I remarked earlier that it can be misleading to classify muscles as
stabilisers and movers, or as 'tonic' vs 'phasic' entities because muscles
really carry out moving and stabilising or tonic/phasic functions. Are we
really justified in making this sort of distinction? I agree with Basmajian
("Muscles Alive") who commented that all muscles act synergistically and that
these types of classification are rather tenuous.
This whole saga of this type of muscle classification can be traced back to
the controversial Vladimir Janda, Czechoslovakian neurologist. He appears to
be the first person who placed so much emphasis on the importance of muscles
being either tonic or phasic, where tonic (postural) muscles are involved in
stabilising or maintaining position whereas phasic muscles are involved in
movement.
Janda noted that postural muscles tend to be hyperactive and more apt to
become spastic with lesions of upper motor neurons. Conversely, phasic
muscles with a tendency for inhibition, are the same muscles that became
flaccid under the same conditions. These typical imbalances in motor patterns
are enhanced by pain or fatigue. Janda calls this condition
"microspasticity." (Lewit K. Manipulative Therapy of the Locomotor System.
Boston, Butterworths, 1985).
For example, Janda found that subjects with chronic painful knee conditions
have weak or flaccid vasti, but very tonic or tight rectus femoris. Those
with shoulder pain often have taut pectoralis and subscapularis while the
supraspinatus, infraspinatus, and deltoid muscles test weak.
Much of this therapeutic system hails back to the practice of so-called
‘manual medicine’ founded in Czechoslovakia by Drs Karel Lewit and Vladimir
Janda. Apparently, their work was originally inspired in the 1950s by a
chiropractor in Prague and not by any real scientific study. These two
workers combined their own clinical research with that of various medical
and osteopathic researchers and even adapted many of the same basic
techniques used by osteopaths and chiropractics. Their former students
subsequently went on to establish the Associations of Myoskeletal Medicine in
Czechoslovakia. In other words, when one is evaluating the work of Janda, it
is relevant to examine its origins and scientific foundations.
Janda and similar work seems to have had a huge impact on the current
chiropractic and physiotherapeutic overemphasis on manual muscle testing,
despite its tenuous research foundation. Nevertheless, it is refreshing to
find at least one chiropractor who questions what his colleagues are
accepting without adequate scientific evidence. His comments (based upon his
review of the American Back Society in Las Vegas) are well worth reading:
Robert Cooperstein
<http://www.chiroweb.com/archives/17/05/25.html>
<Dr. Janda's ideas are certainly interesting and provocative, and perhaps
confirmed on the shop floor to many's satisfaction. However, I do not think
many of his hypotheses would fly well had they been first formulated by a
chiropractor, neither at the chiropractic research symposia I attend, nor at
the ABS, nor with MDs and DCs. Such a presenter would have to offer at least
some supportive evidence from the basic and clinical science literature, if
there is any.
It is interesting to see how one type of model builder attracts mostly
skepticism, whereas another with a different degree earns respect for having
had the courage to take liberties before an audience as august as the
American Back Society. I'm sorry, but to put it bluntly, sometimes there's a
fine line between being revered as a visionary and being seen as someone just
over the edge.>
Maybe this additional information will shed some more light on the concepts
of tonic and phasic muscles, the current manual muscle testing mania, and
'balancing of the body'. There is undoubtedly an interesting and useful
mixture of science and belief in the work of Janda and others; let us be
aware of such limitations and use it to re-examine and refine his system more
objectively and impartially, but let us not blindly accept anything largely
because of an individual's stature.
Maybe others in this group would be able to share more of the science and
less of the belief that underlies the modern manual testing and body
balancing mania. There are some fascinating hypotheses and techniques there
and they certainly warrant more scrutiny. Over to the rest of you!
Dr Mel C Siff
Denver, USA
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