I do Matrix Repatterning therapy using the A9 device that doesn’t switch between different frequencies. I have used it on patients with knee problems and on a spiral fracture of the wrist as well as numerous other ailments , concussions, GERD, restless leg…Try using it on the lowest power setting. You will get some pain but that is not a bad thing, it means it is working. And tingling is normal, even beneficial I would say. I get tingling in my palms when I use it and work on patients. I did my thesis on the wrist fracture and documented Before and after range of motion for each session and the increases were amazing. On the last session of six for the wrist fracture on I decided to turn the power up to extra high despite the patient testing out a lower level, because she cannot afford to come back. And immediately following this treatment she had minimal gains and some pain. When I used a much stronger PEMF machine (too strong in my opinion for regular use) that colleagues have just moving the tubing around my body it would cause pain in my areas where I had problems. It was just picking up where the issues were. Neat! I personally keep my A9 or M1 one on myself for 24 hours most days. The pain should dissipate the longer you use it. I had a 65-year-old man with a decades long knee problem, and not in great health overall, it does depend on your cellular health how you respond. After each session on his knee he had swelling and heat and pain so that he could not bend. I explain to him this was a likely side effect that was temporary. After three sessions he said he did not want to continue because of the 2 to 3 days information afterwards. But luckily for him when he came in the fourth time his knee issue was completely gone. And he was sold on Matrix repatterning and I worked on his hand problem which was alleviated in 3 to 4 sessions as well. There is a way to Determine what is the appropriate power setting for yourself. But I would use it on low for longer periods time for healing your injuries.