I am really new to anybody modelling system, and now I have encountered a problem on AnyMechOutputFileForceExport class result.

This is the procedure that I have done and the problem is mentioned at the end (4):

  1. I have loaded standing model of repository

  2. then added the mentioned class in this way in my study:

    AnyMechOutputFileForceExport FEAOutPut =
    FileName = “FEAOutPut.txt”;
    AnySeg &Pelvis = Main.HumanModel.BodyModel.Trunk.SegmentsLumbar.PelvisSeg;

  3. then run the inverse dynamics

  4. got the FEAOutPut.txt as an output

  5. encountered these problems:
    4.1. What is the meaning of F[3] or F[i] in which i>2? (anybody tutorial says F[0]=Fx, F[1]=Fy, F[2]=Fz)
    4.2. What is the meaning of M[3] or M[i] in which i>2? (anybody tutorial says M[0]=Mx, M[1]=My, M[2]=Mz)
    4.3. I have imported the output file to MS Excel and added the forces in each row and summed them up but the results were:
    ΣFx = -4.64E+02 (?)
    ΣFy = 5.84E+02 (?) (maybe because of pelvis segment weight but not this much)
    ΣFz = -1.56E+01 (?)
    which were not zero in x and z directions and equal to the segment weight in y direction.

would any body please tell me why this is happening and how can i fix this issue?

In advanced I have attached the Output file “FEAOutPut.txt”, Excel file which I have made “FEAOutPut.xls” and the code in which I have inserted the class in zip file.


You are probably looking into the SpineRhythm reaction forces - if you look closer there are 18 components (6 joints:t12l1, l1l2, l2l3, l3l4, l4l5, l5sac) - each one has 3. This is just the way this part of the body and corresponding output was constructed.
Secondly, summing up absolutely everything is not correct - you can only do that if you summing up all forces in a single point (joint).