Response of the cervical spine to applied axial load

When the head is in the neutral position, with the normal cervical lordotic curve, forces transmitted to the head are dissipated in the cervical muscles and ligaments, as depicted in image A above. When the neck is flexed to 30 degrees, the cervical spine is straight and becomes collinear with the axial force which is directly transmitted from one vertebra to the next, as depicted in image B above. At the time of impact, the cervical spine buckles under the compressive load, as depicted in image C above.