Sitting straight down — no backward travel
Weight shifts to toes; misses the posterior chain loading purpose of the box squat.
Overactive muscles
QuadricepsHip flexors
Corrective work
Foam RollHip flexors↗StretchHalf-kneeling hip flexor stretch↗Weight shifts to toes; misses the posterior chain loading purpose of the box squat.
Valgus collapse out of the box.
Core decompresses on the box; torso collapses.