The multifidus (multifidus spinae : ''pl. multifidi'' ) muscle consists of a number of fleshy and tendinous
fasciculi
Fascicle or ''fasciculus'' may refer to:
Anatomy and histology
* Muscle fascicle, a bundle of skeletal muscle fibers
* Nerve fascicle, a bundle of axons (nerve fibers)
** Superior longitudinal fasciculus
*** Arcuate fasciculus
** Gracile fasci ...
, which fill up the groove on either side of the
spinous processes
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
of the
vertebrae
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...
, from the
sacrum
The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30.
The sacrum situates at the upper, back part ...
to the
axis
An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to:
Mathematics
* Axis of rotation: see rotation around a fixed axis
*Axis (mathematics), a designator for a Cartesian-coordinate ...
. While very thin, the multifidus muscle plays an important role in stabilizing the joints within the spine. The multifidus is one of the
transversospinales
The transversospinales are a group of muscles of the human back. Their combined action is rotation and extension of the vertebral column. These muscles are small and have a poor mechanical advantage for contributing to motion. They include:
* the ...
.
Located just superficially to the spine itself, the multifidus muscle spans three joint segments and works to stabilize these joints at each level.
The stiffness and stability makes each
vertebra
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
work more effectively, and reduces the degeneration of the joint structures caused by friction from normal physical activity.
These fasciculi arise:
* ''in the
sacral
Sacral may refer to:
*Sacred, associated with divinity and considered worthy of spiritual respect or devotion
*Of the sacrum
The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spi ...
region:'' from the back of the sacrum, as low as the fourth
sacral foramen, from the
aponeurosis
An aponeurosis (; plural: ''aponeuroses'') is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join musc ...
of origin of the
sacrospinalis
The erector spinae ( ) or spinal erectors is a set of muscles that straighten and rotate the back. The spinal erectors work together with the glutes (gluteus maximus, gluteus medius and gluteus minimus) to maintain stable posture standing or sittin ...
, from the medial surface of the
posterior superior iliac spine
The posterior border of the ala, shorter than the anterior, also presents two projections separated by a notch, the posterior superior iliac spine and the posterior inferior iliac spine. The posterior superior iliac spine serves for the attachment ...
, and from the
posterior sacroiliac ligaments
The posterior sacroiliac ligament is situated in a deep depression between the sacrum and ilium behind; it is strong and forms the chief bond of union between the bones.
It consists of numerous fasciculi, which pass between the bones in various d ...
.
* ''in the
lumbar
In tetrapod anatomy, lumbar is an adjective that means ''of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum.''
The lumbar region is sometimes referred to as the lower spine, or as an area of the back i ...
region:'' from all the
mamillary processes.
* ''in the
thoracic
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the crea ...
region:'' from all the
transverse processes
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...
.
* ''in the
cervical
In anatomy, cervical is an adjective that has two meanings:
# of or pertaining to any neck.
# of or pertaining to the female cervix: i.e., the ''neck'' of the uterus.
*Commonly used medical phrases involving the neck are
**cervical collar
**cervic ...
region:'' from the articular processes of the lower four vertebrae.
Each fasciculus, passing obliquely upward and medially, is inserted into the whole length of the
spinous process of one of the vertebræ above.
These fasciculi vary in length: the most superficial, the longest, pass from one vertebra to the third or fourth above; those next in order run from one vertebra to the second or third above; while the deepest connect two adjacent vertebrae.
The multifidus lies deep relative to the
spinal erectors
The erector spinae ( ) or spinal erectors is a set of muscles that straighten and rotate the back. The spinal erectors work together with the glutes (gluteus maximus, gluteus medius and gluteus minimus) to maintain stable posture standing or sittin ...
,
transverse abdominis
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral (anatomy), lateral (front and side) abdominal wall which is deep to ...
,
abdominal internal oblique muscle and
abdominal external oblique muscle
The abdominal external oblique muscle (also external oblique muscle, or exterior oblique) is the largest and outermost of the three flat abdominal muscles of the lateral anterior abdomen.
Structure
The external oblique is situated on the lateral ...
.
Atrophy and association with low back pain
Dysfunction in the lumbar multifidus muscles is strongly associated with
low back pain. The dysfunction can be caused by inhibition of pain by the spine. The dysfunction frequently persists even after the pain has disappeared. Such persistence may help explain the high recurrence rates of low back pain. Persistent lumbar multifidus dysfunction is diagnosed by
atrophic replacement of the multifidus with fat, as visualized by
magnetic resonance imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ...
or
ultrasound
Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...
.
One way to help recruit and strengthen the lumbar multifidus muscles is by tensing the
pelvic floor muscles
The pelvic floor or pelvic diaphragm is composed of muscle fibers of the levator ani, the coccygeus muscle, and associated connective tissue which span the area underneath the pelvis. The pelvic diaphragm is a muscular partition formed by the leva ...
for a few seconds "as if stopping urination midstream".
Additional images
File:Gray803.png, The posterior divisions of the sacral nerves.
File:1111 Posterior and Side Views of the Neck Deep Posterior.png, The multifidus muscles (labeled left) as seen in a posterior view of the neck.
See also
*
Rotatores muscles
The rotatores muscles (rotatores spinae muscles) lie beneath the multifidus and are present in all spinal regions but are most prominent in the thoracic region; they are eleven in number on either side.
Each muscle is small and somewhat quadrilat ...
References
External links
*
PTCentralDissection at ithaca.edu
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Muscles of the torso