Lumbar Spine Functional InstabilityRehabilitation

Convention or Evidence?

Paul Schoonman, DCSchoonman Chiropractic and Rehab

Health Science Advisory Board, Merrimack College

Andrew Cannon, MHS, PT, SCSDir., Sports Medicine, NRHN

Team PT, Lecturer, Merrimack College

CONVICTION!!

Critical consumers of dogmaticapproach to lumbar spine care

and exercise

Disc location

Trunk Performance

No such thing as trulyfunctional exercise

Function is context andindividual specific

GPP, SPP Input versus outcome? Motor skill in, stability

out! Ankle sprain, MDI Like the trunk, ROM is

poor indicator of overallability

Shoulder any different?

Phases of Rehabilitation for Shoulder InstabilityPhase I Rest and immobilization Pain control with nonsteroidal anti-inflammatory drugs and ice applied to the shoulderPhase II Isometric strengthening Isotonic strengthening Begin exercises with shoulder in adducted, forward- flexed position, progressing to

abducted positionPhase III Endurance building along with strengthening exercises Goal: the patient reaches 90% strength in the injured shoulder compared with the uninjured

shoulderPhase IV Increase activity to sport- or job-specific activities

What is best for people with acutelow back pain with or withoutradicular symptoms to do?

Bed rest for acute low-back pain and sciatica

People with acute low-back pain who are advised to rest in bed havemore pain and are less able to perform every day activities, on

average, than those who are advised to stay active.

As many people get some relief from low back pain and sciatica (paindown the back and leg) by lying down, bed rest is often recommended.However, this review found that, for people with acute low-back pain,

advice to rest in bed is less effective in reducing pain and improving anindividual's ability to perform every day activities than advice to stay

active. For people with sciatica, there were no important differences inthe effects of advice to stay in bed compared with advice to stay

active.Page 106

Hagen KB, Hilde G, Jamtvedt G, Winnem M. Bed rest for acute low-back pain andsciatica. Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.:

CD001254

Williams flexion exercises

I have not been able to find one shredof evidence that they are better thanany other form of exercise or thatspecifically they are indicated over othertherapeutic exercise interventions

Does Stretching DecreaseInjury?

Evidence says pre-exercise does not Not pre-exercise 3x day does

– 20 seconds, 5-7 reps, comfortable– Frequency is key– Limited value in spine care relative to spine

stretching

Finally, separate out

what is indicated to do what seems good to do, “clinical wisdom” what other people do what the patient wants to do what you have time to do what their parents/employer want them to do What the insurer will pay you to do

New Path

Simple --- Complex Isolated --- Integrated

Slow --- Fast

SAID SPECIFIC ADAPTATIONS IMPOSED DEMANDS

What patient is this new path for?

Acute? No. Sub acute and beyond, Episodic Can they be radicular? Yes!, non progressive,

stable, neurologically improving, weaknessdecreasing, reflexes increasing

Change from victim to patient Pain versus function

Neuromuscular Function in Athletes Following RecoveryFrom a Recent Acute Low Back Injury,

Cholewicki et al, jospt vol. 32 #11, 11:2002

Chronic LBP, delay in shut off of agonist , switch on antagonist withfewer # of trunk muscles responding

Varsity athletes with hx 1 episode of LBP, >6 months prior @injury pain 4.4/10, FVAS 30/100, min. 3 days OOP @testing, avg. 56 days post, pain 0/10, full participation A shutting off of a fewer number of agonists with an increased latency

as well compared to matched controls

Stability

Synergistic coordinationof neuromuscularsystem to provide astable base forsuperimposedfunctional movement oractivity

Shoulder MDI and handplacement

But, the trunk??

What Do We Know About Lumbar SpineSegmental Instability?

Clinical instability is a sagittal plane translation of >3mm or 9% of vertebral body width on either anflexion or extension radiograph, and/or sagittal planerotation >9 degrees for lumbar motion segments

Clinical instability is a deficit in the end of rangepassive restraints

Functional instability is a decrease in the capacity ofthe stabilizing system of the spine to maintain thespinal neutral zones within physiological limits sothat there is no neurological deficit, no majordeformity and no incapacitating pain

Functional instability is a failure of the neural andcontractile units to guide normal segmental motionwithin the neutral zone.

Cause or Effect??

Functional instabilitycan be both the causeof and the result ofinjury

Not just tissue based Motor control aspects

– Coordinated contractionstiffens the joints andultimately determinesfunctional (in)-stability

How much load/shear is too much?

Shear tolerance of vertebral motion segment of2000-2800N one time loading

Repetitive shear loads may be more likely 500N The osteoligamnetous spine buckles at 20N! How do muscles that compress make the spine

more functionally stable?Luca d e al. Stability of the ligamentous spine. Technical Report #40, Biomechanics Laboratory, San Francisco, University of California

So what is stability from a spineperspective?

Potential energy = PE= mass x gravity x height Stable equilibrium prevails when the PE of the system is

minimum A ball in a bowl is stable. At the bottom of the bowl it is at

minimum potential energy The deeper the bowl, the steeper the sides the more stable

the system

Bergmark A (1989) Stability of the lumbar spine: A study in mechanical engineering. Acta Orthop. Scand 1989; 60:3-53.2

The Continuum of Stability

Slope of sides = stiffnessof passive tissues =mechanical stop/endpoint

Width of the bottom ofthe bowl = joint laxity

Bergmark A (1987) Mechanical stability ofthe human lumbar spine. Doctoraldissertation, Department of SolidMechanics, Lund University, Sweden

how many sides does the bowlneed?

Spinal joints can rotate in 3 planes, along 3 axes Requires a 6 dimensional bowl for each 6 lumbar

spinal joints = 36-dimensional bowl If the height of the bowl is decreased in any one

of these 36 dimensions, the ball rolls out! A single muscle having inappropriate force or a

damaged passive tissue can cause instability

Potential energy as stiffness andstorage of elastic energy.

stiffness = (k) deformation = (x) so stretching a band with stiffness x a

distance x will store energy (PE)

Elastic PE = .5 * k * x

Stretching a band withstiffness (k) a distance (x)with store energy (PE)

Increase in k = increase inside of the bowl

Stiffness creates stability tosupport larger loads (P)

Most important is stiffnessis balanced

Increased stiffness of just 1spring will lower PE in onedirection and decreaseability to bear load

Symmetrical Stiffness

Active muscles act like astiff spring

Modest levels of muscleactivation createsufficient stiff and stablejoints

Motor control systemmodulates stiffnesstherefore stabilitythrough coordinatedmuscle co- activation

How Much Stability is Enough ?What is Sufficient?

Too much stiffness and musclecoactivation imposes a loadpenalty/prevents motion

Muscular stiffness necessary forstability with a modest extra formargin of safety

How hard do the muscles need towork to provide adequate stability inthe neutral zone?

5%-20% MVC with ADL to athleticactivities

Strength or endurance? Remember the bowl needs all its

sides!!

Is a single muscle most important

Inappropriate application of “Queensland”research, did not say tva and mf “more”important

Was any single string more important? All muscles play a role in stability, roles vary

based on task at hand and resourcesavailable

Myths, Legends,Misconceptionsn

You need a strongtrunk to protect your

back

10% of MVC abdominalwall cocontraction

Endurance over strength Proper daily motion is

“endurance training”

An exercise repeated in away that grooves motorpatterns and ensures astable spine

Consider loading as tohow good an exercise is

An athlete requires astable spine during c-vdemanding, complexmotor skill.

It is not whole bodystability, balance

What are stabilization exercises

What is the most important muscle

Which wire is mostimportant to the towerstanding

How canwires/muscles that addcompression,decreasecompression?

Upper and lower rectus There is no functional

separation of the rectusabdominis

Is a separation of neuraldrive, rarely!

Once activated, functionas a cable throughout itslength

If you mean, lower abs,could be TVA, that wouldbe the lateral ‘V’

We give patients lumbar stabilityexercises

Input or output? We train motor skill They get stability

WELL??