I very much appreciate Dr. Siff's following analysis.  The questions he
raises point to some of the problems in discussing "back pain" which I have
previously addressed on this list.  Specifically, "back pain" (though it is
an ICD-9 code) is not a workable diagnosis for determining effective
treatment of back problems.  I believe in my limited discussions with
McKenzie certified therapists that only "bulging" discs will respond to
this regime.  When there is an actual herniation, ie., a tear through the
outer layers of the annual fibers, this process of McKenzie does not work.
So, now we have two different causes--one with a "partial tear" and one a
"full thickness tear".  My experience suggests that various treatments will
work for partial tears and bulging discs--comfortable rest positions,
extension exercises (if comfortable), almost any activity--walking,
aquatic, some "decompressing" weight (lat pulldowns for example) all seem
to at least maintain activity while not aggravated the condition, lumbar
traction, etc.  When there is a herniation, this is not true, almost
nothing seems to work and the patient becomes a good surgical candidate.
Compound these statements with the findings in our clinics, that only about
10% of "back pain" is disc related--the overwhelming majority of problems
seem to us to come from the joints and muscles.  In these cases, almost
anything "helps" (but does not directly treat the causative
factors)--abdominal exercises, stretching, walking, avoiding certain
positions, etc. and the worst thing is rest.  Telling these patients to
"get up and get going" is much better than being told to "rest".  BUT, I am
only claiming that these interventions "help".  To really cause a dramatic
treatment effect, the practitioner must be able to identify whether the
problem is disc, nerve, muscle or joint, (and possibly other factors that I
don't really understand such as dura, fascia, qi/chi, etc.) and design a
treatment based on objective clinical findings. This is where I find the
various "schools" of treating so lacking.  If they do not have a way to
differentiate when different structures are involved, their treatments will
be nothing more than a "shotgun" approach.  Hence, treatments are dependent
on which course the therapist most recently attended.  I limit my
treatments to "things" I can objectively identify using "standard"
criteria.  If the person has normal reflexes, normal strength, normal
sensation and negative nerve root tension signs, I assume that they do not
have "pressure" on a nerve (pressure on the nerve is much disputed in the
literature although still clinicians refer to "pinched nerves" commonly--in
fact, the evidence suggests it is more of a local inflammatory response).  

In defense of my not using the cranio sacral techniques and myofascial
techniques, I just am not good enough to get good "objective" findings.
For example, after several years of trying to study acupuncture, I never
got the "nack" of taking pulses to determine energy flow--hence my
interventions could not be objective.  I used electrical devices for a
while but the results seemed too variable for me to be comfortable with the
technique.  I study some myofascial techniques as well, but found them to
again be too subjective--the treatment effects did not seem to be better
than the techniques I learned with acupressure, which despite discussions
of quantum mechanics, etc. seem best explained with lymphatic/local
swelling, congestion.  So, it is not for lack of wanting to incorporate
more interventions, but if they aren't objective, it just makes it too
difficult to determine effectiveness.

Herb Silver, PT


At 05:08 AM 4/4/99 EDT, you wrote:
>This commentary on McKenzie exercises which I submitted to another user
group 
>may also be of interest here in stimulating some further discussion on back 
>care.
>
>Member A wrote:
>
><<The McKenzie Exercises are actually a series of stretches, either backward 
>or forward. They work by stretching the spine  and this, in turn,  increases 
>the intervertebral space. . . . 
>
><<When the pressure on the spine is relieved, the fluid flows back into the 
>center
>for the disc, essentially re-inflating it.  Daily changes in the amount of 
>fluid retained and expelled from intervertebral discs account for daily 
>variations in body height of as much as 2 centimeters.>>
>
>***This implies that a significant flow of cerebrospinal (CS) fluid takes 
>place through the poroelastic annulus fibrosus during the few minutes of a 
>typical Mc Kenzie procedure.   This suggests a fairly rapid flow rate
through 
>this thick ring.  Yet, research indicates that this type of flow requires 
>several hours, as is corroborated by the remark that there are daily 
>variations in body height of as much as 2cm.  Is there now new research
which 
>shows definitively that stretching manoeuvres such as the McKenzie exercises 
>produce a much higher flow rate?
>
>Now, this height variation of some 2cm takes place over a period of at least 
>8 hours and is most marked during the period of sleep when no forced active 
>or passive stretching of the spine takes place!  If increase in the volume
of 
>the nucleus pulposus is indeed the primary cause of reduced low back pain, 
>then inactive bed rest or sleep logically would appear to be more effective 
>than McKenzie methods, since the reflux of CS fluid occur quite naturally
and 
>to a greater extent during unstretched bed rest.
>
>Another issue - McKenzie most frequently involves controlled prone lumbar 
>hyperextension and presumably stretches the anterior aspect of the fibrous 
>annulus. This frequently reduces LBP, depending on the individual case, but 
>if one performs marked forward flexion (as is also sometimes used with 
>McKenzie), which presumably also stretches the posterior portion of the 
>fibrous annulus, this action can further traumatise the lumbar spinal 
>structures.  Yet, this opposite stretching action would, according to the 
>above theory, also cause reflux of CS fluid into the nucleus of the disc.
In 
>other words, there appear to be several contradictions in this CS reflux 
>hypothesis.
>
>Fortunately, McKenzie suggests that reduction or exacerbation of LBP by each 
>bending manoeuvre tells us which action is most appropriate for a given 
>patient.  However, there is no certainty at all that any change is due 
>predominantly to increase in volume of the nucleus of the lumbar discs.
>
>There are several other biomechanical issues involved:
>
>1. Basic physics tells us that the fluid pressure is the same everywhere 
>inside the nucleus, irrespective of where any stretching of the anulus 
>occurs.  In other words, if one stretches the annulus anywhere, anyhow, an 
>equal drop in pressure will occur throughout the nucleus - whether one bends 
>the spine forwards, backwards, sideways or longitudinally (by traction).  Of 
>course, we do know that some of these actions can severely exacerbate LBP.
>
>2.  Besides stretching one aspect of the lumbar discs (and compressing the 
>opposite side!), lumbar extension implicates stretching of other structures 
>including the abdominal musculature and connective tissue, the hip flexors, 
>and the anterior longitudinal ligament of the spine. It is also possible
that 
>some stretching of the lower spinal nerves also takes place.  How can we 
>state categorically that the stretching of the discs is the most important 
>issue involved?'
>
>3.  As noted in 2 above, if lumbar hyperextension causes stretching of the 
>anterior aspect of the lumbar discs, then it simultaneously causes 
>compression of the posterior aspect of the same discs.  Since McKenzie 
>sometimes may involve lumbar flexion exercises, then it presumably
implicates 
>both types of stretch and leads to some sort of hypothetical balance.
>
>4.  Sometimes stretching of the spinal structures produces sudden (phasic)
or 
>gradual onset (tonic) protective spasm, so that avoidance of any form of 
>stretching (as imposed by McKenzie or slumped sitting) would appear to be
the 
>wisest option in such cases.
>
><<As daily stresses and pressure on the spine (e.g., from activity and 
>sitting) compress the intervertebral space, dics fluid flows out into the 
>surrounding tissue.   As this happens, dics flatten out and some eventually 
>begin to impinge on nerves which branch out from the spinal cord.   The 
>result is pain, discomfort and decreased mobility.>>
>
>***Even this theory is rather tenuous, since there is not a greater
incidence 
>of LBP among long-term Olympic weightlifters, whose type of training imposes 
>extremely large compressive loads on the lumbar spinal discs.  In fact,
quite 
>the opposite is noted among competitive lifters.  Research suggests that 
>sustained low intensity loading of articular joints, rather than regular 
>impulsive loading is associated with a greater incidence of articular 
>degeneration, so that it is not simply a matter of daily stress which leads 
>to spinal deterioration, but the type and pattern of loading involved.  
>Regular periodic loading of the spine would seem to cause adaptation which 
>then minimises the occurrence of spinal and other joint deterioration.
>
>Interestingly, some of the Olympic lifting exercises such as snatches, 
>overhead pressing and pulls from the ground involve a type of active 
>extension of the lumbar spine, thereby invoking a special variation of what 
>loosely may be called a McKenzie manoeuvre.  Yet, the medical and fitness 
>professions generally are opposed to this type of physical loading.
>
><<The designer of the BackTracker device calls it a personal traction
device, 
>but it is primarily a stretching machine with natural traction.  I use the 
>word "machine" lightly, however:  it is not electrical, but more like a
small 
>home exercise unit.>>
>
>***When I was on a research visit to Russia I was given extracts from a book 
>written over 20 years ago on back care and training, which even claimed to 
>increase the height of children.  In it were designs for progressively
loaded 
>personal natural traction devices (using weights inter alia) to be used even 
>while one was sleeping. It claimed great success in reducing LBP and 
>increasing height of children, but especially if used as part of a special 
>intensive weightlifting regime. The use of passive stretching alone was not 
>encouraged, because this apparently does not enhance the ability of the body 
>to adapt to the compressive loads encountered in daily life. 
>
>There were also Russian designs for devices which imposed ballistic 
>longitudinal loading of the body and this produced very significant
increases 
>in spinal integrity and jumping strength and power, as has been corroborated 
>by Italian scientists more recently (I believe that they have patented and 
>produced a ballistic loading device based on their work).
>
>Please note that none of this commentary is intended to denigrate McKenzie 
>exercises (which, after all, are just a modern adaptation of therapeutic 
>yogic and Taoist postures used thousands of years ago in India and China) - 
>it simply questions if current theories underlying its successful 
>applications are scientifically acceptable.
>
>Dr Mel C Siff
>Denver, USA
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>
>
>
>
>
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Herb Silver
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