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 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 characteristi ...

, 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 o ...

to the axis. 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 The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral c ...

. 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 characteristi ...

work more effectively, and reduces the degeneration of the joint structures caused by friction from normal physical activity. These fasciculi arise: * ''in the sacral 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 muscl ...

of origin of the sacrospinalis, 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 attachme ...

, 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 bone A bone is a rigid organ that constitutes part of the skeleton in most ...

. * ''in the

lumbar In tetrapod Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids ( pelycosa ...

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 ...

. * ''in the cervical 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 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 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,

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 (front and side) abdominal wall which is deep to (layered below) th ...

abdominal internal oblique muscle The abdominal internal oblique muscle, also internal oblique muscle or interior oblique, is an abdominal muscle in the abdominal wall that lies below the external oblique muscle and just above the transverse abdominal muscle. Structure Its fiber ...

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 latera ...

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 ...

ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...

. 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 l ...

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.

References

External links

*
PTCentral

Dissection at ithaca.edu
{{Authority control Muscles of the torso

Atrophy and association with low back pain

Additional images

See also

References

External links