title: Effects of temperature and fatigue on the electromechanical delay components.
abstract: BACKGROUND
  Neuromuscular activation can be influenced by both muscle temperature (Tm) and fatigue.
  
  
  METHODS
  To assess the effects of Tm and fatigue on the electromechanical delay (EMD), 15 participants performed voluntary isometric contractions of different intensities under neutral (TmN), low (TmL), and high (TmH) Tm, before and after a fatiguing exercise. During contraction, electromyogram (EMG), mechanomyogram (MMG), and force (F) were recorded from the biceps brachii muscle. The EMD and the latencies between EMG and MMG (Δt EMG-MMG, which includes the electrochemical processes of EMD) and between MMG and F (Δt MMG-F, which includes the mechanical processes of EMD) were calculated.
  
  
  RESULTS
  TmL increased only Δt EMG-MMG, both before and after fatigue. Fatigue lengthened EMD, Δt EMG-MMG, and Δt MMG-F under all Tm to a similar extent.
  
  
  CONCLUSIONS
  While fatigue increased all EMD components, muscle cooling affected only the electrochemical but not the mechanical processes of EMD.
authors: Department of Biomedical Sciences for Health, University of Milan, Via G. Colombo 71, 20133, Milan, Italy.
authors: Emiliano
authors: E
authors: Cè
authors: Susanna
authors: S
authors: Rampichini
authors: Luca
authors: L
authors: Agnello
authors: Eloisa
authors: E
authors: Limonta
authors: Arsenio
authors: A
authors: Veicsteinas
authors: Fabio
authors: F
authors: Esposito
mesh_terms: D000293:Adolescent; D000328:Adult; D001132:Arm / Q000502:physiology; D001831:Body Temperature / Q000502:physiology; D004576:Electromyography; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009213:Myography; D013696:Temperature; D013997:Time Factors; D055815:Young Adult