Torque in ground reaction data

[yuma ieshiro]

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

[Rudolf Klemetti]

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

[yuma ieshiro]

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

[Rudolf Klemetti]

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

[yuma ieshiro]

Hi　Rudi,

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

Yuma