Optimization

[Reza Fazel]

Dear Biomech readers,

On the papers published by K.R. Kaufman, K.N. An and E.Y.S. Chao[1],
the following equation is used for the limits of the muscle force:

0 < F(i) < ( Alpha*Factive(i)+Fpassive(i) )*PCSA(i)*Sigma ;i=1:M

Alpha : Muscle activation
Sigma : Muscle stress
M : Number of muscles

Then, they have used Muscle activation (Alpha) as a cost function
in optimization method, i.e.,

Minimize(Alpha)

(Q1)- Is there one Sigma and Alpha for all muscles (i=1:M) ?
Or in the equation, they should be written Sigma(i) and Alpha(i).
In the second case, what will be the cost function?

(Q2)- I would like some information regarding the recent works on the
muscle force distribution problem (FDP) using optimization method
or any other approach. Is there any paper on FDP of the upper limb?


Thanks for your time,
Reza.

[1]- K.R. Kaufman, K.N. An W.J. Litchy and E.Y. Chao, "Physiological
prediction of muscle forces- I. Theoretical formulation", J. of
Biomech., Vol. 40, No.3, pp.781-792, 1991.


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& Reza Fazel-Rezai fazel@ee.umanitoba.ca &
& Biomedical Eng. Lab. fax: (204) 261-4639 &
& Dept. of Elect. Eng. &
& University of Manitoba &
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