Optimization of Body Anthropometry in Mocap Model

Main Forum
1

Hi,

I have been trying to simulate Gait kinematic parameters from my c3d files using Mocap Lower Body Model, but when I run Parameter and motion optimization study to align my markers with the default one, I see various out of shape human model in MocapModel.
Also, when I run the model without performing motion optimization studies, I see that the foot markers never follow my c3d foot marker. and ultimately, the model looks as if the foot is penetrating inside the force plate.
Once the results obtained from these, I have observed that there is a huge shift in Hip, Knee and ANkle values, with profile being the same.
I feel there is some problem with the human anthropometry optimization, which is creating this shift in angle and torque profiles.
Kindly help me how to overcome this issue.
I have only these following set of anthropometry data for human c3d files:

  1. leg length
  2. height, weight
  3. pelvic width
  4. knee and ankle diameter

Please refer an excel file attached here whihc contains data from AMS and gait lab

2

Hi,

Probably I’m not 100% sure but you may have more design parameters ( segment lengths and marker positions to optimize) than the information that you can use.

The first thing I would try is to reduce the number of your design parameters in your optimization study.

If this does not help to solve your problem, then it will be nice for us to figure out your problem if you can upload the zip file of your model here with detail information regarding your versions of AMS and AMMR.

Best regards,
/MJ

3

Hello Mr. Moonki,

I am uploading my model. Kindly check the attachment
AMS Version: 7.0.0
AMMR version: 1.6.6

4

Dear Sakshi Agarwal,

I tried to use your C3D files (Nandi A Normal Walk.c3d, Nandi Walk.c3d) in order to customized the AnyMoCap model.

I used the AMMR version 2.1.0 to finish this very quickly.

Also I attached the model that I made for you.

And in my result, the optimization of marker locations look very nice.

I would recommend you to have a look at the following files in order to figure out what I’ve changed for you.

Setup/TrialSpecificData_LowerExtremity.any
Setup/MarkerProtocol.any
Setup/ExtraDrivers.any

Best regards,
/MJ

5

Thank You for your guidance Mr. Moonki Jung.
I will look for changes and get back to you if I see any further issue.