Very good with problems in the arm

I bought this mouse because of an acute tennis elbow. First, switching to a vertical posture is already used to, succeeds after a long work but good. The up / down buttons on the thumb I was initially difficult to reach, after some time I have gotten used to it and meet them but now unerringly.
Thus, the hand bale remains on the table and the hand has a pleasant attitude, I can work longer again on PC despite my complaints.
First, I had the feeling that the mouse slips from my hand out. This is definitely not the case. This is probably more on the surface of the mouse, which is from the feeling rather slippery.
After nearly two weeks but I do not want to give up the mouse, because I get along great with her, and she brings a significant relief for the arm.