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Old 04-08-2013, 12:50 PM   #14
JW's Avatar
Location: San Diego CA USA
Join Date: Aug 2000
Posts: 561
Re: "Conventional Muscles" and Internal Power

Hi Benjamin, I appreciate a skeptical point of view very much. But I am not sure what specifically you are arguing-- do you disagree with any of these specific points, which this thread addresses?

1. The human motor system is plastic, that is, it can be modulated by the individual. So, if a given task requires 3 big muscle groups, the individual can change at will and in real-time, the relative amount of activation in those muscle groups. This is often done using visualizations. The task will thus vary a bit in outcome but as long as the barbell goes up you are happy, thus you are free to vary which muscles get loaded (and thus exercised) more using this method.
2. Due to this same plasticity, there can be multiple "versions" of a given task, like the type of jump before and after retraining in the basketball players. One version may be awkward and inefficient at first but with development can become superior. Strikingly different versions are created not in real-time, but over the course of tissue strength training.
3. Different circumstances may allow the individual to benefit from the ability to do a task with a "version" that is normally slightly inefficient. (Like if you need to jump in basketball but your hamstrings have become injured or fatigued)
4. As a corollary to #2 and #3, you may get stuck in a "crappy" pattern of motor unit activation in a situation where certain muscles (or other, passive load-bearing structures like ligaments) have atrophied.

I don't think any of that is controversial or disputed in the field of motor learning and behavior. It all points to 2 conclusions:
1. There is no single "most efficient way" to do something, except in the specific context of a given physical situation and a given individual's muscular/tissue development. That context is not set in stone so "most efficient way" is not set in stone.
2. There can be very different global patterns of motor unit recruitment, with each pattern having some activation barrier that inhibits switching. The source of the activation barrier is muscular and connective tissue strength, as well as mental habit. As we get comfortable moving a certain way, unused muscles will atrophy and used muscles will strengthen - thus we get comfortable in a certain pattern. But, if certain weak muscles were strengthened, there may be a much better way to do things.

So what is it that is the actual source of disagreement?
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