RecruitingDevice studySensory-specific Peripheral Stimulation for Tremor ManagementThe purpose of this study is to understand the neurophysiological mechanisms of peripheral electrical stimulation (PES) in modulating supraspinal tremorogenic input to motoneurons. For this purpose, the investigators will use transcutaneous PES, high-density electromyography (HD-EMG), transcranial magnetic stimulation (TMS), electroencephalography (EEG), magnetic resonance imaging (MRI), and neuromusculoskeletal modelling. This study will be carried out in both healthy participants and patients with essential tremor (ET) and Parkinson's disease (PD).