Hello!
I want to change muscle length in OpenSim. How can I change muscle length or which parameter should I need to change for muscle lengthening or shortening.
Thank you
Regards,
Hassan
Muscle Length
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Emil Walczak
- Posts: 50
- Joined: Fri Feb 06, 2015 6:45 am
Re: Muscle Length
Hello!
What do you mean by changing muscle length? Changing the optimal fiber length value and tendon slack length value?
What do you mean by changing muscle length? Changing the optimal fiber length value and tendon slack length value?
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Mahdi Hassan
- Posts: 7
- Joined: Mon Sep 23, 2013 8:10 pm
Re: Muscle Length
Hello!
James Dunne gave a solution regarding CMC warning. He told that
" This issue can occur when a muscle is either very short or very long. The excitations that go the muscle produce almost no forces. So essentially the muscle is in a (very) bad part of its operating range."
https://simtk.org/forums/viewtopic.php? ... ing#p11144
Therefore, I want to know how can I change the muscle length.
Thanks
Hassan
James Dunne gave a solution regarding CMC warning. He told that
" This issue can occur when a muscle is either very short or very long. The excitations that go the muscle produce almost no forces. So essentially the muscle is in a (very) bad part of its operating range."
https://simtk.org/forums/viewtopic.php? ... ing#p11144
Therefore, I want to know how can I change the muscle length.
Thanks
Hassan
-
Emil Walczak
- Posts: 50
- Joined: Fri Feb 06, 2015 6:45 am
Re: Muscle Length
Hello!
Muscle ability of producing active force is related with its optimal fibre length. Propably muscles that you are yousing possess too big optimal fibre length compared to maximal length that they can achieve during simulation. Zajac in his work writes that each muscle length in maximal position is equal to 1,5 of muscle optimal length. You can calculate muscle maximal length by introducing the motion from Inverse Kinematics tool and than ploting muscle fibre length.
You can change muscle properties in OpenSim GUI, you need to chose the muscle in Navigator window find optimal fibre length in the muscle properties(Properties window) and introduce the new value.
Muscle ability of producing active force is related with its optimal fibre length. Propably muscles that you are yousing possess too big optimal fibre length compared to maximal length that they can achieve during simulation. Zajac in his work writes that each muscle length in maximal position is equal to 1,5 of muscle optimal length. You can calculate muscle maximal length by introducing the motion from Inverse Kinematics tool and than ploting muscle fibre length.
You can change muscle properties in OpenSim GUI, you need to chose the muscle in Navigator window find optimal fibre length in the muscle properties(Properties window) and introduce the new value.