I had two back surgeries, and had worse pain after than before, I took percocet, and oxycontin, and finally ended up in a wheelchair, because of the pain in walking also much pain in sleeping. I went to Texas to see my daughter in law, who is an occupational therapist. She said that maybe low level laser would help me. I had had both facet nerves burned, and SI joint nerves burned and the pain just increasted. So I had little hope that low level laser would do anything. She gave me two treatments in two days. I went home and suddenly realized that I didn't need the wheel chair anymore. My pain was more than cut in half. and I am slowly getting better each week. II think that it was an Ercronia low level laser 650 that was used. it was a miracle to me.