Read the second paragraph in my post #37 in this thread. My problem seems to relate mainly to my right arm and hand, which seem to to have a developed a mind of their own that I can't fully control.The 'yip' always seems to be fingers/hands/wrist. But I'm not certain whether that's cause or simply effect. Fingers/hands/wrist is certainly the 'easiest' to move physically so more likely to be where any 'jerk' is triggered/detected.