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| Q&A: Dr David Hartman on Head Injuries (824 Posts)
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More thinking experiments
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On 5/23/2002
Wesley Tucker
wrote in from
(152.163.nnn.nnn)
Dr. Dave, I follow your Jello experiment with no problem. Only one issue to address. You forgot to wrap the jello in a "liquid" shell (my silicon cells.) So there is one layer of impact-absorbing material missing from your process.
I have another thought experiment to consider: drop an EGG from your 10 foot ladder. The shell breaks, the white splatters BUT the yolk remains intact (usually until you try and clean it up.) Why? I'm assuming because the concussion of the impact was transferred through the shell and DISSIPATED by the egg white. Thus, the yolk (brain) survives.
Of course, I realize that you could drop an egg from such a height as to ensure complete destruction. The same is true of helmets. As my father explained to me one time, "a hard hat doesn't protect you from a falling I-beam. But if some nimrod on the third floor drops a 2" screw, it won't plow through you all the way to you feet!"
The same is true when considering helmet design. We have to be reasonable. (Which in a society filled with litigious attorneys is almost impossible!) NOTHING is going to protect a wearer from all injury. The idea is to reduce the severity of injury while allowing a certain freedom of movement to enjoy our sport. Otherwise, we could all practice the safest head protection of all: sitting at home watching TV.
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Helmet design
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On 5/23/2002
kmg
wrote in from
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Dr. Dave,
Correct me if I'm wrong, but I'm thinking that a good helmet slowly crushes/collapses kinda like crumple zones in automobiles, to gradually decellerate (sp) the skull in an impact with the ground. This reduces the G-forces encountered by the brain, thereby reducing the impact of the brain against the interior of the skull. Shouldn't the shell of the helmet have a little "give" instead of being hard and rigid?
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A thought experiment for Wes involving Jello
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On 5/23/2002
Dr. Dave
wrote in from
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Wes,
Here's a picture for you: Imagine a hemisphere of jello (pick the flavor (g)), that is set in one of your kevlar helmets with a little bit of padding. Got it? O.K. Now go up on a 10 foot ladder and drop the kevlar-helmetted-jello onto the concrete. What will happen?
Answ: The Kevlar will be undamaged - the jello will be internally fissured, if not actually broken into pieces.
Anyway, your brain has the consistency of jello. If the shock of impact is transferred directly into a gelatinous medium (e.g., brain tissue) the shock will fissure and tear the medium. Since the kevlar does not absorb the shock, it just gets passed into the next layer. In high impact collisions you can have cavitations (holes) produced, or broken axons (shearing) from the stretching and deforming of brain tissue on impact. In some cases, having your skull fracture is actually associated with a *better outcome. Why? Because it means that your skull absorbed enough of the shock to crack, rather than remaining intact and transferring the shock directly into the brain tissue.
The risk for real brain tissue is worse, because there are knife-like bony projections (sphenoid wings) in the frontotemporal region, and portions of the frontal bone are rougher than a surform file. So the brain can get cut on its own bony casing.
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Greatful Heads helmet
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On 5/23/2002
Kaylee
wrote in from
(68.35.nnn.nnn)
I'd like to report that although my Hawg helmet is in desparate need of some ventilation, it is not nearly as heavy as a motorcycle helmet or the like. It doesn't seem heavy at all, and is in fact much more comfortable than your standard $30 skate helmet. The extra foam padding I added in the back helps keep it locked on my head, and the main stock foam is supposed to be multi-impact. I reallu just wanted to chime in and say that "heavy" is not a term I'd use to describe this helmet at all.
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Snell RS98 Standard
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On 5/22/2002
Dr Dave
wrote in from
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Check the Snell site. It has a complete description of what this helmet standard will tolerate in terms of shock etc.
http://www.smf.org
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Wes the Centurian or Crushing is Better than Hard
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On 5/22/2002
Dr. Dave
wrote in from
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Wes,
Helmets need the padding more than the shell. It's the padding that reduces g forces to manageable levels. Without it, you just have a hard shell that transmits all the force of impact directly into the brain. This is bad. This is why old cars like those tank-like Mercedes that are relatively undamaged in accidents can pulp their occupants, while people can walk away from cars that crumple up like a wad of paper on impact. You want a helmet where the padding crushes, crunches, etc., because it's the crunch/crush which absorbs the impact. I'm not sure that silicon would be very "crunchable" with very rapid impact collisions. Plus it's heavy and hot.
One last thing,to Vasocreta - a 40 mph boarding impact is much worse than falling off a rail because the acceleration physics are much more severe the faster you're going.
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Subduing Friends of Wes
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On 5/22/2002
Dr Dave
wrote in from
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If someone is irrational or belligerent after a head injury or wants to drive in that condition, you are not going to argue them out of it. Unless you are a paramedic trained in subduing intoxicated or delerious patients, don't even try it yourself. Call 911, your local police or FD paramedics. If your irrational buddy drives away, sic the cops after him or her. You're doing them a favor. If you were delerious, you'd want the same from your friends.
drD
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Head Injury Alone - Vasocreta
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On 5/22/2002
Dr. Dave
wrote in from
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Symptoms like that sound like a concussion. First thing is do not get back on a board or continue what ever got you dinged in the first place. Sports studies suggest that two concussions in a short time period have more than additive effects and may even prove fatal.
The second issue is getting some help. Carry a cell phone in a hard case if you're boarding alone. Let people know where you'll be. Get someone to drive you home or the local ER. If your vision gets blurred, or you feel nauseous or you have any kind of cognitive symptoms (slurred speech, confusion, memory problems, etc) just get yourself to the ER ASAP.
You could carry a chemical ice pack, but that's not a substitute for getting to an ER if there is really something wrong.
drD
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Getting the injured to help
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On 5/22/2002
Wesley Tucker
wrote in from
(152.163.nnn.nnn)
Take away the keys, suffer the abuse and call an ambulance. Let the pros do their job of subduing and transporting an irrational and possibly self-destructive head trauma victim.
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doh driving
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On 5/22/2002 longy
wrote in from
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true wes, i drove myself back home after threatening friends with extreme violence due to my concussion...i dont remember any of it....if you ever have a bro or sis slam and have concussion and they want to drive whats the best way to "convince" them they can't drive knowing full well concussion creates abnormal behaviour?
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Head injury first aid
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On 5/22/2002
Wesley Tucker
wrote in from
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Vaso, I just wrote a lengthy response related to specific first aid procedures for a head injury. Then I decided, "nah, this is Dr. Dave's forum, it's for him to address." (Besides, some of my first aid training is 15 years old. Maybe things have changed.) Not to be completely left out of the discussion, though, I do want to add one thing to whatever information the doctor provides:
DON'T DRIVE YOURSELF TO THE EMERGENCY ROOM! Damned if I want someone on the road who just took a blow to the head. That's good advice for both your condition and my well-being!
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Snell RS98
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On 5/22/2002 MoonDoggie
wrote in from
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This helmet is rated RS 98 what does that mean?
Snell Certified To The RS98 Ski Helmet Standard
http://www.prorider.com/pro/images/ski.jpg
David"MoonDoggie"Garcia
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Actual question
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On 5/22/2002
vasocreta
wrote in from
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Dr. Dave--
what is one to do if they find themselves in a situation where they have suffered a significant impact to the head and are alone, and feeling a bit dizzy?? Should a person stand, sit, etc...
I am not sure if this question complies with your inability to provide treatment via the web, but I am hoping that this is more of a question related to injury precaustion--how to prevent further injury, for example-- than actually treating a pre-existing condition.
Thanks.
vasocreta
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helmet
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On 5/22/2002 Gary H.
wrote in from
(17.255.nnn.nnn)
I'm gonna' jump in here, I agree that you have to know how to fall. At the recent donner FCR race, on a toe side turn, on Sundays G/S course, at the fastest part of the course, I lost traction, I ejected and planted as much plastic (knee and wrist guards) on the ground and slid something like 30 feet. My neck was sore as hell from fighting gravity so my head would not get near the ground...had I just relaxed during the fall I may have had a pretty severe impact on the front of my head/face...my point is you can have the best safety equipment and you can still get hurt. You have to know HOW to fall.
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Pro-tec "Brainsaver"
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On 5/22/2002
vasocreta
wrote in from
(198.4.nnn.nnn)
I just purchased a Triple 8 "Brainsaver" helmet made by Pro-tec. To be honest, I didn't even check if it was Snell certified and stuff like that. However, I agree with John Gilmour's earlier post, how do we determine the characteristics needed in helmets for this sport? I can't imagine that the helmets needed for slalom skateboarding would be very different than those needed by freestyle skateboarders. The level of impact that the head would endure when thrown from a skateboard moving at 40 mph as oppossed to a rider who comes straight down on his/her head when falling off a rail would be pretty comparable. I think that the effectiveness of helmets overall does not just lie in the hemet, but in the persons ability to use the helmets protective features effectively.
Knowing how to fall is just as important as the level of protection provided by the equipment you wear. We have to remember that the human head is only as hard an unripe watermelon. So, any amount of shell around a watermelon would still impose bruising.
My thoughts on this topic is twofold: more time needs to be spent be people learning how to fall in such a way that the effects of impact are minimized and that helmets manufacturers spend more time on shell lightness, and overall shell strength, and not enough time on shock absorbtion. When you play on concrete, I would venture to guess that shock absorbtion would be much more important than overall shell hardness. The body can take quite an impact if shock is minimized.
matt::vasocreta
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Helmet notion
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On 5/22/2002
Wesley Tucker
wrote in from
(205.188.nnn.nnn)
Ok, while we're discussion "pefect" skate helmets, here's my suggestion.
Ever seen those old Roman epics? The centurians wear what looks like a "skull cap" of bronze. Very form fitting with little or no space between head and hat. For skating, why would not such a configuration be ideal? Molded from Kevlar and a slight amount of padding to improve fit.
Ok, I know the objections. Most helmets have a 1/2 or more of padding and it feels like sticking your head into a box full of pillows. What, though, does a skater really need for impact protection? Two things: no crushing impact on the skull (accomplished,) and resistance to concussive reverberations. Well, I don't care if you skate wearing a chaise lounge over your head, concussions are going to happen. With a Kevlar "skull cap," odds have it the concrete would be dented before the helmet. As long as something gives on impact, all the laws of physics are obeyed. I'd rather it be the street than my cerebellum.
As far as reducing concussion, what about a completely different kind of padding? Instead of some sort of bulky foam, how about some sort of liquid? Don't laugh, but here's my idea for a form fitting cushion to reduce concussive reverberations: silicon pouches. (Yes, just like THOSE that Dow used to make.) What if my "skull cap" were lined with thin, indestructable (according to the manufacturer,) pouches of liquid silicon? Form fitting, concussion-absorbent and the ability to dissipate heat. What a great combination.
So such an impenetrable skull cap would reduce injury to the head and provide the needed freedom and light weight to ride with little interference.
Hey, we're skateboarders, not hockey players or motorcycle rider. Thinking out fo the box is the only way to go.
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heads up
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On 5/21/2002 longboardbuddha
wrote in from
(62.31.nnn.nnn)
i see what you are saying, my lid as i think i mentioned cost upwards of 200 quid (i think thats about 3,000 usd....only joking)but i needed some getting into as there was a support at the rear of the neck which actually held the helmet on in my slam...a good thing!!we need a helmet that is an amalgamation of light weight reinforced plastic or kevlar with an adjustable loop strap system which cossets the back of the neck just like the us and british army kevlar helmets....i use the british army version for ramps and pools its heavy but its protective qualities are second to none.
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helmets
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On 5/21/2002 beau brown
wrote in from
(216.103.nnn.nnn)
I was first going to post on a different subject(injuries from impact to the lower torso & extremities), but need to adress the helmet issue from my experiences. First, I am a former Downhill Racer and current Slalom Racer. I say former downhill, because I felt that I was doing as much hockey playing(hip checks mandatory)at the races as actual races. It was no longer fun, and certainly wasn't safe. Slalom racing on the otherhand is clean racing, challenging and (relatively) safe in comparison. Helmet safety became an all important issue for me when I witnessed the death of a close friend and racer, Dave Perry at the 1998 Lake Elsinore EDI race. His helmet was Snell and DOT approved. This didn't stop the design flaw that allowed his helmet to fly off(fully strapped down)when thrown violently foward. This was a full face motorcycle helmet. I also witnessed another friend carted away in an ambulence with concussion and multiple facial lacerations from crashing in an unrated, homemade "downhill ski racer" helmet. Although I agree that Snell & DOT ratings are great, appropriate equipment for the activity is more so.
I have had numerous highspeed crashes(above 50mph)myself, but luckily have never had head injuries. Embarassed to say that in the past(pre '98) helmets were not so important to me. Since then, although money is not everything, my motto has been "if you got a $10.00 head, wear a $10.00 helmet." This is not meant to be a horror story, just first hand experience.
I believe The TSG skateboard helmet is at very least DOT approved(I have one on the way), as are some of the Vigor helmets. I am hearing a lot about the Giro helmets as well. They seem to be all workable options.
We as skateboarders are seeing the day when helmet mfg's will be regonize an economic advantage to make sports specific equipment for us.
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WhiteWaterBoarders
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On 5/21/2002
Dr. Dave
wrote in from
(12.249.nnn.nnn)
I forwarded the question as to whether a whitewater helmet could work for us, to Snell (http://www.smf.org/). If they answer, I'll post their reply.
drD
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Grateful Heads/ Shred Ready helmets
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On 5/21/2002
kmg
wrote in from
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Dave G,
I checked out the Grateful Heads and Shred Ready helmets myself. They look very solid, but very heavy, and are designed for white water. I think the weight could be a negative factor in a fall. Also, there is no provision for ventilation, since it wouldn't be necessary when you're soaked in water anyway.
Do you have any juice with these guys? I bet they could easily come up with a helmet specifically designed for skateboard racing.
I'd be interested to hear Dr. David's impression of these helmets.
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'elmets
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On 5/21/2002 longboardbuddha
wrote in from
(194.117.nnn.nnn)
i think we got the wrong end of the stick here...what i meant was obviously the extreme nature of downhill and gravity sports dictates that you have the best protection you can possess (note that i dont say afford as its my opinion if its the best then pay the money or dont do the sport)now specialist mtb and motorcross helmets are peddled as safe helmets but my opinion on these are that if the face guard can shatter and take off a guys ear then there is nothing to stop said shard from entering the eye orbit and the brain (sods law says its only a matter of time)i reckon the design of these helmets will get better with time and may be an option in the future but for now i wouldn't buy one.
mike
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Dr. Dave on Impact
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On 5/20/2002
Dr. Dave
wrote in from
(12.249.nnn.nnn)
My real position is that ANY helmet is better than NO helmet. Even low speed falls without a helmet can mean major and permanent brain damage. 30-40 mph speed falls from a board can generate a 2000 to 4000 g's at the point of impact. That is skull and brain crushing, non-survivable territory.
Yes, Snell is unquestionably better, but wearing any helmet is much much better than nothing. Winding up in a tertiary care nursing home as a brain-damaged quad is not worth having the feel of the wind in your hair.
drD
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Grateful Heads/ Shred Redy
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On 5/20/2002 Dave G
wrote in from
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I know Dr. Dave recognizes no helmet that has not passed Snell, But these 2 brands are the "bullet" proof version for anyone wanting a Great helmet!! They are not subjected to snell standards (white water has no need) , But I'm sure would be willing to go there!
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full face helmets...
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On 5/20/2002 Patio
wrote in from
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hey longboardbuddah,
so you are saying that the helmet saved this guy's face from impact, but when the helmet "blew apart", (absorbing energy), a piece of it cut his ear.
That's cool.
I'd much rather have a cut off ear, than to have my unprotected face driven into the ground, breaking my nose, knocking out my teeth, not to mention the chance of "putting my eye out".
P@io
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Bicycle Helmet Safety Institute
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On 5/20/2002
Mad Hack
wrote in from
(202.95.nnn.nnn)
I know it's been said before, but here is a good link to helmet info and this place seemed appropriate to mention it:
http://www.bhsi.org/helmet02.htm
scott
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