Swimming is actually bad for a bad back, it puts undue strain on your spine having to drag yourself through the water with your arms. For bad backs you should rest and get a sports massage if you can, followed by a cool shower, this should reduce swelling and relax your back, then take it easy and try to maintain good posture.

I think I've just found out the cause of my back pain. Actually collapsed the other night and couldn't get up the stairs so had to sleep in the living room. Never had back pain before in my life, can't believe how debilitating it is. Ibuprofen works wonders though, I must say.

Diclofenac Sodium.... 50 mg tabs, 3 a day.......... sorted !