Went to the physio this morning. He doesn't think I've done anything to my back (e.g. discs or pulled muscles etc), he just thinks that i have inflammed the muscles there. He had a feel around and did a movement type test (great, had to show another person that i cannot touch my toes!) and he concluded that all the parts were working but they didn't seem to working together (plus a lack of flexibility) means that my back is taking the brunt of it.
Therefore he has given me some exercises to do at home and ordered me to stretch and improve my flexibility. He is working on improving my back strength, opening up my hips, chest and back, and working on my ankle movement. He saw that when i did a squat, i wasn't able to go down very far and it was caused by my ankles. He wants to me to a seated calf raise as it removes the calf muscle as being the primary muscle worked on and instead focuses on the smaller, deeper muscles connecting the calf and achilles.