Lower back arches off the floor
Lumbar spine lifts as tight hip flexors tilt the pelvis anteriorly.
Overactive muscles
Hip flexor complexErector spinaeQuadratus lumborum
Corrective work
Foam RollHip flexors / TFL↗Foam RollLumbar erectors↗StretchKneeling hip flexor stretch↗StretchKnee-to-chest stretch↗