Has anyone experienced jolting pain, spasms/and numbness in their legs

I have been diagnosed with PMR… prednisone has managed my low back and upper body pain, however the electric jolts of pain and spasms/cramps as well as numbness in my legs and feet not so much. Really harsh when I first wake up.
I am now on gabapentin for nerve pain and a muscle relaxer plus prednisone; and as long as I standup I generally feel ok. I cannot sit comfortably for more than a few minutes and if I lay down the whole cycle begins again.
If you have experienced this I would love to hear how you manage it.