Cervical flexion stretch with retraction (Cervical retraction/flexion suboccipital stretch, with assist, sitting)

Sit up straight in a chair looking directly ahead.
Perform a chin tuck, keeping your gaze directly forward and your head in the same rotation.
Think about lengthening through the back of your neck.
Place your hands over the top of your head.
Maintaining a chin tuck, gently pull your head downwards.
You may feel a stretch at the very base of your skull.
Hold this position.