I think a lot of it depends on the nature of the injury, the individual body anomalies, like having an elongated neck, short bands that support the neck to the collar bone. Previous whiplash, long hrs of data entry, weight lifters, fall impacts, someone using a jackhammer, one man was installing an overhead auto garage door opener and it had a spring break, sticking him and hitting the concrete on his shoulder.
Another young girl, reached hanging curtains, short as she was she stretched just that little bit more and ended up with a nerve stretch injury "TOS"

Many ways to get TOS, many bodies with anomalies to feed it...

some calm down, some get worse, some are stuck. It is about taking what you have and keeping down the pain, and aiming for remission.

I am a believer in using the steroid pack in flares, a shot of Toradol which is not an opioid but an anti inflammatory. Also, Valium in reasonable amount as a true muscle relaxant.
I have Lexapro that I noticed has kept me migraine free, and keeps me from the flight or fight tightness of the days.
Di