schutte1993 to milliard

[raman samberia]

sir the problem I am getting with upper extremity arm model is converting the schutte19993 model to milliard2012. the tendon force length curve given in upper extremity arm model starts from 0 instead of 1 . The tendon force length relationship given in upper arm extremity model is

untitled.jpg (16.28 KiB) Viewed 298 times

and the prescribed tendon force length curve given in opensim api is

Screenshot (3).png (80.61 KiB) Viewed 298 times

even If I normalize it, it will still start from zero
and another problem I am facing is that same force length curve is used for every muscle. Every muscle has different values max isometric and tendon slack length. how can the same curve work for every muscle.if it works how can I normalize it for every muscle.The values given in model for tendon force length curve is
<SimmSpline name="tendon_force_length_curve">
<x> -10 -0.002 -0.001 0 0.00131 0.00281 0.00431 0.00581 0.00731 0.00881 0.0103 0.0118 0.0123 9.2 9.201 9.202 20</x>
<y> 0 0 0 0 0.0108 0.0257 0.0435 0.0652 0.0915 0.123 0.161 0.208 0.227 345 345 345 345</y>
</SimmSpline>
and sorry sir for posting wrong plots in my previous post.

[Thomas Uchida]

In untitled.jpg, what is plotted on the x-axis? In the Millard muscle model, the tendon generates force when its length exceeds its slack length. There's more information about the muscle model in Millard's paper and on the "Millard 2012 Muscle Models" page in the Confluence documentation (https://simtk-confluence.stanford.edu/d ... cle+Models).

[raman samberia]

Sir x-axis is the length of tendon and y-axis is the force,but the units of these parameters is not specified in the model file. Sir i have read that paper that is why asked how the curve can start from zero. Theses values are given in the model upper extremity arm model provided on opensim website.

Screenshot (10).png (52.6 KiB) Viewed 262 times

.
and sir i dont know whether the curve given by model is normalized or not . as anything about normalization is not mentioned and the values given in the curve seems to bit higher for a normalized curve. if it is not normalized then i don't understand that how can i normalize it. because this curve is used for every muscle but every muscle has different tendon slack length and different isometric force

[Thomas Uchida]

how the curve can start from zero

I'm unfamiliar with the Schutte muscle model, but I would expect the x-axis in untitled.jpg to be percent strain where 0 indicates slack length (whereas slack length would be at 1 in Screenshot (3).png).