Location: Seattle/Southern Wisconsin
Join Date: Jul 2002
<In Neurophysiological Basis of Movement ( Latash 1998) the author discusses a technique used to isolate a motor unit (for those of you who unclear on the term MU means 'The motorneuron and the muscle fibers it innervates...' -Latash 98) called needle electromyography whereby "...a thin needle (with a diameter of less than 1 mm) is inserted into a muscle (figure 6.6). Inside the needle is a very thin wire that is electrically isolated from the needle. The tip of the wire is not isolated." "Such electrodes are designed to record the patterns of activity of individual motor units." (Latash 98).
Interestingly enough, though I have already addressed this research in Motor Development and Motor Learning, we were just discussing (in Neuromotor Control) last week the study whereby using this technique combined with biofeedback a person can actually isolate a single motor unit and contract only those fibers without contracting the full muscle. Not only can we choose consciously to contract one muscle, but we can individuate a set of fibers within that muscle.>
And this has what to do with training?
<I would agree, had I known that a simplification which I used to discuss training, for the sake of avoiding ad nauseam forensic discussion, would be flagged and labeled 'cartoonish' I'd have been more careful. I think for the sake of others though, discussing enough curricula to enable one to attain a BS in Kinesiology should be unnecessary.>
I deliberately strive to avoid unnecessary complication in explanation, and talk about training in practical terms. What was 'cartoonish' was your reduction of the whole field of supplemental and preparatory conditioning with weights to 'isolating specific muscles', not the lack of technical jargon.
<Hmmm, I don't agree. How do you come by this assertion?
True, the body develops coordinative structures, but it is possible for the body to respond to an action potential meant for a specific motor unit, and depending upon recruitment need, possibly more than one.>
Once again, acadamic irrelevancies. When one is training with weights, training in Aikido, or doing anything outside of a biofeedback lab, in terms of intent and action, one can only do movements, and every movement is a coordinated effort of many muscles and motor units, some isometric, some kinetic. To break it down in terms of individual muscles is an impractical and possibly misleading oversimplification of a complex process. Luckily, one need not go down that road - one can learn movements and train movements quite productively without ever referring to individual muscles.
<These components, would it be too much to ask if we are talking about vestibular, visual, or kinesthetic components of balance? (<<my emphasis of study) When you speak of control, are you speaking of neuro-motor control? Is that too specific, should we simplify? Would that be cartoonish?>
Once again, academic overload. If one is performing an elbow extension movement in a chair, with one's upper arm in a fixed position, pushing against a lever arm that can only move in one plane of motion, one cannot balance the weight nor exert any control over it, other than to merely push within the fixed track set by the machine. If one does a leg press in a machine, once again, there is nothing to the movement except pushing along a linear track. However, if one does a back squat with free weights, in addition to pressing through roughly the same range of hip, knee, and ankle motion, one must also balance the body plus the weight in two other planes of motion - which components of balance aren't important, in one exercise one is challenging one's ability to balance and stabilize, in the other, one is not.
<Yes there are agonists, antagonists an synergists, but do you think everyone wants to hear the long of it?
You're right. For those of you still reading this discourse: when you use the 'Lat' Pull-down Machine' you are using more than your latissimus dorsi, in fact you would not be able to grip the machine if you could only use your lats.
I would assert that by using weights in a fashion that targets a particular muscle to be used as the Prime Mover, one is reducing the number of Degrees of Freedom, and reducing the need for complex Coordinative Structures used in a more complex movement, so that one can concentrate on a possibly more weak area, though it should be noted that weights are not purely isolationary in their function.
Is that verbosity necessary?>
No, especially since what you are saying is incorrect. Your 'Prime Mover' analysis is a classic case of putting the analytic cart before the horse. 'Prime Movers' only exist in the minds of analysts - it only has utility as a description, yet you are working backwards from the observation that one muscle does more of the work than the others in a move and making poor assumptions about how the movement works. In complex multi-joint movements such as a pulldown, one is only 'reducing degrees of freedom' insofar as doing any specific movement requires one to do something specific, thereby reducing movement possibilities - this has nothing to do with a taxonomical scheme of primaries vs. secondaries or isolating muscles. Virtually every muscle from the waist up is involved in the pulldown - which one stabilizes where, or generates motion where isn't of much practical import. Do the free-hanging version: the pull-up, and even more muscles come into play. Pulling something heavy down, or one's body up is not even close to 'isolationary' in any way - but it is a useful movement chain to become strong at.
<Oh, I get it, this is a sermon.
No wait, it's a sales pitch.>
Talk about the low road. I wrote what I wrote because you threw out a couple of flippant sentences that seemed to presume some very simplistic, dismissive things about training methodologies. My reply was to counter these, because too many people in Aikido seem to ignore or dismiss the usefulness of training methods that are universally used and valued in virtually every other athletic endeavor from the high school level up. It had nothing to do with your ego or academia, which seems to be what most of what you've written here is about.