Back pain can be due to many different problems including nerve irritation from disc bulges, facet joint irritation, muscle or ligament issues or degenerative changes.
If your symptoms keep coming back, then its certainly useful to look into why it is happening.
Strengthening your back is definitely an important option and focussed treatments with a physiotherapist can help.
However, if symptoms continue, then seeing a Sports/MSK physician is certainly sensible - they can assess you, organise investigations and in some cases give you focussed treatments to help your symptoms.
Keep up the good work with your physiotherapist and good luck with your symptoms.
BW
Dr Dinesh
