I had bad muscle spasms in my back -right side. I would sometimes lie flat on my back on the floor to ease it. Sometimes a back support belt would help. For a lon g time I didn't think it was PD related, then from reading more about dystonia. I decided it was just another "perk" ( side effect of sinemet)! I started taking Mirapex in February and cutting back the sinemet and have not had the back problem. I'm not sure Mirapex has helped in many other ways, but it has helped that! However I have had to increase my sinemet again, but so far, so good for my back spasms. Ruth Clark 67/9