I am interested in increasing/decreasing muscle stiffness of certain muscles in a model. What property of the muscle would I change to do this? The FmaxMuscleStrain property is the passive muscle stiffness, but is there a way to change the active muscle stiffness? Thanks!
Margaret
Muscle Stiffness
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Thomas Uchida
- Posts: 1792
- Joined: Wed May 16, 2012 11:40 am
Re: Muscle Stiffness
Hi, Margaret.
The force-length relationship for the active element is described by the active-force-length curve.
If you are using the Thelen2003 muscle model, adjusting the KshapeActive parameter will change the shape of the Gaussian used to model this relationship (see the attached image). KshapeActive is equivalent to gamma in equation (4) of Thelen's paper (http://homepages.cae.wisc.edu/~thelen/pubs/jbme03.pdf).
If you are using the Millard2012Equilibrium muscle model, several parameters can be used to adjust the shape of the active-force-length curve. Please see the Confluence page (http://simtk-confluence.stanford.edu:80 ... cle+Models) or ASME paper (http://dx.doi.org/10.1115/1.4023390) for details.
Hope that helps.
Tom
The force-length relationship for the active element is described by the active-force-length curve.
If you are using the Thelen2003 muscle model, adjusting the KshapeActive parameter will change the shape of the Gaussian used to model this relationship (see the attached image). KshapeActive is equivalent to gamma in equation (4) of Thelen's paper (http://homepages.cae.wisc.edu/~thelen/pubs/jbme03.pdf).
If you are using the Millard2012Equilibrium muscle model, several parameters can be used to adjust the shape of the active-force-length curve. Please see the Confluence page (http://simtk-confluence.stanford.edu:80 ... cle+Models) or ASME paper (http://dx.doi.org/10.1115/1.4023390) for details.
Hope that helps.
Tom
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