simtk.org

Hi,
Please tell me about the torque of ground reaction data.

I use the ground reaction data which I measured by oneself for analysis.
My ground reaction data include the following contents.

ground_force_vx , ground_force_px
ground_force_vy , ground_force_py
ground_force_vz , ground_force_pz

Because a parameter of the torque is not included, I cannot carry out RRA and CMC Tool when I use these data.
In ground reaction data included in OpenSim 3.0\Models\Gait2392_Simbody include the torque, are these data the things which measured it?
Or is it a thing led by a calculation?

Best regards,
Yuma

Hi Yuma,

Your force plate that you used to collect ground reaction force data should provide torque data as well - or you need to compute the torque data from moments, forces, and centers of pressure. That is, OpenSim does not calculate torque, you have to have it.

Hope this helps,

Rudi

Hi　Rudi,

Thank you for your kind reply.
Once again, I check a setup of a force plate.
Probably, I think that it is necessary to calculate by oneself.

Would you teach the calculation method of torque?

Best regards,
Yuma

Yuma,

I don't give you any equation for calculating torque, since such an equation depenends on how forces and moments are defined in your force plate. I am positive that if your force plate even has sufficient output measures for torque, its manual also describes how to calculate torque with that specific device. Qualitatively, a force plate measures (vertical) moment that is a sum of (vertical) torque and moment of forces about the (vertical) axis. I wrote "vertical" because normally only vertical torque is non-zero.

Rudi

Hi　Rudi,

Thank you for your kind reply.
I intend to check a force plate.
I appreciate your support and help so much.

Yuma