Thank you very much, they are indeed using a newton-raphson to determine the length of the muscle and the velocity of the musculotendon is split depending the relative stiffness of the tendon and muscle. Once the initialization is finished, the velocity of the muscle is used to predict the length of...

Dear all, I'd like to have some information about the musculotendon dynamics. A detailed publication https://web.stanford.edu/~tkuchida/papers/Millard-2013-FlexingComputationalMuscleModelingSimulationMusculotendonDynamics-JBE.pdf about the equations solved by the models but a I've got some equations...

Thanks for the answer !

I know what went wrong.

OpenSim 3.3. For information, I use matlab 2015 and both are in 32 bits.

Dear all,

Sorry to revive this topic, but it seems this manipulation doest not work now, as the function getLocationInParent has to have a VEC3 and a "rLocation" argument but i don't know to create this kind of object in matlab.

Any ideas ?

Thank you

No it is ok, I manage to see where the problem was.

I did an Inverse dynamics analysis and I'll show you the results of the knee force, is it what you were talking about ?

Sorry but it says that even when I change the pathfile type from 3 to 4. Did you change/suppress something else for these datas ?

Hi Sorry for my suggestion, I did not see you already checked the GRF. Just in case, the gravity at the beginning is defined downward the y-axis. I think after doing an inverse kinematic analysis, the model will rotate and the z-axis will be the new upward axis, be sure to change the gravity vector ...

Thanks for your reply,

I don't know why, but after waiting for 10/15 minutes, the static optimization began to run normally, I guess that's because of the low performance of my computer and the high number of frame it had to analyze.

Sorry for this.

Dear Linjie,

Maybe it is related to the position of the applied GRF, to check if it's ok, you can visualize them with file => preview_experimental data => .mot file.

What was the name of the motion file you use from the Knee challenge ?

Yanis