Orthostatic tremor during modification of standing

Objective: Primary orthostatic tremor (OT) occurs only during standing. We studied, whether modification of the condition „standing“ influences OT. Methods: In 7 patients with OT, surface EMG was recorded from both tibialis anterior and gastrocnemius muscles during two manoeuvres: 1. „relief“: the patient was gradually lifted by a crane. 2. „tilting“: the patient was tilted by a tilting table to positions of 90° (=upright standing), 45° (=diagonal position), 0° (=lying position). We determined the parameters tremor frequency, tremor intensity, coherence, and phase shift between the different muscles. Results: „r…