John  Spencer<[log in to unmask]> writes:

<< If you have read/carried out such research, how did you measure TA timing
(ie what equipment did you use and how were you sure of picking up TVA - it
being such a deep muscle?) Also, how did you measure
'dysfunction' - ie what parameters lead you to conclude a lack of normal
function. Such measurements would be a really interesting contribution to the
literature on TVA - has it been published? Can you supply an abstract? >>

*** If you read my letter carefully, you will note that I never stated that I
carried out those "tests" - on the contrary, the athletes concerned visited
clinicians who claimed to have used familiar therapeutic tests to assess
"muscle imbalances".   I thought that was clear from my letter.  Because
these tests are commonly applied by physical therapists and chiropractors,
you should be quite familiar with them.  Since the rest of your case depends
on your misinterpretation of my letter, enough said about your subsequent
remarks which relied on that incorrect interpretation!

And, yes, as someone who has carried out many EMG analyses, I fully agree
with you about the problems of monitoring individual muscle activity, even
with needle electrodes, because electrical activity can vary with muscle
topology, surface preparation and depth.  Some scientists have even raised
some important questions about the accuracy of MRI tests of muscle action.
That is one reason why I have grave doubts about the abundance of many manual
muscle tests a la Kendall etc., and their relevance to the whole superficial
approach to assessing "muscle imbalance" and intersegmental muscle
deficiencies and imbalances, and so forth.  If you read my previous letters,
you will note that I am not convinced about the current approach to
extrapolating findings about muscle activity and postural stabilisation under
laboratory conditions to the real world of heavily loaded, prolonged or
explosive complex activity.

<Secondly, even if the research does indicate dysfunction in TVA in people
without pain this does not confound the TVA researchers conclusion. In fact
Paul Hodges has said that we need to carry-out a huge prospective study in
people without LBP to see if TVA dysfunction leads to back pain or back pain
leads to TVA dysfunction.>

***Nevertheless, it does make one wonder if existing tests of local spinal
stability and core stability can be applied to the "real world" of complex
forceful activity without any major modification and statement of limitations
of the testing.  Yes, as Hodges correctly states, we cannot yet rely on
existing findings with any level of certainty until much more research has
been done on a far wider cohort of subjects.  Currently, there is far too
much speculation on the role played by TVA in all types of activities and
that was precisely one of the major issues raised in my original post.

< (maybe they [weight and power lifters] wouldn't have had recurrent back
pain at all if they were more willing to undertake effective core stability
rehab.) >

*** Note that my original letter stated that these lifters experienced
periodic, not recurrent, pain.  In most cases, an analysis of their
periodised training programs and the use of video analysis showed that their
problems probably had a great deal more to do with deficient lifting
technique, lapses of efficiency with near maximal loads, or excessive volumes
of loading with certain exercises.  What their therapists interpreted as
deficient TVA or multifidus activity may have been due to individual
peculiarities in responding to those tests or various delayed after-effects
of training.  How does one identify the prime cause?  Well, I don't think
that this is always possible unless the injury was a traumatic one that
occurred in a clearly identified single incident.  Even then, the failure may
have become more likely because of pre-existing problems, fatigue, lack of
concentration or many other subtle factors.

Dr Mel C Siff
Denver, USA
http://groups.yahoo.com/group/Supertraining/