This post got me thinking so I got out a tape yesterday and did both ATK and FTK measurements sitting and standing with knee slightly bent. Interesting, if you look at CCM sizing chart it says to measure standing, while the Warrior chart says measure while sitting. My measurements differed between sitting and standing by about 3/4 inch. My takeaway is that if you are looking for a perfect fit..go to a well stocked store and try everything on. If, you are like me with no store close and trying to take advantage of online deals, then you might ultimately have to use your best estimate and it will probably fit ok, if not perfect.
I am curious what the general consensus is when between leg pad sizes..order up or down? Would you rather be just below or above center of knee block?