It's not that literal or direct. That's not an apt comparison because it's about what constitutes 60 pounds of force on the cervical spine, not the head. Because "weight"(in this study, Newtonian force on the cervical spine converted into pounds) isn't the same thing as mass. Your head only weighs say, 13.5 pounds in…

You think doctors who wrote that weren't aware how much a head weighs? They're talking about the effects with the force of gravity.