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jtelle79
10-07-1998, 12:00 PM
In a message dated 10/7/98 4:52:50 AM, you wrote:

MC--This is my problem, find a way to colect reliable data on what I
am

>looking at:

>What happens when a subject moves a load on a (let's say) a Leg
Extension with

>different cammes shapes ?

>And what at different speed ?


>about komi and Hakkinens EMG cam methodology



*** Sorry bu t I do not understand what is Komi and Hakkinen's cam
methodology ??? I read extensively about these two authors but I do not
understand this sentence.

Scientific evaluation of specific loading of the knee extensors with variable
resistance, Isokinetic and barbell exercises.

Keijo Hakinen, Paavo V Komi and Haikki Kauhanen

Dept of biology of physical activity
University of Jyvaskyla
sf 40100 Jyvaskyla
Finland

Date ??


MC--- The point is:

>There is a weight stack to move, and it is atTached to a pulley, or a cam
or 3

>different cam types.....what is going on in our joints or muscles ?

telle--time under tension is one--


MC->So the point is: creating an ergonomic station on which joint and
muscle

>performance is optimized.


Telle--this ergonomic station already
exists-------the--DUMBBELL--followed by

>the BARBELL. Variations in specific torque capacities can be addressed
much

>easier with a dumbbell (or cable pulley unit) than with any camed
machine.
*** Again, I think we missed the point there. I perfectly agree with you
that dumbells and barbells are the best way to train ATHLETES. Myself
also when conditioning athletes, prefer to use barbells and dumbells,
However, my interests are more directed versus the Fitness World, where
the Mr.John Average who is not aware of proper lifting techniques and
does not want to spend a second with a fitness instructor for doing some
pecs exercises, jump on a chest press and does his daily workout. This is
the point, I am not discussing about effectiveness of cams versus
barbells, I am just trying to develop a research design to evaluate
different machines and develop some useful ideas for their improvement.

>*** SNIP******I am talking about exercise
machines we

>can find in a Fitness center where they can be used by the 20 years old
fitnes

>fun, the 25 y.o. atlete and the 50 years old average person who is
willing to

>improve his/her fitness status.

>

TELLE---Read Siffs "Supertraining" on machines---M Siff regards them so
dangerous that this type of equipment often --all the time ?requires more
supervision then free weights cables..

thats MY point youre tilting weight machines instead of windmills.

*** My point was. Dear biomechanist of
the World.....I am willing to do this kind of investigation, would you
help me out in a research protocol able to look at these things
accurately ?

TELLE--what about total work for 10 reps @ similar rep speed and
accel/decelerations.
--or total EMG or mean EMG for any given number of reps
--good luck with the ergonomics. Prime example; any arm extension or flexion
is a triarticular (three joint) movement--count the number of axis' on these
machines---one !!!

I think I am smart and experienced enough to understand the difference
between cams and barbells and their respective effectiveness in strength
training.

By the way, thank you for your considerations.

Your welcome.


>>My research findings are that you positively cannot test dynamic

>>strength(isometrics is useless)accurately with either inertial or
speed

>>controlled devices--leading me to a combination of the two as
necessary.


>*** Well, I am convinced by the fact that speed controlled devices
cannot be

>useful in determining dynamic strength accurately expecially if the goal
is to

>verify training adaptations, since the best way is to determine it
through

>testing the same exercise used in the training plan.


>TELLE--Then your only testing against the training device--with
any inherent

>problems associated--are not strength increases a function of training
and

>testing modality similarities ?



*** This is always the reason why there are coaches and researchers.
Research goes step by step in understanding phenomena. If we do not
understand the simplest ones, how can we even think about the most
complex ?

TELLE--I agree, I believe we're getting closer to the same wave length.

------------

>Telle--concentric torque is, in part, a function of the
eccentric--like the

>horse before the cart. You CANNOT accuartely test the wide range of
concentric

>forces with out some eccentric lenghtening !!



*** What about the Squatting Jump test (Concentric only activity) and the
Counter Movement Jump test (Concentric activity preceded by pre-stretch
of muscles). These tests have been extensively used by us and by every
scientist to measure the possible re-use of elastic energy and the neural
activities here connected.

Telle --right, but the ROMs are all truncated--not full ROM--its obvious you
can start a concentric rep anywhere in the arc(s)--I imagine you even
controlled for elastic energy/force? during the single concentric rep.

We can absolutely discriminate between concentric and eccentric muscular
activity.

TELLE--Not full ROM-whether or not this is splitting fibers??


>Another point is:

>In order to work as planned, the weights on a cam-ype machine, need to
be

>moved at a constant low velocity.

>How can we measure reliably EMG patterns if we are asking subjects at
a

>constant velocity something ?

>Which can be the optimal velocity for testing ?

>Or......

>At which speed is the function of a cam optimized ?

>

>telle --whatever the OPTIMAL speed for a cam is --is purely
wasted

>academia--the cam is far less amenable to specific training adaptations
then

>is a free weight--unless you can vary the shape of the cam every rep--to
match

>the exercisers force !



*** Well....I do not see why there are hundreds of companies wasting time
and billions to produce exercise machines. and thousands of fitness
centers spending money to buy them.

TELLE--the answers obvious to me-- when you understand the limitations of
machines---the users are just uneducated!

MC----Whay are also we discussing then ? We
could train aour people telling them to lift rocks, shopping bags, or
laundry boxes ??

TELLE--GET 2 equal size rocks and put a handle between them---and your right

When computers started their development there were people asking
themselves why it wasnecessary to buy one of these colored, and full of
lights boxes, that were very slow in calculating even a simple equation.
These computers were then developed and are permitting now our
conversation even if we live thousands of km far from each other.

I think there is a need for developing exercise machines, user friendly
and useful for most of the population.

TELLE----Ive built machines that do everything Ive mentioned and have designs
for better ergonomics.--I understand the problems--what your after is
archaeological advice --your focus' are obsolete--its just not widely known
yet.........

I suggest you study ways to use free weights more effectively.!!! thats the
next step-then again if you really get into machine eval maybe youll see this
also--

Jerry

>>

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