Lumbar hyperextends during the stretch
Lower back arches instead of the hip flexor lengthening.
Overactive muscles
Erector spinaeHip flexors
Corrective work
Foam RollErector spinae↗StretchHalf-kneeling hip flexor stretch↗Lower back arches instead of the hip flexor lengthening.
Without glute contraction the hip flexor reciprocal inhibition is missed.