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Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
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Muscle Activation Patterns During Different Squat Techniques.

Lindsay V Slater1, Joseph M Hart

  • 1Department of Kinesiology, University of Virginia, Charlottesville, Virginia.

Journal of Strength and Conditioning Research
|January 26, 2016
PubMed
Summary
This summary is machine-generated.

Altering knee alignment during squats changes lower extremity muscle activation. Malaligned squats increase biceps femoris and gastrocnemius activity while affecting quadriceps engagement, impacting exercise biomechanics.

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Area of Science:

  • Biomechanics
  • Exercise Physiology
  • Sports Science

Background:

  • Bilateral squats are fundamental in athletic training.
  • Knee alignment significantly influences lower extremity muscle engagement during squats.

Purpose of the Study:

  • To investigate and compare lower extremity muscle activation patterns across different squat techniques, specifically focusing on knee alignment variations.

Main Methods:

  • Electromyography (EMG) was used to measure muscle activation in the vastus lateralis, vastus medialis, rectus femoris, biceps femoris, and gastrocnemius.
  • Participants performed squats with controlled alignment, anterior-posterior (AP) malalignment, and medial-lateral (ML) malalignment.

Main Results:

  • ML malaligned squats showed decreased vastus lateralis, medialis, and rectus femoris activity compared to control.
  • AP malaligned squats demonstrated varied quadriceps responses and increased biceps femoris and gastrocnemius activation.
  • Both malaligned squat variations led to increased biceps femoris and gastrocnemius activation relative to the control.

Conclusions:

  • Intentional frontal and sagittal knee malalignments during squats alter muscle activation patterns.
  • Quadriceps, biceps femoris, and gastrocnemius activation are significantly affected by squat malalignments.