Re: Shimano foot-stretcher and rowing shoe system?

Walter Martindale wrote:
On Dec 23, 2:48 am, Tinus <martijn.weteri...@xxxxxx> wrote:
On Dec 22, 11:51 am, Carl Douglas <c...@xxxxxxxxxxxxxxxxx> wrote:

Can you be more explicit, Frank? Which of the various sections of that
site had you in mind?
http://batlogic.com.au/BATLAB/RDNotes/tabid/153/Default.aspx

It's in the third note. They summarise a bunch of arguments to support
the claim that a flexed position of the foot/toes is bad. However none
of these arguments are conclusive and they only seem to be plausible.
The same arguments could also be used to claim, for instance, that
sprinters should not use the ball of the foot but the entire surface
instead.

While I don't always agree with everything in Kleshnev's rowing
biomechanics newsletter, I think that despite the lack of flash, the
information is more useful.

Sprinters would run more slowly if they used their entire foot.
"midfoot strike" running was something we found by accident to be
associated with fewer foot and low leg injuries in runners than heel
strike running.

A gradual student was looking to measure the effecs of orthotics on
the feet of runners and wanted to study the lateral moments at the
ankle (as well as all the other moments at the ankle) with a Kistler
force platform synched with a 500 frame/second "Locam" (it was the
80s, video wasn't as good as it is now). He spent quite a long time
looking for two groups of runners, those who had orthotics (got 20)
and those who didn't (found 10 runners in the Vancouver area who
hadn't been injured in the low-leg foot and didn't use orthotics).
All 20 of the orthotics users were heel-strike runners. 9 of the 10
uninjured runners were midfoot strike runners, one was heelstrike..

Feet aren't made to run with landing on the heel - that shock is meant
to be absorbed and reused by the muscles and tendons (e.g., Achilles
tendon), and the loads in sprinting are pretty darned big...

W

I presume we're talking about #7 in the "R&D Notes"?

1. Terminology! The ankle does not "transfer power", it transmits force. One has to worry when so fundamental a distinction is misunderstood in a document claiming a scientific basis.
2. Why is the ankle "not a power-producing joint"? Only if a joint does not flex can it do no work. Are they assuming there is no flexion in that joint? I don't think that can be correct. Indeed a fair proportion of rowers, especially those of a short-legged persuasion, will deliberately & usefully extend their feet at the finish.
3. It then goes on to discuss at what point the ankle "locks up". So the ankle does flex! Mmmm.
4. I'm right with Walter. The human foot has evolved to transmit very large forces through relatively small contact areas of its underside. It, including the ankle joint & all the associated tissues, muscles & ligaments, is a resilient section of a resilient system involved, inter alia, in force transmission, in power production & in energy storage & return. We're not designed to walk or run on fixed, flat feet, athletes tend not to be flat-footed. Those animals better designed to run than humans have evolved to use only what, in us, are the balls of our feet & can no longer take ground contact loads on their anatomical equivalents of our heels, even when standing.
5. It seems unreasonable to assume any single proper amount of foot splay for a given foot. I'm sure they are right in hinting that opposite feet might require different amounts of splay (since we're rarely completely symmetrical) but I'm also sure that we need to vary foot splay (& do vary it as far as equipment allows) through the stroke cycle.
6. They would be right in suggesting that what feels most comfortable will work best. Comfortable means not coming up against hard restrictions. But that should not be dressed up as a scientific analysis, nor be grandly termed "Advanced Sports Engineering".

My 2 pennorth -
Carl
--
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