I purchased this for myself for pain relief of my shoulder & knee. It is unlike anything else (non pharmacological) that I have tried! I have a bone spur that is causing bicep tendinitis & inflammation of the rotator cuff. I also have calcium deposits that are causing severe pain. I am having surgery soon to remove the bone spur & calcium deposits & to repair any damage that they might find when they go in there. In the meantime, I'm using my Red Light for relief and I will most certainly be using it after surgery...especially after physical therapy appointments! I have my husband using it on his elbow & have told many friends about the benefits I have experienced. Looking forward to experiencing relief after surgery! This is a must have for anyone experiencing muscle, arthritic, or joint pain! Well worth the $.