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What Are We Aiming for in Eccentric Hamstring Training: Angle-Specific Control or Supramaximal Stimulus?

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Summary

Eccentric hamstring training using the Nordic Hamstring Exercise (NHE) can be performed at constant or increasing velocity. The downward acceleration angle (DWAangle) helps differentiate these methods, impacting training adaptations.

Keywords:
eccentric resistance traininghamstring strengthkinematic analysismovement velocitytime under tension

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Area of Science:

  • Biomechanics of resistance exercise
  • Sports science and training adaptations

Background:

  • Eccentric hamstring training modulates musculotendinous adaptations.
  • The Nordic Hamstring Exercise (NHE) has two velocity execution modes: increasing or constant velocity.

Purpose of the Study:

  • To determine if the downward acceleration angle (DWAangle) can classify NHE velocity execution.
  • To examine kinetic and kinematic differences between increasing and constant velocity NHE.
  • To analyze DWAangle in relation to the angle of peak moment.

Main Methods:

  • Cross-sectional analysis of 613 unassisted NHE repetitions from 12 trained male sprinters.
  • Analysis of the downward acceleration angle (DWAangle) and its relation to the angle of peak moment.

Main Results:

  • Constant velocity NHE demonstrated significantly higher impulses (+61%) and time under tension (+143%).
  • Peak moments were higher for constant velocity NHE, but emerged at similar knee flexion angles.
  • DWAangle strongly correlated with impulse (Rmean2=60.8%) and the difference between DWAangle and peak moment angle (Rmean2=83.6%).

Conclusions:

  • DWAangle, relative to peak moment angle, effectively distinguishes between constant and increasing velocity NHE execution.
  • These findings are crucial for coaches and athletes to tailor eccentric hamstring training for specific adaptations.