Files Quiet Standing (QS) • Eyes open and Eyes Closed • FP1 = Force plate 1; FP2 = Force plate 2 • COP = Center of Pressure in x,y, and z • For = Force in x, y and z

Task : 1. Graph sway (combine force plate data)

2. Analyze sway data– come up with some measures. How are the data sets different?

Here are some answers to questions that I have been getting about the homework due Tuesday.

what is the meaning of pre-Quiet Standing and post-Quiet Standing? For example, pre-QS closed = subject closed eye and step on the force plate, post-QS closed = subject close eyes after stand still on the platform  These are 4 different trials of collecting the same data.  One time the subject had their eyes closed another open and then after we did an intervention

– does unit of CopX and CopZ are in Meter(m) or Newton?  COP = center of pressure and is a location in Meters

-, As we need to merge two stabiligram, Are we simply take the middle point of FB1-COP and FB2-COP? For example, FB1-COP = A(-2,1) and FB2-COP B(3,2) => Merged COP = C(0.5, 1.5) or we need to consider Force vector( X,Y,Z). If we need to consider force vector apply at 2 foots, can you give me the equation? I had read the book and the article but they seem to not using two force plates.

Yes a simple way to merge the COP of the two force plates would be to just take the average.  I encourage you to think if this is the best solution and if so state your reason for that algorithm.

-Does sum of FB1-ForY and FB2-ForY equal to weight of the subject. Yes it should