Dear Doctor when I use laptop i laying in bed and bend my both legs and then keep this laptop over my legs for last of one year. First i feel little pain in my back but last night suddenly a very siviour pain from back to my left left to toe started. I took first aid my Emergency. the Doctor injected me pain killer. but now my lower part of left leg is senseless. So tell me that please is it a nerve musal problem or my vertebra or disc affected. And what is its treatment and excercise .