Hello All,

I noticed a recent post on elementary school runners. I was hoping that I might get a little biomechanics data on young runners so I could compare it with an analysis I am doing on adult runners.

I am currently working on a mathematical model with some biomechanics labs. The "spring mass? model is used to understand a runner's performance in terms of basic physiological parameters. It uses the runner's mass or weight, leg length and running-in-place stride-rate. The model may be able to predict their sustained pace and stride-rate.

The data I get from the labs is mostly for elite or college runners. I?d like to compare it with some data on young runners. I'd appreciate it if I could get some. It would certainly help. I would like to get:

The weight of a few young runners in pounds.

The standing leg length as measured from the Greater Trochanter to the ground. You can see a drawing of the Greater Trochanter at:

http://en.wikipedia.org/wiki/Greater_trochanter[/URL" target="_blank">

The last number would be the running-in-place stride rate without leaving the ground. To do this the runner would determine how many seconds it would take to make 30 strides (same foot hitting the ground) while standing in place and NOT becoming airborne. If you could start the count with "zero" at the same time that you start the stopwatch, that will ensure an accurate measurement. The number should be in the area of .75 to 1.5 strides per second, or 45 to 90 strides per minute. (Steps are Left-right-left-right. Strides are left-left-left-left. I need strides per time, not steps.)

(The running-in-place stride-rate with the mass can be used to estimate the runner's leg stiffness that is used in the model. It?s a number between 12,000 and 18,000 for adults.)

I'd also like to know the runner's sustained speed or pace, not their fastest speed. Maybe their 5K or 10K distance time. I could also use their stride-rate when they are running at their sustained speed, but that is not critical.

I'll use the data to compute the runner's leg stiffness and power-output per kilogram, so I can compare it with the values I have on adult runners. This may help me understand why young people seem to be able to run so much faster than trained adults.

I'd appreciate any data (mass, leg length, stride-rate and sustained pace (with optional stride-rate)) you might send me at tjacmc@aol.com. I'll respond by sending you the results of my findings.

Sincerely,

Ted Andresen