With the increasing attention being given to the potential
dangers of concussions and repetitive head impacts, interest in helmet
technology has increased also. While this attention has led to advances, it
also has led to widespread misinformation about the ability of helmets to protect
athletes from head injuries.
An understanding of the protective capabilities and
deficiencies in helmets is the best way to ensure athletes have the correct
information.
What Helmets Do Well
Helmets can be classified also as single-impact use or multiple
impacts. For example, football helmets are designed for repetitive/repeat
exposure, whereas most bicycle helmets are designed for only a single
significant impact. In other words if you fall off your bicycle and hit your
head that helmet should be discarded and replaced with a brand new one (never a
good idea to buy a used helmet). Team
sport helmets are designed to protect against multiple head impacts typically
occurring in the sport (e.g., ball, puck, or stick impacts; player contact;
etc.), and, generally, can continue to be used after such impacts. (1) From my
experience baseball helmets are often slammed to the ground out of game related
frustration and take on a lot of general abuse being tossed around in the bench
area. Paying close attention to this off the field wear and tear should be
noted in addition to making yourself aware of manufacturer’s recommendations
for replacement or reconditioning.
Laboratory data clearly show that helmets, including padded
headgear, are generally good at distributing impact forces. This is a result of
not only the impact absorption of the material but also the ability of the
helmet to spread the force over a greater surface area. Helmets therefore have
the potential to decrease injuries caused by such forces. These types of
injuries include skull fractures, cerebral contusions, and intracranial
bleeding. However because each head impact/injury is an almost infinitely
unique combination of multi-directional forces, it can be difficult to
extrapolate laboratory data to real-world safety. (2)
Football carries a significant risk of head injuries and
accounts for the majority of sport-related catastrophic injuries in the United
States. According to the National Center for Sports Injury Research, brain
injury-related fatalities decreased from 128 (1961 to 1970) to 32 (2001 to
2010) (3). This number has been relatively stable, though slowly decreasing,
since 1981 (3). This coincides with some improvement in helmet technology, but
significant rule changes were also instituted in this time frame. The decrease
in fatalities is likely related to both improved helmets and these changes, but
it is unclear how much of the effect should be attributed to each. These
injuries almost are seen exclusively in high school and college athletes. This
most likely is due to the increased numbers of participants versus
professionals.
Other helmeted sports, ice hockey, and to a lesser degree,
rugby and soccer have generally overall lower risk of fatal or incomplete
recovery. There are some data suggesting helmet effectiveness and no reported
fatalities in Sweden since 1963 when mandatory helmets were introduced, but
helmet introduction in hockey also coincided with an increase in facial
injuries and concussion. It is unclear whether a more aggressive playing style
(risk compensation) or increased attention may have led to this increase. There
have been few direct head injury-related deaths reported since 1983 in high
school or college ice hockey. There are little data on fatal or incomplete
recovered head injury in soccer with the small number of soccer deaths almost
all related to a goal falling over onto a participant.
What Helmets Do Not
Do Well
There are two important anatomic issues that may limit a
helmet’s ability to protect against concussive injury. First brain tissue has
very little resistance and deforms easily to shear forces. An example of a
shear force to the neck would be a football player that is hit form the side,
his torso will travel in the direction of the hit while the head/neck tilt in
the opposite direction of the force applied to the torso. Based on our current
understanding of concussion, it is these shear forces that contribute most to
concussive injury. Secondly the brain is a free-floating structure, making it
susceptible to injury from these forces. (4) In other words the helmet offers
little protection against shear forces and due to the weight of the helmet may
even contribute to the shear stress.
Clinical data
Clinical data related to concussions can be difficult to
interpret. Concussion rates have been increasing in recent years, and it is
unclear whether this is a true increase in incidence or an increase in
reporting. Given our increased awareness of concussive injuries and significant
educational and legislative efforts, the increase is likely in large part a reporting
difference. This does however make older studies on helmets and concussion
difficult to compare, and these increased rates would suggest that modern
helmets do not provide significant protection from concussive injury. This is
consistent with the findings of several recent expert summaries on concussion
(5,6).
Risk compensation
This theory suggests that the protective value of helmets,
or any protective equipment, may be limited by the tendency of the wearer to
increase risk-taking behavior while wearing the equipment. This theory is weakly
supported by some data but it would be nearly impossible to prove it.
The value of any protective equipment is clearly limited by
the circumstance under which it is used and whether the participants are
willing to use it; however the effect of risk compensation on the protective
effect of helmets seems logical and should shine a spotlight on the fact that
coaches should always emphasize the importance of proper hitting/tackling
technique and point out what a helmet was designed for (protection) and what it
was not designed for (weapon/hitting aid). USA Football the developmental arm
of the NFL has created the “Heads Up” program to help teach proper tackling
technique and raise awareness for concussions at the youth level. It should
also be noted that field/spatial awareness (“eyes on the back of their head”)
and the ability of athletes to absorb impacts is just as vital for their
protection. (7)
The Cool Factor
Major League Baseball has approved a padded cap designed to protect
pitchers from potentially dangerous line drives. One issue however could be the
size and feel of the cap. The
padding adds seven ounces to the weight of a cap, which currently weighs 3-4
ounces. The company does not believe the caps will interfere with a pitcher's
motion or comfort adding that the best available stats indicate that 12
pitchers have been hit in the head by line drives during the past six seasons.
Many pitchers feel differently or at the very least are skeptical:
Brandon McCarthy, who worked with the company as it
developed prototypes and was also a pitcher that was struck in the head by a
line drive and suffered a serious head injury, proved how tough a sell this
could be for Major Leaguers when he told ESPN.com that the model he had tested
was "too big" and "didn't pass the eye test" and was
"too hot."
Blue Jays left-hander J.A. Happ, who suffered a fractured
skull when struck by a line drive last May 7, was also non-committal.
"I'd have to see what the differences in feel would be
-- does it feel close enough to a regular cap?" Happ told ESPN. "You
don't want to be out there thinking about it and have it take away from your
focus on what you're doing."
National League CY Young Award winner Clayton Kershaw told
MLB Network that he also has some reservations, although he's optimistic that
baseball is moving in the right direction.
"I've actually tried one of those on," said
Kershaw. "I've thrown with it. You don't look very cool. I'll be honest.
You don't look very cool out there.” (8)
In other words this cap has no chance at sticking in Major
League Baseball unless it’s mandated.
Conclusion
Helmets have shown the ability, both in the laboratory and
clinically, to decrease the risk of serious head injury in some circumstances.
Because of study design limitations, the magnitude of this protection is
difficult to quantify. Current data do not suggest that modern helmets are
protective against concussive injury.
Phil Loomis
Youth Athletic Development/Nutrition Specialist
Related Topics
NFL Players would
prefer head injury to knee injury
USA TODAY Sports surveyed 293 players on 20 NFL teams and
asked what body part they were most concerned about injuring in a game:
-46% said knees or other parts of their legs
-24% said head and neck
-26% said none
The results seem surprising given all of the emphasis the
NFL and the culture at large have given to the life-altering dangers of
concussions in recent years.
“Anytime you can avoid hits to the head it’s great,” Chicago
Bears running back Michael Bush said, “but if you get hit in your knees, that’s
your career.”
You know what’s even crazier? The USA TODAY Sports survey
also asked players whether NFL rule changes on hits to the head had made the
game safer:
-39% said they had
-53% said safety was about the same
-8% said the game was less safe
“Heads Up,” is it
nothing more than NFL propaganda?
Participation in youth football has been on the decline
largely because many parents feel it is unsafe for their children. (9) Many
critics think this program is the NFL’s attempt at image control and protecting
the long-term interest of its brand. Learn more here:
Detecting concussions
in young athletes, there’s an app for that!
GE and the NFL have teamed up to potentially make concussion
detection more precise. Unlike traditional concussion screening methods, which
require cumbersome equipment or medical training, take a long time to
administer and are prone to manipulation by athletes, this patent-pending
technology can be run on a mobile device and recognizes the changes in speech
acoustics that occur with concussions. The result is a more objective, highly
mobile concussion screening test that takes only two minutes to perform and can
protect athletes from the danger of repeated concussions.
Study reveals this
soccer population is the most vulnerable to concussion
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