MoCapModel for lifting and lowering task

Hi

I have a few questions and I have encountered some problems with driving the MoCap full body model for a simulated lifting and lowering task.

Questions:

  1. For this specific analysis there were no force plates used. Can I run the model without this data? If so, what commands do I insert into the ForcePlate input file. I have inserted:

AnyFixedRefFrame GlobalRef ={
Origin={0,0,0};
AnyDrawRefFrame drw={ScaleXYZ=0.4*{1,1,1};};
};

However this does not appear to be correct.

  1. The motion capture data was captured using Xsens motion capture system. Do I have to create new markers or can I use the markers already established in the Marker file?

Problems:
I have encountered a problem with the TrialSpecific file in the input folder. It seems to come up with an error after I have added the C3D file and anthropometric data. I only changed the file name, stature and mass. I do not have the other segment lengths or stating angles. Is this an issue?

The error message in the Trial Specific file consists of:
ERROR(SCR.SCN6) : C:/U…s/k…n/D…s/A…y/F…1/M…l/I…t/TrialSpecificData.any(49) : ‘UseUpperExtremities’ : Unexpected character.

The error message in the main model consists of:
ERROR(SCR.SCN1) : C:/U…s/k…n/D…s/A…y/F…1/M…l/MoCap_FullBody.main.any(1) : Cannot open file : C:\Users\kirsten.huysamen\Documents\Anybody technology\Frank 011\libdef.any

Could you please help me. I have loaded the file as an attachment.

Regards,
Kirsten

Hi Kirsten,

  1. If this is a some sort of kinematic analysis - then it is possible not to use the force plates. Whereas if it is supposed to be kinetic - the missing force plate data will lead to incorrectly computed muscle and joint reaction forces .

It might be possible to predict the ground reaction forces - you can check some publications, e.g.
“Prediction of ground reaction forces and moments during various activities of daily living”, Fluit et al… But this is typically not so easy to do.

We are in a process of developing a ground reaction force predicting mechanisms, but you would need to wait some time.

  1. And this question seems to be answered in another thread.
    Please try avoiding making multiple threads - we overlook both threads and effectively just see it twice.

Kind regards,
Pavel