I've used diclofenac for years on and off and although it's pretty effective it doesn't cause any drowsiness or similar things,from my experience.Not disagreeing with what you say Matt,it's just very mild as pain killers go,again from my exerience.When I was in bad pain they put me on Tramadol which made me feel I was stoned and more recently co-codamol which also contains mild opiates.Not an unpleasant feeling if I'm being honest!I've got scoliosis,curvature of the spine,which flares up from time to time which has led to real chronic lower back pain.Cripplingly bad on occasion.NHS sent me to a physio but although they do their best they don't really do more than give you strength building exercises which you can get from the internet or wherever.Mostly core exercises on the swiss ball.None of them helped greatly though frankly.Osteopaths do help but as said,are expensive,and if I'm honest found them to only offer temporary relief.