Search found 6 matches

by hans kainz
Tue Apr 23, 2024 5:13 am
Forum: OpenSim
Topic: Scaling - Low Error but Wrong Posture
Replies: 2
Views: 905

Re: Scaling - Low Error but Wrong Posture

Hi,
Do you have experimental markers on the torso of your participant?
If not, the torso will move in the same way as the pelvis segment, which might look strange and explain your observation.
by hans kainz
Thu Oct 21, 2021 3:27 am
Forum: OpenSim
Topic: Rajagopal's Model - Joint Coordinate System
Replies: 1
Views: 2046

Re: Rajagopal's Model - Joint Coordinate System

Hi Axel, Each joint has a partent and child frame. If you want to match an OpenSim model with your clinical model you need to account for the offset (if there is one). E.g. the pelvic frame in most clinical models is defined based on the ASIS and PSIS markers which creates an offset around 15 degree...
by hans kainz
Tue Nov 17, 2020 12:16 pm
Forum: Resolving Medial and Lateral
Topic: How to make the model subject specific
Replies: 1
Views: 707

Re: How to make the model subject specific

Hi Todd,
I guess modifying the orientations of the parent/child segments in the additional 'joints' would do the job.
Cheers,
Hans
by hans kainz
Mon Nov 11, 2019 4:13 am
Forum: OpenSim
Topic: Missing Geometry files
Replies: 4
Views: 681

Re: Missing Geometry files

I had the same or similar problem when I used a model from OpenSim 3.3 in OpenSim 4.0. For some bones the link to the correct vtp files was missing. I copy and pasted the geometry folder from OpenSim 3.3 to the folder in which my model was saved and it worked fine afterwards.
by hans kainz
Sun Sep 27, 2015 9:35 pm
Forum: OpenSim
Topic: Changing Segment Frame Location and Orientation
Replies: 1
Views: 534

Changing Segment Frame Location and Orientation

Hello all, I want to change the location of the segment frame relative to the geometry (e.g. bone). In the generic OpenSim model the segment frame of the femur is located at the hip joint center. I built a model based on MRI images and therefore the segment frames are somewhere outside the bone geom...
by hans kainz
Sat Jun 28, 2014 11:23 pm
Forum: OpenSim
Topic: Are joint angles calculated intrinsic or extrinsic?
Replies: 5
Views: 1717

Are joint angles calculated intrinsic or extrinsic?

Hello, I'd like to do some kinematic comparisons between different models and therefore I need to know how OpenSim calculates joint angles. Are the Cardan/Euler angles calculated in an intrinsic way (second and third rotation occur about axes of the rotated coordinate system, same as in the paper fr...