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RRA - Average residuals definition

Posted: Tue Sep 20, 2022 6:17 am
by mhora
Hi,
I would like to ask what the difference is between 'Final Average Residuals' and 'Average residuals after adjusting torso COM' provided in the message at end of the RRA analysis.

My 'Average residuals after adjusting torso COM' are all low but 'Final Average Residuals' have high Mx:

Code: Select all

************************************************************
* Average residuals before adjusting torso COM:
*  FX=-2.70865 FY=4.64985 FZ=4.62981
*  MX=-0.0129689 MY=1.45229 MZ=-0.586011
************************************************************
* Average residuals after adjusting torso COM:
*  FX=-2.70326 FY=4.6387 FZ=4.66937
*  MX=0.0038438 MY=1.44777 MZ=-0.020786
************************************************************

************************************************************
*                   Final Average Residuals                *
************************************************************
* After torso COM and Kinematics adjustments:
*  FX=0.633272 FY=1.74341 FZ=0.645408
*  MX=21.2624 MY=1.32902 MZ=1.20413
************************************************************
I hoped that knowing what the difference between the two residuals is could help me to get lower Mx final residuals.

If the only difference is that 'Average residuals after adjusting torso COM' does not use adjusted kinematics, is there a way to prevent the kinematics from adjusting during RRA? How could I get 'Final Average Residuals' equal to the 'Average residuals after adjusting torso COM'?

Best,
Martin

Re: RRA - Average residuals definition

Posted: Wed Sep 21, 2022 11:09 am
by ongcf
Odd that MX increases so much. In any case, since the kinematics are not tied to the model, you can ignore any changes in the kinematics by just using the updated model file (.osim) but not the updated kinematics file generated by RRA (and just use the original input kinematics file you used for RRA) for whichever next steps you want to take.

Re: RRA - Average residuals definition

Posted: Fri Oct 21, 2022 6:57 am
by mhora
Excellent idea, it works great, thank you!