I Have A Very Complicated Spinal Issues. My Last Surgery

I have a very complicated spinal issues. My last surgery was Jan 15 2013. I have been pain free since May and now my problem when I sit as soon as I get up it is as if someone hit me with a baseball bat. I am bent over like a cave women until it releases. Sometimes it will not release all it will do is keep grabbing and will not release. Walking is not an issue. Sleeping is a problem and sitting and getting up and down. I have had MRI Cat Scans and EMG the EMG was abnormal but my doctors now want to do a Mylogram Cat scan any suggestions on what may be going on the hardware I have installed is K2 Mesa in my lower. Thank you