No, what I said was that I never had to restrain a child. I worked with a bunch of thugs and quacks that seemed to get off on doing it. My point is that it is never necessary, period (before anyone moans and groans, yes, if the kid is actively harming self or others I would intervene physically to stop the violence, but kids like this shouldn't be candidates for these places).
So, yes, restraint is extremely common in these places and more often than not, it is administered for the wrong reasons and done incorrectly by untrained, uneducated staff.