 |
 |
For several years I used to suggest a series of "Puzzles and Paradoxes" for discussion and, at the request of some list members, I have once again agreed to create a few more for some further hedonistic speculation. PUZZLE & PARADOX 125 INTRODUCTORY NOTE For newcomers to this forum, these P&Ps are Propositions, not facts or dogmatic proclamations. They are intended to stimulate interaction among users working in different fields, to re-examine traditional concepts, foster distance education, question our beliefs and suggest new lines of research or approaches to training. We look forward to responses from anyone who has views or relevant information on the topics. TRANSVERSUS ABDOMINIS ACTION Here is a quick puzzle and paradox - is the role of transversus abdominis (TVA) as supremely important as some individuals have been suggesting? After all, the body is extremely efficient at recruiting different systems and processes if one of the important systems involved in a given action is injured, ill-adapted, fatigued or otherwise compromised in its ability to offer its optimal contribution. Not only does this happen in the muscular system, but MRIs show that this plasticity of function even happens in the brain. Those who work clinically often will notice how many patients with physical differences or dysfunctions "compensate" by using different muscles or patterns to carry out a given task without any apparent ill-effects. One example close to home -- my paraplegic wife who is paralysed from thoracic level T3 is able to carry out tasks that nobody should be able to do with that level of injury, but she often does and does so without injury. So much has been written recently about how essential transversus abdominis is to trunk stabilisation and mobility, but has anyone ever undertaken studies to show that people who may not be able to activate it very effectively may compensate very effectively by using other patterns of muscle activation and use? Is there really any convincing proof that "less than optimal" TVA activation definitely results in significantly less efficient and more dangerous trunk action in all daily activities? Studies of actions other than trunk stability have shown that the same muscles do not necessarily become involved or become involved to the same extent or in the same pattern in different people or in the same person at different times (e.g., there was an article in the Scientific American within the last 2 years which used fMRI - functional MRI to demonstrate this). If this happens with other movements, why should actions involving TVA be any different? Is there any genuine proof, other than the current conjecture, that TVA contributions to trunk action is not as predictable and deterministic as is being claimed by some therapists? Does it really matter all that much if it sometimes does not contribute as it "should" during human movement and its decrease in function is compensated for by other muscle actions? Are there any references which help to resolve this paradox? Dr Mel C Siff Denver, USA http://groups.yahoo.com/group/Supertraining/