So, in essence, you make it even more difficult to insert an
injection. So, by alternating your
sites, you lesson that possibility, because you give each area a longer recovery time.
I can understand the difficulty in trying to give yourself the shots on the back of your arms, or on your backside hips. If my wife (who is afraid of needles and normally passes out at the sight of a needle) did not give me those shots, I couldn't do it myself.