In principle you could use RRA to reduce the residuals when the subject is in touch with the force plates. In the user documentation: https://simtk-confluence.stanford.edu/display/OpenSim/How+RRA+Works it is mentioned that RRA is primarily intended for walking and running. I am not familiar with th...

"For the shoulder, GRF measurements are only needed if an external force is applied to the arm or hand. As Dimitar said, you can apply a floating base (6 DOF) to the thorax and measure or prescribe those motions. Another common method is to weld the thorax to ground so it does not move, if that corr...

Hello all, sorry for posting a lot. I have started over on the full-body model I have been working on in order to fix previous errors. The main error I am coming to is when I run Inverse Dynamics. The results only provide the moments of the lower extremities while the upper extremities remain 0. I h...

Hi, This can happen if ground reaction forces are not applied correctly or if the tracking tasks' gains are small. In the first case, please make sure that for the time interval of the RRA analysis you always apply ground reaction forces. If they are not applied, the model falls and is not dynamica...

A java.lang.IndexOutOfBoundsException exception has occurred. can someone explain this to me and what I should consider because I'm unsure of what to fix or how to go about it. java.lang.IndexOutOfBoundsException: Index: 251, Size: 210 at java.util.ArrayList.rangeCheck(ArrayList.java:657) at java.ut...

Thank you, I will open a bug report.

Hello, I am having trouble when I scale my model. It is able to execute scaling but when the scaled model is loaded, the software crashes every time. I am wondering if it has to do with leaving some body parts unassigned as the component is minor where a scaling factor of 1 should be fine? Any advic...

Hello, You need to understand the various joint types, how coordinates are defined etc. I'd advise you to start from an existing model and modify it to fit your need, if necessary, rather than starting from scratch. Model building is a non-trivial task and you're better of building on other people'...

Hello, I am wondering what I am missing if the joints in my model won't rotate properly. For example, when I rotate the humerus around the shoulder joint, it doesn't stay in the socket and rotates around the whole model.

Hello, I have created a full body model and when I load it I get the following errors. Model unable to assemble: AssemblySolver::assemble() Failed: SimTK Exception thrown at Assembler.cpp:871: Method Assembler::assemble() failed because: Optimizer failed with message: SimTK Exception thrown at Inter...