Hips sag under band tension
Band adds load to the plank; core must work harder to resist.
Overactive muscles
Hip flexorsErector spinae
Corrective work
Foam RollHip flexors↗StretchHalf-kneeling hip flexor stretch↗Band adds load to the plank; core must work harder to resist.
Pec minor and anterior delt compensate as the band gets heavier.