I've recently started being a bit more active. One thing I've noticed is when I'm doing leg exercises, sometimes chair excercise, especially with my right leg, at the same time as moving my leg I get a weird popping clicking sensation and noise in my upper back/neck. It's really freaked me out. What is it!? It doesn't happen with my left leg only my right. It doesn't hurt it's just uncomfortable and a really strong feeling of a click. I've googled to no avail, it's really worrying me. Anyone know what it could be?