This video and accompanying text by Vincent S. DeOrchis, MD, MS, Howard L. Geyer, MD, PhD and Steven Herskovitz, MD combines an EMG chart with the audio of the OT signature sign of the ”helicopter" sound.
<Click Image to watch
Link to full article on Neurology.org website
Teaching Video NeuroImages: Orthostatic tremor - The helicopter sign
Neurology April 2, 2013 vol. 80 no. 14 e161