1 New Message
Digest #4598
Message
Mon Jul 23, 2012 10:00 am (PDT) . Posted by:
"Giovanni Ciriani" gciriani
I'm not sure who is reporting what in this debate, but if the statement
attributed to John Buckley is correct, it seems that he doesn't understand
how storage of elastic energy works:
"the deformation and recoil of the prosthesis needs to occur at an optimal
frequency".
The answer is that that the deformation and recoil take place at exactly
the same pace at which one is running.
Giovanni Ciriani - West Hartford, CT - USA
On Sun, Jul 22, 2012 at 9:25 PM, <CoachJ1@aol.com > wrote:
> **
>
>
> Hi Ken!
>
> In a message dated 7/22/2012 12:56:48 P.M. Central Daylight Time,
> facilitation@msn.com writes:
>
> I feel I should mention that I recently saw Oscar Pistorius run in the
> Prefontaine Classic. While the 'blades' may have mechanical advantage they
> definitely have limitation, especially in initial acceleration
>
> Yes. You are indeed accurate. This is what I observed when former World
> Paralympic Sprint Champion Tony Volpentest came to Lisle to run on my high
> school track back in 1997.
>
> Regardless of how technically advanced his carbon fiber blades are (and
> Pistorius's Cheetahs are for more advanced than Volpentest's keel bars),
> they
> don't offer any advantage during the start and acceleration phase.
>
> Volpentest experienced similar problems with the start. Of course,
> missing his lower arms,and having to place his remaining upper arms on
> padded
> paint cans just to start didn't help, but as John Buckley once noted:
>
> "All a (passive) prosthesis can do is return (in an elastic manner) the
> energy it is able to store following foot contact. But of course, for an
> amputee to benefit from this energy return, the deformation and recoil of
> the
> prosthesis needs to occur at an optimal frequency (related to contact
> time).
> It is difficult to imagine that this could occur for all phases of the
> 100m
> sprint, i.e. both the acceleration and maximum speed phases."
>
> Volpentest ran both the 100 and 200 in Lisle. He was actually beaten in
> the 100 (I had assembled an impressive field of Masters athletes to race
> against him).. But the 200 was a completely different story. Once he was
> up
> to speed, he simply blew away the same field who raced against him in the
> 100.
>
> Ken Jakalski
> Lisle High School
>
> Lisle, IL USA
>
> [Non-text portions of this message have been removed]
>
>
>
[Non-text portions of this message have been removed]
attributed to John Buckley is correct, it seems that he doesn't understand
how storage of elastic energy works:
"the deformation and recoil of the prosthesis needs to occur at an optimal
frequency".
The answer is that that the deformation and recoil take place at exactly
the same pace at which one is running.
Giovanni Ciriani - West Hartford, CT - USA
On Sun, Jul 22, 2012 at 9:25 PM, <CoachJ1@aol.
> **
>
>
> Hi Ken!
>
> In a message dated 7/22/2012 12:56:48 P.M. Central Daylight Time,
> facilitation@
>
> I feel I should mention that I recently saw Oscar Pistorius run in the
> Prefontaine Classic. While the 'blades' may have mechanical advantage they
> definitely have limitation, especially in initial acceleration
>
> Yes. You are indeed accurate. This is what I observed when former World
> Paralympic Sprint Champion Tony Volpentest came to Lisle to run on my high
> school track back in 1997.
>
> Regardless of how technically advanced his carbon fiber blades are (and
> Pistorius's Cheetahs are for more advanced than Volpentest's keel bars),
> they
> don't offer any advantage during the start and acceleration phase.
>
> Volpentest experienced similar problems with the start. Of course,
> missing his lower arms,and having to place his remaining upper arms on
> padded
> paint cans just to start didn't help, but as John Buckley once noted:
>
> "All a (passive) prosthesis can do is return (in an elastic manner) the
> energy it is able to store following foot contact. But of course, for an
> amputee to benefit from this energy return, the deformation and recoil of
> the
> prosthesis needs to occur at an optimal frequency (related to contact
> time).
> It is difficult to imagine that this could occur for all phases of the
> 100m
> sprint, i.e. both the acceleration and maximum speed phases."
>
> Volpentest ran both the 100 and 200 in Lisle. He was actually beaten in
> the 100 (I had assembled an impressive field of Masters athletes to race
> against him).. But the 200 was a completely different story. Once he was
> up
> to speed, he simply blew away the same field who raced against him in the
> 100.
>
> Ken Jakalski
> Lisle High School
>
> Lisle, IL USA
>
> [Non-text portions of this message have been removed]
>
>
>
[Non-text portions of this message have been removed]
GROUP FOOTER MESSAGE
Modify/cancel your subscription at:
http://groups.yahoo.com/mygroups
Sign all letters with full name & city of residence if you
wish them to be published!
http://groups.yahoo.com/mygroups
Sign all letters with full name & city of residence if you
wish them to be published!
No comments:
Post a Comment
Finish Reading ? Make Your Comment Now..!