I think you've completely misread the question. Nothing about what
@Goodlife1119 is asking makes me think they're trying to "bridge the specialties." It makes me think they're in EM, want to go into pain, and want to focus on procedural skills that they think might translate well into pain procedure skills as they eject from EM and become a pain attending.
At the end of the day, I doubt there is much you can focus on in EM that's going to make a huge difference in pain though I would imagine that when it comes to procedural skills in general, you likely have a large leg up on applicants from any field other than gas in that I'm sure you're going to be more facile with a needle than folks from say PM&R.