Arm Swing Gyroscopic Effect?



T

Topcounsel

Guest
Got frustrated this morning with slowing down for the many slippery sand-covered concrete tight
corners I run over (this a.m. was a particularly dark moonless morning), and decided to push hard
through them and swing my arms like a banshee during the turns. It occurred to me that those 1st-
year physics demonstrations with the surprising lateral stability of a rotating bicycle wheel might
have some analogy to arm swing in running, and I thought I'd see if I could feel it keeping me on
track through the turns.

I think it makes a noticeable difference (I didn't slip and fall, anyway). The sprinters among
us who run 200's and longer must surely be knowledgable about this. I'm not really aware of
much commentary on it, and it seems most comments on arm swing focus on how it can help you
find your best "stride rate" -- and not on any gyroscopic effect -- but I did find a link to a
page on the Harvard Math Department website entitled "Running," apparently suthored by an
"Ultimate Frisbee" guy:

http://abel.math.harvard.edu/~lee/cvhrunning.html

There are 3 paragraphs well into the piece which discuss "lean angle," "acceleration" and "arm
swing," for those interested in this (admittedly somewhat arcane) subject. As for me, if I'm trying
to pinch seconds on the clock, I will now feel more confident keeping up my velocity on corners.
 
D

Doug Freese

Guest
TopCounsel wrote:

> Got frustrated this morning with slowing down for the many slippery sand-covered concrete tight
> corners I run over (this a.m. was a particularly dark moonless morning), and decided to push hard
> through them and swing my arms like a banshee during the turns.

Put screws in your shoes and stop worrying about slipping and return to proper form.

I

--
Doug Freese "Caveat Lector" [email protected]
 
T

Topcounsel

Guest
>Put screws in your shoes and stop worrying about slipping and return to proper
form.

On dry concrete and asphalt? We have as much snow here in our part of SoCal as you have of 90+degree
winter mornings. I have enjoyed your screw-shoe posts and links, but for me they're largely
academic. I'm just sort of logging your info away in the event I ever get up into the mountains in
winter and want to run there. I just might.
 
D

Drlith

Guest
"TopCounsel" <[email protected]> wrote in message
news:[email protected]...
> >Put screws in your shoes and stop worrying about slipping and return to
proper
> form.
>
> On dry concrete and asphalt? We have as much snow here in our part of
SoCal as
> you have of 90+degree winter mornings. I have enjoyed your screw-shoe
posts
> and links, but for me they're largely academic. I'm just sort of logging
your
> info away in the event I ever get up into the mountains in winter and want
to
> run there. I just might.

LOL. I guess "slippery sand-covered concrete" means something entirely different depending on
whether you're in New York in the middle of winter or in Southern California.
 
D

Doug Freese

Guest
DrLith wrote:

> LOL.

It WAS meant to be funny.

> I guess "slippery sand-covered concrete" means something entirely different depending on whether
> you're in New York in the middle of winter or in Southern California.

But....if the "slippery sand-covered concrete" was more than just an occasional spot screws would
help. They are not for snow and ice. So there... ;)

--
Doug Freese "Caveat Lector" [email protected]
 
M

Miss Anne Throp

Guest
It's not your arms that give you that lateral stability. It's your giant cranium.
 
L

Lyndon

Guest
>Got frustrated this morning with slowing down for the many slippery sand-covered concrete tight
>corners I run over (this a.m. was a particularly dark moonless morning), and decided to push hard
>through them and swing my arms like a banshee during the turns. It occurred to me that those 1st-
>year physics demonstrations with the surprising lateral stability of a rotating bicycle wheel might
>have some analogy to arm swing in running, and I thought I'd see if I could feel it keeping me on
>track through the turns.
>
>I think it makes a noticeable difference (I didn't slip and fall, anyway). The sprinters among
>us who run 200's and longer must surely be knowledgable about this. I'm not really aware of
>much commentary on it, and it seems most comments on arm swing focus on how it can help you
>find your best "stride rate" -- and not on any gyroscopic effect -- but I did find a link to a
>page on the Harvard Math Department website entitled "Running," apparently suthored by an
>"Ultimate Frisbee" guy:

From the standpoint of sprinting 200/400, the armswing is adjusted somewhat and sort of like the
link says. The outside arm is brought outward from the hip and beyond the hip (exaggerated swing).
The inside arm is held close to the hip and not beyond the hip. The imbalance between the two
armswings imparts centripetal force which pulls the runner (sprinter) into and around the curve. The
inside foot is also turned slightly into the curve. A sprinter does not lean with his body into the
curve much, as this changes mechanics and slows the sprinter down.

The above paragraph is a common method used by sprinters on a track running in spikes keeping
constant traction. I don't know if the arm mechanics mentioned will work if your shoes are breaking
force contact. Also, this is not used so much in 800 and longer events, as the speeds are slower and
endurance is more important (the arm mechanics wastes some energy).
>
>http://abel.math.harvard.edu/~lee/cvhrunning.html
>
>There are 3 paragraphs well into the piece which discuss "lean angle," "acceleration" and "arm
>swing," for those interested in this (admittedly somewhat arcane) subject. As for me, if I'm trying
>to pinch seconds on the clock, I will now feel more confident keeping up my velocity on corners.
>
Dr. Yessis would claim that the lean angle is zero if you are a distance runner or you are not
accelerating (followers of Romanov like Ozzie would tell you to lean forward from the ankles and
Yessis would tell you that they're wrong). If you are accelerating (as in the block
clearance/transition phases in sprinting) the lean angle is dertermined by the force applied and
that is determined by the strength of the athlete. The footstrike during acceleration must occur
at or behind the center of mass (COM), and the stronger the athlete is, the farther forward the
athlete can lean and keep the footstrike under the COM. But the farther forward the athlete can
lean, the faster the leg turnover needs to be to keep from falling down. So both lean angle and
turnover rate are determined by the strength of the athlete.

Lyndon "Speed Kills...It kills those that don't have it!" --US Olympic Track Coach Brooks Johnson
 
B

Bill

Guest
> >There are 3 paragraphs well into the piece which discuss "lean angle," "acceleration" and "arm
> >swing," for those interested in this (admittedly somewhat arcane) subject. As for me, if I'm
> >trying to pinch seconds on
the
> >clock, I will now feel more confident keeping up my velocity on corners.

> Dr. Yessis would claim that the lean angle is zero

During each stride, the runner adds "pushoff's" with a forward component: to counter air drag, to
counter any braking at footstrike, and assist in leg swing, etc. Doesn't drag torque, about a
fulcrum at ground level, need to be countered by some other above ground level forward force, such
as gravity from a lean. For a not so fast distance run, one estimate is a lean of about .25 inch at
head level, or, .2 degrees, depending on speed and body type. If you double speed, you quadruple
lean, e.g., a world class miler might lean four times more. The differential drag forces on the
swinging legs might affect this as well.

> if you are a distance runner or you are not accelerating

Though, running on a curve implies acceleration perpendicular to the direction of motion.

(followers of Romanov like Ozzie would tell you to
> lean forward from the ankles

When one attempts this adjustment, what actually happens? Do you essentially push off further behind
and strike less forward? Does the knee flex differently? The hip? It does seem to recuit the
forefoot more in propulsion, and can lead to some spectacular falls when trying it on rough ground.

and Yessis would tell you that they're wrong). If
> you are accelerating (as in the block clearance/transition phases in
sprinting)
> the lean angle is dertermined by the force applied and that is determined
by
> the strength of the athlete. The footstrike during acceleration must
occur at
> or behind the center of mass (COM)

Must occur at or behind the COM? Or, recommended to be efficient?

, and the stronger the athlete is, the
> farther forward the athlete can lean and keep the footstrike under the
COM.
> But the farther forward the athlete can lean, the faster the leg turnover
needs
> to be to keep from falling down. So both lean angle and turnover rate are determined by the
> strength of the athlete.
>
> Lyndon "Speed Kills...It kills those that don't have it!" --US Olympic Track
Coach
> Brooks Johnson
 
O

Ozzie Gontang

Guest
[[ This message was both posted and mailed: see the "To," "Cc," and "Newsgroups" headers for
details. ]]

In article <20040131013647.11514.000[email protected]>, Lyndon <[email protected]> wrote:

Dr. Yessis would claim that the lean angle is zero if you are a distance runner or you are not
accelerating (followers of Romanov like Ozzie would tell you to lean forward from the ankles and
Yessis would tell you that they're wrong). If you are accelerating (as in the block
clearance/transition phases in sprinting) the lean angle is dertermined by the force applied and
that is determined by the strength of the athlete. The footstrike during acceleration must occur
at or behind the center of mass (COM), and the stronger the athlete is, the farther forward the
athlete can lean and keep the footstrike under the COM. But the farther forward the athlete can
lean, the faster the leg turnover needs to be to keep from falling down. So both lean angle and
turnover rate are determined by the strength of the athlete.

Lyndon,

Don't consider myself a follower of Romanov, as I haven't taken the time to see what piece of truth
he is sharing in his teachings.

I do speak of the forward lean from the ankle which I see as necessary to keep a steady speed. The
image for me is the broom handle in my palm falling forward and I keep moving with it so that the
speed is constant.

Say more regarding what Yessis would see wrong/incorrect/inaccurate/false regarding the lean
from the knee.

Many thanks.

In health and on the run, Ozzie Gontang Maintainer - rec.running FAQ Director, San Diego Marathon
Clinic, est. 1975

Mindful Running: http://www.mindfulness.com/mr.asp http://www.faqs.org/faqs/running-faq/
 
T

Tim Downie

Guest
Ozzie Gontang wrote:

> I do speak of the forward lean from the ankle which I see as necessary to keep a steady speed. The
> image for me is the broom handle in my palm falling forward and I keep moving with it so that the
> speed is constant.

Arrrghhh!!

Sorry Ozzie, whilst you might find it a helpful image, in the world of real physics, it's just plain
wrong. As I've explained before, there is *no* constant speed at which you can maintain a constant
angle of lean with an unbalanced broom handle.

Tim

--
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D

Doug Freese

Guest
Tim Downie wrote:

> Ozzie Gontang wrote:
>
>
>>I do speak of the forward lean from the ankle which I see as necessary to keep a steady speed. The
>>image for me is the broom handle in my palm falling forward and I keep moving with it so that the
>>speed is constant.
>
>
> Arrrghhh!!
>
> Sorry Ozzie, whilst you might find it a helpful image, in the world of real physics, it's just
> plain wrong. As I've explained before, there is *no* constant speed at which you can maintain a
> constant angle of lean with an unbalanced broom handle.

So what the hell are you arguing?

1. The image is ok but the physics leaves you cold?
2. The image and the physics are wrong?
3. You're just grumpy maybe over training and need an outlet?

--
Doug Freese "Caveat Lector" [email protected]
 
T

Tim Downie

Guest
Doug Freese wrote:
>
> So what the hell are you arguing?
>
> 1. The image is ok but the physics leaves you cold?
> 2. The image and the physics are wrong?

I think it's the fact that Ozzie seems to use this fundamental fallacy to underpin some of his ideas
about running form. The thought that many folk will take this particular image as "fact" bugs me
somewhat (as you've noticed).

> 3. You're just grumpy maybe over training and need an outlet?

Nah. Just got too much time on my hands. ;-)

Talking of overtraining, two of my running companions from our 25 miler on Saturday, were also out
for an hour and a half on the Sunday whilst I was out for a gentle walk. On our Tuesday night 5k, I
trounced both of them (one of whom I've *never* beaten) and ran a 20:13 in very windy conditions.
Not a PB but only 18 seconds over.

Tim

--
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I

In Another Life

Guest
On Thu, 05 Feb 2004 12:08:35 GMT, Doug Freese <[email protected]>
wrote:

>>>I do speak of the forward lean from the ankle which I see as necessary to keep a steady speed.
>>>The image for me is the broom handle in my palm falling forward and I keep moving with it so that
>>>the speed is constant.

>> Arrrghhh!!

>So what the hell are you arguing?

Far be it from me to leap to the defence of young Timmy, but I think he has a valid point. If the
sheer logic of your 'image' is wrong then it serves little purpose, and an image more applicable to
the lesson you're trying to impart should be sought.

In many ways, I think Oz and his theories are indicative of what's wrong with Yankee culture.
They're innovative, thought-provoking, and they try damn hard, but they're usually wrong. Not from
any sense of malice I hasten to add, but simply because they don't apply rigorous thought to a
problem. 'Near enough is good enough' is the Yankee watchword. We see it in your foreign policy, in
your internal civil structures, and in your approach to your fellow citizens.

Try harder to Get. Things. Right., my American cousins.
 
D

Doug Freese

Guest
Tim Downie wrote:

> I think it's the fact that Ozzie seems to use this fundamental fallacy to underpin some of his
> ideas about running form. The thought that many folk will take this particular image as "fact"
> bugs me somewhat (as you've noticed).

Ozzie can speak for himself but he always claims his suggestions are his lore and never, ever
presents anything as fact and always invites anyone to disagree. Simarily, there are a lot a ways to
evaluate Janet Jackson's breast from the Super Bowl last Sunday.

> Talking of overtraining, two of my running companions from our 25 miler on Saturday, were also out
> for an hour and a half on the Sunday whilst I was out for a gentle walk.

Sounds like they are either more experienced and can do the doubles or they are over training and
possibly in for some potential down time.

> On our Tuesday night 5k, I trounced both of them (one of whom I've *never* beaten) and ran a 20:13
> in very windy conditions. Not a PB but only 18 seconds over.

You are gaining speed off raw strength and the way most people should train in general.
Unfortunately many people get the running bug and jump too quickly to speed without a solid base.

Wanna bet if they had a rest day they would have blown your doors off? ;)

--
Doug Freese "Caveat Lector" [email protected]
 
D

Doug Freese

Guest
In another life, when we are both cats wrote:

> In many ways, I think Oz and his theories are indicative of what's wrong with Yankee culture.
> They're innovative, thought-provoking, and they try damn hard, but they're usually wrong.

You sound like the stereotypical tight ass - not enough grain in your oat bag today? Childish cracks
like this don't do anything to help your position either. Talk about calling the kettle black....

--
Doug Freese "Caveat Lector" [email protected]
 
I

In Another Life

Guest
On Thu, 05 Feb 2004 14:01:02 GMT, Doug Freese <[email protected]>
wrote:

>You sound like the stereotypical tight ass - not enough grain in your oat bag today?

Surely one would expect oats, not grain, in ones oat bag? See? Another example of Yankee
carelessness. You fail to land the killer punch by virtue of the fact you can't be bothered to look
too closely at what you're trying to hit. Rather like what you've done in Iraq, and your healthcare
systems, and your management of the disadvantaged in your society, and...blah-de-blah .

>Childish cracks like this don't do anything to help your position either.

I didn't realise I had a position. I was offering an observation, with which you're free to disagree
or to point out the faults in my thinking.
 
O

Ozzie Gontang

Guest
[[ This message was both posted and mailed: see the "To," "Cc," and "Newsgroups" headers for
details. ]]

In article <[email protected]>, Tim Downie
<[email protected]> wrote:

> Ozzie Gontang wrote:
>
> > I do speak of the forward lean from the ankle which I see as necessary to keep a steady speed.
> > The image for me is the broom handle in my palm falling forward and I keep moving with it so
> > that the speed is constant.
>
> Arrrghhh!!
>
> Sorry Ozzie, whilst you might find it a helpful image, in the world of real physics, it's just
> plain wrong. As I've explained before, there is *no* constant speed at which you can maintain a
> constant angle of lean with an unbalanced broom handle.
>
> Tim

Tim,

What would the words, images, pictures you'd use to explain my incorrrect physics.

All I know is that I can balance a broom handle or was just doing it with my digeridoo and as it
starts to lean, I can keep walking with it as it falls so that it doesn't fall. I'm sure I'm missing
something.

Help me understand or get the phyics correct.
 
T

Tim Downie

Guest
Ozzie Gontang wrote:
> [[ This message was both posted and mailed: see the "To," "Cc," and "Newsgroups" headers for
> details. ]]
>
> In article <[email protected]>, Tim Downie
> <[email protected]> wrote:
>
>> Ozzie Gontang wrote:
>>
>>> I do speak of the forward lean from the ankle which I see as necessary to keep a steady speed.
>>> The image for me is the broom handle in my palm falling forward and I keep moving with it so
>>> that the speed is constant.
>>
>> Arrrghhh!!
>>
>> Sorry Ozzie, whilst you might find it a helpful image, in the world of real physics, it's just
>> plain wrong. As I've explained before, there is *no* constant speed at which you can maintain a
>> constant angle of lean with an unbalanced broom handle.
>>
>> Tim
>
> Tim,
>
> What would the words, images, pictures you'd use to explain my incorrrect physics.
>
> All I know is that I can balance a broom handle or was just doing it with my digeridoo and as it
> starts to lean, I can keep walking with it as it falls so that it doesn't fall. I'm sure I'm
> missing something.

It's perfectly possible to balance it as you move (as you've proved to yourself by experimentation).
If we ignore air resistance for the moment , what you cannot do is maintain the broom at a constant
angle of lean.

When the broom first starts to fall, you accelerate yourself forwards to bring it back upright. Now
you and the broom have acquired forward velocity. Barring minor purturbations, both you and the
broom are upright again, but now moving forwards at a constant speed. The broom (if it is in
balance) is no longer leaning forwards.

If you watch a racing motorcyclist pulling a wheely off the line (when, like the broom, the bike is
leaning forwards), you'll see that he is accelerating like the proverbial bat out of hell. The only
way on a bicycle or motorbike to *maintain* a wheely, is for the cyclist to raise the front wheel to
the point where the bike's centre of gravity is over it's centre of contact. The bike is now in
effect "upright", not leaning any more and the cyclist can now move forward at a constant velocity.

> Help me understand or get the phyics correct.

I hope this helps.

Regards.

Tim

--
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O

Ozzie Gontang

Guest
In article <[email protected]>, In another
life, when we are both cats <[email protected]> wrote:

>I n many ways, I think Oz and his theories are indicative of what's wrong with Yankee culture.
>They're innovative, thought-provoking, and they try damn hard, but they're usually wrong. Not from
>any sense of malice I hasten to add, but simply because they don't apply rigorous thought to a
>problem. 'Near enough is good enough' is the Yankee watchword. We see it in your foreign policy, in
>your internal civil structures, and in your approach to your fellow citizens.
>
> Try harder to Get. Things. Right., my American cousins.

Thanks, and I'll stand on my own regarding my viewpoint and perspective. I believe that you can find
many of the running coaches over the years in the US came from other countries. They wanted to share
what they learned while making a living.

My attempt at provoking thought and sharing my folklore is my way of sharing what I have learned and
seeking to learn from others who see it differently and often more correctly. That allows me to
continue to corect and grow in my teaching and training of others to run as fast and gracefully and
injury free as is humanly possible for them.

The rigor over the 8 years here at rec.running has been to continue the dialogue and make my
assumptions and viewpoints as visible and transparent as I am able. I am appreciative of those who
have showed my faulty or incorrect thinking.

Ozzie Gontang Director, San Diego Marathon Clinic, est. 1975 Maintainer - rec.running FAQ http://www.faqs.org/faqs/by-
newsgroup/rec/rec.running.html Mindful Running http://www.mindfulness.com/mr.asp
 
I

In Another Life

Guest
On Tue, 10 Feb 2004 08:33:53 -0000, "Tim Downie"
<[email protected]> wrote:

>I hope this helps.

***********, Tim, kids are taught basic forces in year 1 physics.

When Oz first posted I wondered whether my youngest, at year 1 in High School, understood this
principle. Although he chose a different analogy (and he didn't discount the effect of air
resistance on an accelerating object, which becomes highly significant as speed increases) even *he*
understood that it's impossible to maintain a constant 'angle of lean' from a stable horizontal base
without maintaining a constant acceleration in the direction of 'lean'. At some stage, in the real
world, air pressure on the 'leaning' object should enable the acceleration to drop to zero and, so
long as speed remains constant, the downwards vertical force on the handle will be balanced against
the air pressure on the handle acting in the horizontal plane.

Yunno, Oz, if you can't work this one out for yourself I seriously doubt whether you should get out
of bed. REAL physics is all around us.