Why helmets don’t prevent concussions — and what might | David Camarillo


The word concussion evokes a fear
these days more so than it ever has, and I know this personally. I played 10 years of football, was struck in the head thousands of times. And I have to tell you, though,
what was much worse than that was a pair of bike accidents I had
where I suffered concussions, and I’m still dealing with the effects
of the most recent one today as I stand in front of you. There is a fear around concussion that does have some evidence behind it. There is information
that a repeated history of concussion can lead to early dementia,
such as Alzheimer’s, and chronic traumatic encephalopathy. That was the subject
of the Will Smith movie “Concussion.” And so everybody is caught up in football
and what they see in the military, but you may not know that bike riding is the leading cause
of concussion for kids, sports-related concussion, that is. And so another thing
that I should tell you that you may not know is that the helmets that are worn
in bicycling and football and many activities, they’re not designed or tested for how well they can protect
your children against concussion. They’re in fact designed and tested for their ability to protect
against skull fracture. And so I get this question
all the time from parents, and they ask me, “Would you let your own child
play football?” Or, “Should I let my child play soccer?” And I think that as a field, we’re a long way from giving an answer
with any kind of confidence there. So I look at that question
from a bit of a different lens, and I want to know,
how can we prevent concussion? Is that even possible? And most experts think that it’s not, but the work that we’re doing in my lab is starting to reveal more
of the details around concussion so that we can have
a better understanding. The reason we’re able
to prevent skull fracture with helmets is because it’s pretty simple.
We know how it works. Concussion has been
much more of a mystery. So to give you a sense of what might
be happening in a concussion, I want to show you the video here that you see when you type into Google, “What is a concussion?” The CDC website comes up, and this video essentially
tells the whole story. What you see is the head moves forward, the brain lags behind, then the brain catches up and smashes into the skull. It rebounds off the skull and then proceeds to run
into the other side of the skull. And what you’ll notice is highlighted
in this video from the CDC, which I’ll note was funded by the NFL, is that the outer surface of the brain, where it was to have
smashed into the skull, looks like it’s been damaged or injured,
so it’s on the outer surface of the brain. And what I’d like to do with this video is to tell you that there are
some aspects that are probably right, indicative of what the scientists
think happens with concussion, but there’s probably more
that’s wrong with this video. So one thing that I do agree with,
and I think most experts would, is that the brain
does have these dynamics. It does lag behind the skull and then catch up and move
back and forth and oscillate. That we think is true. However, the amount of motion
you see in the brain in this video is probably not right at all. There’s very little room
in the cranial vault, only a few millimeters, and it’s filled entirely
with cerebral spinal fluid, which acts as a protective layer. And so the brain as a whole probably
moves very little inside the skull. The other problem with this video is that the brain is shown as a kind of rigid whole
as it moves around, and that’s not true either. Your brain is one of the softest
substances in your body, and you can think of it
kind of like jello. So as your head is moving back and forth, your brain is twisting
and turning and contorting, and the tissue is getting stretched. And so most experts, I think, would agree that concussion is not likely
to be something that’s happening on this outer surface of the brain, but rather it’s something
that’s much deeper towards the center of the brain. Now, the way that we’re
approaching this problem to try to understand
the mechanisms of concussion and to figure out if we can prevent it is we are using a device like this. It’s a mouthguard. It has sensors in it
that are essentially the same that are in your cell phone: accelerometers, gyroscopes, and when someone is struck in the head, it can tell you how their head moved at a thousand samples per second. The principle behind
the mouthguard is this: it fits onto your teeth. Your teeth are one of the hardest
substances in your body. So it rigidly couples to your skull and gives you the most precise
possible measurement of how the skull moves. People have tried
other approaches, with helmets. We’ve looked at other sensors
that go on your skin, and they all simply move around too much, and so we found that this
is the only reliable way to take a good measurement. So now that we’ve got this device,
we can go beyond studying cadavers, because you can only
learn so much about concussion from studying a cadaver, and we want to learn
and study live humans. So where can we find
a group of willing volunteers to go out and smash their heads
into each other on a regular basis and sustain concussion? Well, I was one of them, and it’s your local friendly
Stanford football team. So this is our laboratory, and I want to show you the first concussion
we measured with this device. One of the things that I should point out
is the device has this gyroscope in it, and that allows you
to measure the rotation of the head. Most experts think
that that’s the critical factor that might start to tell us
what is happening in concussion. So please watch this video. Announcer: Cougars bring
extra people late, but Luck has time, and Winslow is crushed. I hope he’s all right. (Audience roars) Top of your screen, you’ll see him come on
just this little post route, get separation, safety. Here it comes at you in real speed.
You’ll hear this. The hit delivered by — David Camarillo: Sorry, three times
is probably a little excessive there. But you get the idea. So when you look at just the film here, pretty much the only thing you can see
is he got hit really hard and he was hurt. But when we extract the data out of the mouthguard that he was wearing, we can see much more detail,
much richer information. And one of the things that we noticed here is that he was struck
in the lower left side of his face mask. And so that did something first
that was a little counterintuitive. His head did not move to the right. In fact, it rotated first to the left. Then as the neck began to compress, the force of the blow caused it
to whip back to the right. So this left-right motion
was sort of a whiplash-type phenomenon, and we think that is probably
what led to the brain injury. Now, this device is only limited in such
that it can measure the skull motion, but what we really want to know
is what’s happening inside of the brain. So we collaborate with
Svein Kleiven’s group in Sweden. They’ve developed a finite element
model of the brain. And so this is a simulation using the data from our mouthguard
from the injury I just showed you, and what you see is the brain — this is a cross-section right in the front of the brain twisting
and contorting as I mentioned. So you can see this doesn’t
look a lot like the CDC video. Now, the colors that you’re looking at are how much the brain tissue
is being stretched. And so the red is 50 percent. That means the brain has been stretched
to 50 percent of its original length, the tissue in that particular area. And the main thing I want to draw
your attention to is this red spot. So the red spot is very close
to the center of the brain, and relatively speaking, you don’t see a lot of colors like that
on the exterior surface as the CDC video showed. Now, to explain a little more detail about how we think
concussion might be happening, one thing I should mention is that we and others have observed
that a concussion is more likely when you’re struck and your head
rotates in this direction. This is more common
in sports like football, but this seems to be more dangerous.
So what might be happening there? Well, one thing that you’ll notice
in the human brain that is different than other animals is we have these two very large lobes. We have the right brain
and the left brain. And the key thing
to notice in this figure here is that right down the center
of the right brain and the left brain there’s a large fissure
that goes deep into the brain. And in that fissure,
what you can’t see in this image, you’ll have to trust me, there is a fibrous sheet of tissue. It’s called the falx, and it runs from the front of your head
all the way to the back of your head, and it’s quite stiff. And so what that allows for
is when you’re struck and your head rotates
in this left-right direction, forces can rapidly transmit
right down to the center of your brain. Now, what’s there
at the bottom of this fissure? It’s the wiring of your brain, and in fact this red bundle
here at the bottom of that fissure is the single largest fiber bundle that is the wiring that connects
the right and left sides of your brain. It’s called the corpus callosum. And we think that this might be one of the most common
mechanisms of concussion, and as the forces move down,
they strike the corpus callosum, it causes a dissociation
between your right and your left brain and could explain some
of the symptoms of concussion. This finding is also consistent
of what we’ve seen in this brain disease that I mentioned,
chronic traumatic encephalopathy. So this is an image of a middle-aged
ex-professional football player, and the thing that I want to point out
is if you look at the corpus callosum, and I’ll page back here so you can see
the size of a normal corpus callosum and the size of the person here
who has chronic traumatic encephalopathy, it is greatly atrophied. And the same goes
for all of the space in the ventricles. These ventricles are much larger. And so all of this tissue
near the center of the brain has died off over time. So what we’re learning
is indeed consistent. Now, there is some good news here, and I hope to give you a sense
of hope by the end of this talk. One of the things that we’ve noticed, specifically about
this mechanism of injury, is although there’s a rapid transmission
of the forces down this fissure, it still takes a defined amount of time. And what we think is that if we can
slow the head down just enough so that the brain
does not lag behind the skull but instead it moves
in synchrony with the skull, then we might be able to prevent
this mechanism of concussion. So how can we slow the head down? (Laughter) A gigantic helmet. So with more space, you have more time, and this is a bit of a joke,
but some of you may have seen this. This is bubble soccer,
and it’s a real sport. In fact, I saw some young adults playing this sport down the street
from my house the other day, and as far as I know
there have been no reported concussions. (Laughter) But in all seriousness,
this principle does work, but this has gone too far. This isn’t something that’s practical
for bike riding or playing football. And so we are collaborating
with a company in Sweden called Hövding. Some of you may have seen their work, and they’re using the same principle
of air to give you some extra space to prevent concussion. Kids, don’t try this at home please. This stuntman does not have a helmet. He instead has a neck collar, and this neck collar has sensors in it, the same type of sensors
that are in our mouthguard, and it detects when he’s likely
to have a fall, and there’s an airbag
that explodes and triggers, the same way that an airbag
works in your car, essentially. And in the experiments
we’ve done in my lab with their device, we found that it can greatly reduce
the risk of concussion in some scenarios compared to a normal bicycle helmet. So it’s a pretty exciting development. But in order for us to actually realize
the benefits of technology that can prevent concussion, it needs to meet regulations. That’s a reality. And this device is for sale in Europe but is not for sale in the US,
and probably won’t be any time soon. So I wanted to tell you why. There are some good reasons and then
there are some not so good reasons. Bike helmets are federally regulated. The Consumer Product Safety Commission
has been given jurisdiction to approve any bike helmet for sale, and this is the test they use. This is back to what I was telling you
at the beginning about skull fracture. That’s what this test is for. And that’s an important thing to do. It can save your life,
but it’s not sufficient, I would say. So for example, one thing
this test doesn’t evaluate is it doesn’t tell you
is that airbag going to trigger at the right time and place,
and not trigger when it doesn’t need to? Similarly, it’s not going to tell you is this helmet likely
to prevent concussion or not? And if you look at football helmets,
which aren’t regulated, they still have a very similar test. They’re not regulated
by the government, anyway. They have an industry body,
which is the way most industries work. But this industry body, I can tell you,
has been quite resistant to updating their standards. So in my lab, we are working on not only
the mechanism of concussion, but we want to understand
how can we have better test standards? And we hope that the government
can use this type of information to encourage innovation by letting consumers know how protected are you with a given helmet. And I want to bring this back finally
to the original question I asked, which is, would I feel comfortable
letting my child play football or ride a bicycle? And this might be just a result
of my own traumatic experience. I’m much more nervous
about my daughter, Rose, riding a bicycle. So she’s a year and a half old, and she’s already, well, wants to anyway,
race down the streets of San Francisco. This is the bottom
of one of these streets. And so my personal goal
is to — and I believe this is possible — is to further develop these technologies, and in fact, we’re working
on something in my lab in particular that really makes optimal use
of the given space of a helmet. And I am confident
that we will be able to, before she’s ready to ride a two-wheeler, have something available that can in fact really reduce
the risk of concussion and comply with regulatory bodies. And so what I’d like to do — and I know that this is for some of you
of more immediate nature, I’ve got a couple years here — is to be able to tell parents
and grandparents when I’m asked, it is safe and healthy for your children
to engage in these activities. And I’m very fortunate
to have a wonderful team at Stanford that’s working hard on this. So I hope to come back in a few years
with the final story, but for now I will tell you, please don’t just be afraid
when you hear the word concussion. There is hope. Thank you. (Applause)

100 thoughts on “Why helmets don’t prevent concussions — and what might | David Camarillo

  1. It is a misconception that biking causes more concussions than football in youth under 19. When you control for gender (much fewer females play football, but they bike just as much as males) and control for age range (most youth do not start football until about 10 yrs old, but youth start biking much sooner), then you see that football definitely leads biking in the number of tbi's. This information is reported by the CDC.

  2. why dont try some deformable material right outside de rigid one, it will cause a reduction of energy -deformation_ and also time during that. of course after that the rigid layer Will continue spreading the stress over more surface .
    maybe a cheap removable outside deformable layer that could be replace after a Big Crash or damage

  3. particularly with his comments about airbags, I guess that his solution is active and not merely a new type of material

    it detects the acceleration and adjusts real time to that particular acceleration

    computers are pretty cheap these days, and the actual calculations involved are probably minimal

  4. I search for David Camarillo helmets Stanford

    and his university listing came up 3rd

    easy to see the publication lists and abstracts

  5. I pray that he does push the standards up for helmets. I myself have had a serious head injury that really set me back for some years until I started to restart educated myself again and now with a son on the way I concern his safety so he never has to endure the troubles I have.

  6. how to prevent concussions? DONT PLAY AMERICAN FOOTBALL….also, concussions in regular football are rare if not non existant because people aren brutes. its about skill and not contact

  7. It seems to me that it would be unethical to do this type of research on the football players. I understand that the players would be getting concussions anyway, but it seems wrong that the researchers are capitalizing on their injuries.

  8. Wait, Did I miss the point of the video? I feel like I did not learn anything by watching this…What is the answer to ''Why helmets don't prevent concussions?''

  9. Brain injuries in football are not "accidents". They are caused on purpose by someone using their helmet as a weapon. Airbags and seat belts protect both parties from car "accidents". You can't equate the two. Perhaps you should compare football and soccer.

  10. Seems like young brains are much tougher, you often hear of older people hitting their head and dying from a minor fall yet a kid can get hit in the head ten times harder and recover from it.

  11. if we keep smashing our heads, then probably in few thousand years, evolution can give us a better skull and brain. :-p

  12. I'm not saying not to do research on anti-concussion helmets but damn…. how about just not play this dumb as f**k sport where you slam your skull against other players skulls about 10 times per game. I mean it's funny how the government regulates helmets but does not regulate sports activities in which 30% of professional players end up with dementia. To the question "Would I let my daughter play this dumb sport" your answer should be "NO F***ING WAY" , you idiot.

  13. 1:00
    Against all probability, the leading cause of concussion in kids is bike riding, not football or the military. Who'd have guessed?

  14. 10:17 "This is an image of a middle aged ex-professional football player" XD Yeah I can tell that he is an ex-professional.

  15. Mike Gazzaniga experimented on patients with a severed corpus callosum, and one of the most interesting results was that they didn't seem to have any problems to speak of. Why would an atrophied corpus callosum be responsible for concussion symptoms?

  16. Helmets are supposed to protect from lacerating the head, head wounds bleed excessively and are a good deal of the time what sends a victim into shock or bleeding out over the ground because a physically active human has a high heart rate and while bleeding it only increases due to fear and confusion.

  17. How bout instead of a hard helmet, they use a swishy helmet with some layering inside(made of sponge or smth)? This way when ya fall ya head won't like bounce of the floor but will slowly protect ya head

  18. Tanks have explosive armor platining where, when hit, it explodes outward… Maybe this could be done with (several small) airbags on helmets too: an impact of X force would cause the airbag to depoy outward… Just an idea.

  19. Anyone know what the density difference between cerebral fluid and brain matter is? It's probably pretty close, I imagine?

  20. MiPS helmets are a type of helmet that are designed to prevent concussion. They use and internal and external she'll that are connected by a pin which breaks during an impact to prevent rotational forces reaching the brain

  21. That part of the jaw there's a nerve, in boxing you use it to knock someone out and in ninjutsu you use it too.

    He might have got no concussion, the hit there could have done that. It sends a big shock to the brain when you hit a nerve

    EDIT: but you have scans and pictures showing differences within the brain so nevermind

  22. Throughout recent years, the media has called extensive attention to concussions. This has brought on an abundance of information and talk concerning those activities most likely to cause concussions (i.e. football, boxing, biking). However, it has also brought about a substantial amount of fear about these activities. The research performed by David Camarillo and his team has the possibility to completely change the outlook about concussions, which is an absolutely incredible discovery!. Through the use of the mouth piece, the typical view of how a concussion is formed was disproved. Instead, it draws attention to the severe problems that are created in the inner brain, especially the corpus collosum and inner ventricles. This shows the importance of a new helmet more equipped to protect against these injuries. This is an incredible advancement in the study of concussions. Through these discoveries, protective devices are able to be created that are better equipped, allowing for millions of individuals to keep participating in the activities they love. My hope is that after David Camarillo and his team perfect their helmet that combats concussions, the media will advertise this fix as widely as they have with the problem.

  23. I had 4 concussions in the span of 4 years due to unrelated freak accidents and I'm horrified to get a scan like that

  24. i only clicked on this video to get educated about my own situation. i quit hockey about 3 years ago because i kept getting hit in the head and getting injured so i was sick of it. but i've started to notice lately that i get headaches weekly and my diet is balanced i sleep well and i don't really get stressed so i'm wondering if maybe i should see a doctor? i had 3 diagnosed concussions in my 7-9 years of hockey. please let me know ppl

  25. Dear american youtube commenters,

    I feel compelled to tell you it is time to learn that other sports exist besides football, with participants numbering in the hundreds of thousands, that depend on good head protection technology -who are also not going out of their way to slam their heads into each other or the ground.

    Thank you for your time. Now please continue going back to yelling in caps over what the meaning of 'triggered' was originally supposed to be.

  26. The "airbag" trigger idea should also be used on every Airlines, but instead it triggers a foam that encapsulates each passenger giving the added protection against impact.

  27. Using FΔt=mΔv, it's not likely that decreasind an already relatively short amount of time will have much of an effect…although it's possible.

  28. But this has changed a little bit with the introduction of MIPS technology. It will not protect you a 100% but it will give some extra added protection against concussions which isn't found on helmets without MIPS.

  29. For cycling, good infrastructure is way, way more important than a helmet. But for full contact sports like American Football, how about just playing a sport that doesn't involve contact?

  30. Was anyone else uncomfortable throughout this entire video? It started when he said "cerebrospinal fluid", and after that, I couldn't stop touching my head.

  31. https://cyclingtips.com/2016/12/origins-the-story-of-mips-helmet-technology-for-brain-injury-prevention/

    Enjoy 😉

  32. Helmets do reduce concussions because they reduce the g-forces your head experiences when it hits something but they don't prevent them. It's the difference between your hard skull hitting the road and your skull having a somewhat loose and giving helmet around it and hitting the road.

  33. In the Uk all motorcycle riders have to wear helmets apart from Sikhs : they have the best protection of all which is a lifetime of wrapped up hair contained by a turban that cushions the brain. This is a near perfect helmet. If the turban receives a glancing blow it will start to disintegrate rather than pull the head around.

  34. I have a theory when I play tackle football with no equipment we don’t smash each other we only tackle no ramming or spearing so what I’m guessing is that they feel secure when they have helmets and equipment

  35. It is interesting his point about sideways head movement being worse than straight forward and back. Maybe that is why you do not see CTE prevalent in soccer players who can suffer 100gs when heading a goal kick. Most of the time, not all the time, we are moving our head straight forward when heading.

  36. The mouth guard with its new technology will provide a valuable data set to understand the forces athletes face while playing football, hockey, and other contact sports. The video is a valuable incite into what is happens from such force being applied to the head. Michael Sefton, Ph.D. see: www.concussionassessment.wordpress.com

  37. People can say any sport may not be worth it. We can come up with examples for not doing lots of activities based upon risk. We don't have to drive cars either. I so much wish we could test for concussions with better science rather than observation. I hope the day soon comes.
    The prevention by not participating argument can be taken with any endeavor where someone may be injured.
    As far as science, if we bring it into the discussion, there really is not enough science by scientific method – yet. After the fact analysis is too speculative. We have to come up with better real time diagnosis and methods before claiming a position around concussions.
    Fear can skew science. Money does too. Common sense tells me maybe I shouldn't take a chance and participate in lots of sports. It's a lively debate, but some people love boxing, football, hockey and on and on. And yeah, you don't see rich kids boxing. There's another thought.

  38. Real life CTE crimes from lack of full data please follow false label crimes https://youtu.be/xh8U1JluQOw

  39. That was a surprisingly disjointed presentation. I was expecting a scientific presentation with sensible theories tested out with data. Instead, it meanders around brain areas, weakly tries and fails to refute the received wisdom on concussions, makes a big deal about corpus callosum but fails to follow through, differentiates lateral versus vertical movements but does not connect it to the solution, and finally, after talking up much hope, reveals a solution as an airbag. Then goes on to take on government regulations! Confused as to what the take away is. We are not even going into the fact that Takata airbags are being recalled for unintended release since 2013, predating the date of upload of this presentation. This is not a Ted talk. This is a dud talk.

  40. Why not just combine the older helmet with the new airbag prototype? Just put the airbag on the outside so that way it passes the test and can be sold

  41. I’ve heard rugby is safer due to no pads and helmets from false sense of security even football back in the 1950s was safer due to less equipment how about we go back to leather helmets just a thought

  42. So based on what I understand (and please correct me if I'm wrong), the 'whiplash-type phenomenon' happened because the impact initially only influenced the part of his head that was hit, causing that particular portion to go right as the rest of the head 'lags' behind and tries to catch up. As it 'lags', more of the head is gradually pulled along by the site of impact, resulting in his head rotating left until the rest of his head caught up with the sight of impact and dragged it to the right.

  43. We now know: concussions don't cause CTE, hits do. They've found CTE in youth Football players that were never diagnosed with a concussion. Its all those "little" hits, that add up.

  44. The shock that the spinal fluid cannot absorb moves thru the brain. smack a bucket full of oil or grease, that shock wave goes thru the brain in the same way. I am sure that wave causes problems. Neurons probably get disconnected due to this shock.

  45. There is a new helmet company creating helmets using better protection based on the data generated from research. It took a new company to try the new technology however and a lot of the old companies are transitioning. New NFL players generally prefer the newer helmets according to what I have been reading while finding this video.

  46. Why is Will smith seems to be more credited on discovering CTE ? Than Dr. Bennet Omalu . Just saying ive been on different videos. Good discussion

  47. Ok but if damage to the corpus callosum is largely responsible for concussive symptoms, why is it the case that split-brain patients do not show concussive symptoms, and largely carry on with their lives as normal?

  48. Your presentation was very informative, Dr. Camarillo. Thank you and your team for this needed effort! When I boxed on our California high school boxing team, complete with lunchtime bouts, and the annual "fight night", my parents had the unfortunate experience of watching me get clobbered, after 3 knockdowns. My dad, who was then Chief of Internal Medicine residency program at a SF hospital, brought home an article from JAMA for me to read. This was in 1981 or 82. The article showed a walnut shell (representing the cranium) with a pea inside of it, the pea representing the brain. The article then went on to describe the whiplash effect that occurred, even with boxing headgear. I appreciated the information. I continued to do some sparring even on my college campus, but the sparring was light in comparison to those bouts. Today, I do have memory issues that startle both me and my wife, and my employer. I take statins, and asked my doctor if these statins could be contributing to my memory lapses. He recommended an evaluation, which is pending. My biggest concern now is my 10 year old daughter. She loves sports, which I encourage, but I will do my best to ensure she reaps the positives from such healthy activities, while minimizing any adverse consequences. Thanks again for the work you do!

  49. Doesn’t the Motorsport f1 have helmet braces that significantly reduce concussion rates? I remember seeing cars virtually explode with the driver succumbing little to no injuries.

  50. The issue with a football helmet is that it needs to sustain repeated impacts (in a single game) without the helmet losing its protective performance nor shape/fit. The solution to avoid a concussion is already there: use a, literally, motorcycle helmet, which uses a different type of much-thicker much-protective foam. Problem? Said protective foam in a helmet is only good for one hit to the head, so a player would need to go through dozens of such helmets in a game. Ergo, the solution to avoiding concussions is there; it's just not practical.

    This all leads to the question of, why should an individual expose himself on a weekly basis to the huge risk of not just one but MULTIPLE concussion-causing impacts in a single game. Don't get me wrong, I like American football and also competed in the sport of rugby. But perhaps the solution to this big problem isn't improving helmets (already improved enough) but, rather, to stand back for a moment and try to objectively see the whole picture of what happens in a football game. Don't want to change the game or rules of the game to spare players from concussions? Fair enough, then enter at your own risk. It's the same with motorcycles, but we motorcycle riders are, at least, wearing way-more protective helmets and only need to use their protection once.

  51. Riding a bike yes. If you crash. Acute event. Football, soccer, rugby etc, the pure accumulation of impacts, any one of which may not seem like a big deal, can lead to problems too.

  52. I only played little league football and I am fine as an adult. I don't know what this guy is talking about. The game was safe.

  53. I have an idea that is similar to what the speaker has demonstrated on the video's, to prevent concussions, why not create a full body suit, with clear plastic, that protects the whole body, to give it impact balance!

Leave a Reply

Your email address will not be published. Required fields are marked *