As I get older, every time I find myself cruising at 50mph in traffic on the freeway on my motorcycle, I ask myself how the fuck younger me thought this was an acceptable speed at which to start lanesplitting. Was I insane? Nowadays I'll start around 40, more like 30, and never more than 10 over.
It's a shame so many motorcyclists die young, before they get a chance to "grow into" some safety sense. I distinctly remember talking with my friends age 12 about how (apologies) "gay" helmets were on our bicycles. We'd speedbomb hills too, it was fun. I remember feeling no fear back then. I remember my parents telling me "you're an idiot for thinking you're invulnerable."
Why do we think that way when we're young, that we're immune to damage? What changes? We experience more death firsthand? If I hadn't had to clean up car accidents and watch a friend lose her intelligence to a helmetless bicycle accident, would I still feel invulnerable?
I wonder about this woman - did she do this because she lacked the fear? Or did she feel it, and all the positives of doing it overruled her fear? Maybe she was just confident enough in her safety measures to do it anyway?
I was maybe 10 or younger and I was speedbombing downhill with my younger sister. We were fearless and very, very fast. Of course we weren't wearing any helmet or whatever. One time as we were racing, she was winning, she shifted her bike toward my direction and slowed down. I ran into her bike and flew out of my bike. Next thing I know I'm in the air, falling down towards the hill. When I finally hit the ground, I uncontrollably rolled downhill another maybe 10 meters. All my face and body was covered in blood and soil. My mom, seeing this incident from far away, ran for help. She told me, when I grew up, that when she was close enough to see me she was sure I was dead because of all the blood on the asphalt and what not. But thanks to the gods of probability, I didn't even break a bone. I don't understand how can human body can be so resilient that a 10 year old kid can survive such an accident without any damage other than his skin (and it wasn't permenant, I forgot about this event until now). I was stupid and I probably did that again and again, possibly even the next day. Now 15 years later, I bike everyday, but I bike very cautiously. I was lucky once, I don't wanna try my luck again.
Cyclists tend to break bones at slower speeds. Pro-cyclists racing down mountains will lose a lot of skin in a fall but unless they hit something hard (rock, pole, wall) they don't tend to break bones. At walking speeds, a sideways fall often results in broken collar bones and wrists.
It is all about the angular momentum of the cyclist wrt to the road.
Whenever I go on a group ride with someone that doesn't even have gloves on, I say I'll give them five bucks for every second they're able to lightly press their knuckles to the concrete, then rub them back and forth vigorously.
Nobody's ever managed to make it more that a second.
I was 9 when I fell off my bike and broke my femur. Being in traction for 4 weeks followed by a full body cast for 12 was not a very fun way to spend the 4th grade.
> At walking speeds, a sideways fall often results in broken collar bones
That's pretty much what happened to me. I was going walking speed on a bike, popped a wheelie, handle bars came off, I tumbled forward and landed collar bone first onto a curb. Hairline fracture at about age 14.
I pulled the brake lever on my road bike once, and it FELL OFF. Went right into the front spokes and launched me over the handlebars like a cannonball. It was like putting a metal rod right into the front spokes.
Square-cube law; someone twice the size has eight times the mass and eight times the force, with only four times cross-sectional area to support it. A ten-year-old's bones and other tissues suffer half[1] the force per unit area in a crash, so require only half the material strength to avoid whatever level of damage.
force is proportional to the cross section of the muscle.
This never made any sense to me. Muscles are made up of groups of fibers, which are made up of chains of sarcomeres. How could strength be proportional to cross sectional area rather than volume of the muscle?
> How could strength be proportional to cross sectional area rather than volume of the muscle?
The same reason that's true of strength of passive members; the limiting factor is the force that will cause shearing, which is basically the strength of one bond in the lengthwise direction times the number of them supporting in parallel in the cross section. So, given the same material, cross sectional area determines strength.
> But, by my understanding, the sarcomeres, which are the source of the actual movement, don't run end to end, they're chains.
It doesn't really matter, except the not being homogenous end-to-end means it's the weakest point that matters. But, irrespective of the structural details, there is some force in the direction of contraction that will cause failure, and that force is proportional to, basically, the number of linkages it is distributed across in parallel (not connections in series, such as along the chain) which is proportional to cross-sectional area.
> The entire line of reasoning seems to rest on the idea that the smallest unit we consider runs from one end all the way to the other.
It is not (in fact, the entire reason it is true of any material is because even structures which seem to be end to end are composed of smaller structures with fallible linkages; if there were indivisible end-to-end structures, this would cease to be a concern.)
To clairify, I was talking about the force exerted by a asphalt plane slamming into you at X m/s, not the force exerted by your muscles.
Although I was basing that on force exerted by gravity (which is proportional to mass), whereas deceleration might be spread out proportional to length, so it might work out to L² anyway. It's too late to edit though.
That is indeed a big factor, but another important factor is that the bones of children are less brittle than adults. I retired from being an EMT last year and it's amazing what kids literally bounce back from while adults break a hip from just falling in the yard.
I believe that's true, but I doubt it's really a factor in this phenomenon of kids surviving high speed crashes that would likely be fatal to adults. It's really just a matter of a less massive body generating (exponentially) less force on impact.
I didn’t know there was a name for this. Speedbombing...Like another commenter, aged 10 I took on the biggest hill in the area. 30 years later, I still bare the scars and memories of the pain at being cleaned up by a very unsympathetic nurse at the hospital. Which was more painful than the crash, as I remember it.
I have come to realise that there's quite a survivor bias in childhood experience, too, whenever someone suggest that today's kids are pampered and parents are hysterical and after all, when we were kids we did all these fun things you cannot do anymore because safety - but yet we survived just fine, didn't we?
I looked up the stats going back a few decades - in the sixties, an average hundred kids died in traffic each year here in Norway. Now? Two or three. Yet we drive more and the population is significantly larger, too.
Drowning (the other biggie) is down by a similar factor.
Generic accidents? Also down by at least an order of magnitude.
We may sigh all we want that kids today are glued to their playstations while we were out building tree huts, conducting -ahem- applied pyrotechnics experiments and similar - but the fact of the matter is that kids today survive childhood. We didn't. :/
The main difference is being supervised by a reasonable adult or not and how streets near homes have changed.
Kids can only be left to free roam in a very safe environment - and even that is not entirely without risks. Alternatively only kids who are shown to be reasonable can do that - it takes parental sensitivity.
I remember doing stuff like this as well when I was younger. I think it should be a collective responsibility of parents to instill in their children that safety is important. I don't let my children ride their bikes without helmets and that's the norm where I live, not the exception, and I think a great deal of it has to do with the fact that the parents around here are very involved in their children.
When you're young and lucky you lack both the experience of bad things happening to you and others and, if you're healthy, you think 'well I've always felt pretty much the way I feel now and when I get hurt I heal pretty fast' so you don't think too much about it. Also, most of the people around you tend to be in the same state, though there were probably at least a few exceptions but they were so few that they're easy to overlook.
Then you get older and experience aches and pains where there were none before, when you get hurt instead of shaking it off you either take longer to heal and/or need a trip to the doctor, maybe you deal with a nasty illness/injury or two, see people you know dealing with and/or taken out by nastier things. Throughout all this you start becoming your parents saying things like 'stop running around with that... you could put an eye out' (hell, by this time you probably met someone who did just that)
I figure in a few more years I'll be driving 20mph in the fast lane with my blinkers on... after all, what's the rush? Hey kids, get off my lawn! ;-)
> Why do we think that way when we're young, that we're immune to damage? What changes?
I'm not saying that all of the "life experiences" answers are wrong, but I think there's more to it. For an organism to be successful it has to survive (to a point), but it also has to be efficient at doing physical tasks. I think we're naturally inclined to push our limits at a young age so that we know where those limits are, and we can more safely straddle them when we're older. Evolution could have made children cautious, and it did, to an extent. But there is a balance. A child who is too cautious never learns how to run safely, and an adult who doesn't know how to run safely can't chase a gazelle very well.
"Why do we think that way when we're young, that we're immune to damage? What changes?"
I see you've received a lot of answers already, but not an explanation (worthy by my standards). Here's my stab on it:
1. Remember how everyone got to ride a bike in the first place. It looked dangerous, yet we had to get over our fear AND try to suppress it consistently long after the point of riding and not falling any more. And that kind of fear suppression exercise was necessary again and again all over our childhood. It's no wonder that with so much repetition it grew to become part of our character, at least for a while, at least until the voices that once encouraged us to overcome our fears went silent.
2. The level of responsibility we bear and the awareness of it, including the responsibility for ourselves, especially enough to feel it in our choices, grows only with time. As younglings, we care less about "serious and boring" (i.e. "act responsible") and more about "fun and exciting" and weight our decisions accordingly.
My current theory on "why do we think that way when we're young" is a disconnection in logic between the older perspective and younger perspective. You don't think you're invulnerable when you're young you simply just don't think about what happens next. When your brain matures and you get older you realize you're going to be around a much longer time than you ever imagined. Your pre-frontal cortex gets a stronger voice and says "watch out you'll die in a second doing that!"
An adults perspective is they young think they will never get hurt. A youths perspective never thinks about getting hurt in the first place.
>Why do we think that way when we're young, that we're immune to damage?
Probably overprotection by parents. When I was a kid I was left alone with my friends with no parents supervision a lot.
We did very risky things and risked our lives several times, but in controlled and normal environments like climbing trees and going to the mountain. When something went wrong you will get painful feedback like bruises. But you knew what your limits were.
Quite interesting, those children that had their parents forbidding them to go with us actually had traumatic experiences later in life, once they were free from their parents. They will buy a motorcycle or car, take risks and die or almost die.
It was like they lacked the experience we had and replicated it, but with machines in non humane environments. Instead of bruises they will crash a very expensive car.
I took risks as a kid and then went out and crashed cars and motorcycles as an adult. I didn't learn anything about motorcycle dynamics from falling out of trees or face-planting off shoddy bicycle ramps.
In my case it's not that I've gained fear, it's that self-preservation is now worth more, mostly because I've spent so much time filling this brain with things. I'm legitimately worth more now than I was in my daredevil days, so I expend more effort protecting myself.
Well, one could easily make the opposite argument: the life of a young person is worth more because more life is left. Presumably that's why we find it more tragic when a young person dies than an old person.
At least kids seem to be getting better about helmets. It’s really really rare that I ever see a kid not wearing one when mountain biking, at least where I am.
Helmets have become more common for a lot of activities. They used to be unheard of in skiing unless you were a racer and now are probably worn by most--especially kids.
Of course, e-scooters and bike shares provide a counter-trend as they don't make it convenient to have a helmet.
> They used to be unheard of in skiing unless you were a racer and now are probably worn by most--especially kids.
Yea this one surprised me recently. I learned to downhill ski as a kid in the 80s, and never once saw anyone with a helmet. I obviously gave it up when I moved to Florida, but now, decades later I’m living somewhere I can go skiing again and was shocked to see so many people (even adults!) wearing them. The group from work I was with was equally shocked that I wasn’t wearing one. They were also shocked that I was wearing jeans and not one of those hundreds-of-dollars skiing outfits, but whatever. I mean I guess helmets make sense but it just feels unnatural, as unnatural as bicycle helmets (which we also did not wear back in the 80s) feel to me. I’ll never get used to wearing one of them either.
> They used to be unheard of in skiing unless you were a racer and now are probably worn by most--especially kids.
What, seriously?
What kind of skiing are you talking about? I've never once seen anyone wear a helmet for cross-country skiing, and I wouldn't think it's necessary anyway. For one thing it's usually walking pace, but also snow is soft.
Presumably grandparent means downhill. Twenty years ago, you basically couldn't buy an adult-sized helmet for alpine skiing even if you wanted to. These days, it's weird not to have one.
I think the change was due to some high profile deaths from tree collisions in the late 90s.
As I recall, racers have worn helmets for decades but it was pretty rare for recreational skiers until 15-20 years ago. I think another factor is that helmets for a lot of kids' activities have become more or less expected, especially among demographics who do downhill skiing as a family. And, if you're telling your kid they have to wear a helmet, a lot of parents probably feel they sort of have to as well.
ADDED: I also wonder if the rise of snowboarding played a role because backward falls where it's easy to hit your head on ice is probably more common than with skis.
I don't downhill ski much these days but I did ski at Squaw Valley a couple times recently because of an event there. And I was definitely an outlier in not wearing a helmet. (In my partial defense, I do wear a hat with impact resistant material sewn in (D3O) and I'm not exactly banging down moguls through the trees these days.)
In the longboarding community, it's considered extremely bad taste to film without a helmet un, precisely because kids are impressionable. I've seen people shouted out of meets.
I have never seen someone at the mountain bike park without a helmet. That would be just insane. Also most of the people taking on the tough trails have full face helemets.
> Why do we think that way when we're young, that we're immune to damage? What changes? We experience more death firsthand? If I hadn't had to clean up car accidents and watch a friend lose her intelligence to a helmetless bicycle accident, would I still feel invulnerable?
There's a theory that, from an evolutionary standpoint, young men are wired to fearlessly fight and die to protect the rest of the community. If they survive long enough, they calm down and take on other roles, letting the new generation of kids take over as cannon fodder.
Take with a grain of salt, obviously, because we're all a lot more complex than our evolutionary history, but it seems plausible.
There's definitely a fearless aspect that comes with youth. I recall mine vividly and there were certainly times I gambled with my life. It's helped me grow as a person but I could never recommend such recklessness in hindsight. Perhaps some things can be learned but not taught.
I have been experiencing the same. A few factors I can think of.
Exposure -- As kids, we aren't exposed to consequences of accidents, blood, etc. So because we have 'seen' less of it, we believe it cannot happen to us.
Responsibilities -- I believe the 'responsibility' factor kicks in as we age. When we are kids, we are for ourselves so we end up taking more risks. As we get older, get married, have kids, watch our parents getting older, we start caring more for security as life seems to be important because of our dependents.
We are adults for majority part of our lifetime so as we grow older we only become habituated to remain careful about our life.
> Why do we think that way when we're young, that we're immune to damage? What changes?
We've evolved this way — not just humans, but mammals in general, and probably other species too. Risk-taking when young is adaptive for the community, if not always for the individual. If no one ever hunts in the place where a tiger was once seen, how will the tribe ever find out that the tiger has moved on?
An EMT in the family told me they call the ones without helmets "future, organ donors." Said they see too many of them that don't make it. I just try to stay away from anyone on a bike when I'm driving. I don't do it myself, though, cuz I was worried about potholes, deer, and so on. I figured I'd crash over something small I didn't see or avoid in time. My reflexes aren't that good. ;)
I think people are overestimating the merit of normal bicycle helmets. I think the actual effect is something like this ([1]):
> The most reliable estimates indicate that at speeds of up to 20 km/h helmets reduce the risk of head injury by 42%, the risk of brain injury by 53%, and the risk of facial injury by 17%, whereas they increase the risk of neck injury by 32%. These estimates are partly based
on research carried out in countries like the United States and Australia, where standards for bicycle helmets are stricter than they are in Europe and can offer protection at higher impact speeds.
In wikipedia [2] I find this quote: "This effect is statistically significant in older studies. New studies, summarised by a random-effects model of analysis, indicate only a statistically non-significant protective effect"
And to the parents around here, make sure your kids know when to not wear a helmet (choking accidents [3])
Bicycle helmet safety is one of those things that will never be accurately covered by statistics, because most cases where the helmet did its job don't end up in the stats as there are no significant injuries.
In the only serious bike accident I have been involved in, the victim would have walked home on their own feet had they worn a helmet. Instead, a fall from the bike on low speed and hitting their head on tarmac ended up in serious head injury and 6 months in the hospital.
Had they walked home, it would have not ended in the stats.
+1 I once landed head first on a mountain bike going downhill. The helmet literally exploded in a million pieces. Walked away home unharmed. Didn't go in the stats.
It was my third time snowboarding and the snow was compact and icy. I was going relatively fast for my control. Caught an edge and fell on my back with my head doing a whiplash. I was probably unconscious for 10 seconds or so. Lay there for another half a minute to gather myself and stood up. Checked the helmet, there was a massive crack. Checked head for bleeding. No bleeding! I walked away and went to the car to get some rest.
I wonder if the neck injury thing is just because a "lesser than" injury is actually getting reported? I haven't seen anything in the article about it, but for example iirc there was this hullabaloo about motorcycle helmet data indicating an increase in back injuries for helmet-wearers, until someone pointed out that dead-on-site riders would be reported as simply "dead," with their injuries unaccounted for.
The helmet sticks out a couple of centimeters and can increase torque if you don't fall straight down. It's plausible that it can cause more serious neck injuries.
A flat shell on front and back would not absorb a hit well if at all - and those are relatively common accidents.
Typical fall has the first contact either direct front or direct back based on kinematics which means they're subject to most force. Falling on side of head is somewhat more rare. Falling on top of the head is rare.
> only a statistically non-significant protective effect
I don't think this phrasing makes sense. A particular study may find a positive effect but with p>0.05, but that depends as much on the size of the study as on the effect itself.
Not sure why you were down voted. The risk taking mechanisms in our brains aren’t fully developed until around that age. I thought this was reasonably well understood
It's a shame so many motorcyclists die young, before they get a chance to "grow into" some safety sense. I distinctly remember talking with my friends age 12 about how (apologies) "gay" helmets were on our bicycles. We'd speedbomb hills too, it was fun. I remember feeling no fear back then. I remember my parents telling me "you're an idiot for thinking you're invulnerable."
Why do we think that way when we're young, that we're immune to damage? What changes? We experience more death firsthand? If I hadn't had to clean up car accidents and watch a friend lose her intelligence to a helmetless bicycle accident, would I still feel invulnerable?
I wonder about this woman - did she do this because she lacked the fear? Or did she feel it, and all the positives of doing it overruled her fear? Maybe she was just confident enough in her safety measures to do it anyway?