Answer transcribed from Brightway's interview with recreational therapist Allison Huck:

Depending on the avenue of a brain injury, you may or may not have received this education. A lot of neurologists or neurosurgeons will do this education, but whether or not people are receptive to it at that time is questionable and it’s different for everyone. In terms of things that are unsafe, I typically tell people at least six months if not more and when cleared by a neurologist, they really shouldn't be engaging in anything that reasonably requires a helmet. “Reasonably requires a helmet” is a funny phrase to say because some people don't wear helmets for things that reasonably would require a helmet. This includes bike riding, scooters, and things like that. Those activities are not necessarily safe at that point and reasonably anything that could put you at risk for a fall, which could add on to your injury. 

Then there's also a lot of weird things that people don't necessarily think of, like roller coasters, trampolines, and diving in a pool. All of those activities that leave an opportunity for further injury, including contact sports, of course, are something that we always go over. I think it's always important to identify not only that those things might not be safe at this point, but that there are some safe ways that you can engage in those or find satisfaction and activities similar to those.