Hi Michael,

I realize it's been a while - did you ever find a solution to your problem? I also have the same question.

Ryan

Hi all, I have done some searching on the Forum, but haven't quite found an answer I am looking for. I was hoping someone could help guide me on how to obtain body accelerations used during Joint Reactions Analysis step (which utilizes results from Static Optimization). I am working in Matlab throug...

Thanks Dimitar, I will take a look at these resources. The model is a lumbar spine joint undergoing flexion with a moving joint center in the superior-inferior direction. I found differences in super-inferior joint reaction forces, although differences were only small <0.6% when using accelerations ...

Hi all, I am attempting to compare OpenSim 3.3 JRA estimates to hand calculations for a simple model (one joint, 4 muscles). I am getting values that are slightly off (1% or so). My main question is with regards to the accelerations of the bodies used during the Joint Reactions Analysis. How can I f...

Hi Muhammad, I have seen this issue brought up a few times and have gone through it myself. Here's a link that should give you some insight. https://simtk.org/plugins/phpBB/viewtopicPhpbb.php?f=91&t=3221&p=11248&start=0&view= Basically, it seems that accelerations derived form BodyKinematics are not...

Hi all, I am attempting to run CMC on a full body model with a lot of muscles (238 or so). I've noticed that in some example files from other users that at times the "ignore tendon compliance" box is checked for some pf the Millard muscles. When I check this for all of my muscles, CMC runs (although...

Hi all, I am attempting to find instantaneous individual muscle forces placed on a particular body in that body's local reference frame (body axes). Does anyone know of a straightforward way which I can do this (preferably through the API)? I'm not sure whether ForceReporter has this capability. Tha...

Hi all, I am working on a lumbar spine model consisting of several joints (moving joint centers), ligaments, and muscles. The general flow of the process is IK > SO > JRA. I am using the forces.sto and muscle control files from SO, motion file from IK, actuators files, and ground reaction forces to ...

Hi all, I have a pretty basic question here (I think). I am trying to understand how the BushingForce is treated during Joint Reaction Analysis. My question is whether the BushingForce forces and moments are included within the resulting joint reaction forces and moments. From what I've gathered, I ...

Thanks Tom. That is exactly what I was looking for. Still getting used to the language!