Pedal force point of application...

[Andrea Morelli]

Good Morning to all.
I have data from 2 force pedal with 2 component each (X,Y data right and left) but I not understand how to create a virtual point of application to include in OS analisys. Or better I have calculated a point of application and I have X,Y,Z point coordinates but when I preview it in opensim the model became a "point" and toggle trayectory of the point of application seems to be very big...
I try then to preview only the force using 0,0,0 data for px,py,pz on both pedal and force seems scaled correctly.
Can anybody help me to understand how to add a point of application to this force ? And/or suggest if I'm doing the right things ?
After that to simulate cycling I need to costrain to ground both pelvis and "foot" (i don't have a crank in the model) ?
Thank you a lot
Andrea

[Yi Wang]

Pay attention to the "UNIT" in .trc file, usually your data coming with "m"(meter unit), so sometimes, the model became a "point"....

Change your unit accordingly to the actual unit.

Hope to help

[Andrea Morelli]

Yesterday speaking with a friend about a reference problem I came up with it... in fact data are in "mm" and OS was in "m"
Thank you for the help
Andrea

[Yi Wang]

Hi Andrea, have you figured out how to apply your pedal force?

I got some thoughts these days from my experience. In my research, we used two force plates, so we got the COP(center of pressure) which OS need. But if your force just came from kind of force sensor, you could choose "the force is global" in the version 2.0.2 external loads panel.

Hope to help.
Yi.

[Andrea Morelli]

Hi Yi.
I will try this option and let you know if solve my problem.
When I use two force plate (gait) I've no problem for COP. With force pedal (powertec) we have tangential and radial force applayed to the crank and so is not possible to "measure" COP trajectory.
Thank you for your help
Andrea