Sensor Overload

With all that is new to the concussion realm, nothing is really new.  This includes: how the injury occurs (traumatic variable force vectors – often unanticipated – jarring the brain case), its recovery (unique and undefinable), its identification (mainly subjective but overtly obvious when objective), overall education and general understanding from day-zero to day-undetermined.

The current “hot topic” for concussions is sensors.  These sensors are nothing new, they have been around for years.  As with most technology the devices are getting smaller and more accurate; natural evolution, if you will, for sensors.  I have had the fortune of testing some products, getting deep information on others, and curiously viewing some brought to my attention.  The constant thought I have is: no product has provided a clear-cut reason for inclusion – at this moment in time.

Are sensors a good idea?

Sure, if and when they become accurate enough for trained individuals to use them without impeding current standards of care.  Further, I also believe that down the road we will be looking for a product that can accurately and systematically determine the gross effects of every blow the brain case takes.  The key being EVERY BLOW.  Not just hits to the head, or at full speed, or only in practice, or in helmeted sports.

The overwhelming information we have on concussions and their occurrence is that we just don’t know a threshold; for mine, yours, your son’s, your daughter’s or anyone.  We have a general idea of what is “bad” in terms of force transmitted to the head, but some can withstand that force without issue.  While others need half or less of this “number” to sustain the brain injury.  One of my biggest issues and pet peeves is the use of linear force to quantify and qualify concussive forces.  There is SO MUCH more that goes into getting this complex injury.

Sure there are products that have multi-axial accelerometers used to compute forces, but what research and hard data do we have that quantifies the algorithm?  Do linear forces get more weight added to them, versus angular and rotational (I certainly hope not).  What about the often innocuous looking deceleration of the skull like being clothes-lined running down a court?

I bet you could put a sensor on a race car driver in an accident and the forces be great enough to illicit a response, yet the driver has no concussion, this would be due to the HANS device and other safety measures in a race car.  While, you could put a sensor on a lacrosse player who happened to get a stick or ball to the head and no sensor response, yet that player gets concussed.

I haven’t even mentioned the general liability (see legal) issues with add-on products, which are all valid by those that deal with risk management and the legal aspects of an organization.

We know a lot about concussions.   We know that this brain injury is an inherent risk associated not only with sports but life.  What I know and we all should know is that sensors or any product does not make anyone “safer” at this time.  Concussions can only be abated/avoided by exposure limitations.  In other words if you want to avoid concussions – completely – then you should avoid doing anything that may cause one.  This includes: standing up in the morning, driving your car, horsing around with your children, playing sports, riding a bike, etc.  You get my point.   But we just don’t know what we know, when all is said and done.

When it comes to this topic (sensors) I am asked my – often over spoken – opinion.  The simple answer is that nothing warrants their inclusion at this time.  Some products even show promise and could be helpful.  However there is no need to rush out and get them.  The more complex answer is that if you want to invest money on such neat things as injury identifiers, spend it on getting athletic trainers to the places where they are needed.  We can’t see it all – hence the talking point of some products – but we do see a lot.  Not only that we aren’t out there just for concussions, we identify and treat: sprains, strains, possible fractures, life threatening emergencies.  Heck, some of us are junior meteorologists and watch for environmental issues that could create harm (heat and lightning).

Would you send your kid to a swimming pool with out a life guard on duty?  Why send your kids to collision sports without an athletic trainer?  Even if they have a sensor on their head for possible concussions, what about the nagging hip flexor strain that could turn into an avulsion fracture of the hip?  Or the quad strain that predisposes your kid to an ACL injury?

Be smart about what you know; sensors are not a magic pill and make you no more or no less safer.  Use at discretion.

Here is a handy-dandy infographic my good friend Kat made…  It’s a good teaching point:

Technology in Sports Concussion Space (7)


5 thoughts on “Sensor Overload

  1. Paul McNally August 12, 2014 / 17:02

    Sensors do not help the student athlete who receives a TBI and whose coach continues to play him.
    Senors for Soccer players? How.

    The answer is rule change. Period. Been researching this two years. A Soccer coach for 40. I believe.
    Last team refused to allow heading during training. Bunch of rec kids made HS Quarterfinals.
    Any more need to be said?

    • Tom August 13, 2014 / 15:27

      Certainly we’re not going to make wholesale sport and medical decisions based on one HS soccer team’s apparent success. There are already devices out there which can be attached to headbands or the skin to measure head kinematics in non-helmeted sports.

      To the blog post, as usual, Dustin is right on the money. Leave the sensor systems to those of us medical researchers who know we’re doing and understand the underlying biomechanical principles. They are largely research tools a this point, although I do believe they can augment (not replace!!) an ATs recognition of a potential concussion but identifying high risk activities.

      I disagree with Dustin on the point of prevention. Certainly there is no way to prevent all concussions, but there are likely ways to reduce the risks. One, as mentioned, is to reduce the number of impacts that occur. Further, it is likely that improving tackling techniques and increasing cervical strength/reaction time (Eckner 2014) may reduce the number of concussions. Much like ACL injuries, you can’t prevent them all, but that Tim Hewett has showed us how to reduce the ACL rate – hopefully in 20 years someone will be citing a new researcher who cut the Concussion rate.

      • Glenn Beckmann August 16, 2014 / 12:39

        Certainly, we’re not going to make wholesale sport and medical decisions based on one medical researchers apparent success (or lack thereof – as you submitted no basis for your authority).

        Why the judgement on Paul, Tom? While his viewpoint is anecdotal, he’s on the money in terms of facilitating some change in the current conditions. As someone who works in the helmet industry and whose company talks with medical researchers and product developers every day, I can tell you that they’re just as guilty of overreaching as you charge Paul with.

        So far, as Dustin stated, there are no third party products that make claims to absorbing force or reducing concussions or claiming accuracy with its data – that stand up to scientific scrutiny.

  2. Steve August 14, 2014 / 06:16

    Dustin…been a while since I’ve written in, but this is right up my ally. You are correct that no sensor can accurately detect a concussive impact 100% of the time. The best anyone has been able to do mathematically is ~25% accuracy, which isn’t that good considering you can flip a coin and be right 50% of the time.

    Other issues:
    1) Only one company has published validation studies. Lots of the companies will tell you their systems work, accurately measure head center of mas, motion, etc. But ask them for the PUBLISHED data and you will be met with radio silence.

    2) Adding anything sensor to the helmet (other than HITS) voids its certification. So if you (as a parent or medical professional) want to assume that risk, go for it. But many companies fail to mention this when they are giving you their sales pitch. There are a couple of companies doing non-helmet mounted systems. Once they are available (and validated) they will be great for soccer, wrestling, etc.

    To clarify…The sensors are all measuring head acceleration, not force. A force is applied to the head (or body) resulting in an acceleration (change in velocity) of the head. While the magnitude of force generally predicts head acceleration, many things can influence the acceleration (eg neck stiffness). So a 100N force to you may result in a high head acceleration value compared to a 100N force to me. So the force of a NASCAR crash is huge, but the HANS decreases head acceleration by restricting motion. The lacrosse player will be hit with a smaller force, but his/her head acceleration may be greater because the head is free to move.

    Are sensors worth it? Not as a diagnostic tool at this time, but I think we will eventually be able to. Right now the best we can do is say ‘Your son or daughter took a big impact and needs to be evaluated.’ So they serve as an extra set of eyes for the ATC that is charged with simultaneously looking after 100 kids on a football field.


    • Dustin Fink August 18, 2014 / 12:11

      Thanks Steve! Good to hear from you again!

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