What Causes Sharp Pointing Pain In Lower Back?

I have a back problem, I was GETTING A BOTTLE OF BLEACH FROM THE CUPBOARD WHEN IT FELT LIKE I HAD BEEN HIT IN THE MIDDLE OF THE LOWER BACK AND THE SHOCK TYPE PAIN WENT FROM THE LOWER MIDDLE OUT TO BOTH SIDES SIMULTANEOUSLY AND I AM HAVE GREAT DIFFICULTY MOVING AROUND AND IN ALOT OF PAIN ALSO I HAVE ARTHRITIS AND I AM UNSURE IF THIS IS THE CAUSE CAN YOU TELL ME WHAT I SHOULD DO TO HELP THIS I HAVE TAKEN ZAPAIN AND THEY HAVE EASED IT SOMEWHAT