Electromyographic Characteristics of Postactivation Effect in Dopamine-Dependent Spectrum Models Observed in Parkinson's Disease and Schizophrenia.

This study aimed to test the hypothesis that the postactivation effect (PAE, involuntary normal muscle tone) is modified by dopaminergic mechanisms. The PAE was tested with surface electromyography (sEMG) in the "off medication" phase in participants with Parkinson's disease (PD) and in the "on medication" state in participants with schizophrenia (SZ), which modeled hypodopaminegic conditions, and in participants with PD "on medication" (PD) and in participants with SZ "off medication" (SZ) state which modeled the hyperdopaminergic conditions. Healthy age-matched participants constituted the control group (HC, = 11).