Special Report: Concussions & Neck Injuries in Sports –
A Pro-Active Approach
Jim Kielbaso MS, CSCS
Adam Stoyanoff MS, CSCS
Before we begin, it needs to be clear that there is inherent risk associated with playing sports,
and there is no way to completely eliminate concussions and neck/spinal injuries. We do know,
however, that there are ways that we can reduce the forces encountered by the head and neck,
especially in sub-concussive blows. We can protect ourselves.
The aim of this report is to arm you with information about concussions and neck/spinal injuries
and what can be done to reduce an athlete’s risk. Rather than accepting the view that absolutely
nothing can be done, we are taking a pro-active approach to the problem. We believe that proper
use of safety equipment, coaching techniques, and comprehensive training of the head & neck
musculature may be beneficial.
There are really four basic components of neck injury and concussion prevention:
1. Protective equipment – In most sports, this means properly fit, quality helmets and mouth
pieces. Unfortunately, no equipment or training currently known to us will eliminate
concussions. “The best helmet on the market can still lead to injuries of the head including
concussions,” said Scott Peck, a certified athletic trainer in Washington. “To decrease
concussions, athletes need to practice good technique in tackling and blocking by keeping their
heads away from contact.” As you will read later in this report, however, we now have ways of
determining which helmets are better able to protect us.
2. Technique – Some sports include more contact than others. Good coaches always teach
athletes not to initiate contact with the head, but we still see a lot of young athletes using poor
form when tackling or hitting.
3. Awareness – It seems crazy, but there are still a lot of coaches, parents and coaches who
simply do not understand how dangerous a concussion can be or that there is inherent risk
involved in participating in most sports. This site was set up to help heighten awareness at the
same time we discuss prevention options and proper treatment.
4. Training – This component is just now picking up momentum, but some coaches have
known about this concept for years. This is also the least publicized aspect of concussion
prevention for several reasons that are discussed further in this report. Research being done on
strength development, combined with mathematical models derived from the auto industry are
showing that a larger/more rigid neck can help dissipate forces during an impact.
Comprehensive strengthening exercises for the head & neck seem to have the most promise, but
vision/awareness training is another component that is being explored.
Concussions and neck injuries have had a huge impact on sports. Recently, some of the greatest
athletes in the world have been sidelined (potentially forever) by injuries. Peyton Manning and
Kyle Vanden Bosch had to undergo surgery to repair damage in their necks. Vanden Bosch, who
takes neck training very seriously, has made a full recovery. Sidney Crosby and Brian
Westbrook were sidelined for an entire year due to concussions that may even be responsible for
ending their careers.
The sub-concussive blows that build up over the years may be even more devastating long-term.
Even recently successful players like Wayne Chrebet are now suffering from the debilitating
effects of concussions and piled-up sub-concussive blows.
6th grader Evan Coubal from
Wisconsin and high schooler Ridge
Barden are just two boys who have
died due to head trauma suffered
during sports. Their families will
never see these boys again, and these
are just two of many kids who have
sustained life-threatening injuries.
Our approach is similar to the ACL
Prevention movement that has gained
enormous popularity over the past 10 years. Ten years ago, ACL prevention programs were
virtually non-existent. Today, female athletes all over the country understand that proper
training will limit their risk of sustaining an injury. Yet, ACL injury rates haven’t slowed down.
It doesn’t mean that the training has not helped. And, going through a training program does not
mean you will never hurt yourself. Training is meant to reduce risk or severity of an injury.
The same goes for properly training the neck & head to reduce the risk of concussions and
serious neck injuries. The training does not eliminate the injuries, but it may help to lessen the
risk or severity.
The leading researcher on neck training, Ph.D.
candidate Ralph Cornwell, put it best when he said “If
we know that it might help, and it’s not going to hurt,
why wouldn’t you want to do this kind of training?
People do ACL prevention programs all the time.
This is like an ACL prevention program for your
brain and spinal cord. You can replace your ACL, but
as far as I know, you only have one brain. It just
makes sense to protect it.”
Research done by the NFL is now revealing that the
repetitive sub-concussive blows – the hits that don’t
knock you out, but just ring your bell a little – may be
the main culprit behind the long-term brain damage
seen in many former athletes. Many of these athletes are now suing major sports organizations
because they are mentally and physically disabled due to these blows. It seems that every brain
has a certain number of hits it can take before long-term damage sets in. The more G-forces the
brain encounters, the worse it gets.
Training may reduce the G-forces encountered on
these sub-concussive blows, raising the bar on the
number of hits it will take before the long-term
damage sets in. This is some of the best news ever
presented on this topic, because it gives us hope
that we may be able to combat this problem.
Major sports organizations like USA Hockey and
the NFL are recognizing that something must be
done, so rules are changing quickly. Even Dr.
Robert Cantu, who is considered one of the leading
experts on the subject, has said that he thinks young
athletes should wait until they are stronger and
more mature before engaging in intense
contact/hitting sports. This means that the leading
authority on concussions understands that being
stronger will have a positive effect and is part of the
concussion prevention equation.
With the knowledge that resistance training may
help prevent injuries and, when done properly, can cause no harm, why would we NOT
strengthen the muscles surrounding the head and neck?
We also want to make it clear that most of this
pro-active approach is based on theory. We
acknowledge this and still feel it is incredibly
valuable information that has the potential to help
a lot of people.
Many people completely accept that mouth-guard
usage, which is now mandated by most football
organizations, is an important part of concussion
and injury prevention. Interestingly, all of the
evidence supporting mouth-guard usage is based
on the theoretical modals of Newtonian’s Law of
Physics that states that an increased separation
between two adjacent structures increases time to
contact.
All of this stuff is based on theory because it’s
almost impossible to test in real life. Researching
the benefits of training the musculature of the head and neck would be even more difficult to test
in real life because of several complicated issues.
First, most people don’t know how to safely and
effectively train the head and neck musculature. In
fact, most of the neck training being done in
America is absolutely terrible and potentially
dangerous. The use of neck harnesses, poorly
spotted manual resistance and neck bridges are just
some of dangerous methods we’ve seen. Isometric
holds, exercises with balls and self-spotting are
other techniques that are ineffective at best. The
lack of neck training in college football, hockey,
lacrosse and soccer is mind-blowing, and it’s
MUCH worse at the high school level. Many
coaches who don’t know how to safely and
effectively train the neck simply don’t do it, which is leaving kids and parents in the dark. It’s
certainly not easy to implement, but properly training the neck should be a priority for all
coaches in contact sports.
Second, it would be next to impossible to produce scientific evidence to show that training will
help prevent concussions because you would have to use real human beings and expose them to
potentially life-threatening blows. This would never pass any ethics committee, so the research
probably cannot be done.
Still, the automotive industry has known for years that a stronger and stiffer neck significantly
reduces the G-forces encountered by crash test dummies in crash research. It seems obvious that
a stronger neck would be extremely helpful during a blow to the head, but most doctors aren’t
yet ready to admit that. That could be because:
a. Doctors won’t make any money from the prevention side of this issue.
b. Most doctors are probably unaware of how to properly train.
c. The long-term effects of thousands of sub-concussive blows is nearly impossible to track.
Reducing the forces encountered during these sub-concussive blows that build up over time may
be the most important reason for strengthening the neck.
d. Doctors typically refer to the scientific literature, but we already established that this evidence
will probably never be published in any scientific journal.
Sports Concussion Basics
It is estimated that over 300,000 sports related concussions occur every year. Football has the
highest rate of concussions, but ice hockey, soccer, lacrosse and field-hockey are not far behind,
and younger athletes are more susceptible. Long-term research suggests that 10-15% (some as
high as 20%) of participants in contact sports suffer a concussion. It has become such an
epidemic that even Sports Illustrated has devoted considerable coverage to the issue.
In lay terms, a concussion is a “brain sprain” or a
“bruised brain.” A concussion is brain injury caused
by a blow to the head, a fall, or another injury that jars
or shakes the brain inside the skull. The brain is a soft
organ surrounded by spinal fluid and protected by the
hard skull which acts kind of like a helmet. Normally,
the fluid around your brain acts like a cushion that
keeps your brain from banging into your skull. But if
your head or your body is hit hard, the brain can crash
into your skull and get injured. The shaking causes
energy to be created that travels through the brain,
disrupting normal function.
Some people will have obvious symptoms of a
concussion, such as passing out or forgetting what
happened right before the injury. But other people
won’t. You don’t have to pass out (lose
consciousness) to have a concussion. With rest, most
people fully recover from a concussion, sometimes
within a few hours, but it can sometimes take a few weeks (or even months) to recover from
more severe blows.
The human brain has not fully matured until the early 20′s. Younger brains take longer to
recover from a concussion and may be more vulnerable to the effects of another concussion
when it has not fully recovered from the previous one. In rare cases concussions cause more
serious problems. Repeated concussions or a severe concussion may require surgery or lead to
long-lasting problems. Because there is a chance of permanent brain problems, it is important to
contact a doctor if you or someone you know has symptoms of a concussion. When in doubt –
check it out.
What Happens During a Concussion
The human brain is very complex and it maintains a delicate balance between the chemicals
inside and outside of its cells. During a concussion the membranes of the brain cells are
distorted causing chemicals that are normally on the outside to rush inside the cells, forcing out
the chemicals that are normally inside the cell. This starts what is known as a cascade of
chemical changes in the brain. As it attempts to return to normal, the brain’s demand for energy
(glucose or sugar) increases by about 150%. To complicate the issue, the brain’s ability to
deliver the required glucose drops to only 50% of normal. This mismatch between supply and
demand is what causes the problems after a concussion.
Types of Sports Concussions
Most sports concussions are divided into two types: simple and complex (also referred to as
Uncomplicated or Prolonged). A simple concussion is when there is no detectable damage to the
brain itself. A complex concussion is when there is overt or detectable damage to the brain such
as a bruise or bleeding.
Many doctors also use a grading system where concussions
are rated as grade 1, 2, or 3. In reality, there are over 20
different grading systems that have been used. Unfortunately,
none of the grading systems have effectively established
treatment guidelines and none have been able to accurately
determine recovery rates.
When symptoms last more than three weeks, a diagnosis of
Post Concussion Syndrome (PCS) is often made. It has been
shown in research that dizziness directly after the injury often
leads to an increased incidence of PCS. There are many
medical options for athletes with PCS including therapy and
medication.
Concussion Symptoms
You don’t necessarily have to lose consciousness to have a concussion, but if you did, then it is
definitely considered a concussion. Just after a concussion an athlete may be confused and/or
disoriented any may have a hard time recalling events immediately before or after the blow. The
athlete’s balance may be affected and they may repeat themselves. Sensitivity to light and sound
is common as well as headache and irritability. Below are common symptoms of a concussion:
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Headache
Poor balance
Nausea/Vomiting
Affected smell
Fatigue
Irritability
Affected hearing
Tearfulness/Sadness
Feeling slowed down
Increased sleep
Decreased appetite
Feeling “foggy”
Decreased sleep
Sensitivity to light or noise
Blurred vision
Poor memory/concentration
Dizziness
Symptoms can linger for several days, and much longer in some cases. Headaches, fatigue,
irritability, fogginess, and memory problems are common, but not the only symptoms.
Sometimes there can be neck stiffness from the blow and balance problems.
What Do You Do If You Sustain a Concussion?
Typically, low-grade concussions do not require extensive medical treatment. Because of the
potential for serious complications, they must be monitored closely and often after the event. If
urgent medical attention is needed, you want it to be close by. You should be evaluated
immediately after the concussion and closely monitored in case symptoms worsen. If there is
symptoms worsen (such as lethargy, headache, vomiting, stiff neck, slurred speech, and
confusion) then immediate medical care is required. If you were not evaluated at the event, you
should contact a physician or seek an emergency room evaluation.
It is extremely important not to return an athlete to play before they have fully recovered from a
concussion.
There is not one system for grading concussions, but
doctors generally check all of your senses and ask
questions to check your memory and how you
respond. Sometimes a CT scan or MRI is taken to
make sure your brain is not bruised or bleeding. These
scans are non-invasive and give a much clearer picture
of what is going on inside your skull.
Rest is the best way to recover from a concussion, but
here are some tips to help you get better:
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Get plenty of sleep at night, and take it easy during the day.
Avoid alcohol and illegal drugs.
Do not take any other medicine unless your doctor says it is okay.
Avoid activities that are physically or mentally demanding (including housework,
exercise, schoolwork, video games, or using the computer).
Ask your doctor when it’s okay for you to drive a car, ride a bike, or operate machinery.
Use ice or a cold pack on any swelling for 10 to 20 minutes at a time. Put a thin cloth
between the ice and your skin.
Use pain medicine as directed. Your doctor may give you a prescription for pain
medicine or recommend you use a pain medicine that you can buy without a prescription.
Second Impact Syndrome
A second concussion sustained before the first one has fully healed is called second impact
syndrome (SIS). SIS occurs when the brain losses its ability to control blood flow and the
pressure builds up to unsafe levels and damages the brain. When SIS occurs, it can be lifethreatening as the brain may swell rapidly and require emergency surgery. While SIS is rare, it
has lead to rapid, severe and permanent brain injury and many do not survive. All of this is
preventable by not returning to sport too soon, which is why it is so important to allow a young
athlete to fully recover before returning to sport.
Return to Sport After a Concussion
In sports, every state is now coming up with their own return-to-play rules. Concussions are
unique to the individual, and each person will recover differently. No one can accurately predict
when concussion symptoms will clear up, so it’s important to take things slowly.
A doctor must always determine when an athlete is ready to return to play. A gradual,
incremental approach is recommended based on recommendations from the Zurich international
panel of concussion experts. Before starting a return to play protocol, an athlete must be free
from symptoms and not have any memory or concentration issues. After that, the Zurich panel
recommends the following steps:
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Day 1: light aerobic exercise (walking,
swimming, or stationary cycling) keeping
exercise heart rate less than 70% of maximum
predicted heart rate. No resistance training
Day 2: sport-specific exercise, any activities that
incorporate sport-specific skills (skating in
hockey, running in soccer, etc). No head impact
activities.
Day 3: non-contact training drills
Day 4: full contact practice, participate in normal
practice activities
Day 5: return to competition
There should be approximately 24 hours between each step and the athlete must be free of
concussion symptoms after each step. If concussion symptoms return, the athlete must rest (no
exercising) until all symptoms have gone away then return to the previous level.
There does not seem to be a magic number of concussions that force an athlete to “retire” from
sports. This is determined by the severity of the concussions and how long it takes for symptoms
to clear.
The best method for determining recovery from a sports concussion is through a thorough
medical assessment of cognitive abilities, balance and other possible symptoms. , While
neurological examinations and CT scans or MRIs are relatively insensitive in detecting a sports
concussion, tasks such as memory, concentration, reaction time, and how quickly you think are
the most sensitive measures of a concussion. The best method for measuring the effects of sports
concussion is through baseline testing BEFORE an athlete is concussed so a doctor can compare
the results of the same athlete. This is why baseline testing has become so important to most
sports concussion programs. Baseline tests such as ImPACT, Axon Sports, Concussion Vital
Signs, and HeadMinder have been developed specifically for this purpose and the testing is
simple and easy to understand. The results give a doctor an objective measure of cognition,
allowing for a more accurate diagnosis and treatment plan.
Concussion Statistics in High School Sports
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There are between an estimated 1.6 and 3.8 million sports-related concussions in the
United States every year,1, 2 leading The Centers for Disease Control (C.D.C.) to
conclude that sports concussions in the United States have reached an "epidemic level."
A 2011 study8 of U.S. high schools with at least one athletic trainer on staff found that
concussions accounted for nearly 15% of all sports-related injuries reported to ATs and
which resulted in a loss of at least one day of play.
According to the C. D.C., 6.5% of all sports-related emergency room visits (173,285)
involved a traumatic brain injury, including concussion.
Football Players Most at Risk
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At least one player sustains a mild concussion in
nearly every American football game.
According to research by The New York Times, at
least 50 youth football players (high school or
younger) from 20 different states have died or
sustained serious head injuries on the field since
1997.
Anecdotal evidence from athletic trainers
suggests that only about 5% of high school
players suffer a concussion each season, but
formal studies surveying players suggest the
number is much higher, with close to 50% saying
they have experienced concussion symptoms and
fully one-third reporting two or more concussions in a single season.
One study estimates that the likelihood of an athlete in a contact sport experiencing a
concussion is as high as 20% per season.
According to the National Center for Catastrophic Sport Injury Research, there were 5
catastrophic spinal cord injuries in high school football in 2010. 67.8% of all catastrophic
injuries in football since 1977 are from tackling.
According to a study reported in the July 2007 issue of The American Journal of Sports
Medicine:
o Football players suffer the most brain injuries of any sport;
o An unacceptably high percentage (39%) of high school and collegiate football
players suffering catastrophic head injuries (death, nonfatal but causing
permanent neurologic functional disability, and serious injury but leaving no
permanent functional disability) during the period 1989 to 2002 were still playing
with neurologic symptoms at the time of the catastrophic event.
Are Girls More Susceptible?
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While a study published in the Journal of Athletic Training3 suggested that girls were
much more susceptible to concussions in sports like soccer and basketball than boys.
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The reason for the higher concussion rate
for girls are unknown, although some have
theorized that female athletes have weaker
neck muscles and a small head mass than
male athletes5 or that male athletes are
more reluctant to report concussions for
fear of being removed from competition,
which may result in the well-documented
underestimation of the incidence of
concussion among boys.6
Multiple concussions
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16.8% of high school athletes suffering a concussion had previously suffered a sportrelated concussion, either that season or in a previous season
More than 20% of concussions in boys' and girls' soccer and basketball were repeat
concussions.
Once an athlete has suffered an initial concussion, his or her chances of a second one are
3 to 6 times greater than an athlete who has never sustained a concussion.
Slightly more than a third of high school players in one recent survey who reported two
or more concussions within the same school year.8
High school athletes who suffer 3 or more concussions are at increased risk of
experiencing loss of consciousness (8-fold greater risk), anterograde/post-traumatic
amnesia/PTA (reduced ability to form new memories after a brain injury) (5.5-fold
greater risk), and confusion (5.1-fold greater risk) after a subsequent concussion.
Children who are seen in a hospital emergency room for a head injury, concussion, skull
fracture or intracranial injury) are more than twice as likely to sustain a subsequent head
injury of similar type within 12 months as are children seeking care for an injury not
related to the head, regardless of their age.
Athletic Trainer Attempts Research
Sandra Black, an ATC from Texas Tech University, examined a possible relationship between
neck strength and concussions in Division I Football players in her Master’s Thesis. Limited
resources and subjects made it difficult for her to come up with statistically significant results,
but the body of evidence that she provides still makes an obvious case for the implementation of
direct neck strength training.
Her study examined 12 athletes who sustained concussions and 12 who had not. She then went
back and compared their strength training records to see if there were any differences in strength.
There were no differences, but it’s clear that the study has plenty of flaws. Most obvious is the
fact that the 12 who had no concussions may not have been hit either. We don’t know.
Still, by digging into the relevant literature, she draws the conclusion that strengthening the neck
may be helpful in reducing the forces encountered during a hit.
Again, we are not claiming that the one-time, big hit you see on SportsCenter is going to be
nullified by a strong neck. These major blows are like a helmet to the knee – there’s pretty much
nothing that can prepare you for it.
We are more worried about the sub-concussive forces encountered on just about every play - the
small dings and hits that players get when helmets are knocked against each other or against the
ground. The player may not get knocked out or feel disoriented, but these hits can build up over
time and cause long-term damage. If we can raise the bar on the number of sub-concussive
blows an athlete can sustain, we may be able to prevent serious problems. The research that
Sandra Black conducted supports this theory.
Football Helmet Ratings from Virginia Tech
Researchers at Virginia Tech have produced the first brandby-brand, model-by-model ranking for the likely concussion
resistance of helmets. They created a star-rating system
modeled on crash safety rankings for automobiles. These
rankings clearly identify the best and worst helmets.
Virginia Tech researchers give high marks to the following
helmets:
 Riddell Revo Speed
 Riddell Revolution
 Riddell Revolution IQ
 Schutt Ion 4D
 Schutt DNA
 Xenith X1.
The Virginia Tech researchers give medium grades to the
following helmets:
 Schutt Air XP
 Schutt Air Advantage
The Virginia Tech rankings warn players not to wear these
helmets:
 Riddell VSR4
 Adams A2000
None of the research was funded by a helmet company or any
other organization with the potential to profit from the results.
Interestingly, the report found absolutely no correlation
between cost and ratings.
In fact, the lowest-ranked helmet, the Adams A2000, costs $200, while the four-star Schutt DNA
retails for $170. The DNA looks like the best value on the market right now -- nearly as good in
safety ranking as the top-rated Riddell Speed, but costs about $75 less. This can make a huge
difference when purchasing a large number of helmets for a team.
Virginia Tech's current findings pertain to pro, college and prep football, but they have already
started to study helmets for youth football. No results are available yet.
Studying hockey and lacrosse helmets would probably
produce similar results and differences, but we have not
found any studies or rankings yet.
In the 1960’s, football helmets were vastly different than
what is available today. In fact, skull fractures were very
common in football back then. Today, with upgraded
helmets, skull fractures are very rare, but we still see plenty
of concussions and neck injuries.
To help regulate helmet standards in the 60’s, the National
Operating Committee on Standards for Athletic Equipment
(NOCSAE), an independent organization, was formed. Today, the NOCSAE sticker MUST be
put on all helmets allowed to be worn in the NFL. Helmet manufacturers must be granted
approval from NOCSAE after going through their "severity index" of what happens in a linear
impact.
What’s funny is that ALL helmets on the market get to put the NOCSAE seal on them.
To receive the NOCSAE seal, a helmet must score no more than 1200 on their index. ALL
helmets on the market in the past decade have passed the NOCSAE test as long as they score
below 1200.
"Because every helmet always passes the NOCSAE test, in effect that test says nothing," says
Stefen Duma the Virginia Tech engineer who led the rankings project. "An Adams at a severity
index of 1150 and a Riddell Speed at an index of 400 offer vastly different protection. But to the
NOCSAE seal system, they're the same. NOCSAE ranks all helmets as equal, and that is just not
true."
NOCSAE makes money by licensing the use of their logo. That, and their inadequate rating
scale, discounts the value of what having their logo on a helmet means. This should not be the
only factor used when deciding which helmet to purchase for an athlete.
Researchers at Virginia Tech seem to be taking the same pro-active approach to prevention that
we are taking. "There will never be perfect information, but we know enough to do something
today," Duma says. He went on to note that many kinds of safety advances that were initially
controversial, and are now considered great ideas -- seat belts and air bags, warnings about
cigarettes and cancer -- were put in motion long before scientific certainty. If it was unethical to
offer guidance absent scientific certainty, the National Institutes for Health, American Medical
Association and the Centers for Disease Control would rarely say anything.
Again, we are not claiming that concussions and neck injuries can be eliminated, but it seems
there is enough information available for us to move forward with preventive measures. While
these preventative measures may not be “scientifically validated” by research yet, we feel there
is an ethical responsibility to at least present pro-active options for keeping young athletes safe.
More research needs to be done in this area, and we hope that it takes place before more kids are
severely injured or dead.
1. Halstead M, Walter K. Clinical Report - Sport-Related Concussion in Children and
Adolescents, Pediatrics 2010; 126(3): 597-615 at n. 22, 23 (citing studies);
2. Lincoln A, Caswell S, Almquist J, Dunn R, Norris J, Hinton R. Trends in Concussion
Incidence in High School Sports: A Prospective 11-Year Study. Am. J Sports Med. 30(10)
(2011), accessed at
http://ajs.sagepub.com/content/early/2011/01/29/0363546510392326.full.pdf+html
3. Gessel LM. Fields SK. Collins CL. Dick RW. Comstock RD. "Concussions among United
States high school and collegiate athletes" J. Athl Train. 2007; 42(4): 495-503.
4. Lincoln A, Caswell S, Almquist J, Dunn R, Norris J, Hinton R. "Trends in Concussion
Incidence in High School Sports: A Prospective 11-Year Study" Am. J. Sports Med. 2011; 30
(10), accessed January 31, 2011 @
http://ajs.sagepub.com/content/early/2011/01/29/0363546510392326.full.pdf+html.
5. Halstead M, Walter K. Clinical Report - Sport-Related Concussion in Children and
Adolescents. Pediatrics 2010; 126(3): 597-615 at n. 31, 32
6. Meehan W, d'Hemecourt P, Comstock D, High School Concussions in the 2008-2009
Academic Year: Mechanism, Symptoms, and Management. Am. J. Sports. Med. 2010; 38(12):
2405-2409 (accessed December 2, 2010 at
http://ajs.sagepub.com/content/38/12/2405.abstract?etoc).
7. Meehan WP, d'Hemecourt P, Collins C, Comstock RD, Assessment and Management of
Sport-Related Concussions in United States High Schools. Am. J. Sports Med.
2011;20(10)(published online on October 3, 2011 ahead of print) as
dol:10.1177/0363546511423503 (accessed October 3, 2011).
Much of the research compiled here was taken from www.momsteam.com, a great site helping to
increase the awareness of concussions.