Human Movement Science & Functional Anatomy of the:

Multifidus

by Brent Brookbush MS, PES, CES, CSCS, ACSM H/FS

Note the cross-sectional area and location of the multifidus relative to the facet joints of the lumbar spine - http://classconnection.s3.amazonaws.com/694/flashcards/597694/png/multifidus_cross-section1310444956368.png

Multifidus - from the latin roots "multi" and "findire", translating roughly to "to split into many parts".

• Origin and Insertion:
  • Lumbar: The lumbar multifidus span between two and four segments - the deepest fibers span from lamina to mammillary process of the vertebrae two below, the longer fibers arising from the spinous process and inserting into the mammillary process or the vertebrae or comparable area of the sacrum 4 to 5 vertebrae below. The longest fibers (L1, L2 and L3) have attachment to the posterior superior iliac spine, while some of the deepest fibers have attachment to the capsule of the zygapophyseal joints themselves.
  • Thoracic and Cervical Spine: The multifidus are less developed in the thoracic and cervical spine where they originate from the spinous process, cross 2-4 segments, inserting into the transverse process below.
  • The multifidus are the deepest and most medial of the paraspinal muscles; abutting the zygapophysial joints. These muscle lay between the spinous process and erector spinae, and deep to the superficial layer of the thoracolumbar fascia in the lumbar spine.
  • * The lumbar multifidus may be palpated. With your patient/client relaxed in prone position, place your fingers just lateral to the spinous process, but medial to thick lumbar erectors. As the multifidus work synergistically with the transverse abdominis - having your patient/client "draw-in" without compensatory flexion or extension will "inflate" the multifidus muscles under your fingers. If you press a little deeper and rub superiorly or inferiorly you will feel the individual fascicles running obliquely.
• Nerve: Medial branch of the dorsal ramus of the spinal nerve - segmentally innervated
• Action:
  • Extensor of the lumbar vertebrae
  • When acting unilaterally may contribute to lateral flexion and contralateral rotation (15)
  • Deep fibers may assist in increasing zygapophysial capsule tension, ensuring the capsule is not impinged during extension (13)
  • Segmental (vertebrae on vertebrae) stabilization and alignment of vertebrae, especially in the lumbar spine

This picture was added to assist in sites visualization of attachment sites of the lumbar multifidus - http://upload.wikimedia.org/wikipedia/commons/6/6d/Processusmammillaris.PNG

Integrated Function:

• Stabilization:
  • The multifidus have relatively low receptor density when compared to the transversospinalis, interspinalis, intertransverserii (deep muscles of the spine), and even the erector spinae muscles (13, 15). The implication that these muscles are key in segmental stabilization (vertebrae on vertebrae alignment and stiffness) is due to there relatively short length, position close to the axis of rotation, and the well organized segmental neural innervation - each fascicle is innervated by the nerve exiting the segment it crosses (13, 15). It is likely that the activity of these muscle is paired with receptor activation within the facet joint capsules (ruffini endings and pancini corpuscles), and muscle spindle activity of the inter- and transverso-spinal muscles.
• Eccentrically Decelerates:
  • Eccentrically deceleration of flexion
  • Eccentric deceleration of contralateral flexion and contralateral rotation
  • Eccentric deceleration of anterior translation (superior vertebrae on inferior vertebrae)
• Synergists:
  • The multifidus muscles are considerable extensors, especially in the lumbar spine, working synergistically with the erector spinae and latissimus dorsi.
  • As segmental stabilizers, the multifidus function synergistically with the transversospinalis, intertransversarii, and interspinalis muscles (deep muscles of the spine).
  • The multifidus act synergistically with the transverse abdominis , diaphragm, pelvic floor, internal obliques and deep muscles of the spine to increase intra-abdominal pressure, thoracolumbar fascia tension, and improve segmental alignment of the lumbar vertebrae. This is discussed further under the heading "Subsystem" below.

Multifidus Muscles - http://resistthesloth.files.wordpress.com/2013/07/multifidusanatomy.png

Subsystems

• As mentioned above, studies show synergistic recruitment of the lumbar multifidus with activation of the transverse abdominis  ("drawing in"). Further, similar recruitment strategies relative to load have been noted in the pelvic floor and diaphragm (13). The synergistic recruitment of these muscles increases intra-abdominal pressure, tension in the thoracolumbar fascia, segmental rigidity between vertebrae, and improves segmental alignment. It is believed that the optimal function of these muscles is part of a feed forward mechanism that enhances the stability of the spine, including - increased efficiency of force generated by global stabilizers to resist external loads. This muscular synergy is often referred to as the "intrinsic" or "local" stabilizers, and is discussed further in the "Core Subsystem " articles under "Intrinsic Stabilization Subsystem ". In my analysis, the transversopinalis, interspinalis and intertransversarii (deep muscles of the spnie) and the internal obliques should also be included in this subsystem. Research has shown greater receptor density in the deep muscles of the spine, implying that they may act as "proprioceptive organs" to monitor intervertebral alignment. As the multifidus are ideal for altering intervertebral alignment, increasing rigidity, and imparting segmental motion, the multifidus are ideal for ensuring optimal length/tension of the deep muscles of the spine. It is likely that these "proprioceptive organs" are intimately tied via reflex arc to the multifidus playing a role in multifidus muscle activity and resting tone. Further, based on the research by Richardson, Hodges and Hides the internal obliques may also play an intricate role in increasing thoracolumbar fascia tension, SI joint stiffness and intra-abdominal pressure (13).

Intrinsic Stabilization Subsystem

Arthrokinematics:

• The multifidus play a special role in optimal arthrokinematics of the spine, especially the lumbar spine. Their position abutting the facet joint, close to the axis of rotation of each vertebrae, and the segmental innervation of these muscles implies a primary role in maintaining optimal vertebrae on vertebrae alignment both statically and dynamically. Due to the anterior to posterior sagittal obliquity and deep position on the spine, these muscles have the capacity to resist arthrokinematic anterior shear (superior vertebrae on inferior vertebrae) and superior glide. Further, the superior to inferior, lateral obliquity and medial position on the spine allows these muscles to resist segmental rotation. However, the most notable arthrokinematic motion that the multifidus can impart is compression. Compression is often considered a problematic stress in the spine, but the ability to compress each segment greatly increases stability. As each segmentally innervated group of fascicles may function independently to adjust the position of individual vertebrae moment to moment and maintain the axis of rotation about the intervertebral disks you may consider these muscles as the "fine-tuning mechanism that keeps the Jenga Blocks of our lumbar spine stacked perfectly on top of one another"
• Further, the deep fibers of the multifidus invest in the zygapophyseal capsule and maintain capsule tension during extension to ensure the capsule is not impinged between facets. Research has shown altered morphology and activity of the multifidus in low back pain patients, reinforcing the notion that these muscles play a key role in preventing discogenic, facet, and soft tissue injury (13, 15).

"Notice How the Multifidus Abut the Facet Joints" Ultrasound image of Multifidus (Lateral View): The "M" stand for "Multifidus" which are represented by the grainy lines running horizontally in the top half of the image. The "F" stands for "Facet" joint represented by the dark area in the lower half the image. http://origin-ars.els-cdn.com/content/image/1-s2.0-S1356689X04000839-gr6.jpg

Fascial Integration:

My Fascial Hypothesis: Large fascial sheaths not only play a role in the transmission of mechanical force, but may also play a role in dictating the function of muscular synergies. This is likely caused by reducing or increasing tone of invested musculature via reflex arcs formed between mechanoreceptors imbedded in the connective tissue and the attached musculature. In this way my view of fascia differs slightly from noted expert on the subject Tom Myers. I think of these large fascial sheaths (specifically the thoracolumbar fascia, iliotibial band, and abdominal fascial sheath) as natures "mother board." A place for mechanical information to be communicated to the nervous system for more efficient recruitment of the muscular system. Despite having a slightly different philosophy it does not change the fact that fascia plays an important communicative role in the human body and we have Tom Myers to thank for his work.

Fascial Integration of the Multifidus:

• Other than the investment of the deep fibers into the zygapophyseal joint capsule (discussed above in terms of reflexive recruitment) it is unlikely there are fascial links between the multifidus and other structures. The idea that the multifidus and erector spinae may have a "hydraulic effect"; increasing spine stiffness and resisting flexion moments - filling their respective fascial compartments during active contraction - has been researched and no significant affect was observed (13).

Behavior in Postural Dysfunction:

This muscle may be prone to adaptive shortening and over-activity, or asymmetrical under-activity and atrophy.

The multifidus is prone to adaptive shortening and over-activity, although chronic and/or traumatic pathology of the low back may result in under-activity, adaptive lengthening, and atrophy of these important muscles. This atrophy is most often seen as a chronic maladaptation to low back pathology and is generally asymmetrical (although it is hard to determine from research whether the contralateral side is hypertrophied, overactive, and relatively short) (13, 15). Generally speaking, these muscles are addressed with "intrinsic stabilization subsystem " integration; however, manual release of overactive fascicles is often necessary. A self-administered release techniques for the multifidus, that does not risk the exacerbation of dysfunction via anterior shear, is needed and I will continue my work to contribute to the development of such technique.

In Upper Body Dysfunction (UBD) the multifidus may be over-active with little or no change in length, becoming synergistically dominant with the global stabilizers of the lumbar spine in the presence of an under-active/inhibited Intrinsic Stabilization Subsystem (ISS) . However the multifidus rarely play a significant role in this dysfunction.

In Lower Leg Dysfunction (LLD)  the multifidus, again, rarely lay a key role. As in upper body dysfunction, the multifidus may be over-active with little or no change in length; however, in LLD this synergistic dominance pairs with the over-activity the erector spinae and the Deep Longitudinal Subsystem (DLS) .

In Lumbo Pelvic Hip Complex Dysfunction (LPHCD) the multifidus are most often short/over-active as an extensor of the lumbar spine. In Sacroiliac Joint Dysfunction (SIJD)  it is common to see the asymmetrical changes in activity discussed above, resulting in an over-active and hypertrophied side and a presumably atrophied side. In this case, release of the over-active side has to be carefully paired with exercise that challenges the Intrinsic Stabilization Subsystem to stabilize the lumbar spine and resist rotation to the ipsilateral side (rotation of the superior vertebrae).

In short, I do not often address the multifidus specifically. Rather they are integrated with Intrinsic Stabilization Subsystem exercises (See Below). Although trigger point release and stretching may be indicated (for short/over-active muscles), these muscles are difficult to release with self-administered techniques and stretched during lumbar extensor/latissimus dorsi stretching ("Child's Pose" - See Below). Generally, the lats and extensors adopt adaptive shortening and over-activity in the same dysfunctional movement patterns. Manual release is often necessary if the muscle is a considerable contributor to dysfunction and will likely need to be paired with manual mobilization/manipulation of the affected segments.

The Extensors - Grays Anatomy: 20th Edition

Clinical Implications:

• Lumbar spine pain
• Sacroiliac joint pain and dysfunction
• Hip hike
• Lateral shift of lumbar spine

Signs of Altered Length/Tension and Tone:

• Overhead Squat:
  • Anterior Pelvic Tilt: Short/Over-active
  • Asymmetrical Weight Shift: Short/Over-active on side of dysfunction
• Goniometric Assessment
• * Decreased Spine Contralateral flexion
  • Decreased Spine Flexion
  • Decreased Spine Rotation
• Palpation of the Multifidus (and Lumbar Extensors):
• See image below for common trigger point locations and referral pain pattern for active trigger points.

http://www.triggerpoints.net/sites/default/files/styles/triggerpoint_display_for_muscle_pages/public/Multifidi%2C%20Rotatores.png?itok=CH39tHMn

Exercises involving the Multifidus:

Child's Pose (Multifidus would be stretched during this technique)

Active Stretch and Spine Mobilization (Again, the multifidus would be affected during this active stretch):

Intrinsic Stabilization Subsystem Activation:

TVA Isolated Activation

Intrinsic Stabilization and Gluteus Maximus Activation Progression:

Reactive Integration for the Core (Crunch and Catch):

Reactive Activation for the Core (Modified Mountain Climbers):

Bibliography:

• * * 3. Phillip Page, Clare Frank , Robert Lardner , Assessment and Treatment of Muscle Imbalance: The Janda Approach © 2010 Benchmark Physical Therapy, Inc., Clare C. Frank, and Robert Lardner

6. Dr. Mike Clark & Scott Lucette, “_NASM Essentials of Corrective Exercise Training_” © 2011 Lippincott Williams & Wilkins9. Donald A. Neumann, “Kinesiology of the Musculoskeletal System: Foundations of Rehabilitation – 2nd Edition” © 2012 Mosby, Inc.

12. Michael A. Clark, Scott C. Lucett, _NASM Essentials of Personal Training: 4th Edition_, © 2011 Lippincott Williams and Wilkins

15. Leon Chaitow, _Muscle Energy Techniques: Third Edition_, © Elsevier 2007

18. Tom Myers, _Anatomy Trains: Second Edition_. © Elsevier Limited 2009

21. Shirley A Sahrmann, _Diagnoses and Treatment of Movement Impairment Syndromes,_ © 2002 Mosby Inc.

24. David G. Simons, Janet Travell, Lois S. Simons, _Travell & Simmons’ Myofascial Pain and Dysfunction, The Trigger Point Manual, Volume 1. Upper Half of Body: Second Edition_,© 1999 Williams and Wilkens

27. Cynthia C. Norkin, D. Joyce White, Measurement of Joint Motion: A Guide to Goniometry – Third Edition. © 2003 by F.A. Davis Company

30. Cynthia C. Norkin, Pamela K. Levangie, _Joint Structure and Function: A Comprehensive Analysis: Fifth Edition_ © 2011 F.A. Davis Company

33. Florence Peterson Kendall, Elizabeth Kendall McCreary, Patricia Geise Provance, Mary McIntyre Rodgers, William Anthony Romani__,_ Muscles: Testing and Function with Posture and Pain: Fifth Edition © 2005 Lippincott Williams & Wilkins_

36. Brent Brookbush, _Fitness or Fiction: The Truth About Diet and Exercise_ © 2011 Brent Brookbush - [http://www.amazon.com/Fitness-Fiction-Truth-About-Exercise/dp/0615503012](http://www.amazon.com/Fitness-Fiction-Truth-About-Exercise/dp/0615503012)

39. Carolyn Richardson, Paul Hodges, Julie Hides.  Therapeutic Exercise for Lumbo Pelvic Stabilization - A Motor Control Approach for the Treatment and Prevention of Low Back Pain: 2nd Edition (c) Elsevier Limited, 2004

42. Andrew Biel, Trail Guide to the Human Body: 4th Edition, © 2010

45. Stuart McGill, Low Back Disorders: Second Ediction © 2007 Stuart M. McGill

© 2013 Brent Brookbush

Questions, comments, and criticisms are welcome and encouraged.