I have gained the following experience with this massager, overall it is very effective for the ' hobbiest' user and you have to be patient and get to know how to 'calibrate' with you own body geometry. Then results will follow.The heat function. Fantastic.Upper legs vibration, good too.So, ' calibration'.You have 2 buttons on the remote. Horizontal and vertical 'rake', I.e. How wide and how high the nodes travel.This the key to getting good results.Their is one more topic I must mention.'Positioning'.So 'rake' calibration.Put the massager on the chair and strap. Vertical to the chair back.Sit on the chair. Don't push into the nodes, just relax and rest against them. Legs can be extended or bent 90 degrees, hands on knees. Switch on and now you can Calibrate horizontal. So as guide, if your spines a straight line, where is the pressure on either side? is it wide or narrow, this is what the button will set, but only on the rolling setting, once set then switch to shiatsu. Play with this setting and you will find the 'magic angle' specific to you alone. If you are the going for ' full back' the top button is to set the highest movement of the nodes, again specific to you.Positioning. It's not just back vertical to the nodes. You may want to do the 'sides' How?With your legs at 90 degrees, hands on knees, move them as a pair left or right, and slightly twist your torso. Hardly move it at all, just slightly you are know massaging your side muscle ( obliques ), so this extends the use of this machine. Using this teqnique you can hit spot on the big lower muscles, it may take a while, get the position just right and bang, it's the best cash you've ever spent, because this will help you stay healthy.