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Elzinator
October 1st 04, 01:15 PM
I wonder how (or, if) this would apply to other sports, such as OL.
Might have more applicability for Highland Games? (Wayne?)

ENGINEERING OF SPORT MEETING:
To Throw Farther, Waste Energy
Adrian Cho

DAVIS, CALIFORNIA--From 13 to 16 September, researchers from many
disciplines discussed sports from curling to skydiving, from table
tennis to boxing, at the 5th International Conference on Engineering
of Sport.

When throwing, the arm works against itself and wastes energy. But a
new mechanical analysis suggests that such seemingly profligate
efforts actually enable the limb to fling things farther.
In throwing and other physical activities, the first step forward is
often a step back. For example, to jump straight up, a person first
crouches toward the ground. "The downward motion is kind of strange
when you think about it," says Sam Walcott, a doctoral student in
theoretical and applied mechanics at Cornell University in Ithaca, New
York. "I'm moving in the direct opposite direction that I want to go."

The body briefly continues to move downward even after the muscles in
the legs and torso begin to pull it upward, which means it works
against itself. As muscles don't store energy like springs, that
"negative work" essentially goes to waste. Similarly, in throwing, the
forearm momentarily moves backward even as the upper arm pulls it
forward, again squandering energy. Biomechanists aren't sure what
purpose this "countermovement" serves.

But Walcott believes that wasting a little energy lets the body use
what energy it has left more effectively. Walcott used a computer to
study an idealized arm consisting of two straight
segments--representing the upper arm and forearm--that hurled a
virtual ball. The upper arm could move about a pivot, but only in a
plane; the forearm could then move so that it swept out a cone
perpendicular to that plane, creating a throwing motion that resembled
the whipping action of a baseball player's arm. Torques at the
"shoulder" and the "elbow" set the arm in motion. Walcott gave the
stick-figure limb a fixed amount of energy to expend and then let the
computer search for the arm motion that produced the longest throw.

If the computer program allowed the arm to work against itself, it
threw the object farther. The design of the arm doesn't allow it to
chuck the object at any old angle and speed, Walcott explains, but
"doing this negative work somehow allows us to get closer" to the
optimal angle and speed.

It's an interesting argument, says Michele LeBlanc, a biomechanist at
California Lutheran University in Thousand Oaks, but the abstract
analysis probably isn't the entire explanation of countermovement. The
details of how specific muscles, bones, and sinews interact will also
play a role, she says. Jill McNitt-Gray, a biomechanist at the
University of Southern California in Los Angeles, says that the
precise function of countermovement will probably vary even from
person to person: "You and I can jump together, and how you get your
vertical impulse and how I get my vertical impulse might be
different."

From this week's issue of Science.

Wayne S. Hill
October 1st 04, 02:12 PM
Elzinator wrote:

> I wonder how (or, if) this would apply to other sports, such
> as OL. Might have more applicability for Highland Games?
> (Wayne?)

It seems like they're lumping a stretch-shorten reflex (jumping
with a dip) with a dynamic counter-movement (the forearm in
throwing).

Accelerating the hand as quickly as possible, given a two-section
arm, is a nonlinear problem that depends on lots of variables.
The fact that optimizing the result calls for a strategy that
isn't obviously energy-efficient is no surprise at all.

Stone putting in HG is "simpler" than throwing a baseball, in that
the implement is heavy enough that you have to manage the stone
throughout the motion. This militates against any countermotion:
you want to accelerate the stone monotonically.

The story in weight for distance throws is much, much more
complicated. You use a lot of counter-movements, in this case
playing one side of the body against the other, or the upper body
against the lower body.

The caber toss and weight over bar events are largely about
getting a big, explosive pull, which takes advantage of a stretch-
shorten cycle.

--
-Wayne

Lyle McDonald
October 1st 04, 04:05 PM
Elzinator wrote:

> I wonder how (or, if) this would apply to other sports, such as OL.
> Might have more applicability for Highland Games? (Wayne?)
>
> ENGINEERING OF SPORT MEETING:
> To Throw Farther, Waste Energy
> Adrian Cho
>
> DAVIS, CALIFORNIA--From 13 to 16 September, researchers from many
> disciplines discussed sports from curling to skydiving, from table
> tennis to boxing, at the 5th International Conference on Engineering
> of Sport.
>
> When throwing, the arm works against itself and wastes energy. But a
> new mechanical analysis suggests that such seemingly profligate
> efforts actually enable the limb to fling things farther.
> In throwing and other physical activities, the first step forward is
> often a step back. For example, to jump straight up, a person first
> crouches toward the ground. "The downward motion is kind of strange
> when you think about it," says Sam Walcott, a doctoral student in
> theoretical and applied mechanics at Cornell University in Ithaca, New
> York. "I'm moving in the direct opposite direction that I want to go."

This may be the most moronic paragraph I have ever read.
It's not strange at all if you actaully KNOW anything about muscular
physiology.

>
> The body briefly continues to move downward even after the muscles in
> the legs and torso begin to pull it upward, which means it works
> against itself. As muscles don't store energy like springs,

Err, that series elastic component of the muscle stores energy very much
like a spring. Add to that the myotatic stretch reflex and...

> From this week's issue of Science.

Might as well have been Muscle and Fitness.

Lyle

Brandon Berg
October 1st 04, 05:28 PM
"Lyle McDonald" > wrote in message
...
> Elzinator wrote:
>
>> ENGINEERING OF SPORT MEETING:
>> To Throw Farther, Waste Energy
>> Adrian Cho
>>
>> For example, to jump straight up, a person first
>> crouches toward the ground. "The downward motion is kind of strange
>> when you think about it," says Sam Walcott, a doctoral student in
>> theoretical and applied mechanics at Cornell University in Ithaca, New
>> York. "I'm moving in the direct opposite direction that I want to go."
>
> This may be the most moronic paragraph I have ever read.
> It's not strange at all if you actaully KNOW anything about muscular
> physiology.

I don't know anything about muscular physiology, but I still see an obvious
explanation. To jump, you need an upward velocity. To increase velocity with
finite force, you need to apply the force over time. You can't do that if
you start with straight legs. I imagine that this is a factor in throwing a
baseball, too, although there does seem to be some spring-like action there.

--
Brandon Berg
Fix the obvious homonym substitution to reply.

Wayne S. Hill
October 1st 04, 06:32 PM
Brandon Berg wrote:

> "Lyle McDonald" > wrote...
>> Elzinator wrote:
>>
>>> ENGINEERING OF SPORT MEETING:
>>> To Throw Farther, Waste Energy
>>> Adrian Cho
>>>
>>> For example, to jump straight up, a person first
>>> crouches toward the ground. "The downward motion is kind
>>> of strange when you think about it," says Sam Walcott, a
>>> doctoral student in theoretical and applied mechanics at
>>> Cornell University in Ithaca, New York. "I'm moving in the
>>> direct opposite direction that I want to go."
>>
>> This may be the most moronic paragraph I have ever read.
>> It's not strange at all if you actaully KNOW anything about
>> muscular physiology.

True. I can't believe he said that.

> I don't know anything about muscular physiology, but I still
> see an obvious explanation. To jump, you need an upward
> velocity. To increase velocity with finite force, you need
> to apply the force over time. You can't do that if you start
> with straight legs.

Ah, but if you start your jump at the fully dipped position,
hold it, and then jump, you probably won't jump as high as if
you just dip and jump. The reason is sorta complicated.

> I imagine that this is a factor in
> throwing a baseball, too, although there does seem to be
> some spring-like action there.

That's mostly different. The effect they're referring to in
the throwing thing is the particular paths of the forearm and
humerus. You whip it.

--
-Wayne

Lyle McDonald
October 1st 04, 07:13 PM
Wayne S. Hill wrote:

> Brandon Berg wrote:
>
>
>>"Lyle McDonald" > wrote...
>>
>>>Elzinator wrote:
>>>
>>>
>>>>ENGINEERING OF SPORT MEETING:
>>>>To Throw Farther, Waste Energy
>>>>Adrian Cho
>>>>
>>>>For example, to jump straight up, a person first
>>>>crouches toward the ground. "The downward motion is kind
>>>>of strange when you think about it," says Sam Walcott, a
>>>>doctoral student in theoretical and applied mechanics at
>>>>Cornell University in Ithaca, New York. "I'm moving in the
>>>>direct opposite direction that I want to go."
>>>
>>>This may be the most moronic paragraph I have ever read.
>>>It's not strange at all if you actaully KNOW anything about
>>>muscular physiology.
>
>
> True. I can't believe he said that.

not aimed at you: But this is why engineers should stay the **** out of
exercise physiology.

>
>
>>I don't know anything about muscular physiology, but I still
>>see an obvious explanation. To jump, you need an upward
>>velocity. To increase velocity with finite force, you need
>>to apply the force over time. You can't do that if you start
>>with straight legs.
>
>
> Ah, but if you start your jump at the fully dipped position,
> hold it, and then jump, you probably won't jump as high as if
> you just dip and jump. The reason is sorta complicated.

nah, two primary factors:

stored energy in the series elastic component which you return when you
reverse
stretch shorten cycle (SSC) aka the myotatic reflex increases muscular
force output

A third issue is putting the muscle in a more favorable
length-tension/biomechanical relationship. Why dipping deeper doesn't
necessarily.

IAE, you end up with greater force with the countermovement vertical
compared to dip, pause, then jump. For a fixed mass, larger force =
larger acceleration = higher jump.

>
>
>>I imagine that this is a factor in
>>throwing a baseball, too, although there does seem to be
>>some spring-like action there.
>
>
> That's mostly different. The effect they're referring to in
> the throwing thing is the particular paths of the forearm and
> humerus. You whip it.

Do you whip it good?

Lyle

Keith Hobman
October 1st 04, 08:13 PM
In article >,
(Elzinator) wrote:

> I wonder how (or, if) this would apply to other sports, such as OL.
> Might have more applicability for Highland Games? (Wayne?)
>
> ENGINEERING OF SPORT MEETING:
> To Throw Farther, Waste Energy
> Adrian Cho
>
> DAVIS, CALIFORNIA--From 13 to 16 September, researchers from many
> disciplines discussed sports from curling to skydiving, from table
> tennis to boxing, at the 5th International Conference on Engineering
> of Sport.
>
> When throwing, the arm works against itself and wastes energy. But a
> new mechanical analysis suggests that such seemingly profligate
> efforts actually enable the limb to fling things farther.
> In throwing and other physical activities, the first step forward is
> often a step back. For example, to jump straight up, a person first
> crouches toward the ground. "The downward motion is kind of strange
> when you think about it," says Sam Walcott, a doctoral student in
> theoretical and applied mechanics at Cornell University in Ithaca, New
> York. "I'm moving in the direct opposite direction that I want to go."
>
> The body briefly continues to move downward even after the muscles in
> the legs and torso begin to pull it upward, which means it works
> against itself. As muscles don't store energy like springs, that
> "negative work" essentially goes to waste. Similarly, in throwing, the
> forearm momentarily moves backward even as the upper arm pulls it
> forward, again squandering energy. Biomechanists aren't sure what
> purpose this "countermovement" serves.

Huh?!?!?

Jeez, I've only got rudimentary knowledge of this stuff, but I understood
there was stored energy as well as the creation of a myotatic stretch
reflex.

(Hope I spelled that right.)

Keith Hobman
October 1st 04, 08:16 PM
In article >, Lyle McDonald
> wrote:

> Elzinator wrote:
>
> > I wonder how (or, if) this would apply to other sports, such as OL.
> > Might have more applicability for Highland Games? (Wayne?)
> >
> > ENGINEERING OF SPORT MEETING:
> > To Throw Farther, Waste Energy
> > Adrian Cho
> >
> > DAVIS, CALIFORNIA--From 13 to 16 September, researchers from many
> > disciplines discussed sports from curling to skydiving, from table
> > tennis to boxing, at the 5th International Conference on Engineering
> > of Sport.
> >
> > When throwing, the arm works against itself and wastes energy. But a
> > new mechanical analysis suggests that such seemingly profligate
> > efforts actually enable the limb to fling things farther.
> > In throwing and other physical activities, the first step forward is
> > often a step back. For example, to jump straight up, a person first
> > crouches toward the ground. "The downward motion is kind of strange
> > when you think about it," says Sam Walcott, a doctoral student in
> > theoretical and applied mechanics at Cornell University in Ithaca, New
> > York. "I'm moving in the direct opposite direction that I want to go."
>
> This may be the most moronic paragraph I have ever read.
> It's not strange at all if you actaully KNOW anything about muscular
> physiology.
>
> >
> > The body briefly continues to move downward even after the muscles in
> > the legs and torso begin to pull it upward, which means it works
> > against itself. As muscles don't store energy like springs,
>
> Err, that series elastic component of the muscle stores energy very much
> like a spring. Add to that the myotatic stretch reflex and...
>
> > From this week's issue of Science.
>
> Might as well have been Muscle and Fitness.

Well. Jeez. I should have just waited to reply.

Makes you wonder if the theoretical and applied mechanics has anything at
all to do with biomechanics, don't it?

Lyle McDonald
October 1st 04, 08:21 PM
Keith Hobman wrote:
> In article >, Lyle McDonald
> > wrote:

>>>From this week's issue of Science.
>>
>>Might as well have been Muscle and Fitness.
>
>
> Well. Jeez. I should have just waited to reply.
>
> Makes you wonder if the theoretical and applied mechanics has anything at
> all to do with biomechanics, don't it?

The mistake engineers seem to make is thinking that the body is SIMPLY
an engineering problem, a collection of levers and pivots and force
generators. Which it is to a first approximation, mind you, but that
loses the minor details. Such as the SEC and the stretch reflex and the
length-tension relationship and a whole host of other ****.

See, for example, the utter hilarity that is Power Factor Training.

Lyle

Keith Hobman
October 1st 04, 08:51 PM
In article >, Lyle McDonald
> wrote:

> Keith Hobman wrote:
> > In article >, Lyle McDonald
> > > wrote:
>
> >>>From this week's issue of Science.
> >>
> >>Might as well have been Muscle and Fitness.
> >
> >
> > Well. Jeez. I should have just waited to reply.
> >
> > Makes you wonder if the theoretical and applied mechanics has anything at
> > all to do with biomechanics, don't it?
>
> The mistake engineers seem to make is thinking that the body is SIMPLY
> an engineering problem, a collection of levers and pivots and force
> generators. Which it is to a first approximation, mind you, but that
> loses the minor details. Such as the SEC and the stretch reflex and the
> length-tension relationship and a whole host of other ****.
>
> See, for example, the utter hilarity that is Power Factor Training.

We've got a whole bunch of skinny/fat guys doing Power Factor training
(and preening between sets) at the PAC on campus. So much for a university
being the domain of higher intelligence.

So they will load up 405 lbs on the rack and then not even walk it out. I
seriously doubt if they could squat 95 lbs - I don't think they would have
the necessary flexibility even if they did have the strength at a deep
ROM. And then they want to come over and talk strength to me, cuz I'm also
using 405 lbs in my squat. (Or was. I'm going to have to take it easy for
a couple of weeks.)

So they've been trying to talk me into power factor training. I've managed
to resist so far. Mebbe that is why my head has been up my ass, Lyle.

:^)

Lee Michaels
October 1st 04, 09:26 PM
"Keith Hobman" > wrote in message
...
> In article >, Lyle McDonald
> > wrote:
>
> > Keith Hobman wrote:
> > > In article >, Lyle McDonald
> > > > wrote:
> >
> > >>>From this week's issue of Science.
> > >>
> > >>Might as well have been Muscle and Fitness.
> > >
> > >
> > > Well. Jeez. I should have just waited to reply.
> > >
> > > Makes you wonder if the theoretical and applied mechanics has anything
at
> > > all to do with biomechanics, don't it?
> >
> > The mistake engineers seem to make is thinking that the body is SIMPLY
> > an engineering problem, a collection of levers and pivots and force
> > generators. Which it is to a first approximation, mind you, but that
> > loses the minor details. Such as the SEC and the stretch reflex and the
> > length-tension relationship and a whole host of other ****.
> >
> > See, for example, the utter hilarity that is Power Factor Training.
>
> We've got a whole bunch of skinny/fat guys doing Power Factor training
> (and preening between sets) at the PAC on campus. So much for a university
> being the domain of higher intelligence.
>
> So they will load up 405 lbs on the rack and then not even walk it out. I
> seriously doubt if they could squat 95 lbs - I don't think they would have
> the necessary flexibility even if they did have the strength at a deep
> ROM. And then they want to come over and talk strength to me, cuz I'm also
> using 405 lbs in my squat. (Or was. I'm going to have to take it easy for
> a couple of weeks.)
>
> So they've been trying to talk me into power factor training. I've managed
> to resist so far. Mebbe that is why my head has been up my ass, Lyle.
>

Careful there Keith.

Doncha know that stuff is contagious??

Wayne S. Hill
October 1st 04, 11:58 PM
Lyle McDonald wrote:

> Wayne S. Hill wrote:
>> Brandon Berg wrote:
>>>"Lyle McDonald" > wrote...
>>>>Elzinator wrote:
>>>>
>>>>>ENGINEERING OF SPORT MEETING:
>>>>>To Throw Farther, Waste Energy
>>>>>Adrian Cho
>>>>>
>>>>>For example, to jump straight up, a person first
>>>>>crouches toward the ground. "The downward motion is kind
>>>>>of strange when you think about it," says Sam Walcott, a
>>>>>doctoral student in theoretical and applied mechanics at
>>>>>Cornell University in Ithaca, New York. "I'm moving in
>>>>>the direct opposite direction that I want to go."
>>>>
>>>>This may be the most moronic paragraph I have ever read.
>>>>It's not strange at all if you actaully KNOW anything
>>>>about muscular physiology.
>>
>> True. I can't believe he said that.
>
> not aimed at you: But this is why engineers should stay the
> **** out of exercise physiology.

Heh: well, he's not an engineer. He's in "theoretical and
applied mechanics", which is, well, kind of made up. If he were
an engineer, he would have known better than to ASSume it should
be simple.

>>>I don't know anything about muscular physiology, but I
>>>still see an obvious explanation. To jump, you need an
>>>upward velocity. To increase velocity with finite force,
>>>you need to apply the force over time. You can't do that if
>>>you start with straight legs.
>>
>> Ah, but if you start your jump at the fully dipped
>> position, hold it, and then jump, you probably won't jump
>> as high as if you just dip and jump. The reason is sorta
>> complicated.
>
> nah, two primary factors:
>
> stored energy in the series elastic component which you
> return when you reverse
> stretch shorten cycle (SSC) aka the myotatic reflex
> increases muscular force output
>
> A third issue is putting the muscle in a more favorable
> length-tension/biomechanical relationship. Why dipping
> deeper doesn't necessarily.
>
> IAE, you end up with greater force with the countermovement
> vertical compared to dip, pause, then jump. For a fixed
> mass, larger force = larger acceleration = higher jump.

Like I said, it's sorta complicated (more complicated than not
jumping with straight legs).

>>>I imagine that this is a factor in
>>>throwing a baseball, too, although there does seem to be
>>>some spring-like action there.
>>
>> That's mostly different. The effect they're referring to
>> in the throwing thing is the particular paths of the
>> forearm and humerus. You whip it.
>
> Do you whip it good?

Now whip it
Into shape
Shape it up
Get straight
Go forward
Move ahead
Try to detect it
Itís not too late
To whip it
Whip it good

--
-Wayne

Lyle McDonald
October 2nd 04, 03:06 AM
Wayne S. Hill wrote:

> Lyle McDonald wrote:
>
>
>>Wayne S. Hill wrote:
>>


> Heh: well, he's not an engineer. He's in "theoretical and
> applied mechanics", which is, well, kind of made up.

Ooh, I wanna make up my own field.

Theoretical and applied bioinformatic neuro-mechano-physiology.

Yeah, that'll look bitching on a business card.


>>Do you whip it good?
>
>
> Now whip it
> Into shape
> Shape it up
> Get straight
> Go forward
> Move ahead
> Try to detect it
> Itís not too late
> To whip it
> Whip it good

After this 2 week training block, I feel pretty damned DEVOlved

Lyle

Wayne S. Hill
October 2nd 04, 03:28 AM
Lyle McDonald wrote:

> Wayne S. Hill wrote:
>> Lyle McDonald wrote:
>>>Wayne S. Hill wrote:
>
>> Heh: well, he's not an engineer. He's in "theoretical and
>> applied mechanics", which is, well, kind of made up.
>
> Ooh, I wanna make up my own field.
>
> Theoretical and applied bioinformatic
> neuro-mechano-physiology.
>
> Yeah, that'll look bitching on a business card.

I like it.

> After this 2 week training block, I feel pretty damned
> DEVOlved

I know just how you feel. Whip it good.

--
-Wayne

Lyle McDonald
October 2nd 04, 06:58 AM
Wayne S. Hill wrote:


>>After this 2 week training block, I feel pretty damned
>>DEVOlved
>
>
> I know just how you feel. Whip it good.

c'mon, let's be all macho and competitive and see who's 2 week training
block was nastier.

I'll start generally, I've got 12 training units/week (not counting the
short supplemental workouts I do 2-3 times/week). 2/day every day
except Sunday.

Lyle

Peter Allen
October 2nd 04, 01:11 PM
"Lyle McDonald" > wrote in message
...
> Wayne S. Hill wrote:
>
>
> >>After this 2 week training block, I feel pretty damned
> >>DEVOlved
> >
> >
> > I know just how you feel. Whip it good.
>
> c'mon, let's be all macho and competitive and see who's 2 week training
> block was nastier.
>
> I'll start generally, I've got 12 training units/week (not counting the
> short supplemental workouts I do 2-3 times/week). 2/day every day
> except Sunday.

I don't think I'm going to beat that for a few weeks yet, not really into
full training. 10/week, plus 25 miles biking to work and training most
weekdays. However much less last week due to having my handlebars reshaped
courtesy of a woman driver turning right into me (current estimate, about
£200 worth of damage - not happy, will be trying very hard to get her
insurance to pay).

Feeling quite good recently, though - 3x6=18km UT2 work yesterday at a
1:52.3 average split on the erg, which isn't bad for a lightweight.

Peter

Pat Styles
October 2nd 04, 04:33 PM
"Lyle McDonald" > wrote in message
...
> Wayne S. Hill wrote:
>
> > Lyle McDonald wrote:
> >
> >
> >>Wayne S. Hill wrote:
> >>
>
>
> > Heh: well, he's not an engineer. He's in "theoretical and
> > applied mechanics", which is, well, kind of made up.
>
> Ooh, I wanna make up my own field.
>
> Theoretical and applied bioinformatic neuro-mechano-physiology.

Will there be mirrors or no mirrors?

> Yeah, that'll look bitching on a business card.

Dude, it's bitchen.
ps

Lyle McDonald
October 2nd 04, 04:56 PM
Pat Styles wrote:

> "Lyle McDonald" > wrote in message
> ...
>
>>Wayne S. Hill wrote:
>>
>>
>>>Lyle McDonald wrote:
>>>
>>>
>>>
>>>>Wayne S. Hill wrote:
>>>>
>>
>>
>>>Heh: well, he's not an engineer. He's in "theoretical and
>>>applied mechanics", which is, well, kind of made up.
>>
>>Ooh, I wanna make up my own field.
>>
>>Theoretical and applied bioinformatic neuro-mechano-physiology.
>
>
> Will there be mirrors or no mirrors?

yes.

Lyle

Lyle McDonald
October 2nd 04, 04:57 PM
Peter Allen wrote:

> "Lyle McDonald" > wrote in message
> ...
>
>>Wayne S. Hill wrote:
>>
>>
>>
>>>>After this 2 week training block, I feel pretty damned
>>>>DEVOlved
>>>
>>>
>>>I know just how you feel. Whip it good.
>>
>>c'mon, let's be all macho and competitive and see who's 2 week training
>>block was nastier.
>>
>>I'll start generally, I've got 12 training units/week (not counting the
>>short supplemental workouts I do 2-3 times/week). 2/day every day
>>except Sunday.
>
>
> I don't think I'm going to beat that for a few weeks yet, not really into
> full training.

Well, several (3 to be exact, and the supplementals) of my units are
more technically based right now. But they are long workouts and
include some conditioning work at the end.

When I get into real aerobic/anerobic training, my current workload will
look totally pussy.

Lyle

Brandon Berg
October 2nd 04, 08:21 PM
"Lyle McDonald" > wrote in message
...
> Wayne S. Hill wrote:
>> Brandon Berg wrote:
>>>"Lyle McDonald" > wrote...
>>>>Elzinator wrote:
>>>>>ENGINEERING OF SPORT MEETING:
>>>>>To Throw Farther, Waste Energy
>>>>>Adrian Cho
>>>>>
>>>>>For example, to jump straight up, a person first
>>>>>crouches toward the ground. "The downward motion is kind
>>>>>of strange when you think about it," says Sam Walcott, a
>>>>>doctoral student in theoretical and applied mechanics at
>>>>>Cornell University in Ithaca, New York. "I'm moving in the
>>>>>direct opposite direction that I want to go."
>>>>
>>>>This may be the most moronic paragraph I have ever read.
>>>>It's not strange at all if you actaully KNOW anything about
>>>>muscular physiology.
>>
>> True. I can't believe he said that.
>
> not aimed at you: But this is why engineers should stay the **** out of
> exercise physiology.

But as I already pointed out, his comments sound stupid even from a purely
mechanical perspective. The real lesson here is that idiots should stay out
of print.

--
Brandon Berg
Fix the obvious homonym substitution to reply.

Lyle McDonald
October 2nd 04, 08:47 PM
Brandon Berg wrote:

> "Lyle McDonald" > wrote in message
> ...
>
>>Wayne S. Hill wrote:
>>
>>>Brandon Berg wrote:
>>>
>>>>"Lyle McDonald" > wrote...
>>>>
>>>>>Elzinator wrote:
>>>>>
>>>>>>ENGINEERING OF SPORT MEETING:
>>>>>>To Throw Farther, Waste Energy
>>>>>>Adrian Cho
>>>>>>
>>>>>>For example, to jump straight up, a person first
>>>>>>crouches toward the ground. "The downward motion is kind
>>>>>>of strange when you think about it," says Sam Walcott, a
>>>>>>doctoral student in theoretical and applied mechanics at
>>>>>>Cornell University in Ithaca, New York. "I'm moving in the
>>>>>>direct opposite direction that I want to go."
>>>>>
>>>>>This may be the most moronic paragraph I have ever read.
>>>>>It's not strange at all if you actaully KNOW anything about
>>>>>muscular physiology.
>>>
>>>True. I can't believe he said that.
>>
>>not aimed at you: But this is why engineers should stay the **** out of
>>exercise physiology.
>
>
> But as I already pointed out, his comments sound stupid even from a purely
> mechanical perspective. The real lesson here is that idiots should stay out
> of print.

I can live with that.

Lyle

Bob MacWilliam
October 2nd 04, 09:52 PM
"Lyle McDonald" > wrote in message
...
> Keith Hobman wrote:
>> In article >, Lyle McDonald
>> > wrote:
>
>>>>From this week's issue of Science.
>>>
>>>Might as well have been Muscle and Fitness.
>>
>>
>> Well. Jeez. I should have just waited to reply.
>>
>> Makes you wonder if the theoretical and applied mechanics has anything at
>> all to do with biomechanics, don't it?
>
> The mistake engineers seem to make is thinking that the body is SIMPLY an
> engineering problem, a collection of levers and pivots and force
> generators. Which it is to a first approximation, mind you, but that loses
> the minor details. Such as the SEC and the stretch reflex and the
> length-tension relationship and a whole host of other ****.
>
> See, for example, the utter hilarity that is Power Factor Training.
>
> Lyle
>

But the original statement was bunk even on a pure engineering/basic physics
level.

>>>>The downward motion is kind
>>>>of strange when you think about it," says Sam Walcott, a
>>>>doctoral student in theoretical and applied mechanics at
>>>>Cornell University in Ithaca, New York.

In terms of pure simple physics, to jump you must accelerate your centre of
mass sufficiently so that the upward velocity is sufficient to lift you off
the ground before the force of gravity slows and then reverses your upward
movement. The only way your legs can accelerate you (push) is to bend
first. Even without any biological complications he was off in left field.

>a collection of levers and pivots and force generators.

Add some damped harmonic motion in there though and the approximation gets
quite a bit better.

Bob
(Medical Biophysics guy once upon a time)

Lyle McDonald
October 2nd 04, 10:48 PM
Bob MacWilliam wrote:

> "Lyle McDonald" > wrote in message

> In terms of pure simple physics, to jump you must accelerate your centre of
> mass sufficiently so that the upward velocity is sufficient to lift you off
> the ground before the force of gravity slows and then reverses your upward
> movement. The only way your legs can accelerate you (push) is to bend
> first. Even without any biological complications he was off in left field.

But even then he could have gotten into why is it more efficient to do a
counterjump (i.e. dip and jump) than to start from a bent knee?

>
>
>>a collection of levers and pivots and force generators.
>
>
> Add some damped harmonic motion in there though and the approximation gets
> quite a bit better.

But that still leaves out perhaps the largest difference: nervous system
activation. Which can probably be modelled on some level but adds a
pretty high level of complexity to the model.

Lyle

Pat Styles
October 3rd 04, 05:35 PM
"Lyle McDonald" > wrote in message
...
> Pat Styles wrote:
>
> > "Lyle McDonald" > wrote in message
> > ...
> >
> >>Wayne S. Hill wrote:
> >>
> >>
> >>>Lyle McDonald wrote:
> >>>
> >>>
> >>>
> >>>>Wayne S. Hill wrote:
> >>>>
> >>
> >>
> >>>Heh: well, he's not an engineer. He's in "theoretical and
> >>>applied mechanics", which is, well, kind of made up.
> >>
> >>Ooh, I wanna make up my own field.
> >>
> >>Theoretical and applied bioinformatic neuro-mechano-physiology.
> >
> >
> > Will there be mirrors or no mirrors?
>
> yes.
>
> Lyle

Ah, I was thinking, "It depends."
ps

Lyle McDonald
October 3rd 04, 06:49 PM
Pat Styles wrote:

> "Lyle McDonald" > wrote in message
> ...
>
>>Pat Styles wrote:
>>
>>
>>>"Lyle McDonald" > wrote in message
...
>>>
>>>
>>>>Wayne S. Hill wrote:
>>>>
>>>>
>>>>
>>>>>Lyle McDonald wrote:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>Wayne S. Hill wrote:
>>>>>>
>>>>
>>>>
>>>>>Heh: well, he's not an engineer. He's in "theoretical and
>>>>>applied mechanics", which is, well, kind of made up.
>>>>
>>>>Ooh, I wanna make up my own field.
>>>>
>>>>Theoretical and applied bioinformatic neuro-mechano-physiology.
>>>
>>>
>>>Will there be mirrors or no mirrors?
>>
>>yes.
>>
>>Lyle
>
>
> Ah, I was thinking, "It depends."

My answering 'yes' to a yes or no question is essentially the same answer.

Meaning yes to mirrors when they are useful/necessary.
And yes to 'no mirrors' when they are not.

Now I have a headache.

Lyle

Pat Styles
October 4th 04, 02:10 AM
"Lyle McDonald" > wrote in message
...
> Pat Styles wrote:
>
> > "Lyle McDonald" > wrote in message
> > ...
> >
> >>Pat Styles wrote:
> >>
> >>
> >>>"Lyle McDonald" > wrote in message
> ...
> >>>
> >>>
> >>>>Wayne S. Hill wrote:
> >>>>
> >>>>
> >>>>
> >>>>>Lyle McDonald wrote:
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>>Wayne S. Hill wrote:
> >>>>>>
> >>>>
> >>>>
> >>>>>Heh: well, he's not an engineer. He's in "theoretical and
> >>>>>applied mechanics", which is, well, kind of made up.
> >>>>
> >>>>Ooh, I wanna make up my own field.
> >>>>
> >>>>Theoretical and applied bioinformatic neuro-mechano-physiology.
> >>>
> >>>
> >>>Will there be mirrors or no mirrors?
> >>
> >>yes.
> >>
> >>Lyle
> >
> >
> > Ah, I was thinking, "It depends."
>
> My answering 'yes' to a yes or no question is essentially the same answer.

I take your point.

> Meaning yes to mirrors when they are useful/necessary.
> And yes to 'no mirrors' when they are not.

Very good.

> Now I have a headache.
>
> Lyle

Oops, sorry about that. :-)
ps

Helgi Briem
October 4th 04, 09:50 AM
On 1 Oct 2004 17:32:03 GMT, "Wayne S. Hill" > wrote:

>That's mostly different. The effect they're referring to in
>the throwing thing is the particular paths of the forearm and
>humerus. You whip it.

Whip it good.
Into shape.


--
Helgi Briem hbriem AT simnet DOT is

"Don't worry about it, son. God is just messing with your head."