction rate of all muscle. Prior to a muscle contracting, a nerve impulse originates in the brain and travels through the spinal cord to the muscle.

Energy is needed for the muscle to contract (work). Mitochondria (cellular level) produce ATP (adenosine triphosphate), a chemical cells need for energy. ATP is produced as the mitochondria burn glucose (sugar). Blood vessels deliver the oxygen and nutrients the mitochondria needs to provide a steady supply of ATP.

 

?posterior
Muscles of the Posterior Cervical and Upper Thoracic Spine
1.
Semispinalis Capitus (head rotation/pulls backward)
2. Iliocostalis Cervicis (extends cervical vertebrae)
3. Longissimus Cervicus (extends cervical vertebrae)
4. Longissimus Capitus (head rotation/pulls backward)
5. Longissimus Thoracis (extension/lateral flexion vertebral column, rib rotation)
6. Iliocostalis Thoracis (extension/lateral flexion vertebral column, rib rotation)
7. Semispinalis Thoracis (extends/rotates vertebral column)


Muscles of the Spinal Column

CERVICAL MUSCLES FUNCTION NERVE
Sternocleidomastoid Extends & rotates head, flexes vertebral column C2, C3
Scalenus Flexes & rotates neck Lower cervical
Spinalis Cervicis Extends & rotates head Middle/lower cervical
Spinalis Capitus Extends & rotates head Middle/lower cervical
Semispinalis Cervicis Extends & rotates vertebral column Middle/lower cervical
Semispinalis Capitus Rotates head & pulls backward C1 – C5
Splenius Cervicis Extends vertebral column Middle/lower cervical
Longus Colli Cervicis Flexes cervical vertebrae C2 – C7
Longus Capitus Flexes head C1 – C3
Rectus Capitus Anterior Flexes head C2, C3
Rectus Capitus Lateralis Bends head laterally C2, C3
Iliocostalis Cervicis Extends cervical vertebrae Middle/lower cervical
Longissimus Cervicis Extends cervical vertebrae Middle/lower cervical
Longissimus Capitus Rotates head & pulls backward Middle/lower cervical
Rectus Capitus Posterior Major Extends & rotates head Suboccipital
Rectus Capitus Posterior Minor Extends head Suboccipital
Obliquus Capitus Inferior Rotates atlas Suboccipital
Obliquus Capitus Superior Extends & bends head laterally Suboccipital

 

THORACIC MUSCLES FUNCTION NERVE
Longissimus Thoracis Extension, lateral flexion of vertebral column, rib rotation Dorsal primary divisions of spinal nerves
Iliocostalis Thoracis Extension, lateral flexion of vertebral column, rib rotation Dorsal primary divisions of spinal nerves
Spinalis Thoracis Extends vertebral column Dorsal primary divisions of spinal nerves
Semispinalis Thoracis Extends & rotates vertebral column Dorsal primary divisions of spinal nerves
Rotatores Thoracis Extends & rotates vertebral column Dorsal primary divisions of spinal nerves

 

LUMBAR MUSCLES FUNCTION NERVE
Psoas Major

Flexes thigh at hip joint & vertebral column

L2, L3, sometimes L1 or L4
Intertransversarii Lateralis Lateral flexion of vertebral column Ventral primary division of spinal nerves
Quadratus Lumborum Lateral flexion of vertebral column T12, L1
Interspinales Extends vertebral column Dorsal primary divisions of spinal nerves
Intertransversarii Mediales Lateral flexion of vertebral column Dorsal primary divisions of spinal nerves
Multifidus Extends & rotates vertebral column Dorsal primary divisions of spinal nerves
Longissimus Lumborum Extends & rotates vertebral column Dorsal primary divisions of spinal nerves
Iliocostalis Lumborum Extension, lateral flexion of vertebral column, rib rotation Dorsal primary divisions of spinal nerves

Muscle Fascia
Fascia is thickened connective tissue that envelops a muscle or a group of muscles. Superficial fascia is found directly under the skin. Epimysium is the fascia closest to the muscle. Perimysium divides the muscle into facicles – muscle fibers. Endomysium is another type of connective tissue that covers each muscle fiber.

Updated on: 05/29/13
Mary Rodts, DNP
Understanding the terminology associated with spinal problems is very important as health care providers discuss the problems and the solutions for the spinal disorder with patients and families. This article helps clarify a difficult topic.
Cancel
Delete
Continue Reading:

Spinal Blood Supply

The function of the vascular system is to nourish each cell in the body. This includes the vertebral column, spinal cord, neural elements, muscles, and other related structures.
Read More