whats wrong with my back,  have a numb leg&foot, &handand am i going to feel numb forever? I hurt my back when in the hydrotherapy pool doing a excercies i was given by a physiotherapist,i was only lifting my left leg up to stand on the spot, and to do a marching type exercise, as I have spinal stenosis and osteoartritis as disk protrusion, AT S1 L4-L5, i had a motor bike accident when i was 16 yrs old and fractured my pelvis and pubic bone.  I had been in almost constant pain for three yrs, night time day etc, when sitting standing.I was not able to move without pain, and now it seems, my back is stuffed, i think its my disc, when i cough my back hurts, feels like there is pins sticking in to me. because of the movements i cannot make now becuase i have got sciatica as well at times. my leg does not seem to be able to support me, when i try to stand up my back  is very painful, as well as numb from ankle to knee, and  my foot is numb as well but not the whole foot, i notice pain in my leg, and back at night, coming from i think my hip.
My doctor says he cant give me a scan

Summarized question: What are possible treatments for a numb leg, numb foot, and numb hand after a back injury?