PAINLESS INJECTIONS

I have been an ER nurse for 27yrs. About 20 yrs ago, an LVN showed me a technique for giving injections that really are painless to patients. They are always amazed. I have been researching, and there is not a technique in texts for this. If you have heard of it,pleas e let me know.
What I do is I first have them relax the muscle,putit in a dependent position. this is the trick: I MAKE A WIDE V WITH MY THUMB AND THE REST OF MY FINGERS AND I COUNT TO 3 AND SIMULTANEOUSLY TAP THE SKIN (SLAP IT) WHEN I INSERT THE NEEDLE. I DO THE SAME WHEN I REMOVE THE NEEDLE AND THEY NEVER FEEL IT AND ARE ALWAYS SURPRISED. I AM FINALLY GOING TO GET AROUND TO WRITING IT UP AS A RESEARCH PILOT PROJECT. I WOULD LIKE FEEDBACK IF YOU HAVE HEARD OR USED THIS. IF YOU WOULD LIKE MORE FEEDBACK AS TO HOW TO DO IT, FEEL FREE TO EMAIL ME.THANKS JOANNE