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tandresen
06-13-2006, 04:53 AM
Hello,

I am looking for any citations or comments on using vertical leg
oscillations to measure leg stiffness.

I have been using an Excel/VB version of the Spring Mass model to understand
the relation between running kinetics and gait parameters. The model
requires the leg stiffness (kN/m).

I estimate stiffness by measuring the frequency of small vertical (~3 cm)
oscillations while standing on one leg when the knee is flexed to the
approximate angle it has during mid-stance (k=m*(2*PI*f)^2)

Is this a reasonable method for measuring leg stiffness? I obtain values in
the area of 18+/-2 kN/m?

Is there any research that compares this simple method with the approach
that uses the vertical GRF and COM displacement?

Ted Andresen
Math Department
St. Petersburg College
St. Petersburg, Florida
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Will factor polynomials for food.