Achievement of fibromyalgia and chronic fatigue syndrome for years, the proposed aid and many useful for pain involves weekly physiotherapy sessions. The daily stretching I also do at home, but not enough help (the meds either). This is my physio told me about these massage balls. With severe muscle weakness, I use them in self-massage "passive" ie that sitting on the sofa or lying in bed (at wakeup exple) I up 2 of the same size (I bought 2 batches) in the back on either side of the spine at the most painful area or first shoulder. Just the fact to rely on it relieves a lot! In the 1st moments, sensations of pins are not pleasant, but the benefit appears quickly. (As I lean over, I do not put them on the skin, I put a t-shirt) I let 15min, 30 minutes, it depends. And then I move them according to other pains. And following the invaluable advice of my physiotherapist, I combined purchasing these balls Hudora 7.5cm and 9cm other 6cm (Togu) also found on Amazon (thanks Amazon!). Depending on the location of the pain, its intensity or depth of the desired massage, I will use one or the other size. Sometimes I combine 2x2 along the back. Cà done a world of good! My pain will not completely disappear (it would be too good!) But the relief is real. The pain is really reduced. The physio (yes, yes, always she) already noticed that the muscle tissues are more flexible in some places. QED. 100% satisfied! I therefore strongly recommend these products to all the "painful"!