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tandresen
11-20-2006, 12:24 PM
Hello All,

Can someone direct me to any published papers on modeling the restoring
force generated by a human leg during compression?

I wanted to modify my spring mass model (1) so it reflected more closely the
upward restoring force exerted by the leg between foot-strike and mid-stance
while running. The linear spring generates a restoring force that increases
with compression. The leg does not behave this way.

When I used a "hopping" technique (k=m*(2*PI*f)^2) to examine the spring
"constant", k, for different angles of knee flexion, I found that the hopping
frequency, the spring constant and the restoring force decreased the more that
the knee was flexed.

A simple model (2) generates an inverse relation between the force and the
deformation. Has anyone else tried this approach? Any citations would be
greatly appreciated.

Sincerely,

Ted Andresen
Math Dept. (SP/G)
St. Petersburg College
St. Petersburg, Florida

(1) _http://members.aol.com/tjacmc/SpringMass.gif_
(http://members.aol.com/tjacmc/SpringMass.gif)
(2) _http://members.aol.com/tjacmc/KneeModel.gif_
(http://members.aol.com/tjacmc/KneeModel.gif)