Re: Helmets

[Sue Brown <sbrown@wamedes.com>]

>katswig@earthlink.net wrote:
>1.     To what extent does increasing the size of your head change the risks 
>of neck injures?  Nobody knows.

The reason you sleep with a pillow is to get your head up at a better level
with the rest of your body to ease misalignment of the spine.  One of the
things we are very careful about in surgery is positioning the body to prevent
neurological problems and this oftentimes required a couple of folded towels
under the head (when not using a regular pillow) when the patient is on their
back...even more when they're on their side.  I measured the thickness of my
husband's helmet (the only one in the house right now) and it's about an inch
thick.  I doubt very much that this would increase the risk of head
injury...if
anything, it would decrease the hyperextensions keep the head from going into
further misalignment in any direction. 
>
>2.     To what extent does increasing the size and weight of your head
change 
>the chances of hitting your head at all?  Nobody knows.

I also weighed my husband's helmet on the kitchen dietary scale and it weighs
13-14 oz.  Considering that this is spread around the whole head, I don't
think
the amount of weight would be even the slightest bit significant.  Remember,
the head weighs about as much as a bowling ball and a fourteen ounce foam
layer
around the ball would be hardly noticeable.  Of course, you can go put on one
of the old style helmets that *are* heavier, but if you're concerned about
weight, they wouldn't be a good choice.  (Besides, a lot of the old ones are
not ASTM certified.)
>
>3.     To what extent does protecting your skull from direct blows to the
head

>change the effects of these blows on your brain (don’t mistake your brain
for 
>your skull...and helmets are designed to protect skulls, not brains)?
Nobody 
>knows.

This statement is totally false.  The helmets are designed to protect the
BRAINS!!!!!  The problem with head injuries is not when the skull hits (skull
injuries are rarely fatal unless they have uncontrolled bleeding)...head
injuries occur after the skull comes to a sudden stop and the squishy,
jello-like brains are continuing to travel at the speed of descent.  They come
to a stop a short while later and, in the process, squash the brain matter on
the side that hits and pull the brain away from the skull on the other side. 
Subdural hemorrhage occurs at this time...as the brain matter pulls away from
the skull, it rips holes in the blood vessels that aren't very stretchy.  When
we open up people's skulls after an injury like this, we more often than not
open the opposite side from the impact sight.  When a situation like this
occurs, you have a matter of minutes to get the skull opened, relieve the
pressure of the hematoma on the fragile brain, and stop the bleeding before
permanent damage starts to occur.  (A bad situation if you're not within
minutes of a hospital...and even if you are, we're talking literally MINUTES,
not hours.)  

Helmets are designed to absorb the impact so that the skull and the brain
tissue come to a halt **at the same time**!  This is why it's so important to
have a helmet checked if it's ever received a blow...you may not be able to
see
any damage, but it may have lost it's ability to absorb the energy of an
impact.
>
>4.     What are the effects of strapping a narrow piece of “unbreakable”
nylon

>snuggly (if it isn’t snug you aren’t wearing it right, and you are reducing 
>the effectiveness of the helmet as a skull protector) around your thorax?  
>Nobody knows.
>
Little point of anatomy here...the thorax is another name of the chest.  And
yes, strapping a helmet around the thorax would definitely reduce it's
effectiveness. ;-)  Seriously, why would you want something breakable under
your chin that wouldn't hold the helmet on??  And again...the helmet is to
protect the brains not the skull...and I haven't heard of many problems of a
person being choked to death by their chin strap.

>
> I can’t make a quantitative analysis of the risks associated with wearing a 
> helmet v. the risks associated with not wearing them. Because the 
> quantitative data simply don’t exist (and never will).  Until it does; I’ll 
> use my touchy-feely (or even gut instinct) analyses and other people can
use 
> theirs.  So don’t give me this bullshit about cold, hard facts.  The 
> necessary cold, hard facts relevant to this issue don’t exist—but there are 
> plenty of examples of situations where the latest “safety technology” was 
> found to be flawed and to bring with it as many risks as it was intended to 
> mitigate.


If you are interested in facts (and touchy-feely won't save your life), join
the AMEA (American Medical Equestrian Association)...you will get lengthy
reports mailed to you that contain volumes of qualitative data on all aspects
of equestrian injuries...with special emphasis on statistics regarding helmet
usage.  I can give you the info to sign up if you like...the reading's a
little
dry, but very, very relevant.

>
> If helmets didn’t have any disadvantages, we would wear them all the time, 
> since sustaining a blow to the head is something that anybody could 
> experience at any time.  Why don’t you wear a helmet to bed? 


This part is too silly to even comment on!  Check out the AMEA.

>
> But soldiers in a fox hole wear their helmets to sleep since 
> the risk profile for head injuries has changed (although in both instances, 
> these chances are not quantifiable).


And I'd say that the risks of head injury from falling on your head onto a
hard
surface from about 8' or higher, and often done at speed so add a little
momentum to your impact, would significantly increase your risk of head
injury...I'd say a bit more than lying in bed! ;-)

>
> p.s. It REALLY gives me the willies to see people who wear their helmets 
> improperly (i.e. not how they were designed to be worn).  Because these 
> people take on many of the risks of wearing one, while at the same time not 
> reaping the benefits of wearing them.


I'd like to know what the risks are of wearing a helmet that fits correctly
and
is properly adjusted??  So far I haven't read one!

Any other questions I can answer???

Sue 

sbrown@wamedes.com
Tyee Farm
Marysville, Wa.