kgdykes@watbun.UUCP (07/27/86)
>From: junk@ur-tut.UUCP (Jan Vandenbrande) > >> ...However, I opposed the enaction of the >>mandatory seatbelt law in California for the same reason I oppose mandatory >>helmet laws; it's my business what I do with my body.... > Indeed it is anyones business what they do with their body. >But who pays for a person to be patched up after an accident? The insurance. >And who pays the insurance? Right, we all do (so I hope). And now it >becomes my business too. If I indirectly have to pay for you to be >scraped from the pavement and be reassembled, I'd rather have your, >mine and everyone's elses freedom diminished a bit by requiring >everyone to wear protective devices such as helmets, seatbelts, etc. >The small sacrifice is worth the benefit. > There are studies that show how helmets cause more damage than they save (such as spinal injuries) and cause GREATER insurance costs. When there is impact with the head, the greatest damage comes from SUDDEN DECELERATION of the brain against the skull, helmets don't help. The safety of helmets is NOT CUT AND DRY, and as such I see it as a particulary rude intrusion on my rights when I'm forced by law to wear one. In many states were there are no helmet laws, but have driver-rider education programs, the number of collisions, head-injuries and over-all medical costs are GREATLY REDUCED. And the savings are greater than the cost of the educational programs. Also, most fatal or very serious accidents involving motorcyclists not wearing helmets have been with some combination of - unlicenced rider - drunk - drugs - voilation of laws (speeding) The majority of motorcyclists just dont get into head-splitting accidents. I have been involved in several accidents caused by external-forces, and its always been leg injuries! - Ken Dykes {ihnp4,decvax,allegra,utzoo}!watmath!watbun!kgdykes EDUCATE DON'T LEGISLATE!
good@pixar (All of the good ones are taken.) (07/28/86)
In article <473@water.UUCP> kgdykes@watbun.UUCP writes: > >>From: junk@ur-tut.UUCP (Jan Vandenbrande) >When there is impact with the head, the greatest damage comes from >SUDDEN DECELERATION of the brain against the skull, helmets don't help. This is the second such claim I have seen, and I'd love to have someone explain it. My understanding is that the human head can safely decellerate at about 80 gees, and that with a good helmet a 200 gee decelleration can be reduced to below 80 for the head. In other words, the only thing a helmet really can do is lessen the severity of a decelleration. The relative accelleration of the brain vs the skul has got to be proportional to the accelleration being applied to the skull by the sidewalk, right? -- --Craig ...{ucbvax,sun}!pixar!good
ron@argus.UUCP (Ron DeBlock) (07/30/86)
In article <2975@pixar>, good@pixar (All of the good ones are taken.) writes: > In article <473@water.UUCP> kgdykes@watbun.UUCP writes: > > > >>From: junk@ur-tut.UUCP (Jan Vandenbrande) > >When there is impact with the head, the greatest damage comes from > >SUDDEN DECELERATION of the brain against the skull, helmets don't help. > > This is the second such claim I have seen, and I'd love to have > someone explain it. My understanding is that the human head can > safely decellerate at about 80 gees, and that with a good helmet > a 200 gee decelleration can be reduced to below 80 for the head. > In other words, the only thing a helmet really can do is lessen > the severity of a decelleration. The relative accelleration of > the brain vs the skul has got to be proportional to the accelleration > being applied to the skull by the sidewalk, right? > > > -- > --Craig > ...{ucbvax,sun}!pixar!good Craig, you are on the right track. I am not sure about the numbers you claim and I have no way to look them up. Some references, please? Helmets and seatblets (and "controlled crush" in car frames) work by absorbing some of the energy of impact, thereby reducing the amount of energy that must be absorbed by the skull and other parts of the body. In effect, the rate of decelleration is DECREASED. In a helmet, the plastic shell flexes to absorb some energy, the rest is aborbed the the foam lining. My brother's helmet SPLIT IN TWO in a crash (this was NOT a cheap helmet). He messed up his leg and get lots of scrapes, but there was NO damage to his head. The helmet he was wearing was certified to pass the Snell test (I think) which involves dropping a heavy, pointed object onto the helmet, which must sustain no damage. I don't remember the weight or height of the object, but your head would NOT survive such a test. Maybe someone could enlighten us. -- Ron DeBlock KA2IKT uucp: ...!{allegra, ihnp4}!bellcore!argus!ron ...!{siesmo, allegra!princeton}!caip!andromeda!argus!ron arpa: argus!ron@bellcore.arpa "Beware of programmers carrying screwdrivers."
kgdykes@watbun.UUCP (07/30/86)
>From: junk@ur-tut.UUCP (Jan Vandenbrande) > >> ...However, I opposed the enaction of the >>mandatory seatbelt law in California for the same reason I oppose mandatory >>helmet laws; it's my business what I do with my body.... > Indeed it is anyones business what they do with their body. >But who pays for a person to be patched up after an accident? The insurance. >And who pays the insurance? Right, we all do (so I hope). And now it >becomes my business too. If I indirectly have to pay for you to be >scraped from the pavement and be reassembled, I'd rather have your, >mine and everyone's elses freedom diminished a bit by requiring >everyone to wear protective devices such as helmets, seatbelts, etc. >The small sacrifice is worth the benefit. Insurance costs would be greatly reduced (and risks to innocent bystanders) if cigarettes and alcohol were totally illegal. They cost society lots of money, they dont have "benefits" in any real measurable sense, why are they tolerated? (except for the political expediency of keeping certain industries economically healthy, and are great tax-revenue sources) - Ken Dykes Software Development Group, U. of Waterloo {ihnp4,decvax,allegra,utzoo}!watmath!watbun!kgdykes
mojo@mp-mojo.UUCP (Mojo Jones) (07/30/86)
> The helmet he was wearing was certified to pass the Snell test > (I think) which involves dropping a heavy, pointed object onto the helmet, > which must sustain no damage. > -- > Ron DeBlock KA2IKT > uucp: ...!{allegra, ihnp4}!bellcore!argus!ron The Snell test was changed in 1985. Most current helmets will carry the "Snell M85" sticker. The penetration test was changed from a sharp object to an I-beam about the size of a highway guard rail. They felt this was a more realistic test, I'm told. The M in the M85 means the helmet passed the motorcycle requirements, which are different from the automobile requirements. Helmets *significantly* reduce the deceleration of the brain against the skull. Thanks all for helping point that out.
ken@argus.UUCP (Kenneth Ng) (07/31/86)
In article <2975@pixar>, good@pixar (All of the good ones are taken.) writes: > In article <473@water.UUCP> kgdykes@watbun.UUCP writes: > > > >>From: junk@ur-tut.UUCP (Jan Vandenbrande) > >When there is impact with the head, the greatest damage comes from > >SUDDEN DECELERATION of the brain against the skull, helmets don't help. > > This is the second such claim I have seen, and I'd love to have > someone explain it. My understanding is that the human head can > safely decellerate at about 80 gees, and that with a good helmet > a 200 gee decelleration can be reduced to below 80 for the head. > In other words, the only thing a helmet really can do is lessen > the severity of a decelleration. The relative accelleration of > the brain vs the skul has got to be proportional to the accelleration > being applied to the skull by the sidewalk, right? > --Craig > ...{ucbvax,sun}!pixar!good Let's see how well I remember my physics. The cause of injury appears to be rapid acceleration (negative). Acceleration is the change in speed divided by the distance the change in speed occured. Therefore if you stopped something in zero distance, infinite acceleration occurs. My guess is that the helmet enlarges the distance in which the skull decelerates, thus lowering the aceleration. Lowering the deceleration of the skull in turn lowers the deceleration of the brain. Did I miss anything? -- Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102 uucp(for a while) ihnp4!allegra!bellcore!argus!ken !psuvax1!cmcl2!ciap!andromeda!argus!ken WARNING: NOT ken@bellcore.uucp soon uucp:ken@argus.cccc.njit.edu bitnet(prefered) ken@njitcccc.bitnet or ken@orion.bitnet soon bitnet: ken@orion.cccc.njit.edu (We are VERY slowly moving to RFC 920, kicking and screaming) Spock: "Captain, you are an excellent Starship Captain, but as a taxi driver, you leave much to be desired." Kirk: "What do you mean, 'if both survive' ?" T'Pow: "This combat is to the death"