Hi, I didn't use OpenCap before, but I used another camera based pose estimation and inverse kinematics and it works fine for me. I don't know what these graphs represent, but I am assuming they represent markers data. I suggest you to do filtering as a first step, and to do simpler motion so you ca...

Hi all, I am using OpenSim inverse Dynamics tool to calculate moments around the joints. However, the value seem very weird at the elbow joint even for simple motion. I did a simple arm raising motion (generated clean data in Matlab), but the moment seem to be negative all the time (even when it sho...

Thank you a lot for your help, it seemed to work. I have another follow up question (I created a separate question for it too. This is the link for it https://simtk.org/plugins/phpBB/viewtopicPhpbb.php?f=91&t=17058&p=47281&start=0&view= ) I am using ID to calculate moments around the joints. However...

Hi all,
I am trying to understand how to get the lengths of the bones (and possibly the muscles too) in any OpenSim model. The scale tool doesn't show the lengths but only how much scaling is applied. Is there an easy and direct way to know the lengths of the body parts?

Thank you

If you mean showing the original markers position from the data, then you can do that by going to File > Preview Experimental data. This will show the data alone. However, if you want to compare the original data with the IK results, you can do Right click on your IK result from the navigator > Asso...

Hi all, I am doing a Static Optimization and the model seems to be working well visually, but I am getting constraint violation. The values are very small, so I am not sure about how much impact this has. This is an example of the output at one time instant time = 8.55723 Performance = 3.32146 Const...

Hi all, I have a question regarding force data file preparation and specifically the position part px, py, pz . I noticed that it is following a different scale of magnitude and even in Gait2354_Simbody the values where less than 0 usually despite the fact that the motion data is usually in the orde...

Hello,
I am trying to use static optimization to find muscle forces. I saw that there are multiple muscle force-related parameters in the model, and I was wondering what is the best way to tune these parameters for individual cases.
Thanks

Hello, I am trying to use OpenSim for tracking the shoulder, but I don't understand how elv_angle works or why it works this way. I am used to the simple Euler angles where the rotations are independent from each other, which is not the case here unfortunately. I have motion recordings in 3D, but I ...

Hello, I am trying to use visual based motion captured data and feed it to OpenSim and do an analysis after that. The problem is I am getting the angles in quaternions and not Euler angles. Is there a way to use quaternions in OpenSim? Another problem is that the way the joints work in OpenSim is di...