I don't how it does this. There is really no room or reason to what makes it come and go. The doctors think it's an irritated nerve. Personally I think it's an overuse core body muscle injury. This has been ongoing for like 5 years now. Never really annoying enough for me to do anything about it until the last month I'm getting tired of it. I think it's just weak core body muscles. Being active helps to an extent just as long as I'm not on my feet for too long. I do Lawn care and all the walking around is too much sometimes.