Curls
Journeyman Pro
Stretching without doubt is the way to do things. On top of this I would get yourself on an inversion table, will get rid of the pain. We have in our house and it is unreal. One example of how good it is, my girlfriend was in a car crash when she was little and has had to go to a chiropractor every 2 months to crack her back, back into shape and with costs of around £100 a session in Sweden its not cheap. She would not be able to carry her golf bag because of the pain in her back after the round. She has been on an inversion table 3/4 times a week and has never felt better, she can now carry her golf bag fully loaded and not been to the chiropractor for nearly a year because of this.
Sorry you lost me after the words "girlfriend" and "Sweden".
Cheers chap will keep it in mind, hope golf is treating you well