I recently learned of Graston Technique and wondered if anyone here might have experience with it?  It's supposed to help with tendonitis.  I've had pretty bad tendonitis in both knees for decades and as I age, it's showing up in other joints.  I  am always skeptical about this type of stuff, but I tried Active Release Technique on an old torn pec that I trouble with for years and it completely fixed it, so now I am kind of open to it.  Any experience with it?