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Estimate tendon slack length

Posted: Wed Jun 03, 2020 8:44 am
by william_a
Hi,

How to estimate tendon slack length for a musculo-tendon unit? Is there a function in OpenSim to do it?

Thanks,
William

Re: Estimate tendon slack length

Posted: Thu Jun 04, 2020 10:08 am
by mjasmuss
Hi William,

Are you asking about trying to obtain the tendon slack length of a muscle-tendon unit for a certain MSK model? Or are you asking how to extract tendon slack length of a model using something like Matlab?

All the best,

Mike

Re: Estimate tendon slack length

Posted: Thu Jun 04, 2020 10:54 am
by william_a
Hi,

I am asking how to obtain the tendon slack length of a muscle-tendon unit for a certain model?

Thanks,
William

Re: Estimate tendon slack length

Posted: Fri Jun 05, 2020 2:39 pm
by tkuchida
The method is getTendonSlackLength() (see the documentation here: https://simtk.org/api_docs/opensim/api_ ... 8eb5ae0391), which can be called from the scripting interface. The tendon slack length is also shown in the GUI (see the "Muscle Editor" page in the documentation: https://simtk-confluence.stanford.edu/d ... cle+Editor).

Re: Estimate tendon slack length

Posted: Tue Jun 09, 2020 6:56 am
by william_a
Hi,

Sorry for the confusion here.

I am trying to ask this:
How to calculate the tendon slack length when we are developing a model? As far as I understand, all other parameters can be taken from experiments but tendon slack length has to be calculated. What are the steps one have to take to do this?

Thanks,
William

Re: Estimate tendon slack length

Posted: Tue Jun 09, 2020 11:47 am
by tkuchida
I suggest searching the literature for papers on model development. See, for example, Rajagopal et al. (2016) "Full-Body Musculoskeletal Model for Muscle-Driven Simulation of Human Gait" (https://nmbl.stanford.edu/wp-content/up ... 505900.pdf), Table II.