Lots of TV shows and movies show doctors sticking a syringe in a person who appears to be spasming, vibrating, convulsing, or actively wrestling. I would generally think that having a 1 millimeter thick piece of metal stuck into you as you moved about be a good recipe for having a chunk of metal getting broken off inside or a pretty good gash.
In real life do medics do this, or do they use those air-injection things instead, or do they just get the people tied down a lot firmer than is generally shown in TV shows?