Muscle Modeling

Hy, I have a question concerning the hill muscle model. I have read the muscle modeling tutorial and the paper “Analysis of musculoskeletal systems in the AnyBody
Modeling System “but I am not sure about my following statements. Are those correct?
The input parameters of the classical hill model are the muscle activity, the length of the muscle and his contraction velocity. The output is the actual muscle strength (not the max. muscle strength).
The modified hill model, as it is used in anybody, used only the length of the muscle and the contraction velocity as input, and the output is the max. muscle strength.
This max. muscle strength is used as a normalization factor for the optimization problem which calculate the actual muscle strength.
After optimization, the muscle activity is calculated by actual muscle strength divided by max. muscle strength.
Best regards

Hi Manuel (?)

Your description is correct if you replace “actual muscle strength” by “actual muscle force”.

Best regards,
John

PS. Please fill in your name and details in your profile. It is nice for people to know who they are speaking with.

Hy, perfect, do you know also a tutorial in anybody or a scientific paper where I can find a description of calculation of the max. muscle strength by using the hill muscle model?
Thank you,
best regards, Manuel

Unfortunately, this is not very well documented. Here is the list of references that we have used when developing the model.

Anderson, F. C. and M. G. Pandy (1993). Storage and
utilization of elastic energy during jumping. Journal of
Biomechanics 26(12), 1413–1427.

Bahler, A. (1968). Modeling of mammalian skeletal
muscle. IEEE Transaction of Bio-Medical Engineering,
BME 15(4), 249–257.

Daxner, T. (1997, August). Simulation von beuge- und
streckbewegungen des menschlichen knies mit dads. Ph.D.
dissertation, Institut f¨ur Mechabik der Technischen Universit
¨at Wien, A-4810 Gmunden Hochm¨ullergasse 22,
Wien. Matr.Nr.: 8825624.

Gföhler, M., T. Angeli, T. Eberharter, and P. Lugner
(1999). Dynamic simulation of cycling powered by lower
extremity muscles activiated by functional electrical simulation.
In XIIth Biomechanics Seminar, Högfors C, Editor,
pp. 101–122. vol. 12 (ISSN 1100-2247). Göteborg.

Hatze, H. (1977). A myocybernetic control model of skeletal
muscle. Biological Cybernetics 25, 103–119.

Boris I. Prilutsky, B.I. and Gregor, R.J. (2000). Analysis
of Muscle Coordination Strategies in Cycling. IEEE
Transactions on Rehabilitation Engineering, 8, 362–370.

Hill, A. (1938). The heat of shortening and the dynamics
constants of muscle. Proc. Roy. Soc. B. 126, 136–195.

Huxley, A. (1957). Muscle structure and theories of contraction.
Progr. Biophys 7, 255–318.

Best regards,
John