Minipolymyoclonus or polyminimyoclonus is a hyperkinetic movement disorder phenomenology characterized by intermittent, low-amplitude, arrhythmic movements of the hands, commonly of several fingers, with amplitudes just sufficient to produce visible and palpable movements of the joints. It is mostly noticed while the individual is maintaining a posture (commonly outstretched hands) or during action (especially the initial phase of movement). [from
HPO]