Wow, I had forgotten about this thread. Thanks for the comments. Only difference in the motion you see and my regular motion is the push off the ground. When I did this video I had a tear/bruise in the ligaments in the arch of my foot, which did not allow me to push off the ground and into the court. I should update this thread with a vid of me hitting serves with the K90. I'll see if I could do it this weekend.