Weyand Study?

[Guest guest]

Weyand study: finite vs effective mass trunk mass

The Weyand study as posted (39501) by Ken Jakalski stated " the study

focused on determining the mechanical means by which athletes are

able to achieve faster top speeds. The study explored three things:

step frequency, the average mass specific force that a runner

applies to the ground to oppose gravity, and contact length. Of the

three mechanisms for reaching

faster top end speeds, runners use stride frequency to a limited

extent, support forces predominantly, and contact lengths

essentially not at all. "

Outward Action vs Internal Interaction: Starting in mid 1980's

there was group of us from different sports venues including, pro

football to Olympics, that observed what the outward action of the

fast runner appeared to be. We were seeking to understand what was

the mechanism or internal interaction of the musculo-skeletal parts

that was producing the outward action of the speedster.

Of stride frequency, contact lengths and support forces we

eventually look at support forces as possessing the hierarchy of

running speed.

This lead us eventually to spinal posture. It was trunk mass that

needed to be moved under the adverse force of gravity. Great

runners appeared to run with perfect upright trunk posture. They

appeared to have effortless long stride lengths.

Runners with more hunched over posture, appeared stiffer and had

shorter appearing stride lengths. It appeared to me the winner of

the race always appeared the most fluid and as the rest of the

runners finished they appeared more stiff and inflexible.

As runners posture was examined, it was heard over and over again by

runners, that appeared to have poorer posture, that although they

felt they were running fast they were not possessing speed anymore.

Their run was becoming for lack of better term more of a shuffle.

They were feeling they were unable to get a good stride length and

that their front leg was coming down to the ground on its own

volition sooner then it felt to them then it should be.

This is what was heard, but do not take my word for it, anyone here

can question and examine their runners the same way we did to see if

they hear and see the same thing.

To make a long story short we eventually became focused on the

hamstring muscle relative to its job of providing for locomotion and

or maintaining the upright trunk mass.

It was in maintaining the upright trunk mass we discovered it was

not the FINITE weight of the trunk in gravity that influence running

ability it was the EFFECTIVE weight of the trunk mass in gravity

that was determining who had speed and who did not.

We took a person with a trunk mass of 100 pounds with proper posture

and on with poor posture in running position with their rear leg

planted at 60degrees.

For simplicity even though the finite weight of trunk masses was 100

lbs. the hamstring in the person with poor posture was carrying at

our position in their stride effectively a trunk mass of 400 lbs.

The poor posture runners hip and knee joints were subjected to

essentially 20 times the compression and shear forces the runner

with proper posture possessed.

When the smoke cleared from our research viewpoint of spinal posture

affecting finite vs. effective mass or weight force and locomotion

if you want to be fast and want to train to be fast you first train

to get proper posture.

An engineered study of the above can be observed and critiqued for

free on my website.

Scherger

Ridgefield WA