During the concentric phase of a barbell back squat, which muscle group acts as the primary agonist to extend the knee?

During the concentric phase of a barbell

Multiple choice — select the best answer

AGluteus maximus
BGastrocnemius
CHamstrings
DQuadriceps

✓ Correct answer: D. Quadriceps The quadriceps (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius) are the primary knee extensors and drive the concentric upward phase of the squat, while the hamstrings and gluteus maximus act as agonists for hip extension simultaneously.

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During the concentric phase of a barbell back squat, which muscle group acts as the primary agonist to extend the knee?

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