New rules are going to lead to more injuries?

I blogged last week about the new rules in the NFL and NCAA that are targeted at preventing football players from hitting their opponent in the head or leading with their head when making a tackle.  The purpose of these rules is to cut down on the number of head and neck injuries.  I've heard some commentary recently on ESPN from former players saying that these rules will cause an increase in the number of knee injuries.  They think because defenders cannot tackle offensive players by hitting them in the head, they will now target their knees, because they don't have any other option.  Now, I didn't play football, or coach football, but it seems to me like there are a lot of other options besides hitting a player in the knees or the head.  I know when I was working as an athletic trainer with the football teams at Southern Miss and Auburn the players were not taught to tackle by hitting in the head or knees.  They were taught to hit a player in the chest or middle of the body and then wrap them up.  I think there are other options for tackling besides the head and the knees.  It may take some adjustments, but I don't think these new rules should cause a huge spike in the number of knee injuries.

Tackling

If you are a football fan, then you know that the start of football season is less than two weeks away.  One of the hot button issues this off season has been tackling, specifically as it relates to hitting another player in the head or a tackler using his head to hit another player with.  The National Athletic Trainers Association (NATA) released a position statement last week urging officials to consistently penalize players that lead with the crown of their head.  The full statement can be seen here.  I've heard a lot of coaches, analysts, and former players complaining about the new rules and the fact that the NCAA and NFL officials will call more penalties on these types of hits.  While it will change the way some players tackle, the benefits of these new rules far outweigh the risk of a player potentially missing a tackle because he cannot lead with his head.  I will outline the theory behind these new rules below.

As you can see in the picture above, the tackler on the right of the screen is making contact with the offensive player with his head down, or in a flexed position.  This results in axial loading of the cervical spine.  When the head is in a natural, upright position, there a slight forward curvature of the cervical spine.  When the neck is flexed and the head is down, this removes the natural curve from the cervical spine, and easily allows

the force to be transmitted from the head down the cervical vertebrae.  In the picture directly above, you can see how the spine is loaded, and as the amount of force increases, the amount of deformation to the cervical spine also increases.  This can ultimately result in a fracture and/or dislocation of the cervical vertebrae that causes paralysis.  The only tackling technique that results in axial loading to the cervical spine is one in which the head is down and contact is made to the crown of the head.  While it is still possible to sustain a neck injury when tackling with the head up, the chances of sustaining a life threatening/altering injury are greatly decreased.  This article contains more information on tackling techniques and the dangers/risks associated with head down tackling.  While I am sure this issue will remain a controversial topic, the best way to prevent catastrophic head/neck injuries is to prevent players from tackling with the head down.