You Still Don't Want to Wear a Helmet??

On Mar 26, 2:59*pm, Frank Krygowski wrote:
On Mar 26, 2:40*pm, landotter wrote:

On Mar 26, 1:16*pm, DennisTheBald wrote:

On Mar 20, 1:18*pm, "Dien Cai Dau" wrote:

Natasha Richardson, a Tony Award-winning actress ...

Was this alpine or nordic skiing?
One is an extreme sport and the other rather pedestrian.

Bunny slope, very low speed fall.

Yes. *IOW, she was probably going as fast as nordic skiers do.

If we were to take this as an
example of where in life helmets are needed--we'd have to start with
wearing them in our cars, in the shower, and while climbing stairs.

Why do the handwringers ignore all the thousands of head injury
fatalities with those causes?


Concern trolls love drama.

On Mar 26, 11:40*am, landotter wrote:
On Mar 26, 1:16*pm, DennisTheBald wrote:

On Mar 20, 1:18*pm, "Dien Cai Dau" wrote:

Natasha Richardson, a Tony Award-winning actress ...

Was this alpine or nordic skiing?
One is an extreme sport and the other rather pedestrian.

Bunny slope, very low speed fall. If we were to take this as an
example of where in life helmets are needed--we'd have to start with
wearing them in our cars, in the shower, and while climbing stairs.

Helmets are designed to protect a rider's head in a direct 14mph
impact. This just happens to be the speed a object reaches when it is
dropped from about 6 feet. In other words, the helmet is designed to
protect a rider from just falling off and hitting the head on the
pavement. A bit of vector mechanics shows that in such a simple fall,
the forward velocity does not contribute to magnitude of the impact
unless one contacts an obstacle while scrubbing off horizontal
velocity.

Helmets are clearly not the ultimate answer to cycling safety, ie
"sell 'em a bike, sell 'em a helmet and I don't have to worry." "He's
wearing a helmet so he's safe." No, it doesn't work that way. Safe
cycling practices begin with understanding, awareness, and
preparedness.

But a helmet definitely can protect one's head in a simple fall.
Since falling off a bicycle is rarely a simple thing, it can happen
quite quickly, a rider can get tangled up with a bicycle and often has
no control over the fall, wearing a helmet provides a bit of added
insurance in the instance of an untimely get off.

On the list of things a cyclist can do to help avoid injury, I place
wearing a helmet somewhere above wearing gloves and somewhere below
making sure one has sturdy, responsive, reliable brakes.

Jon

"landotter" wrote in message
...
On Mar 26, 1:16 pm, DennisTheBald wrote:
On Mar 20, 1:18 pm, "Dien Cai Dau" wrote:

Natasha Richardson, a Tony Award-winning actress ...

Was this alpine or nordic skiing?
One is an extreme sport and the other rather pedestrian.


Bunny slope, very low speed fall. If we were to take this as an
example of where in life helmets are needed--we'd have to start with
wearing them in our cars, in the shower, and while climbing stairs.


I wonder if she had an aneurism ready to pop anyway, Perhaps the small
impact was enough to finally burst the vessel wall. If that was the actual
case, what would have happened with a doorpost, car door, or a jar falling
out of the kitchen pantry? I believe this is an exraordinary case. Either
that, or we really don't have all of the elements of the story.

Bruce

On Mar 27, 5:14*am, "Bruce Gilbert" wrote:
"landotter" wrote in message

...
On Mar 26, 1:16 pm, DennisTheBald wrote:

On Mar 20, 1:18 pm, "Dien Cai Dau" wrote:

Natasha Richardson, a Tony Award-winning actress ...

Was this alpine or nordic skiing?
One is an extreme sport and the other rather pedestrian.

Bunny slope, very low speed fall. If we were to take this as an
example of where in life helmets are needed--we'd have to start with
wearing them in our cars, in the shower, and while climbing stairs.

I wonder if she had an aneurism ready to pop anyway, Perhaps the small
impact was enough to finally burst the vessel wall. If that was the actual
case, what would have happened with a doorpost, car door, or a jar falling
out of the kitchen pantry? I believe this is an exraordinary case. Either
that, or we really don't have all of the elements of the story.

Bruce

Bruce:

In a simple fall, one where you simply hit the ground (or ice etc),
the magnitude of the impact and possible damage from the impact does
not depend on the forward velocity, it is only the velocity
perpendicular to the surface that matters. As I pointed out above, a
fall from 6 feet can produce an impact velocity of about 14mph, more
than enough to do serious damage.

If one is doing a track stand and falls over, there is more than
enough there to cause serious damage to the brain etc.

The question of whether one wears a helmet in a given situation, say
walking, riding a bike, skiing, sitting in a chair, should really
depend on ones ability to respond and breaking the fall and thus avoid
hitting ones head. Breaking one's fall when on skis with poles in
ones hands and awkward skies on the feet makes is more difficult than
when one is simply walking along. A bicycle presents similar
problems, clearing ones feet from the pedals, getting caught by the
bars etc, etc.

Of course this is a "simple fall." If you hit something that stops
your forward velocity, ie a tree, pole, wall, then the impact depends
on your forward velocity. But helmets are not generally designed to
protect in such an event.

So, one should not be surprised that serious injuries can result when
the forward velocity is low, there is plenty there to do it.

Jon Isaacs

On Mar 27, 12:43*pm, " wrote:
On Mar 27, 5:14*am, "Bruce Gilbert" wrote:



"landotter" wrote in message

...
On Mar 26, 1:16 pm, DennisTheBald wrote:

On Mar 20, 1:18 pm, "Dien Cai Dau" wrote:

Natasha Richardson, a Tony Award-winning actress ...

Was this alpine or nordic skiing?
One is an extreme sport and the other rather pedestrian.

Bunny slope, very low speed fall. If we were to take this as an
example of where in life helmets are needed--we'd have to start with
wearing them in our cars, in the shower, and while climbing stairs.

I wonder if she had an aneurism ready to pop anyway, Perhaps the small
impact was enough to finally burst the vessel wall. If that was the actual
case, what would have happened with a doorpost, car door, or a jar falling
out of the kitchen pantry? I believe this is an exraordinary case. Either
that, or we really don't have all of the elements of the story.

Bruce

Bruce:

In a simple fall, one where you simply hit the ground (or ice etc),
the magnitude of the impact and possible damage from the impact does
not depend on the forward velocity, it is only the velocity
perpendicular to the surface that matters. *As I pointed out above, a
fall from 6 feet can produce an impact velocity of about 14mph, more
than enough to do serious damage.

If one is doing a track stand and falls over, there is more than
enough there to cause serious damage to the brain etc.

The question of whether one wears a helmet in a given situation, say
walking, riding a bike, skiing, sitting in a chair, *should really
depend on ones ability to respond and breaking the fall and thus avoid
hitting ones head. * Breaking one's fall when on skis with poles in
ones hands and awkward skies on the feet makes is more difficult than
when one is simply walking along. *A bicycle presents similar
problems, clearing ones feet from the pedals, getting caught by the
bars etc, etc.

Of course this is a "simple fall." *If you hit something that stops
your forward velocity, ie a tree, pole, wall, then the impact depends
on your forward velocity. *But helmets are not generally designed to
protect in such an event.

So, one should not be surprised that serious injuries can result when
the forward velocity is low, there is plenty there to do it.

Jon Isaacs

Dear Jon,

Actually, it's almost impossible to fall straight down from a bicycle.

Bicyclists usually topple to one side or the other--the frame pushes
them sideways.

The motion is more like the arc of a toppling tree than a severed head
dropping straight down in free-fall.

Surprisingly, an acorn on the top of a toppling oak tree hits the
ground much faster than the same acorn dropping straight down from the
top of the same tree.

(That's why toppling chimneys break as they fall--the brickwork cracks
because it can't stand the strain of trying to whip the top of the
chimney so fast.)

Joe Riel explained that the end of a rod hits the ground at the same
speed as if it had been dropped in free fall from 3/2 the height of
the rod:

http://groups.google.com/group/rec.b...4aad73e9e0cb44

In other words, if you topple sideways like a 6-foot tree, your head
hits the ground at roughly the same speed as if it had fallen 9 feet
straight down.

The difference is about 20 versus 24 feet per second, so the kinetic
energy is about 400x versus 576x:

http://hyperphysics.phy-astr.gsu.edu...raj.html#ffall

Of course, your neck and body bend a bit as you topple sideways, like
the chimney breaking, but your head still ends up hitting the ground
faster than if it fell straight down.

Cheers,

Carl Fogel

On Mar 27, 1:43*pm, " wrote:
On Mar 27, 5:14*am, "Bruce Gilbert" wrote:



"landotter" wrote in message

...
On Mar 26, 1:16 pm, DennisTheBald wrote:

On Mar 20, 1:18 pm, "Dien Cai Dau" wrote:

Natasha Richardson, a Tony Award-winning actress ...

Was this alpine or nordic skiing?
One is an extreme sport and the other rather pedestrian.

Bunny slope, very low speed fall. If we were to take this as an
example of where in life helmets are needed--we'd have to start with
wearing them in our cars, in the shower, and while climbing stairs.

I wonder if she had an aneurism ready to pop anyway, Perhaps the small
impact was enough to finally burst the vessel wall. If that was the actual
case, what would have happened with a doorpost, car door, or a jar falling
out of the kitchen pantry? I believe this is an exraordinary case. Either
that, or we really don't have all of the elements of the story.

Bruce

Bruce:

In a simple fall, one where you simply hit the ground (or ice etc),
the magnitude of the impact and possible damage from the impact does
not depend on the forward velocity, it is only the velocity
perpendicular to the surface that matters. *As I pointed out above, a
fall from 6 feet can produce an impact velocity of about 14mph, more
than enough to do serious damage.

If one is doing a track stand and falls over, there is more than
enough there to cause serious damage to the brain etc.

The question of whether one wears a helmet in a given situation, say
walking, riding a bike, skiing, sitting in a chair, *should really
depend on ones ability to respond and breaking the fall and thus avoid
hitting ones head. *

And your methodology used for measuring this ability is??

Skiing on bunny slopes and sober solo road cycling are statistically
safe. Statistics are what matters--not your bizarre reasoning where
really brave sky divers might eschew a chute altogether because,
"dood, I can break the fall."

On Mar 27, 2:43*pm, " wrote:
On Mar 27, 5:14*am, "Bruce Gilbert" wrote:



"landotter" wrote in message

...
On Mar 26, 1:16 pm, DennisTheBald wrote:

On Mar 20, 1:18 pm, "Dien Cai Dau" wrote:

Natasha Richardson, a Tony Award-winning actress ...

Was this alpine or nordic skiing?
One is an extreme sport and the other rather pedestrian.

Bunny slope, very low speed fall. If we were to take this as an
example of where in life helmets are needed--we'd have to start with
wearing them in our cars, in the shower, and while climbing stairs.

I wonder if she had an aneurism ready to pop anyway, Perhaps the small
impact was enough to finally burst the vessel wall. If that was the actual
case, what would have happened with a doorpost, car door, or a jar falling
out of the kitchen pantry? I believe this is an exraordinary case. Either
that, or we really don't have all of the elements of the story.

Bruce

Bruce:

In a simple fall, one where you simply hit the ground (or ice etc),
the magnitude of the impact and possible damage from the impact does
not depend on the forward velocity, it is only the velocity
perpendicular to the surface that matters.

....

Of course this is a "simple fall." If you hit something that stops
your forward velocity, ie a tree, pole, wall, then the impact depends
on your forward velocity. But helmets are not generally designed to
protect in such an event.

The other event that helmets are not designed to protect is an angular
acceleration of the skull and brain, and in that situation, the
forward velocity may matter.

Angular brain acceleration is thought by many to be more damaging than
linear acceleration. Boxers know this, and use it when trying to
cause brain damage (e.g. a knockout) in their opponent. But bike
helmets are not designed to mitigate angular acceleration.

And in fact, they may make it worse. It's likely that the
characteristics of the human scalp - with its slippery hair and low-
friction attachment to the skull - evolved to reduce such angular
acceleration. Not only do helmets lack those features, but they
increase the moment arm of any tangential force. This may be part of
the reason widespread use of helmets has not resulted in improvements
over bicycling's already low rate (per cyclist) of serious head
injuries.

So, one should not be surprised that serious injuries can result when
the forward velocity is low, there is plenty there to do it.

No matter what your activity.

I was hiking Sunday along a creekside trail at a place famous for its
countless large rocks. At one spot, I tripped over one rock in a rock
field and fell forward very suddenly. Luckily I caught myself with my
hands; but if my hands had not broken my fall, my head hitting a
boulder could have caused a serious head injury.

But despite the many warning signs regarding kayaking with care,
avoiding swimming, monitoring children, etc, there were none
recommending hikers wear helmets. Go figure.

- Frank Krygowski

On Mar 27, 8:37*pm, Frank Krygowski wrote:
On Mar 27, 2:43*pm, " wrote:



On Mar 27, 5:14*am, "Bruce Gilbert" wrote:

"landotter" wrote in message

....
On Mar 26, 1:16 pm, DennisTheBald wrote:

On Mar 20, 1:18 pm, "Dien Cai Dau" wrote:

Natasha Richardson, a Tony Award-winning actress ...

Was this alpine or nordic skiing?
One is an extreme sport and the other rather pedestrian.

Bunny slope, very low speed fall. If we were to take this as an
example of where in life helmets are needed--we'd have to start with
wearing them in our cars, in the shower, and while climbing stairs.

I wonder if she had an aneurism ready to pop anyway, Perhaps the small
impact was enough to finally burst the vessel wall. If that was the actual
case, what would have happened with a doorpost, car door, or a jar falling
out of the kitchen pantry? I believe this is an exraordinary case. Either
that, or we really don't have all of the elements of the story.

Bruce

Bruce:

In a simple fall, one where you simply hit the ground (or ice etc),
the magnitude of the impact and possible damage from the impact does
not depend on the forward velocity, it is only the velocity
perpendicular to the surface that matters.

...

Of course this is a "simple fall." *If you hit something that stops
your forward velocity, ie a tree, pole, wall, then the impact depends
on your forward velocity. *But helmets are not generally designed to
protect in such an event.

The other event that helmets are not designed to protect is an angular
acceleration of the skull and brain, and in that situation, the
forward velocity may matter.

Angular brain acceleration is thought by many to be more damaging than
linear acceleration. *Boxers know this, and use it when trying to
cause brain damage (e.g. a knockout) in their opponent. *But bike
helmets are not designed to mitigate angular acceleration.

And in fact, they may make it worse. *It's likely that the
characteristics of the human scalp - with its slippery hair and low-
friction attachment to the skull - evolved to reduce such angular
acceleration. *Not only do helmets lack those features, but they
increase the moment arm of any tangential force. *This may be part of
the reason widespread use of helmets has not resulted in improvements
over bicycling's already low rate (per cyclist) of serious head
injuries.

Yup.

I would reckon that helmets for bikes should be marketed as laceration
preventors. I've had a couple random facers in the last twenty years
where a lid would have saved me half my stitches. I do ride a hell of
a lot more than the average joe, though. It's all about risk. D. at
the LBS knows his statistics. He wears a lid when he commutes home at
night, but will eschew one for a casual day ride with the boys.

Heck, I'd wear one if I was a regular at the Hamilton Creek trail
where you fall regularly. I can deal with a laceration a decade, but
on that hard trail--count on a good spill every other ride.

So, one should not be surprised that serious injuries can result when
the forward velocity is low, there is plenty there to do it.

No matter what your activity.

I was hiking Sunday along a creekside trail at a place famous for its
countless large rocks. *At one spot, I tripped over one rock in a rock
field and fell forward very suddenly. *Luckily I caught myself with my
hands; but if my hands had not broken my fall, my head hitting a
boulder could have caused a serious head injury.

But despite the many warning signs regarding kayaking with care,
avoiding swimming, monitoring children, etc, there were none
recommending hikers wear helmets. *Go figure.

- Frank Krygowski

In article ,
" writes:

Helmets are clearly not the ultimate answer to cycling safety, ie
"sell 'em a bike, sell 'em a helmet and I don't have to worry." "He's
wearing a helmet so he's safe." No, it doesn't work that way. Safe
cycling practices begin with understanding, awareness, and
preparedness.
But a helmet definitely can protect one's head in a simple fall.
Since falling off a bicycle is rarely a simple thing, it can happen
quite quickly, a rider can get tangled up with a bicycle and often has
no control over the fall, wearing a helmet provides a bit of added
insurance in the instance of an untimely get off.
On the list of things a cyclist can do to help avoid injury, I place
wearing a helmet somewhere above wearing gloves and somewhere below
making sure one has sturdy, responsive, reliable brakes.

Maybe it wouldn't hurt to educate people (especially
middle/high school kids) as to how to fall.

We ancient dinosaurs from the '50s & '60s remember being
taught that stuff in Phys Ed classes. Remember having
your Prone Falls assessed by your phys ed instructor?

Come to think of it, that was actually useful education
after all. And I thought it was pretty dumb at the time.

Wouldn't it be a shame if we "need" bike helmets because
so many school board jurisdictions don't have Physical
Education on their cirriculae any more?

If I was king, I'd bring PhysEd back. Maybe make
stilt-walking and skateboarding integral parts of
the program. 'Cuz that's stuff that would intrigue
the kids and lure them in more than drive them away
like dodgeball and wrestling on those coarse jute
pads, or playing rugby in the muddy slop.


cheers,
Tom


--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

In article ,
" writes:

Dear Jon,
Actually, it's almost impossible to fall straight down from a bicycle.

When the bike steers out from underneath you it's almost
impossible ~not~ to fall straight down. There's a moment,
however brief, when the bike wheels are sidewaysedly horizontal
or almost so, kinda like there's a moment when all the hooves of
a galloping horse are off the ground. I am here to attest that
a bicycle + rider can indeed flip over sideways, and while the
rider may initially draw an arc through Quadrant IV, the rest of
the way down (through Quadrant III) is pretty much straight down.
When I fall over it's always to my left for some reason.

In such cases one generally doesn't bash one's head, but
traditionally sticks a hand out to break one's fall (if
one has enough time to actually think of doing so) and
busts one's clavicle in the process.

Railroad trax in the rain offer a learning adventure.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca