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Related Experiment Video

Updated: Mar 26, 2026

Induction and Assessment of Exertional Skeletal Muscle Damage in Humans
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Induction and Assessment of Exertional Skeletal Muscle Damage in Humans

Published on: December 11, 2016

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Effect of damaging exercise on electromechanical delay.

Lilian Lacourpaille1,2, Antoine Nordez2, Valentin Doguet2

  • 1French National Institute of Sport, Research Department, Laboratory "Sport, Expertise and Performance,", EA 7370, 11 avenue du Tremblay, 75012, Paris, France.

Muscle & Nerve
|January 21, 2016
PubMed
Summary

Eccentric exercise causes muscle damage, but does not significantly alter electromechanical delay components. This suggests moderate muscle damage doesn't impact the timing of muscle activation or force transmission.

Keywords:
eccentric contractionexcitation-contraction couplingexercisehigh-frame-rate ultrasoundmuscle damagemuscle force transmission

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Area of Science:

  • Exercise physiology
  • Biomechanics
  • Muscle physiology

Background:

  • Electromechanical delay (EMD) is crucial for understanding muscle function.
  • Quantifying EMD components is essential for assessing neuromuscular control.
  • Exercise-induced muscle damage (EIMD) may influence EMD, but this remains unclear.

Purpose of the Study:

  • To quantify the impact of EIMD on both electrochemical and mechanical aspects of EMD.
  • To investigate changes in EMD following eccentric exercise using high-frame-rate ultrasound.

Main Methods:

  • Fifteen participants performed electrically evoked contractions of the medial gastrocnemius.
  • Ultrasound imaging was used at the muscle belly and myotendinous junction.
  • Measurements were taken before, 1 hour, and 48 hours after eccentric plantar flexor exercise.

Main Results:

  • Maximal isometric plantar flexor torque decreased significantly post-exercise (1 hour: -41.1%, 48 hours: -11.9%).
  • No significant alterations were observed in the delay between electrical stimulation and muscle activation onset.
  • The delay between stimulation and myotendinous junction motion, and overall EMD, remained unchanged (P=0.063).

Conclusions:

  • Moderate muscle damage from eccentric exercise does not significantly alter the electrochemical or mechanical components of EMD.
  • The timing of neuromuscular activation and force transmission appears resilient to this level of muscle damage.
  • Findings contribute to understanding the functional consequences of muscle damage on neuromuscular performance.