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
Search found 28 matches
- Wed Aug 21, 2019 2:53 pm
- Forum: OpenSim
- Topic: Obtaining accelerations of segment CoM
- Replies: 5
- Views: 1260
- Wed Aug 14, 2019 7:01 am
- Forum: OpenSim
- Topic: Obtaining Accelerations used in Joint Reactions Analysis
- Replies: 0
- Views: 228
Obtaining Accelerations used in Joint Reactions Analysis
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...
- Wed Feb 27, 2019 12:49 pm
- Forum: OpenSim
- Topic: Issue when comparing JRA values to hand calculations
- Replies: 2
- Views: 214
Re: Issue when comparing JRA values to hand calculations
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 ...
- Wed Feb 27, 2019 10:40 am
- Forum: OpenSim
- Topic: Issue when comparing JRA values to hand calculations
- Replies: 2
- Views: 214
Issue when comparing JRA values to hand calculations
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...
- Tue Jan 22, 2019 1:50 pm
- Forum: OpenSim
- Topic: Why acceleration values obtained using Body Kinematics are not correct ?
- Replies: 2
- Views: 423
Re: Why acceleration values obtained using Body Kinematics are not correct ?
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...
- Tue Jan 22, 2019 1:40 pm
- Forum: OpenSim
- Topic: Issue with tendon compliance during CMC
- Replies: 1
- Views: 282
Issue with tendon compliance during CMC
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...
- Wed Nov 07, 2018 12:26 pm
- Forum: OpenSim
- Topic: Finding muscle forces in local body reference frame
- Replies: 1
- Views: 192
Finding muscle forces in local body reference frame
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...
- Wed Oct 03, 2018 6:28 pm
- Forum: OpenSim
- Topic: Joint Reaction Analysis errors (extremely large forces)
- Replies: 1
- Views: 217
Joint Reaction Analysis errors (extremely large forces)
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 ...
- Mon Apr 02, 2018 2:04 pm
- Forum: OpenSim
- Topic: Treatment of BushingForce in Joint Reaction Analysis
- Replies: 1
- Views: 213
Treatment of BushingForce in Joint Reaction Analysis
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 ...
- Wed Mar 07, 2018 5:07 pm
- Forum: OpenSim
- Topic: Setting Joint Reaction Properties via Matlab
- Replies: 2
- Views: 197
Re: Setting Joint Reaction Properties via Matlab
Thanks Tom. That is exactly what I was looking for. Still getting used to the language!