Coordinate system Opensim_ Abaqus

[Hossein Mokhtarzadeh]

Hello everyone,

I am trying to import GRF, Kinematic data to abaqus. I was wondering if joint coordinate systems in Opensim follows Grood and Suntay(1983) coordinate system. However, It seems all the data is relative to the coordinate system in the pelvis in opensim.

In the FE model of lower limb, as the Femur is fixed, we need to transfrom GRF and other kinematic data to Abaqus global coordinate system. But I don't know how to do that.

Is there anyone who may have done this?

Regards,
Hossein

[Hossein Mokhtarzadeh]

Hello again,

I may simplify my question as follows:

Can anyone tell me how I get GRF(both COP and Force directions) or Kinematic data of foot in hip local coordinate system at each frame?

Regards,
Hossein

[Ayman Habib]

Hi Hossein,

If you run the Analyze Tool and attach a BodyKinematics Analysis it should write out a file with the orientation of different bodies in each frame. Then you can write a program to transform your data to the desired frame using this info.

Hope this helps,
-Ayman