the lumbar spine: understanding the science behind both movement and dysfunction by chris gellert,...

5/19/2018 The lumbar spine: understanding the science behind both movement and dysfunction By Chris Gellert, PT, MMusc & Sportsphysio, MPT, CSCS,

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The lumbar spine: understanding the sciencebehind both movement and dysfunction

By Chris Gellert, PT, MMusc & Sportsphysio, MPT, CSCS, AMS

IntroductionThe spine is a complex structure, comprised of nerves, connective tissue, bones, discs,muscles and other essential integrative components. Whether it getting out of a chair or car,lifting or carrying items, some 29 muscles around the pelvic girdle and lumbar spine, providestability. In this article, we will review the anatomy of the spine, common injuries to thelumbar spine, functional assessments and training strategies to work with clients withprevious injuries.

Figure 1. Sit to stand Figure 2. Lifting items

Basic Anatomy of the SpineThe spine is divided into three primary layers(internal, middle and outer).a. Internal layer: Consists of the vertebrae of the spine, the spinal discs, and ligaments andseries of small muscles that connect, one vertebrae to another. The discs and ligamentsperform two important functions:they stabilize the spinal column, and they provide thebrain with information about the exact position of every joint and vertebrae in the spine.

Figure 3. Internal layers of spine


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b. Middle layer: There are four importantmuscles within the middle layer, which providestability for the lower back. Two of these muscles comprise the back, while the other twoare abdominal muscles. The muscles of the back are called the multifidus and the quadratuslumborum. The stabilizers that come from the abdominal region are called the internalobliqueas well as the transverse abdominus.

Figure 4. Multifidi Figure 5. Quadratus lumborum

c. Outer layer:This layer is the thickest. Composed of large, thick muscles, which aid inassist in transitional movements, creating and sustaining muscle contraction. The outer layer isknown as erector spinae.

Figure 6. Erector spinae muscles

Biomechanics of movementWhen we look at how the spine bends, flexes and rotates, there are several structures thatdirectly produce these movements and are also affected.


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Flexion and extension of lumbar spineDuring lumbar flexion,the veterbrae and the intervertebral foramen in the back(posterior) separate,creating tension and stress on the posterior annulus and posterior longitudinal ligament.This forces the nucleus populous backward. Making the disc vulnerable to bulge or herniate.During extension, the opposite motion occurs. During side bendingor lateral flexion, there

is opening on the contralateral side and narrowing on the ipsilateral(same) side.

Figure 7. Source: Hamill and KnutzenAs the trunk rotates, there is tension developed in the outer annulus where the annular fibersbecome taught(tight). While the other half of the annular fibers slacken. At the joint, the siderotated towards approximates while the other side opens(gaps).

Figure 8. Trunk rotationSource: Hamill and Kathleen Knutzen

Common injuries and causes of lumbar spineThere are different types of injuries the ankle can sustain. The most common are lumbarosteoarthritis(DDD), disc injuries, and spinal stenosis. In this next section, we will revieweach condition providing a deeper understanding of each.

a. Lumbar osteoarthritis(DDD)Mechanism of injury/pathophysiology:Is termed the wear and tear arthritis because it isthought that the articular cartilage breaks down because of an imbalance between mechanicalstress and the ability of the joint to handle the given loads. The following are factors that caninfluence the development of DDD; excessive weight, repeated repetitive stressors, andmuscle imbalances.


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Sign and symptoms: patients will typically describe asa deepache in the morning that easesor decreases as the day progresses. During evening, the lower back stiffens once again.

Figure 9. Lumbar degenerative changes

b. Spinal stenosisPathophysiology:A narrowing within the vertebral canal coupled with hypertrophy ofthe spinal lamina and ligamentum flavum or facets as the result of age related degenerativeprocess commonly seen in older individuals(Geenvay & Atlas 2010).

Risk Factors: Poor posture, excessive weight, muscle imbalance between flexors and extensors.

Sign and symptoms: Results in vascular compromise, bilateral pain in lower extremitiesparticularly in back, buttocks, thighs, calves and feet. Pain is increased with spinal extensionand walking. Pain decreases with spinal flexion(bending).

Figure 10. Spinal stenosisMedical treatment: Conservative therapies initially and if unsuccessful, decompressionlaminectomies may be required. In a long term study by Atlas, S et al (2005), 148 patients,Who either had surgery or underwent conservative care(physical therapy), were followed for8-10 years. Results:Patients undergoing surgery had worse baseline symptoms and functional statusthan those initially treated nonsurgical.


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c. Disc injuriesMechanism of injury: Injury to the disc, typically occurs as a result of a combined motionsuch as lifting with twisting. This motion places increased stress on the disc causing aninjury. Per the research and my 15 years of clinical experience, most individuals suffer from abugling disc or herniate disc. This is confirmed by an extensive examination by both the

physician and physical therapist, an MRI, symptoms and objective findings. The four typesare listed below.

Four types of disc injuries:1. In Protrusion or bulge, there is change in the shape of the annulus that it causes to bulgebeyond its normal perimeter.2. In Prolapsedisc,(herniation), the ligamentous fibers give way, allowing the nucleus tobulge into the neural canal. The disc is still contained by the outer layers of the annulus andsupporting ligamentous structures.3 .Extrusionis where the disc protrudes through the annulus but is contained by theposterior longitudinal ligament(PLL).4.Sequestration is where the nuclear material/free floating piece of the nucleus has partiallyseparated from the remaining nucleus, allowing it to be free in the neural canal and moves intothe epidural space.

Etiology/Risk Factors: Overstretching of the annular rings occurs as a result from acombined trunk rotation and unilateral side bending, placing the disc in a vulnerablecompromised position. Repetitive compressive forces, microtrauma or one single movementat end range(flexion) with low loadwill stress the posterior spinal musculature and disc.

Sign and symptomsLoss of trunk motion/mobility, decrease in trunk strength, central/radicular pain, possible parasthesias and painful referred pain peripherally, inability to performactivities of daily living. Usually worse in the sitting position or rising.

Figure 11. Disc injury

Medical treatment: During the acute stage of injury, patient education, rest, and NSAIDSare recommended. Certain positions such as flexion and combined flexion with rotation areavoidedto decrease intervetebral pressure.


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Common assessmentsThere are several ways to assess a client with our without a spinal injury. It is important toassess can the client maintain neutral spine in a static position, can they maintain neutralspine when their center of gravity is altered. Three effective assessments are the quadrupedtest, four point plank test and side plank test.

1. Quadruped testIn the quadruped test, ask the client to place their hands and knees in an all fours position.The first part(3A), as the client to extend one leg up, hold, the repeat on other side. Thenwith second part(3B), ask the client to alternate opposite arm with opposite leg.Observe if the client maintains neutral spine where the vertical arrow is, do they hyperextendtheir spine, excessively rotate their hips or sag?

Figure 12. quadruped exercise2. Four point(plank test)Four point plank tests spinal erectors and paraspinal muscles.Ask the client to assume in the position in figure 13 below, prone with arms bent to 90degrees(similar to a push-up). Then instruct the client to lift their entire body off the ground

or surface while toes are in the extended position. Time them for the length of time theymaintain neutral spine(without hips sagging or spine flexing).

Figure 13. Four point bridge test

a. Grading for both test is as follows:Normal:Able to lift pelvis off and hold straight 15-20 second countGood:Able to lift pelvis off but has difficulty holding spine straight for 15-20 secondsFair:Able to lift pelvis off but has difficulty holding spine straight for 10-15 secondsPoor:Able to lift pelvis off but cannot hold for 1-10 secondsTrace: Unable to lift pelvis off the table


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3. Side plank testThe side plank test challenges the quadratus lumborum and external obliques.

Figure 14. Side plank testAsk the client to position their body is in side-lying position with the knees straight, whilebending the bottom elbow at 90 degrees. Then instruct the client to lift their entire body offthe ground, while keeping the legs straight. Time them for the length of time theymaintain neutral spine(without hips sagging or spine flexing).

Training strategies and programming for lumbar injuriesWith any injury, the most important thing to remember is the type of injury, healing timeand prior level of function of the client. Lets begin with ankle sprains.

a.

Lumbar osteoarthritis(DDD)Recommendations for training:Joint protection, Aqua or pool therapy is anexcellent intervention based upon the buoyancy principle. Closed chain exercisessuch as lunges, ball squats, stretching, core strengthening and aerobic exercise(ie.walking, and recumbent bicycle) are safe and effective. Particular emphasis shouldfocus on glute and hamstring strengthening to improve sagittal stability.

b. Spinal stenosis

Recommendations for training:Anatomically and biomechanically, flexion basedexercises open the neural foramin. Perform flexion based exercises such as; knee tochest, prayer stretch and reverse abdominal crunch. End of range extension basedexercises should be avoided as they close the neural foramin(ie. cobra pressup).

Lower extremity stretching should focus stretching hamstrings, hip flexorsand quadriceps. Yoga and pilates can also be effective to improve a clients flexibilityand core stability. Progressive resistance training exercises such as lat pulldown, seatedmid row, seated reverse flyes, and horizontal leg press are all safe to teach a client withlumbar stenosis based on science.

c.

Lumbar disc injuriesRecommendations for training: Obtain medical clearance from M.D. and communicatewith clients physical therapist prior to exercise training. Emphasis is on strengtheningof core, abdominals, trunk muscles/lower back, and functional strengthening.Avoid combined rotational with side bending exercises, as well as hyper flexionand hyperextension motion.As these two motions place shearing forces on the disc.


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SummaryThe lumbar spine a complex unit that is comprised of a multitude of ligaments, tendons,connective tissue, muscles that synergistically initiate and correct movement, and stabilizewhen an unstable environment. Understanding the anatomy, biomechanics and weak linksof the spine, common injuries and evidenced based training strategies, should provide you

with the insight to better understand and work with clients with these kind of injuries moreconfidently.

Chris is the CEO of Pinnacle Training & Consulting Systems(PTCS). A continuingeducation company, that provides educational material in the forms of home study courses,live seminars, DVDs, webinars, articles and min books teaching in-depth, the foundationscience, functional assessments and practical application behind Human Movement, that isevidenced based. Chris is both a dynamic physical therapist with 14 years experience, and apersonal trainer with 17 years experience, with advanced training, has created over 10courses, is an experienced international fitness presenter, writes for various websites andinternational publications, consults and teaches seminars on human movement.


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REFERENCES

Atlas, S, et al, 2005, Long-Term Outcomes of Surgical and Nonsurgical Management ofLumbar Spinal Stenosis: 8 to 10 Year Results from the Maine Lumbar Spine Study, SPINEvol. 30, number 8, pp 936943.

Beattie, P, 2009, Current Understanding of Lumbar Intervertebral Disc Degeneration:A Review With Emphasis Upon Etiology, Pathophysiology, and Lumbar MagneticResonance Image Findings,Journal of Orthopedic & Sports Physical Therapy,vol. 38, no. 6,pp. 329-337.

Colby, L, & Kisner, C, 1996, Therapeutic Exercise: Foundations and Techniques, 3 rdedition, F.A. Davis Company, Philadelphia, pp. 279-280, 431-452, 482- 508, 525, 600-618.

Genevay, S, & Atlas, S., 2010, Lumbar Spinal Stenosis, Best Practice Residential ClinicalRheumatology,vol. 24, issue 2, pp. 253265.

Hamill, J, & Knutzen, K, 1995, Biomechanical Basis of Human Movement, LippincottWilliams & Wilkins, Philadelphia, pp. 16, 20, 164-165, 223-225, 289-290

Lee, D, 2004, The pelvic girdle: an approach to the examination and treatment of thelumbopelvic-hip region. 3rdedition, New York, Churchill Livingstone, pp. 48-53.

Magee, D, 1997, Orthopedic Physical Assessment 3rdedition, W. B. Saunders Company,Philadelphia, pp. 362-366.

Oatis, C, 2004, Kinesiology The Mechanics & Pathomechanics of Human Movement,Lippincott Williams & Wilkins, Philadelphia, pp. 8, 37-40, 45-51,68-70, 81-88, 101-103, 113-115, 125-128, 149-150, 153, 516-520, 523-527, 776.

Osullivan, P, 2005, Diagnosis and classification of chronic low back pain disorders:maladaptive movement and motor control impairments as underlying mechanism,Journal of Manual Therapy, vol. 10, pp. 242-255.

the lumbar spine: understanding the science behind both movement and dysfunction by chris gellert,...

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