Information on Forceplate position

[Morten Lund]

The synchronized data in the 2011 data set specify COP from the force plates in the global coordinate system. Is it possible to get the approximate corner coordinates for the three forceplates?

I need that information for an automatic algorithm to link the ground reaction force with either the left or right foot stepping on the forceplate.

Another question while I am at it. Is there any way to get the ground reaction forces for the calibration and static trials?

Thanks,
Morten

[Thor Besier]

Hi Morten,
The forcepla.cal file has this information in it. You should be able to view that in the Video Motion Data subdirectory. Please let me know if you cannot find this file or need further explanation.
Regards,
Thor

t.besier@auckland.ac.nz

[Morten Lund]

Hi Thor

Thanks a lot. I found the 'forcepla.cal' in the raw data folder. A trip to google revealed how to interpret the structure of the file.

========================================
1 Forceplate number
2 Forceplate scaling factor and length and width of forceplate
3 6x6 forceplate calibration matrix provided by manufacturer
9 Xo Yo Zo True XYZ origin relative to the geometric center of the force plate (units = cm)
10 Xc Yc Zc XYZ location of the geometric center of the plate with respect to our video coordinate system (units = cm)
11 3x3 forceplate orientation matrix to make the forceplate coordinate system match the laboratory coordinate system.
========================================

How about my other question. Is there anyway to get the synchronized ground reaction forces for the static and calibration trials. The documentation mentions that these force were synchronized manually, but I don't see them anywhere.

Thanks,
Morten

[Thor Besier]

Hi again,
Sorry, I missed that part!
Yes, we have GRF forces for some of the calibration trials. Let me know which trials specifically you need and I can dig them up. Synching these trials was tricky as we sometimes did not have data from our force plate sync channel, which is why it was a 'manual' process.
Thor