title: Effect of damaging exercise on electromechanical delay.
abstract: In this study we aimed to quantify the effect of exercise-induced muscle damage on both the electrochemical and mechanical components of electromechanical delay using very-high-frame-rate ultrasound.
  
  
  
  Fifteen participants underwent electrically evoked contractions of the medial gastrocnemius muscle with an ultrasound transducer on the muscle belly and on the myotendinous junction, before, 1 hour, and 48 hours after eccentric exercise of the plantar flexor muscles.
  
  
  
  Maximal isometric plantar flexor torque was significantly lower at 1 hour (-41.1 ± 14.9%; P = 0.0001) and 48 hours (-11.9 ± 14.9%; P = 0.038) post-exercise compared with pre-exercise. However, the delay between electrical stimulation and the onset of muscle activation, the delay between electrical stimulation and myotendinous junction motion, and the electromechanical delay were not altered significantly by eccentric exercise (P = 0.063).
  
  
  
  These findings suggest that moderate muscle damage does not affect the time for the electrochemical or mechanical components of electromechanical delay. Muscle Nerve 54: 136-141, 2016.
authors.affiliation: French National Institute of Sport, Research Department, Laboratory "Sport, Expertise and Performance,", EA 7370, 11 avenue du Tremblay, 75012, Paris, France.|University of Nantes, Faculty of Sport Sciences, Laboratory "Movement, Interactions, Performance,", EA 4334, Nantes, France.
authors.forename: Lilian
authors.initials: L
authors.lastname: Lacourpaille
authors.affiliation: University of Nantes, Faculty of Sport Sciences, Laboratory "Movement, Interactions, Performance,", EA 4334, Nantes, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Nordez
authors.affiliation: University of Nantes, Faculty of Sport Sciences, Laboratory "Movement, Interactions, Performance,", EA 4334, Nantes, France.
authors.forename: Valentin
authors.initials: V
authors.lastname: Doguet
authors.affiliation: University of Nantes, Faculty of Sport Sciences, Laboratory "Movement, Interactions, Performance,", EA 4334, Nantes, France.|The NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Australia.
authors.forename: FranÇois
authors.initials: F
authors.lastname: Hug
authors.affiliation: French National Institute of Sport, Research Department, Laboratory "Sport, Expertise and Performance,", EA 7370, 11 avenue du Tremblay, 75012, Paris, France.
authors.forename: GaËL
authors.initials: G
authors.lastname: Guilhem
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001265:Athletic Injuries / Q000150:complications* / Q000473:pathology; D001696:Biomechanical Phenomena; D004558:Electric Stimulation; D004576:Electromyography; D016552:Ergometry; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D063806:Myalgia / Q000000981:diagnostic imaging / Q000209:etiology*; D011930:Reaction Time / Q000502:physiology; D019415:Torque; D014463:Ultrasonography; D055815:Young Adult
keywords: eccentric contraction; excitation-contraction coupling; exercise; high-frame-rate ultrasound; muscle damage; muscle force transmission