The Effects of Anchor Scheme and Sex on Performance Fatigability and Neuromuscular Responses Following Sustained, Isometric Forearm Flexion Tasks to Failure

Smith RW, Housh TJ, Arnett JE, Anders JPV, Neltner TJ, Ortega DG, Schmidt RJ, Johnson GO. The Effects of Anchor Scheme and Sex on Performance Fatigability and Neuromuscular Responses Following Sustained, Isometric Forearm Flexion Tasks to Failure. JEPonline 2023;26(3):69-92. The purpose of this study was to examine the effects of anchor scheme and sex on time to task failure (TTF), maximal voluntary isometric contraction (MVIC) assessments, and neuromuscular responses following sustained, isometric forearm flexion tasks. Eight males and 8 females performed MVICs before and after sustained tasks anchored to an RPE = 8 (RPEFT) and torque (TRQFT). The amplitude (AMP) and frequency (MPF) of the electromyographic (EMG) and mechanomyographic (MMG) signals were recorded from the biceps brachii. Mixed factorial ANOVAs were used to examine the mean differences in the MVIC, as well as the normalized neuromuscular parameters. For the TTF, the RPEFT was longer (P = 0.003) than the TRQFT. There were parallel fatigue-induced decreases in MVIC (P < 0.001) and EMG AMP (P = 0.023), while MMG AMP increased (P = 0.002), regardless of anchor scheme or sex. However, the MPF for EMG and MMG remained unchanged. Key Words: Electromyography, Mechanomyography, RPE, Torque