Maximal vs. submaximal voluntary contractions: what is the best way to normalize the surface electromyography activity of the trapezius muscle during a computer task?

Introduction: Normalizing the amplitude of muscle activity measured by surface electromyography (sEMG) helps to reduce variability when comparing different participants or experimental conditions. Although some authors have provided recommendations for normalization of upper trapezius (TRA) muscle sEMG [for full text, please go to the a.m. URL]