Dear the OpenSim team, I want to simulate a surgical intervention. It is a transfer of the rectus femoris muscle where the rectus femoris (RF) tendon is separated from the vastus muscle and then sutured to the gracilis (GRAC) tendon. Here is an article about the procedure https://www.sciencedirect.c...

Thank you for getting to me! My solution for the previous mentioned problem is to replace updDefaultControls() in my personalized class OptimizerSystem with setActivation. However, I still can use updDefaultControls outside this class (in the main function) to update the muscle controls. So it chang...

Is there anyone who can help me?

Hello, I'm working on the simple model shown in the attached photo. The foot is welded to the ground and connected to the tibia by a pin joint at the ankle. The only two actuators are those representing soleus and the tibialis anterior muscles. I already have 3 seconds of state and torque profiles w...

Thank you for the feedback! It's very reasonable to check what you proposed. I can confirm that: The gravity is the only applied force. At each integration step, I make sure that the muscle forces are 0. The value of elements of the residual force produced by calcResidualForce are of the order of 1e...

Hello, I'm trying to understand how the equations of motion is established when weld constraints are implemented. The model I used is in the attached file. I applied the theories from the documentation of SImbody Matter Subsystem in this link https://simbody.github.io/simbody-3.6-doxygen/api/classSi...

I have encountered this problem while using Manager and a model containing SmoothSphereHalfSpaceForce (attached file). Encountered unrecognized Object typename SmoothSphereHalfSpaceForce while reading property components. There is no registered Object of this type; ignoring. There is just no contact...

I found the issue!
It was while it should be However, it only works with SmoothSphereHalfSpaceForce. The error remains with ElasticFoundationForce.

But why does that make the system not realized?

With the snippet of code from example2DWalking, it doesn't work even the system was already realized at Dynamics stage. terminate called after throwing an instance of 'SimTK::Exception::StageTooLow' what(): SimTK Exception thrown at GeneralContactSubsystem.cpp:131: Expected stage to be at least Dyna...

Hello,
How can I retrieve contact forces and Lagrange multipliers after the problem has been solved?
Thank you in advance!