Search found 32 matches

by Aaron Henry
Thu Feb 17, 2022 8:22 am
Forum: Open Knee: A Three-Dimensional Finite Element Representation of the Knee Joint
Topic: Generation 1 Cut Planes
Replies: 2
Views: 1240

Generation 1 Cut Planes

Hello, I am interested in using the geometry files of the Generation 1 Open Knee model. I am curious how the cut planes were defined for both the femur and the tibia. Are they perpindicular to the mechanical axis of the bones? Or are they arbitrary and made during the segmentation of the MRI scans? ...
by Aaron Henry
Sat Nov 20, 2021 9:21 pm
Forum: OpenSim
Topic: OpenSim Joint Angles
Replies: 3
Views: 765

Re: OpenSim Joint Angles

Hi Thomas, Yes I am referring to inverse kinematics. To give some context, I am attempting to compare OpenSim joint angles to those calculated using the typical method of anatomical coordinate frames. I believe my confusion is coming from determining what would cause differences between the weighted...
by Aaron Henry
Fri Nov 19, 2021 6:51 pm
Forum: OpenSim
Topic: OpenSim Joint Angles
Replies: 3
Views: 765

OpenSim Joint Angles

Hello, I have a few questions in regards to how joint angles are calculated in OpenSim. I have looked through the SimTK theory manual but still have some confusion. 1. What method is used to calculate joint angles? Is it quaternions, Euler Angles, or another method? 2. If Euler angles are used how c...
by Aaron Henry
Sun Sep 12, 2021 8:26 am
Forum: OpenSim
Topic: Piecewise Coefficient
Replies: 1
Views: 240

Piecewise Coefficient

Hello,
I am interested in modifying/creating new models and am curious about how the piecewise linear function constants are determined for different joint constraints. Are there any resources that would help explain where these constants are coming from?
Thanks,
by Aaron Henry
Sun Jul 25, 2021 2:29 pm
Forum: OpenSim
Topic: Inertia matrix for modified body
Replies: 0
Views: 229

Inertia matrix for modified body

Hello, I am currently modifying a custom model which only utilized one side of a sheep pelvis. I have mirrored the geometry of the original pelvis to create a single full pelvis geometry file. My question involves the modification of the inertia matrix to account for the change in dynamics as the pe...
by Aaron Henry
Wed Jul 21, 2021 2:24 pm
Forum: OpenSim
Topic: Inverse dynamics not writing output file
Replies: 2
Views: 351

Re: Inverse dynamics not writing output file

Hi Ayman,
Yes, removing the specific file path on the output_gen_force_file did the trick.
Thanks
by Aaron Henry
Wed Jul 21, 2021 7:18 am
Forum: OpenSim
Topic: Inverse dynamics not writing output file
Replies: 2
Views: 351

Inverse dynamics not writing output file

Hello, I am attempting to setup the inverse dynamics tool via python to run ID on multiple models and trials. I have gotten the inverse dynamics tool to run as I receive a 'True' when using the run() method. However, I am not seeing any .sto file being created despite having the results directory an...
by Aaron Henry
Thu Jul 15, 2021 7:11 am
Forum: OpenSim
Topic: Multiple Time Ranges for Inverse Dynamics Force Data
Replies: 1
Views: 286

Multiple Time Ranges for Inverse Dynamics Force Data

Hello, I am running inverse dynamics and have 4 force plates that were used during data collection. I would like to specify a time range for each individual force plate. For example, if my trial is 4 seconds long, I would like force plate #1 to be used for the entirety of the trial, but only use dat...
by Aaron Henry
Wed Jul 14, 2021 8:14 am
Forum: OpenSim
Topic: Rotate Experimental Data Through Python API
Replies: 2
Views: 333

Re: Rotate Experimental Data Through Python API

Update: I ended up just writing a custom script to rotate my trc files.