Neck strains to hold the head up
SCM and scalenes brace instead of the abdominals supporting the position.
Overactive muscles
SCMScalenesSuboccipitals
Corrective work
Foam RollSuboccipitals (lacrosse ball)↗StretchSCM / scalene stretch↗SCM and scalenes brace instead of the abdominals supporting the position.
Anterior core is not engaged; hip flexors pull the lumbar into extension.
At 45° or below the hip flexors overpower the core; raise the legs higher.