Introduction: Fatigue effects on total relaxation delay (R-DelayTOT) components and measurement reliability were investigated. Methods: Electromyogram (EMG), force (F), and mechanomyogram (MMG) were recorded during maximum voluntary contraction from the biceps brachii muscle before and after fatigue. The delays between EMG cessation and onset of F decay (R-EMD), between F decay and onset of MMG largest displacement (MMG p-p) (R-Δt F-MMG), from the beginning to the end of MMG p-p (R-Δt MMGp-p), and from the end of MMG p-p to F cessation (R-Δt MMG-Fend) were calculated. Results: R-DelayTOT lasted 366±10 ms. R-EMD, R-Δt F-MMG, R-Δt MMGp-p, and R-Δt MMG-Fend accounted for 6%, 8%, 59%, and 27% of R-DelayTOT, respectively. After fatigue, R-DelayTOT, R-EMD, R-Δt F-MMG, and R-Δt MMGp-p increased by 38%, 22%, 40%, 40%, and 38%, respectively (Pp-p was the main contributor to R-DelayTOT. Fatigue affected all R-DelayTOT contributors, with a smaller effect on R-EMD.
ASJC Scopus subject areas
- Clinical Neurology
- Cellular and Molecular Neuroscience
- Physiology (medical)