On 10/7/00, Allison Franks<[log in to unmask]> writes:
<< My understanding of the reason for having patients perform an isolated
contraction is this:
When you perform a sit-up or cough etc, TrA is activated phasically, and an
isolated contraction is the only way to induce a tonic activation, which is
the only way to affect the automatic activation of the muscle.
I am happy to be proved wrong if people know otherwise. >>
***Several questions spring to mind:
1. Would you consider this principle to be universally true for all muscle
groups, irrespective of the dominance of any particular muscle fibre type in
a muscle?
2. If your above answer is 'yes', what are the implications for PNF
rehabilitation?
3. Why do you consider the sit-up to involve only phasic stimulation? There
are many ways of executing this exercise at different speeds and in different
patterns.
4. Why is a tonic activation exercise necessarily superior to a series of
'phasic' activations performed in regular or rapid sequence?
5. Why do you maintain that tonic activation is "the only way to affect the
automatic activation of the muscle"? This is certainly not what Guyton
(Textbook on Medical Physiology), for instance, and many other similar texts,
have to say about reflex activation of muscles.
Dr Mel C Siff
Denver, USA
http://www.egroups.com/group/supertraining
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