Model not scaled properly

Hello,
I have built this single leg jump landing model, I could load and run the model to obtain muscle forces. however the model does not look right graphically. I have a feeling that the thorax segment is not getting scaled properly. (Markers do not look to be in right position.) I am not sure how to get the markers on thorax segment to line up to the anatomical land marks on the mannequin. that is C7, T10, SS and XP are not in right position on my model and I believe this will affect the resulting muscle forces.
Please advise me on this!
PS subject is a female of 10 percentile population. (very tiny girl) I want to make sure that the markers are lining up on the segments.

Thank you
G

Hi,

We’ve just run this model again on our computer.

And the result doesn’t look bad.

Could you please try with this new model?

Best regards,
Moonki

hello,
I have successfully scaled the model and everything looks good so far. I am trying to understand as to how anybody calculates the GRF or the Fz total.
My understanding is that anybody codes calculate Fz from the force plate data and calibration matrix. However in 2 models that I have attached with this posting, when you compare input C3D data of model with unbraced to the braced version (ie model 1 with model 2) the input data is almost the same levels of magnitude. But if we observe the Fz total of the model outputs, it is significantly different in magnitude. I am not able to understand this difference in magnitudes for similar set of data. Can someone help with explaining to me how the forces and moments are so different…
Essentially these models are same codes (extracted of one model that I built), just the input C3D marker and GRF data is slightly different…
(Please note:The ground reaction forces are evidently similar in magnitude in attached C3D files.)
Thank you
G

Hi,

Please let us know which version of AMS and AMMR you used.

Best regards,
Moonki

Hello, I have used AMMRV 1.2 (GAIT LOWER EXTREMITY MODEL) and then modified it to suit our needs.
Thanks
G

Hello Gajendra,

I looked at your model, run the braced and the unbraced C3D and I’m not sure what difference you are pointing out. Fztotal are except for the first high peak identical. The difference in this peak is also not a magnitude to me (for unbraced: 1500N and for braced: 2200N). This is most likely due to noise or filtering, as it is only one time step.

The value for the Force is calculated in the class template for the platform:
Data=.Cal’*{Fx,Fy,Fz,Mx,My,Mz};