I have lumbosacral degenerative disc, I get muscles spasms in my lower back/back, & after standing for like 30 minutes, I can go sit & my leg or legs would shake, this happens even after doing quite a bit of bending over, I am 100 pounds overweight, does the sciatic nerve run down both legs or just one? I'm wondering about me having sciatica with those above symptoms, any thoughts would be appreciated