I had it when I was a child actually... tried anti inflammatories, physiotherapy, osteopathy (he cracked my neck a lot, and gave me ultrasound), had one arm in plaster of Paris (yep!) for six weeks, had cortisone injections (OUCH!)... and was offered to dictate my O levels onto tape because I couldn't write a week before (just imagine!)...
and then finally had operations on both arms aged 17. Cured? Nope! So now I know that heavy bags aren't to be carried by yours truly, and certain movements are to be avoided! My muscles still swell if I'm not careful.
If physio got you sorted, great! (Amputation is the only thing I didn't try!)