Back pain and burning sensation on thighs

Patient: My partner has been having back pain for quite sometimes and his been going to the doc, and the, only thing they give him is meds. And class on how to relax the back pain.But its been four days that he has been complaing about his thighs he feels a burning sensation with a some shocks like some one is poking a need on his thighs. What could it be.

Doctor: