The spine was a relatively long and slender lever that would help to balance the head's weight. Since the spine joints were also flexible themselves, the cervical vertebrae were the part of the spine with the greatest movement ability, which also meant that their stability would be slightly weaker in comparison. That was why the cervical vertebrae were the easiest part of the spine to injure. It also wouldn't be wise to just massage the cervical vertebrae unless the doctor already knew specific treatment techniques.