Isn’t that interesting? I’ve had the same vibrations of which you speak, however, mine are always at hip range and lasts for only a second or two! It doesn’t seem to happen very often, but when it does, it feels like a cell phone vibration. Then I realize that my phone isn’t even on me. It doesn’t happen often enough for me take any concern though because I just figured it was some kind of, “body quirk” that just happens as we age. If anyone finds anything else on this, please let me know, as I’m new to this site?