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On 4/3/00, Trevor Allen<[log in to unmask]> wrote: Mel Siff: <Anyway, without entering into an extremely long analysis of every comment, I cannot see any scientific errors of note in my comments on the dubious physiology underlying Pilates training or the inaccurate or imprecise remarks made by Trevor Allen that seemed to be trying to support Pilates pseudo-science.> Trevor Allen: <<My comments made NO reference to Pilates, only to muscle physiology. . . >> ***Correct - the name there should have been Simon Mesner and your name appeared there because of all that confusion over Liz Williams' posting on your behalf. The same applies in several other cases where you and Mesner were confused in that collage of postings. My apologies if I took your name in vain elsewhere. Trevor Allen: <<Your original claim was that it is during the isometric phase, not during eccentric action that tension in the muscle complex reaches its greatest value. To explain this phenomenon with the F-V relation, you would have basically turn it upside down, not prove it is more linear than hyperbolic. That is, for on the lengthening side of the F-V relation (beyond zero velocity) force goes down rather than up. Every force record i have ever seen in my own research shows maximumum eccentric muscle force increasing above isometric force, which is supported by others (eg. Woledge '85, Energetic aspects of muscle contraction). >> Mel Siff: ***Actually, I stated EXPLOSIVE isometrics - as imposed by impulsive loading at the end of a sharply amortised eccentric action, not gradual onset isometrics. Please see that Bosco reference that I quoted before and work done by Dr Verkhoshansky on this (Siif MC & Verkhoshansky YV "Supertraining" 1999). Here is Bosco's reference again - I am sure that you did not read it before making the above remarks. Bosco C (1982) Physiological considerations of strength and explosive power and jumping drills "Proc of Conference '82: Planning for Elite Performance", Canadian T&F Assoc Ottawa, 1-5 Aug 1982: 27-37. Trevor Allen: <<To be honest i have never seen a muscle force record during the stretch-shortening cycle to see this actually happens, if you can provide a reference I would like to look it up. I think the stretch-shortening phenomenon is a very interesting area, and if things happen as you say I would like to understand it from what we know of muscle physiology. >> Mel Siff: ***Besides the work by Bosco, one of my MSc students did part of his dissertation on this topic, using special myotonometer that I designed to non-invasively measure muscle tension during various types of concentric, eccentric and 'plyometric' actions. Kirkby A (1998) Biomechanical Analysis of the Relation between Joint Torque and Muscle Tension for different Modes of Muscle Contraction Unpubl MSc School of Mech Eng, University of the Witwatersrand, S Africa Zatsiorsky V M & Matveev E N (1964) Force-velocity relationships in throwing Teoriya I Praktika Fizischeskoi Kultury (Theory & Practice of Physical Culture) 27(8): 24-28 Zatsiorsky V.M. (1997) The Review is Nice. I Disagree with It. J of Applied Biomechs 13, 479-483, This entire Journal issue is a special on stretch-shortening and well worth studying. In addition, there is a considerable amount of work on the topic of stretch-shortening by Komi, Haekinnen and several other Finnish researchers, as well as many by Verkhoshansky and Zatsiorsky. Many of your subsequent comments on my comments appear to involve a great deal of semantic and definition differences that have occurred since we are unable to have immediate feedback in person. I think that we both realise this fact, as do many others on this group, since we have all studied or researched them over the years. For instance, of course, I agree with you that stretching of tissues in a full squat position is very different from stretching imposed at other angles of the knee. Etcetera, etcetera. I certainly see where you have misinterpreted me and I am sure that you have noted the same with me. That is why I chose to focus on what appear to be the major differences of understanding that we have over certain aspects of muscle action. However, since the original discussion began with my request for proof of the statement that Pilates training produces longer muscles than other forms of training, I would still like to see someone try to apply muscle physilogy to substantiate this claim. I have received numerous comments on Pilates from various folk all over the world (some quite uncomplimentary), but they all announce that Pilates is great, wonderful, safe, has its place in training, that not everyone likes weights or aerobics, but not a single person has addressed the problem of misleading and unscientific claims being made for Pilates. So far, that is telling me a lot about what Pilates folk don't know about Pilates foundations and physiology! Dr Mel C Siff Denver, USA [log in to unmask] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%