RRA analisys in a lateral drop jump

[Andrea Morelli]

I'm studying a drop jump and a lateral drop jump.
RRA during a "simple" drop jump seems to give very "good" data.

I'm also doing the RRA during the lateral drop jump but I can't improve the analysis.

This is the results:

************************************************************
* Summary of Mass Adjustments to Reduce Residuals *
************************************************************
* Body adjusted: torso
* Mass Center (COM) adjustment: dx =-0.1, dz =-0.1
* New COM location: ~[0.0708943,0.31046,0.1]
************************************************************
* Recommended mass adjustments:
* Total mass change: -53.9802
* ground: orig mass = 0, new mass = 0
* pelvis: orig mass = 13.5531, new mass = 5.09529
* femur_r: orig mass = 10.7041, new mass = 4.02423
* tibia_r: orig mass = 4.26662, new mass = 1.60404
* talus_r: orig mass = 0.115081, new mass = 0.0432648
* calcn_r: orig mass = 1.43851, new mass = 0.540809
* toes_r: orig mass = 0.249265, new mass = 0.0937115
* femur_l: orig mass = 10.7041, new mass = 4.02423
* tibia_l: orig mass = 4.26662, new mass = 1.60404
* talus_l: orig mass = 0.115081, new mass = 0.0432648
* calcn_l: orig mass = 1.43851, new mass = 0.540809
* toes_l: orig mass = 0.249265, new mass = 0.0937115
* torso: orig mass = 39.3997, new mass = 14.8124
************************************************************
* Note: Edit the model to make recommended adjustments to *
* mass properties. *
************************************************************
* Average residuals before adjusting torso COM:
* FX=24.4124 FY=529.365 FZ=-24.7954
* MX=42.5813 MY=-3.88462 MZ=-40.7121
************************************************************
* Average residuals after adjusting torso COM:
* FX=24.1207 FY=537.26 FZ=-25.015
* MX=85.6446 MY=-2.33326 MZ=6.40307
************************************************************

************************************************************
* Final Average Residuals *
************************************************************
* After torso COM and Kinematics adjustments:
* FX=24.1716 FY=536.992 FZ=-25.0714
* MX=85.7588 MY=-2.32113 MZ=6.42498
************************************************************

Like you see FY is very high and FZ negative.

I guess if I'm doing a correct analysis because compared to the normal drop jump where the X axis of the pelvis is oriented with the X axis of the reference; with the lateral drop jump (right or left) the subject starting position (and so starting model pose) is 90deg (or -90deg) rotated depending of the side I jump. I should rotate the model ? (I suppose no because is correct to start rotated).

Scaling and IK seems correct looking at the data (confirmed also from the good data of the RRA during the normal drop jump).

Anybody can give me some advice? I did try to change the task, actuators and ControlContrains file but the value doesn't change (CoM of the pelvis is correct after rescaling the model).
I'm using the gait2392 model.

Thank you
Andrea

[Andrea Morelli]

I did transformed the data (Yes, I did a mistake for the lateral drop jump not rotating the experimental data with model reference) in this manner the pelvis rotation is correct. I did rotated also the GRF.

Repetaed the IK for noth right and left lateral drop jump but the RRA results is still high in the Y component.
I see that compared to before now FX and FZ are better.

************************************************************
* Final Average Residuals *
************************************************************
* After torso COM and Kinematics adjustments:
* FX=-7.14125 FY=274.888 FZ=-11.8032
* MX=-0.216748 MY=-2.33735 MZ=2.42243
************************************************************

What does it mean if the value are negative (for FX and FZ) ?

How can I improve, decreasing ,FY ?

I understand in the troubleshooting section for RRA that for low residuals I should reduce maximum excitation for while also "relaxing" tracking weights on coordinates...
This imply that for the higher residual i should increase excitation or weights?

This is some in the task, activator or controlconstrain setup file ?

Thank you
Andrea