A powerplate is more likely to make you ache and be stiff if you haven't used one before. Basically you stand on it to do a range of exercises, the plate moves very slightly so puts you off balance but to such a small degree that you don't notice, except that your body works much harder to keep you in the right position. The effect is that the range of exercises you do works your body harder and you don't have to do such a long workout. You need to be relatively fit before you use it, and get advice first, otherwise you can end up doing some damage. Massage is much better for easing aches and stiffness, although a good sports massage will hurt because all the muscle knots and fibrosis have to be given a good pounding to break them down. So, all in all there will be no gain without some pain!! You need to start slow and gentle and accept that this is going to take a long time to resolve.