Multifidus Muscle: Anatomy, Assessment and Treatment

by Doug Alexander

Introduction  

The lumbar multifidi are small - but important - muscles. They lie on each side of the spinous processes of the lumbar vertebrae (see the pink zone in the illustration at right).  

While the erector spinae and other long muscles move the spine as a whole, the multifidi provide segmental stability by orienting adjacent vertebrae to each other(MacIntosh 1986, Richardson 1999).

Multifidi dysfunction is often interwoven with facet joint dysfunction. Hypertonic, short multifidi are often found in the location of a facet joint hypomobility.

The multifidi may adapt to the hypomobility by becoming short, or they may encourage facet joint hypomobility by keeping the facet joint compressed and altering its ability to function properly.

Multifidi can also be related to spinal disc dysfunction. The tone of multifidi in close proximity to spinal disc pathologies tends to be inhibited (Richardson 1999). The resultant weakness in the multifidi often sets the stage for recurrent disc issues.

In this article we will get to know the multifidi very well. In particular, you will learn to recognize multifidi shortness and high tone associated with facet joint hypomobility and locking, as well as multifidi inhibition that tends to be associated with disc pathology.

Anatomy

Attachment points 

The cephalic (toward the head) attachment of the multifidi muscles is to the spinous processes and the lamina of a lumbar vertebra.

There are five fascicles or bands in each multifidus muscle. The shortest fascicles are the deepest. They arise from the lamina of the vertebra and travel two vertebrae caudally (toward the tail) to attach to the mamillary processes of that vertebra, just beyond the margin of the facet joint (Richardson 1999).

The more superficial fibers attach to the spinous process and travel caudally to insert into the mamillary processes of vertebrae 3, 4 and 5 segments away. Fibers from the lower lumbar vertebrae insert into the respective sacral vertebral regions.

The fascicles of the multifidus from each vertebra overlap the fibers of the multifidus from the vertebrae above. As a consequence they fill the entire region of the back from the spinous processes to about twAnatomyo thumbs breadth laterally.

When one palpates the lumbar mutlifidi, the fibres closest to the surface travel 3, 4 and 5 vertebral segments, while the deeper fibres travel over the next vertebra to insert into the mamillary process of the segment two vertebrae below in close proximity to the facet joint between it and the vertebra below the originating vertebra.

While “multfidus” refers to a single muscle, “multfidi” refers to a group of multifidus muscles. We will refer to both multifidus and multifidi almost interchangeably in the article as it is often difficult to separate a single multifidus from the multifidi in which it is interwoven.

The facet joints are covered on all sides by fibers of the deepest, shortest multifidi fascicles. Some of these fibers even attach to the facet joint capsules (Lewin, MacIntosh cited in Richardson).

Actions: The main purpose of the multifidi muscles is to provide segmental stability to the spine (Richardson 1999).

Multifidi and Facet Joint Locking

 If the multifidi are short on a regional basis, the client will have an exaggerated lumbar lordosis, or a lordosis that isn’t lost when they bend forward (Neumann 2002)).

This helps to set the stage for the lumbar vertebrae to be more approximated or held together at the back than they should be. This may make the person more vulnerable to facet joint approximation and episodes of facet hypomobility and/or locking.

Multifidus shortness can also occur at the level of a single facet joint. Because the multifidi attach adjacent to the margin of the upward facing facet and originate above, tension or shortness in that particular multifidus segment will tend to inhibit movement and/or lock the movement at that facet joint.

  The motion of the spinal segments with respect to each other can be assessed through joint play assessment (Magee). With the client in prone, palpate the lumbar spinous processes and give each one an anteriorly directed pressure. Each spinous process should feel similarly firm and give slightly in an anterior direction as you press on it.

If a spinal segment is restricted in mobility, the spinous process of that vertebra will feel harder because the vertebra doesn’t move anteriorly when it is pressed upon. Clients will often feel an ache or sharp pain when the segment that is restricted is pressed upon.

  You can further explore findings of sensitivity and lack of motion by applying anteriorly directed pressures over the facet joints on either side of the spine. Over time a clinician can develop sensitivity to the quality of motion. Clients will often confirm which joint is most vulnerable as you palpate along the spine.

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Multifidus Wasting

While short and/or hypertonic multifidi can cause lack of movement between vertebrae, inhibited, low tone and/or weak multifidi can contribute to repeated episodes of intervertebral disc pathology.

This is because the normal function of the multifidi is to contribute to stiffness of the lumbar spine to resist flexion and flexion/rotation forces. This adjustable multifidus stiffness is necessary to maintain optimal positioning of adjacent vertebrae. If the multifidi are not contributing adequately, then adjacent vertebrae may experience excessive flexion and rotational forces when a person is bending over and consequently contribute to high intervertebral disc loading. Eventually this can lead to disc failure and sciatic symptoms.

It has been demonstrated that the multifidi inhibition and wasting does not reverse itself as the person recovers from an acute spinal episode (Richardson 1999). Part of the muscle may convert to fat. This is shown in the adjacent MRI photos. The amount of fat that is found in the multifidi is strongly correlated with recurrent back pain episodes in adults (Kjaer 2007).

Even in clients who do abdominal and spinal extension (strengthening) exercises, the multifidi do not regain a normal cross section thickness (Richardson 1999). These hypotonic muscles can be targeted with very specific exercises to regain normal tone and help to avoid recurrent back pain episodes. We will explore these interventions later in this article.

Assessment

S Visual Assessment

People with an excessive lumbar lordosis often have short erector spinae, quadratus lumborum and multifidi muscles.

By asking your client to flex forward at the hips you can determine whether the lumbar spinal segments are stuck in a lordotic (extended) posture or if they can flex with respect to each other.

Clients that maintain a lumbar lordosis as they flex forward have short and inextensible (non-lengthening) erector spinae, quadratus lumborum, and/or multifidi muscles. When there is a more local inability to flex, it is more likely caused by only a single multifidus, or isolated group of short or high tone multifidi.

Clients who flex excessively in their lumbar spine have weak and/or eccentrically overloaded multifidi muscles. This sets the stage for chronic post-exercise muscle soreness in the multifidi as well as the other spinal extensor muscles as well as recurrent spinal disc pathologies.

Myofascial Palpation

  Palpating each side of the client’s spine as they lie in a relaxed prone position assesses muscular development and tone. This can also be done in sitting or standing (Hides 2000), although massage therapists don’t usually assess this way.

There should be a degree of muscular fullness on each side of the spinous processes. In a normally muscled and toned individual you will feel the spinous process along with a symmetrical fullness on either side that prevents you from sinking into their back. 

Sometimes you feel that a particular segment or segments have excessive multifidus tone, fullness and/or a textured ropy quality. These multifidi often have an excessive “stabilizing” effect and may be approximating adjacent facet joints and making them prone to hypomobility and/or locking.

  If you find ropy, full or high-toned fascicles of a multifidus, palpate the fibers fully. One often finds myofascial trigger points in fibres like these that create a local ache (Travell) and may also create sharp buckling or jamming feelings in the spine underneath them. This is likely because of their physical proximity to the underlying facet joints as well as their effect to draw adjacent facet joints together. Palpation may reproduce a familiar quality in the client, with them stating, “Ah, that is my back pain!”

Sometimes you may find multifidus atrophy. As you compare the fullness in the multifidi along both sides of the spine, you may feel a relative softness at one or more spots. Attempt to localize it precisely. This is an area where the multifidi have been inhibited and likely do not contribute to intersegmental stability. This is a region that is vulnerable to excessive flexion and or flexion/rotation loading (Hides 2000, Richardson 1999).

When you find a segment that is underdeveloped in this way, apply a little more testing pressure to it and compare it to adjacent sections of the spine. It will often feel vulnerable and weak to your palpating fingers. Clients often report that it feels weak to them and may create part of the feelings of vulnerability they feel when their back is bothering them!

You can check on the function of the multifidi in these inhibited regions by asking the client to actively contract the muscles. This often confirms their inability to get the segment to contribute to spinal stiffness.

This active test is done in the prone position, by asking the client to “Gently swell the muscle under my fingers (or thumbs). Hold the contraction while breathing normally.” (Richardson 1999))

There should be no spinal or pelvic movement while the client does this. It is often easiest to ask them to do this in a region where they have multifidi fullness. Then when they can do this against the feedback of your fingers or thumbs, gradually move into the region where they seem to be inhibited.

You generally find that their ability to recruit the multifidi deteriorates as they get closer and closer to the region where the muscle has less cross-sectional area.

Treatment

  Your treatment of the multifidi will depend on what you have found during the assessment.

High toned and/or short multifidi require interventions to drop their tone, lengthening manipulations and often some joint mobilization to help restore more normal movement of the related spinal segments.

Inhibited, low toned multifidi and unstable lumbar spinal segments require treatment that is directed toward facilitating contraction and strengthening/stiffening of the multifidi.

In either situation, the erector spinae and quadratus lumborum usually have too much tone, and need to be treated with classic massage manipulations. In clients who have inhibited multifidi, this drop in tone of the longer muscles makes training the multifidi easier to perform and more effective.

Safety / Precaution Issue

While it ought to be safe to treat clients with disc pathology with massage, it is important to avoid stressing the spine in such a way that causes the disc problem to become worse. People with neurological symptoms and/or pain in the buttock and down the leg are not safe to treat in lumbar spine flexed postures!

If your client has these symptoms then they are not safe to treat unless you have training appropriate to their care.

If your client tends to have these types of neurological and lower extremity problems, but doesn’t have them at the moment, then you can probably treat associated multifidus dysfunction as outlined in this article. Just avoid strongly flexing their spine with your manipulations and/or positioning on the table.

Short and/or Hypertonic Multifidi

  Short and/or hypertonic multifidi can be treated with the spine on a bit of flexion (ie. Prone with one or even two pillows under the abdomen (as long as the client is not prone to sciatica as in the note on the previous page)).

The erector spinae, serratus posterior inferior, quadratus lumborum and oblique abdominal muscles usually require some attention. This can be done with a variety of conventional massage manipulations that won’t be discussed in this short article.

The multifidi need to be scanned for hypertonicity by exploring along the two sides of the spinous processes. Allow yourself to concentrate on the fibre directions of all the segments of the muscle that originate from a single spinous process.

Treatment can be through static contact, kneading or sustained bowing of the muscle (these are demonstrated in the associated video clips).

  When the tone drops in a particular multifidus the muscle can be stripped to lengthen it. These stripping manipulations often lead your fingers to the attachments of the multifidi across a hypomobile facet joint. Take your time with these manipulations as the muscle and joint have usually been stiff for months or even years.  

Facet joint hypomobilities can be treated with a variety of joint mobilizations that we also will not be exploring in this article.

Inhibited Multifidi

  An inhibited multifidus or a region of inhibited multifidi need to be facilitated into contracting and gradually strengthened. Ask the client to “swell the muscle up” against the resistance of your thumb and/or finger. Most people cannot do this right away; that’s why the muscle is inhibited!

Contraction of the multifidi is facilitated by contraction of the transverses abdominus muscle. This can be taught by asking your client to draw their belly button toward their spine when they exhale. If they recruit their pelvic floor like they are trying to stop a stream of urine, then the multifidi are facilitated even more.

I often have the client practice just the transverses abdominus and pelvic floor recruitment on their own for a week or two, before asking them during a treatment to swell the multifidus at the same time as the other two muscles.

When the client does this properly, there is a feeling of increased fullness or turgor in the multifidus region close to the spine without any recruitment of the long spinal muscles (erector spinae) and no movement of the spine.

  People with inhibited multifidi need to gradually train the muscle by practicing this exercise every day. Clients often benefit from sticking their own thumb or finger into the muscle when practicing in order to ensure they are recruiting it properly.

Eventually, the multifidus is recruited in preparation for spinal loading such as extending legs or arms in an all fours position, or balancing on a gym ball or just in activities of daily living.

An

Homecare

Short multifidi need stretching. This can be done as part of a general low back and gluteal stretching program, or precisely targeted toward the offending muscles.

 Weak, Inhibited Multifidi need strengthening. This is achieved through learning core stabilization. The transversus abdominus, pelvic floor and multifidi are co-recruited to keep the lumbo-pelvic region in a dynamically neutral posture.

Then, progressively more difficult loads are put through the region by lifting limbs, or the torso either on a mat, sitting, standing or on a gym ball.

The client needs to have more than enough strength and endurance to be more than adequate for any tasks that they commonly undertake, including occupational tasks and sporting activities.

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Biography 

Doug Alexander has been absorbed in his own and other people’s multifidus muscles for over two decades!

He is the editor of Massage Therapy Practice.com and teaches at Algonquin College in Ottawa, Canada. Doug can be reached at alexander2000@sympatico.ca

References 

Bogduk N: Clinical Anatomy of the Lumbar Spine, 3^rd ed. London; Churchill Livingstone: 1997.

Cavanaugh JM, Lu Y, Chen C, Kallakuri S: Pain Generation in Lumbar and Cervical Facet Joints. J Bone & Joint Surgery 2006;88-A(Supp 2):63-67.

Hides J, Scott Q, Jull G, Richardson C: A Clinical Palpation Test to Check the Activation of the Deep Stabilizing Muscles of the Lumbar Spine. International Sport Med Journal 2000;1(4):1-4.

Kjaer P, Bendix T, Lorenson JS, Korsholm L, Leboef-Yde C: Are MRI-defined fat infiltrations in the multifidus msuces associated with low back pain? BMC Medicine 2007, 5:2 doi:10.1186/1741-7015-5-2

Lewin T, Moffett B, Viidik A: The morphology of the lumbar synovial joints. Acta Morphologica Neerlando Scandanavia 1962;4:299-319.

Macintosh JE, Valencia F, Bogduk N, Munro RR: The morphology of the human lumbar multifidis. Clinical Biomechanics 1986;1:196-204.

Magee D: Orthopedic Physical Assessment 4^th Ed. New York; Elsevier:2005.

Matejka J, Zuchova M, Koudela K, Pavelka T: Changes of muscle fiber types in erector spinae and multifidus muscles in unstable lumbar spines. J Back Musculoskeletal Rehabilitation 2006;19:1-5.

Macintosh JE, Bogduk N: The biomechanics of the lumbar multifidus. Clinical Biomechanics 1986;1:205-213.

Morris J, Benner F, Lucas D: An electromyographic study of the intrinsic muscles of the back in man. J Anatomy 1962;96:509-530.

Neumann DA: Kinesiology of the Musculoskeletal System. St. Louis; Mosby:2002.

Richardson C, Jull G, Hodges P, Hides J: Therapeutic Exercise for Spinal Segmental Stabilization in Low Back Pain. London; Churchill Livingstone: 1999.

Travell J, Simons D: The Trigger Point Manual: Volume 1, 2^nd edition. Baltimore: Williams and Wilkins. 24-27, 915-923.