I used to think that patting babies on the back was simply to "burp" them: to coax little gas bubbles out of their tiny digestive systems. But, oh, it is so much more.
First and foremost, it is primarily a tool of Distraction. Anytime you see them on the brink of waking up or crying...if you pat them just right, they'll stop and turn to you, slightly confused...They spend the next few moments trying to isolate the patting.
"Where's that rattling coming from?...Anybody else feel a shaking? Like a thump, thump, thump, thump?...Nobody? Okay, maybe it's just me...as I was about to say...Waaahhh..." And then they go ahead and cry anyway. But for a second there, you feel very clever. You momentarily outwitted an infant.
quoted from "Babyhood" by Paul Reiser of television's "Mad About You", pages 151-152
Small children should be supervised by a caregiver when at a computer,
to ensure no accidents occur that could hurt the child and that no equipment gets broken.