Request for params of arm26

[Alex Priamikov]

Good day,

Can you provide "ratio of slow twitch fibers in the muscle" parameters of arm26 model for metabolic costs calculation.

Best regards,
Alex Priamikov

[jimmy d]

Hi Alex-

The 'ratio of slow twitch fibers in the model' is stored in the metabolics probes, and not in the base musculoskeletal model (arm26.osim).

Check out the metabolics example to see how to attach probes...
http://simtk-confluence.stanford.edu:80 ... bolic+Cost

Here is an example of the twitch fibre code written in the Umberger metabolics Probe...
<Umberger2010MuscleMetabolicsProbe_MetabolicMuscleParameter name="hamstrings_r">
<!--Ratio of slow twitch fibers in the muscle (must be between 0 and 1).-->
<ratio_slow_twitch_fibers>0.49</ratio_slow_twitch_fibers>
<!--An optional flag that allows the user to explicitly specify a muscle mass. If set to true, the <provided_muscle_mass>
<use_provided_muscle_mass>false</use_provided_muscle_mass>
</Umberger2010MuscleMetabolicsProbe_MetabolicMuscleParameter>

and the doxygen page....
https://simtk.org/api_docs/opensim/api_ ... f935575c29

Cheers,
-james

[Alex Priamikov]

Hi James,

I've seen this and already tried this example models.
Due to documentation - "Note that a slow-twitch ratio of "-1" can be entered for muscles whose ratio of slow- to fast-twitch fibers is unknown; the default ratio of 0.5 will be used for these muscles.", so my question was, can you provide this values, because I want to avoid using default ones?

Best regards,
Alex

[jimmy d]

Hi Alex,

twitch parameters are not part of the original model, that's why they are a component of the probe. I would suggest reviewing the literature for upper arm parameters. This is how the OpenSim developers got the lower limb parameters used in the example.

cheers,
-james