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Rotation order when calculating Analysis with Body Kinematics

Posted: Thu Nov 03, 2016 6:24 am

by m.mauersberger

Hi there,

I used the "Analyze" tool for calculating all of the body kinematics in the human model "gait2392" (with OpenSim 3.3). Then I get results for positions, velocities and accelerations for coordinates and angles.

Now my question is: Does someone of oy know in which order the angles are given? You know there are some ways to do that (e.g. with Euler angles). But how can I read for example "calcn_r_Ox", "calcn_r_Oy", "calcn_r_Oz"? What does they mean?

Thank you in advance for help.

Best regards
Michael

Re: Rotation order when calculating Analysis with Body Kinematics

Posted: Thu Nov 03, 2016 6:03 pm

by tkuchida

Hi, Michael.

A description is printed at the top of the .sto files generated by the BodyKinematics Analysis, and indicates that "Body segment orientations are described using body-fixed X-Y-Z Euler angles." The description is generated by BodyKinematics::constructDescription() here: https://github.com/opensim-org/opensim- ... s.cpp#L181.

Regards,
Tom