For those interested in this post, I have apparently solved the problem as follow: instead of calculating the loading on the tibia independently, I have simply changed sign to the loadings on the talus and applied them to the tibia but now defining them in the talus reference system (see xml file, I...

Just to give an update on this, when the internal forces applied to talus and tibia are expressed in ground, everything works as expected, and knee and hip moments are insensitive to the internal forces at the ankle. This would suggest an error in changing reference system from ground to tibia and t...

Dear OpenSimers, I am currently struggling with understanding the output of my ID simulations. I have an MRI-based lower-limb model and I am trying to feed my ID with some extra external forces other than the GRF collected from the force plate. I define my external loads in the "External loads setti...

Dear OpenSimers, We have a lower limb personalised MSK model and we are trying to impose some desired contacting loads at the interface talus/tibia. To do that we are modifying our external loads altering the mot file and adding three force components applied to a certain point in the talus and bala...

Hi Ayman,

thank you very much for your reply and explaination.

I did not consider the fact that, although referenced in my ID workflow, when associating the external forces file to the motion a posteriori the xml file is not called anywhere. Everything makes sense now!

Thank you again

Erica

Hello, I am having issues with the way the GUI (both 3.3 and 4.1) is displaying the external forces. I have an xml (attached) where I have defined GRF (in ground) and two additional internal forces defined in the talus and tibia, respectively. I run my ID through the Matlab API and everything seems ...

Dear OpenSimers, I recently started playing with ligaments in my ankle model and I have a few doubts/issues I hope you will help me with. 1. I tried two different implementations: the Ligament class, defined with pcsa_force, resting length and force_length_curve, and the CustomLigament class (https:...