What Causes Muscle Spasms From Neck To Soles Of Feet?

I have muscle spasms from my neck to the bottom of my feet. my cpk is now up 484. have had 2 lumbar fusions in the past l5-s1 and l4-l5. now I have broad-based buldge at l3-l4with effacement. neuro says no need for surgery. My hamstrings go into spasms as soon as I stand up it also effects my quads when I bend stoop ect. Pain level of 9. When I sit down pain level goes down to 2 sore hamstrings. What do I do? .