I am 54 and up to recently have been exercising quite vigorously. However approx 2 weeks ago i developed muscle spasm in my lower back on the right hand side My GP has prescribed anti-inflammatory medication plus a week of muscle relaxer (I think it was diazepam) so the pain is now much better. However there is still some discomfort, I can’t run and as my GP recommended physio I was wondering what the way forward might be.  

Hi Robert Your GP might be talking sense! 80% of back pain resolves without any intervention in 6 weeks or less. Have a look at this set of videos to start you on your way - and get your thoracic spine moving! The Guru Six Physio