This helmet cam stuff

Those of you who follow me on Twitter might have seen, in between the (well-deserved) rants about Putin, a long series of tweets about helmet issues. These were in answer to @jameyprice, who I’d like to thank for “inspiring” this. It’s something I meant to get to anyway, and I think the time is right.

But before we get to that (oh I should be in advertising) I also wanted to say that I read every comment any of you post. In detail. There are tons that I’d love to answer, and that deserve an answer for any of a number of reasons. I just don’t have the time! I’ll probably make notes and then blog answers in one fell swoop.

Don’t even think about asking about fell swoops. I have no idea what they are.

So. The question is whether having a helmet cam made the impact more severe.

I believe it was concluded that the camera had no influence on the severity of the injury. I will admit to not having read the report. But I’ll tell you what I know about this aspect of helmets. It also helps to understand a bit more about the mechanisms of head injury.

If we confine our analysis to linear forces, I think it’s reasonable to conclude (if the attachment was via suction cups, double-stick tape, etc i.e. a NON-invasive attachment) that the camera probably didn’t significantly weaken the helmet. The camera no doubt broke away on initial impact.

That said, I think it’s important to understand some of the more subtle problems with helmet appendages . . . of any kind.

Almost any interaction with its environment will make a helmet, and the head it contains, turn. Now this may only be a very few degrees, but the point is that the turning movement is an acceleration. Imagine an open wheel car having an angled frontal impact. The driver’s head pitches forward and to the side. As it contacts the cockpit side rest, an ANGULAR ACCELERATION , measured in (I think) radians per second per second, is produced. Since the head turns in a very short timespan, it all means very high acceleration. It’s intuitively obvious that any part of a helmet which increases interaction with the environment also increases angular acceleration (frictionally as in the example above, mechanically as with a helmet cam hitting a rock, or aerodynamically with the various aero appendages on modern racing headgear).

Why is this important?

Let’s take two nested tupperware bowls, put some foam between them. Oh yeah – the inside bowl contains jello, covered with some cling film. Let’s turn them over, and jam it all onto a piece of broomstick. Outer bowl =  helmet, inner bowl = skull. Jello = brain, and, yep, the broomstick is the brainstem.

Now we’ll grab the outer bowl, and twist it about 10° REALLY fast.

The “helmet’s” motion is coupled to the “skull”. The coupling is neither instantaneous nor perfect. The weight of the helmet’s contents cause some delays, as would any degree of slippage of the helmet. No matter.

Once the skull bowl has begun turning, the jello does too, but with another lag, And then, the jello brain transmits rotational energy to the broomstick brainstem. And again, there’s a lag. If you imagine some orange slices INSIDE the jello (thanks mom!) you can even imagine this kind of differential rotation occurring within the brain itself.

Each time contiguous structures are rotating at different speeds a SHEAR force is created. Shear forces are exactly what they sound like – forces acting parallel to each other but in opposite directions.

What’s shear doing at the skull-brain interface? Well among other things, it causes hematomas by tearing delicate veins running right there between the skull and the brain. That’s bad of course, for all the reasons we’ve spoken about in previous posts. Unfortunately, this can also happen WITHIN the brain itself, at areas of differing structural properties. And again, tearing of nerve tracts and blood vessels can occur in these areas. Damage and intracerebral hematomas result.

Worse still is what happens at the interface of the brain with the brainstem. Remember that the brainstem, in addition to maintaining and regulating the vital functions (breathing, blood pressure, etc), also sets up awakening and arousal of the brain. When rotational acceleration causes damage here, it is often devastating. Basically, these patients don’t wake up.

Because of how dramatically they contribute to the severity of head injury, helmet interactions with the environment, and the rotational acceleration they induce, need to be considered when designing a helmet for a specific purpose.

I cannot possibly know to what extent any of this contributed to Michael’s injuries. I, like most of you, am very preoccupied by the silence from Grenoble.

32 thoughts on “This helmet cam stuff

  1. Telling you the most consequential reasons would lead me to have to lawyer up. At least if I told you publicly. I’d win, but I have enough pains in the ass for the moment to not need THAT one.
    One of the less consequential is that it’s he, along with the FIA president, who fired me.

    • Would love to know the low down! Next time I pass through Liege I’d better come equipped with a Cohiba or 6 and be taken (temporarily) unwell … I thought he was next in line for a Sainthood! Jean Todt … He’s French, isn’t he?

  2. Jukes0711 & KC Thank you for sharing your comments about animals. These deaths can be incredibly painful too and people often feel compelled to keep silent about it.

    I have 2 questions for Dr. Gary (or anyone here).
    (1) Can people experience concussions without passing out?
    (2) However the Schumacher accident turns out, I was thinking I’d make a donation to an organization that researches TBI. Can you all recommend one?

    • Hi Siara! Great question. A concussion is defined as transient neurocognitive dysfunction after a blow to the head, and with normal imaging. This can mean problems with memory, concentration, orientation, etc, but does not require a period of unconsciousness. If there IS loss of consciousness, this is a higher grade concussion, that’s all.

      As for TBI research charities, I know that Sid helped found The British Brain & Spine Foundation (or something like that). That might be good. In any event, NOT the Institut du Cerveau et de la Moëlle Epinière – I wouldn’t trust its founder farther than I can throw him.

      • Latest official news according to Pitpass:

        A statement, issued by his official spokesperson, Sabine Kehm, reads:

        “Michael is still in the wake up phase. The situation has not changed. Any medical information published which is not confirmed by the team of doctors treating Michael or his management has to be considered as not valid.”

        Any views?

      • I must admit to being quite shocked at that last remark about the founder of the Institut du Cerveau et de la Moëlle Epinière whom you identify in an earlier comment as Prof. Gérard Saillant. Any chance of telling us a little more about what leads you to feel the way you do?

  3. Latest Statement (as reported in the BBC) “Michael is still in the wake-up phrase,” said his manager Sabine Kehm in a statement on Friday. “The situation has not changed.”

    This suggests to me that no news will be forthcoming until Michael is out of the wake-up phase. This suggests that if MS started to breath on his own without a ventilator but hadn’t “woken up” – i.e., was still in the “wake-up phase”, then this wouldn’t be reported officially. This also suggests that the only thing the Family are presently focusing on is MS waking up. Hence reports of Family speaking to MS for periods of 8 hours at a time.

    It seems to me that whether or not MS is on or off a respirator is not important to the family (hence not worth reporting in their view). The only thing that is important for them is whether MS has woken up or not. Once MS has woken up then that would be the start of a new phase in MS recovery.

    Of course there is speculation in the above but it is consistent with “information” so far provided / available.

  4. Another informative article. Is there a way to reduce such rotation on impact in terms of design of helmet etc, There probably isn’t an obvious solution to this.

    • I understand that the University of Adelaide has been doing some research around double-skinned helmets with lubrication between them, mainly looking at a cycling context where the friction of the helmet skidding along the ground can cause a rotation.

      If it leads to something good for cycling helmets, there’s a fair chance that repurposing it for other applications (skiing, motorsport etc) would follow afterwards as the same corporations make helmets of all kinds under different brand names.

    • That would be fantastic if true. There seems to be indications that MS could have been breathing on his own for some time (maybe taken on and off the ventilator). Massa’s comments suggested that MS was breathing on his own when he visited him – he saw his mouth and his face & he seemed to be sleeping as in normal sleeping.

      I would just like to add the brain is characteristically a parallel type of processor – there is something called remodelling that occurs in the brain that can get brain systems up and running again after a major incident such as a stroke. In the aging brain there is something called the cognitive symptom reserve. I think this tends to occur more in the mid to upper parts of the brain.

  5. The silence out of Grenoble you reference rings in my head daily as if I had been to an F1 race the day before. I wish there were news and then I’m scared of the news I may receive. I hope Michelle is resting without out pain and knows that thousands of people he never met think of him dearly and wish him and his family strength and courage.

  6. Thank you, Gary for your explanation as to how the brain stem can be injured. As an an F1 fan,I’ve only started reading your blog since Michael’s accident, and I would like to thank you for putting your thoughts into language that I understand. It is incredibly painful and too close to home for me, we lost our darling dog last year after an accident which left her with brain stem injuries, and the only stimulus she was responding to was pain. You can imagine what our ultimate decision was when we were told that, also one pupil was blown and and the other was pinpoint. Can I just thank you for your explanation of what exactly having a brain stem injury means, it doesn’t lessen our loss, bur it does ease my mind that we made the right decision for her.

    I do appreciate that there is a big difference between humans and canines, though. I can understand why there is a lack of information coming from the Schumacher family, I found it incredibly difficult have to tell other people what was happening with our dog, but I do feel that with the F1 season approaching, that the PR strategy needs to change, even if it is only a monthly update that says nothing to report.

    As for the helmet can stuff, I’d be interested to know his the can was attached to Michael’s helmet, through my OH’s work as the lead test engineer for airline seats I understand that certain adhesives can make plastics more brittle, it would be interesting to know if this was the case.

    • Jukes0711
      I know this is way off subject, but I wanted to offer my deepest condolences for your profound loss. Even though I am a cat person and have lost two cats with TBI, one died from a dog attack and the other my roommate ACCIDENTLY left in the clothes dryer. The fact that our experience with TBI involved our loved and cherished animals, pain of loss remains pain of loss and frankly, sometimes I wonder if we would all be better off with animals in charge, but that is a very personal thought and VERY off topic. Thank you for sharing on both topics.

      • KC, thank you, it was an incredibly difficult time, as I’m sure you know. Only another pet owner can understand the pain.

    • Thank you jukes0711. My heart goes out to you and ALL the others who have suffered through the gut wrenching pain of loss, animal or human. I’ve lost both my parents & several close friends but nothing compares to the anguishing loss of my pets over the years. I am well read, educated & mentally stable, yet I’ve been berated by many for my “incomprehensible” reaction & grief regarding my beloved animals demise. I salute you for your brave admission, sharing on the recent lost of this special family member. Love is love. Loss is loss. No one has the right to judge the emotional competence of a person grieving. I vehemently believe it must NEVER be compared as to which type of lost life causes more emotional pain. We all have our personal reasons why one tragedy hurts more than another.
      The walls of my home adorn dozens of pictures & posters of Michael Schumacher. He smiles on my computer desktop. My screensaver displays a beautiful gallery of photos; Michael, his F1 cars, his victories etc. A piece of my heart broke on December 29 2013 when I heard the news. Now I grieve. Is it “better” to be alive yet suffer horrendous disability? Or is it kinder to let go in peace & love ?
      I thank you Dr. Gary for all the thought & effort you put into your blog so those of us have somewhere to go for information that is clear & meaningful, when we just don’t know what to think or believe.
      I have absolutely no doubt that wherever Michaels conscience soul is now, he applauds his good friend former F1 doctor for providing some sense of comfort to all his devoted fans in these, their hour of painful chaos.

      • Hey watch it there Liza, you got me choked up. Thanks for the lovely thoughts. And you’re right of course. There’s something very . . . primal about our love for our animals. Maybe because the bonds between humans and domesticated animals actually helped us survive evolutionarily? It’s much more like the love of a child than that for a fellow adult. Qualitatively, not “quantitatively” of course!

  7. Hi Gary – I am pretty sure that you know about this, but if you don’t here is the article:

    “FORMULA 1 ace Michael Schumacher’s brain was damaged in a motorbike accident he suffered in Cartagena (Murcia) in 2009, reveals the doctor who treated him at the time.

    The seven-times world champion damaged the right-hand side of his brain when he fell off a motorbike at high speed just over four years ago in the south-eastern Spanish coastal town.

    “The left artery broke – and there are only two arteries which supply blood to the cerebellum,” explained Dr Johannes Peil, manager of the sports clinic in Bad Nauheim.

    In an interview with German national daily newspaper Bild, Dr Peil said the cerebellum is the part of the brain which controls motor functions, or movement and reactions.

    Despite his injury in Murcia, German-born Schumacher returned to Formula 1 in 2010 after coming out of retirement, joining team Mercedes. Fortunately, Dr Peil does not believe the permanent effects of the injury in 2009 will affect his chances of recovery now, following a skiing accident on Sunday, December 29 at the Méribel resort near Grenoble, where Michael and his family have a holiday home.”
    This 4 years ago injury where the left artery to the cerebellum broke and trauma occurred to the right side of the brain had to be somewhat considered serious, I would think.

    Today, even with the tiniest of understanding, it is hard for me to not consider the possibility that the recent skiing injury may have, could have, impacted in some way because the brain was in fact already affected albeit in 2009. In addition, it is hard for me to embrace that BREAKING an artery to the cerebellum is a just a little – don’t worry too much about it – incident.

    It also seems to me with all the scans and tests that they are doing on a daily basis that someone must have a pretty good idea of where Michael is today. And YES, that Michael apparently is not breathing on his own doesn’t seem to be on anyone’s information list. How this sad for everyone.

    Any insight, or light that you can shine here would be appreciated.

    • Having sustained 3 concussions in my younger years, it was made very clear to me that each subsequent head injury would have a cumulative affect.

    • Hi KC, thank you very much for this. This I think is important and may help to explain the severity of MS current fall. I suppose MS would have known the risks but living life is a risk.

  8. Thanks again Gary, your insight and understanding are well received and the blogs you provide are unparalleled by anything else I’ve seen.

    I’d be interested to know what the knowledge sharing is between the various agencies (FIA, UCI…etc.) regarding head protection and other impact related injuries. From my experiences the knowledge share is poor due to differentials in accident speed (cycling is significantly slower than most F1 accidents). I’d also like to know more about how impacts relate to the body in general. Are there more introductory papers I can read to educate myself on these matters?

    • Hi. There is currently no collaboration at all between the FIA and other Federations in terms of head protection. In fact, this would properly be tasked to the FIA Institute. Now interestingly, the president of the Institute (and president of the FIA Medical Commission) is Jean Todt’s close friend Dr. Gérard Saillant. Interestingly, Saillant is the founder of the Parisian Institut du Cerveau et de la Moëlle Epinière (Institute for the Brain and Spinal Cord). Dr. Saillant is very close to Michael (he was on the rostrum on the Monday press conference).

      And despite these close ties . . . silence. Not at all sure I understand.

  9. Pingback: Schumacher had a bad ski accident - Page 112 -

  10. I remember seeing a tweet from you before on this same subject (well, it was before Michael was injured, so it was a more general case). Like the person above I’m an engineer and really appreciated your jello example.

    Has any studies been done on the effect the HANS device has on this issue? I’d think it would help a little, and just a little change in the time frame of the coupling forces would really help to minimize the accelerations and sheer forces inside…

  11. I assume that during your curtailed time with the FIA you were able to provide valuable inputs to them, and that there are many others who research and work with the design of protective headgear for pilots, racers and others. However your comments on the Schumacher case (and his public persona) have made me, and I am sure many,many others, VERY much more aware of the importance of correct protective headgear, as well as the extreme fragility and vulnerability of the brain. I don’t quite know how, but wish your contributions can be disseminated to a much wider audience in an easily digestible format – maybe a short video presentation. Your comments made me think back to my own early days in motor sport and how little we knew and cared about these matters. I now believe that if your “teachings” could be made available to every motor sport club in the world it will – beyond any doubt – save a few lives. Maybe, we all desperately hope, if Michael recovers sufficiently his persona can be leveraged to spread that message around the world. It may be the only good outcome from his tragic accident.

  12. Thank you for this explanation. I have been wondering how a bonk on the head, even a bad one could cause brain stem injuries. I pray every day this is not the case with MSC, The very thought saddens me to no end, I am from Alabama, I know all about fell swoops! Apparently we have a good number of them. Thanks, again for the information, good, bad, and otherwise.

  13. Thanks Gary for once again give us some clear explanations about all this stuff realated with Michael’s accident. As an engineer I fully understand what happens with the forces, shear forces, accelerations and so on, and beyond all doubt your home-made experiment of what may occur to the brain is simply excellent.
    But after reading your post, I’m not optimistic at all about any possibility of recovery. As you say, the silence from Grenoble is worrying.
    It’s hard to deal with the worst case scenario, but thanks for telling us the things in the way that they are.

  14. 😥 All there is to say really. I really didn’t want to know that, but thank you so much for telling us. At least we can worry cluefully, which seems better than the alternative.

    • I didn’t think about shear due to angular acceleration, but it would make things worse, I guess. I don’t think that wouldn’t explain the helmet being split in two either. I thought that, if you have an appendage on a helmet and if the point of impact was the appendage, the impact load would be applied over a much smaller area, namely the helmet mounts. This would probably also cause the load not to be spread out as efficiently if there is no attachment. Just a hypothesis…

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