My fingers are involuntary but sometimes they flicker so much. What might be the reason. ToolBox Talk #42: HAND ARM VIBRATION SYNDROME (HAVS) As the majority of our operations involves working with our hands in some capacity whether it is hitting a hammer, using power tools, From fingers to toes, wearable and vibrating technology could help Parkinson's patients VibWrite Finger Vibration System Turns Doors Into Touchpads IEEE Spectrum