Journal of Athletic Training 2022;57(2):113–124
doi: 10.4085/1062-6050-0062.21
Ó by the National Athletic Trainers’ Association, Inc
www.natajournals.org
Position Statement
National Athletic Trainers’
Association Position Statement:
Reducing Intentional Head-First
Contact Behavior in American
Football Players
Erik E. Swartz, PhD, ATC*;
Johna K. Register-Mihalik, PhD, LAT, ATC†;
Steven P. Broglio, PhD, ATC‡;
Jason P. Mihalik, PhD, ATC†;
Jay L. Myers, PhD*;
Kevin M. Guskiewicz, PhD, ATC†;
Julian Bailes, MD§; Merril Hoge, BA||
*Department of Physical Therapy and Kinesiology, University of
Massachusetts, Lowell; †Matthew Gfeller Center, Department of
Exercise and Sport Science, University of North Carolina, Chapel Hill;
‡Michigan Concussion Center, University of Michigan, Ann Arbor;
§NorthShore University HealthSystem, Evanston, IL; ||Find A Way,
Fort Thomas, KY
Objective: To provide evidence-based recommendations
for reducing the prevalence of head-first contact behavior in
American football players with the aim of reducing the risk of
head and neck injuries.
Background: In American football, using the head as the
point of contact is a persistent, well-documented, and direct
cause of catastrophic head and cervical spine injury. Equally
concerning is that repeated head-impact exposures are likely to
result from head-first contact behavior and may be associated
with long-term neurocognitive conditions such as dementia,
depression, and chronic traumatic encephalopathy.
Conclusions: The National Athletic Trainers’ Association
proposes 14 recommendations to help the certified athletic
trainer, allied health care provider, coach, player, parent, and
broader community implement strategies for reducing the
prevalence of head-first contact in American football.
Key Words: catastrophic injury, sport injury, helmet, concus-
sion, chronic traumatic encephalopathy
Key Points
Head-first contact behavior during tackling and blocking in American football persists and is associated with an
increased risk of head and neck injury.
We developed 14 recommendations based on the scientific literature and expert consensus to help address the
behavior of initiating contact with the head in American football.
High-level, empirical evidence to support strategies for reducing head-first contact behavior is lacking, highlighting
the continuing need to conduct rigorous research (eg, randomized controlled trials).
Lower-level evidence, combined with education and rule changes, shows promise for reducing injuries stemming
from head-first contact.
I
n 2004, the National Athletic Trainers’ Association
(NATA) position statement ‘‘ Head-Down Contact and
Spearing in Tackle Football’’ presented recommenda-
tions to decrease the incidence of cervical spine and head
injury risk in football participants using head-down tackling
techniques.
1
Head-down tackling uses the top or crown of
the helmet to initiate contact, and spearing is the deliberate
and intentional use of a head-down contact technique.
2
The
original 24 recommendations were aimed at reducing the
risky behaviors that can lead to cervical spine fractures and
dislocations, as well as traumatic brain injuries.
3
At that
time, head-down tackling remained a persistent behavior in
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football players despite a decades-old rule prohibiting spear
tackling. Even with new rules and contemporary educational
programs on tackling intended to protect the head, head-first
contact behavior remains commonplace in tackle football
today and, therefore, necessitates a renewed focus. For the
purposes of this position statement, head-first contact
behavior refers to players initiating contact with their heads,
regardless of where that impact is initiated (top or front of
helmet) or what they are doing when exhibiting that head-
first contact technique (tackling, blocking, or carrying the
ball).
Research
4–12
has revealed that head impacts in American
football, at all levels of play, are frequent and of varying
severity. Technologies permitting in vivo head-impact
measurements indicated that players can experience a high
frequency of head impacts each season, with crown-related
impacts resulting in the highest accelerations (ie, impact
force).
4,7
These impacts pose particular risk for both head
and neck injuries, as evidenced in 2011 with the initial in
vivo biomechanical data of a head-first tackle that resulted
in a cervical spine fracture and concussion.
13
These data
highlight an increasing concern that head impacts can cause
not only cervica l spine injuries but also acute
3
and
chronic
14–17
brain injuries. Since 2004, investigators
3,18–20
have continued to document the prevalence and incidence
of head and neck injuries in epidemiologic studies. For
example, data from the 2011–2012 and 2013–2014 athletic
seasons showed that US high school football players had
the highest sport-related concussion rate.
18
Most impacts
that result in concussion among high school football players
occur at the front of the helmet; the largest proportion of
those involving loss of consciousness occur at the top of the
head.
21
Not only is using the head as the point of contact in
American football a direct cause of catastrophic head and
spine injuries, but accumulated head-impact exposures are
thought to contribute to the risk for long-term neurocog-
nitive conditions such as dementia, depression, and chronic
traumatic encephalopathy,
22–25
emphasizing the importance
of reducing head impacts in football, regardless of the force
or association with acute injury.
Therefore, it is essential to update the 2004 position
statement and address the persistent behavior of head-first
contact in American football players. Our purpose was to
present recommendations that encompassed (1) education
and administration, (2) skill development and behavior
modification, (3) rules and regulations, and (4) technology
and scientific research as they relate to decreasing head
impacts in football.
RECOMMENDATIONS
Through its members, the NATA has provided founda-
tional leadership, research, and education for the preven-
tion, management, and care of athletic injuries.
Highlighting these key principles is the NATA position
statement on preventing sudden death in sports.
26
Thus, the
NATA continues to seek collaborations and interprofes-
sional initiatives to improve the safety of sport at all levels
by reducing injuries and illnesses. Football players must
learn, execute, and maintain head-protective behaviors.
However, we should not expect players to independently
and spontaneously learn these complex behaviors
27,28
or
transfer them to the unpredictable context and emotions of
competition.
29
The responsibility for implementing these
recommendations should not fall solely on an athletic
trainer (AT). Rather, where appropriate, the AT may be part
of a multidisciplinary team that can help implement these
best practices cohesively within the organizational struc-
ture. All stakeholders should commit to working together to
use strategies that enhance football player health and safety
by reducing head-first impacts and limiting both intentional
and unintentional head contact.
The NATA advocates that the following recommenda-
tions be carefully considered as part of an overall
prevention strategy to reduce the prevalence of head-first
contact in tackle football. The recommendations are rated
using the letters A, B,orC in association with the Strength
of Recommendation Taxonomy (SORT) developed by the
American Academy of Family Physicians.
30,31
Although
some methods for reducing head-first contact in football
have been outlined,
32,33
few data from controlled trials’
research designs have supported the effectiveness of such
measures. Nevertheless, the epidemiologic and case study
literature, in addition to models from other sports and
expert consensus, inform the recommendations that lack
high-level evidence.
Education and Administration
1. Develop and require consistent, contemporary educa-
tion for players on the dangers of head-first contact in
football as it pertains to the risk for head and neck
injury.
34
Strength of Recommendation (SOR): C
2. Develop and require documented education for coach-
es at all levels of play, including youth, on the dangers
of teaching, instructing, or allowing head-first contact
in football as it pertains to the risk for head and neck
injury.
34
SOR: C
3. Develop and require education for officials at all levels
of play on the mechanisms and dangers of head-first
contact in football and how they pertain to officiating
scrimmages and games.
1,34
SOR: C
4. Organizational bodies that involve minors should
communicate with parents and legal guardians on a
regular basis to describe the strategies used to reduce
head-first contact behavior and its potentially risky
outcomes. SOR: C
5. Encourage coaches, strength and conditioning special-
ists, administrators, ATs, team physicians, and athletics
or league directors to meet regularly and work together
to discuss, implement, and review strategies (including
the recommendations in this document) that reduce
head-first contact behavior by football players.
1,26,34
SOR: C
Skill Development and Behavior Modification
6. Introduce evidence-based, progressive techniques for
avoiding head-first contact behavior
33,35–38
during ball
carrying, tackling, and blocking before the first
exposure to tackle football (ie, first-time participants,
preseason). SOR: B
7. Teach until mastery is achieved and reinforce the
maintenance of ap propriate tackling and blocking
skills that explicitly deter head-first contact behav-
ior
3,33,35,38
in football at all levels of play. SOR: B
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Rules and Regulations
8. Because full-contact practice sessions (ie, live tackling,
taking the opponent to the ground) increase the
opportunities for head-first behavior, regulate the time
devoted to such sessions each week
39,40
to ensure
sufficient focus on age-appropriate instruction, main-
tenance, and mastery of proper tackling and blocking
skills. SOR: B
9. Adapt the practice structure by eliminating or modi-
fying football drills that do not reinforce proper and
safe tackling and blocking be haviors or tech-
niques.
41–43
SOR: B
10. Consistently enforce the penalties or fines (or both) for
head-first contact behavior, spearing, or targeting at all
levels of play for all player positions.
3,44
SOR: C
Technology and Scientific Research
11. Recognize that helmet and after-market companies that
produce helmet add-on products may overstate injury-
prevention benefits,
45,46
leading to risk-taking behav-
ior.
47,48,49
SOR: B
12. Consider using validated head-impact m onitoring
systems or video capture
50,51
(or both) as a comple-
mentary tool for identifying and correcting head-first
contact behavior. SOR: B
13. Educat e a thletes on the influence of protec tive
equipment and techniques related to avoiding head
contact.
46
SOR: C
14. Engage all stakeholders in the generation of high-level
scientific research to test and validate str ategies ,
techniques, or technologies proposed to support the
reduction of head-impact exposure in football. SOR: C
BACKGROUND AND LITERATURE REVIEW
Education and Administration (Recommendations 1–5)
The need for consensus among stakeholders on the
education and administration of head-safe principles is
obvious and stems from the 1970s, when the risk of spear
tackling was first identified.
44
Players were then instructed
to ‘‘ see what you hit’’ and encouraged to tackle with the
‘‘ head up.’’ Thus, the ‘‘ heads-up tackling’’ phrase was used
in promotional efforts, such as locker room posters. The
National Operating Committee on Standards for Athletic
Equipment (NOCSAE) included such phrases on helmet
shells as a required component of certification. Tracking the
direct effectiveness of these educational efforts remains
difficult because they coincided with rule changes that
made intentional spear tackling illegal. However, after the
rule was implemented, the incidence of catastrophic head
and neck injuries declined by approximately 50%.
44
Despite widely accepted knowledge about the axial-load
mechanism and risks of head-down tackling,
3
the behavior
has not been eliminated, as verified through observation-
al
52,53
and instrumented
4,9,54–56
rese arch. For example,
between 2010 and 2019 in high school and collegiate
football, a total of 287 catastrophic head and neck injuries
were reported, with 40 of these events resulting in
fatalities.
57
Although no football injury rates during this
timeframe have been published, Boden et al
58
determined
that the rate of brain-related injury deaths from 1990 to
2010 was 0.26 per 100 000 athletes (number of fatalities ¼
62) and 4 deaths resulted from cervical fractures. All deaths
were attributed to severe head impact. Justifiably, much
effort continues to be directed at educational strategies for
participants and other stakeholders to raise awareness and
discourage head-first and head-down tackling behaviors.
No authors have directly evaluated the effect of player or
coach education on head-first contact, but expert consensus
is that contemporary education for players and documented
education for coaches should be current practices for both
governing bodies and institutions.
12
Even though they were not necessarily aligned with the
historical understanding pertaining to spine injury preven-
tion and the focus of the original position statement, USA
Football
59
and the US Centers for Disease Control and
Prevention
60
developed educational campaigns promoting
heads-up tackling to improve awareness and encourage
proper tackling and contact training to avoid concussion.
Yet, despite this common-sense approach, little to no direct
scientific evidence has supported a role of heads-up
educational programs in reducing cervical spine and head
injuries. However, early researchers who studied the USA
Football model proposed that implementation of such a
program might reduce head impacts over a season in youth
athletes
61
and reduce concussions among high school
athletes.
36
Missing from the discussion, analysis, and
implementation of educational programs were game
officials, who have a significant influence on the field of
play. Thus, based on consensus and e xpert o pinion,
American football officials should also be part of these
educational efforts.
1,34
American football is not alone in its efforts to reduce the
incidence of head and spine injuries. Recommendations 2
and 3 highlight the similarities with rugby in the requisite
skill of tackling and associated injuries.
62
Although players
sustained multiple impacts during play,
63–65
most of these
occurred on the side and back of the head,
63,65
suggesting
that intentional head-first contact behaviors were not used
in rugby; this was in contrast to American football, in
which front and top impacts were most frequent.
4,7,66
Nevertheless, extensive educational efforts using various
themes (Table 1) to control the head
62
and spine
67,68
injury
risk in rugby demonstrated moderate success. For example,
the RugbySmart p rogra m in New Zealand
69
required
coaches and referees to attend annual workshops to view
video and in ternet re sources related to head safety.
Educational guidelines focused on physical conditioning,
tackling and scrimmaging techniques, and injury-manage-
ment strategies. The RugbySmart program decreased
Table 1. Categories of Educational Programs on Head-Contact
and Playing Behaviors in Rugby
Strategies
General education
Safety workshops and practical trainings for stakeholders
Online educational material specific to head, neck, and spine injuries
Athlete education and information
Supportive environment and community information
Medical care and protocols
First aid in rugby
Medical programs and protocols
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scrum-related spine injuries and overall injury claims.
70
BokSmart, a similarly designed educational program for
rugby in S outh Africa , reduced the prevalenc e of
catastrophic head and neck injuries between 14% and
24%.
71
A national injury-prevention program for rugby in
France, when combined with rule changes to the scrum
event, decreased spine injuries from 1.8/100 000 to 1.0/
100 000 players, yet spine injuries among players catego-
rized as backs increased.
67
However, when Fraas and
Bur chiel
72
reviewed 10 reports on rugby educational
programs and catastrophic head and neck injuries or
concussions, they concluded that little good-quality evi-
dence supported the effectiveness of these programs. Of the
articles included, none provided SORT level 1 (good-
quality) evidence, and only 2 studies offered level 2
(limited-quality [patient-oriented]) evidence.
72
Although
initiatives in rugby can serve as a model for football,
further prospective research is needed to establish the long-
term efficacy of educational programs in these and other
sports involving collisions (eg, ice hockey).
Additionally, for these educational efforts to be effective,
coordination of key stakeholders (eg, coaches, strength and
conditioning specialists, administrators, ATs, team physi-
cians, officials) is essential to ensure that evidence-based
strategies
1,26,34
are part of local football safety efforts.
Experts agreed that organizations involving minors should
also communicate these evidence-based strategies on a
regular basis to parents and guardians, given their role in
the child’s decision making and participation.
1,34
Skill Development and Behavior Modification
(Recommendations 6, 7)
Tackling and blocking are foundational skills that involve
contact or collision, often with subsequent body-to-ground
contact. Thus, it is likely unrealistic to prevent all head
impacts in American football players, and no threshold has
been i dentified for a safe number of head impacts.
Nevertheless, teaching tackling and blocking techniques
that help players adopt skills to avoid or significantly limit
head impacts provides a conservative platform for the
recommendations in this category, especially for young
players and those beginning football participation. Because
reducing the prevalence of impacts derived from head-first
contact behavior is this statement’s logical goal, teaching
skills with the intent of reducing head impacts is essential.
However, rigorous research models for reducing head-
initiated behavior in sports are challenging to design and
carry out. This explains the dearth of p rospective
randomized controlled trials (RCTs) in American football;
to date, most studies have been cohort based and non-
randomized in design, which can carry a high risk of bias
73
(Table 2). For example, a laboratory-based investigation
37
demonstrated that football players could adapt techniques
to avoid or lessen the magnitude of head impacts after a
single training session, but because this work was not
conducted in an active football environment, its external
validity was limited. Field-based research on a team-level
(nonrandomized) intervention using the ‘‘ Heads Up Foot-
ball Program’’ (USA Football) showed a 3.4 impacts/
practice reduction in head-impact exposure,
61
and head
impacts decreased by approximately 30% after midseason
implementation of a tackling training intervention.
35
Other
field-based studies resulted in reductions in concussions,
both when combined with practice contact restrictions
32
and without.
36
Despite these findings, some research on
USA Football’s ‘‘ Heads Up’’ program indicated it was
inconsistently implemented
74
and may be less accessible to
communities of lower socioeconomic status.
75
Furthermore,
USA Football recently revised the ‘‘ Heads Up’’ tackling
training system to include ‘‘ rugby-style’’ tackling, which
emphasizes shoulder contact, but to our knowledge, the
newer protocol’s effectiveness has not yet been assessed.
The concept of incorporating rugby-style tackling
techniques in American football
76
has grown in popularity
based on the presumption that it develops safer skills and
reduces the chance of using the head as the point of contact.
During a properly executed rugby tackle, the defender’s
head is not the focal point of contact, nor is it intentionally
placed in front of the ball carrier.
77
The National Football
League (NFL) promotes a modification of rugby-style
tackling instruction for American football in the ‘‘ Hawk
Tackling’’ method
76
associated with the Seattle Seahawks
and the team’s head coach. Instructional videos remain
prevalent online, although no scientific literature to date
supports the efficacy of the tackling technique to reduce
head-first contact behavior.
Randomized controlled trials have been conducted to
determine the effectiveness of a progressive helmetless-
tackling training (HuTT) program in reducing head-impact
exposures.
33,38
The HuTT technique also models rugby in
that the skill progression and behavioral development
require athletes to complete training without a helmet.
Doing so makes use of inherent reflexes
78,79
that remove the
unprotected head as a point of contact. This is a
manifestation of risk compensation theory,
80–82
whereby
protective measures, such as a helmet, can sometimes result
in unintended consequences or increase risky behavior. For
instance, spear-tackling behavior originated and persisted
because of the advent of helmets with hard outer shells,
which gave players a false sense of security.
83
This conduct
may be countered by time spent in helmetless training.
Early results at the collegiate level showed a 30% reduction
in head -impact exposure throughout the season when
training drills were implemented twice per week in the
preseason and once per week in the regular season.
33
At the
high school level, more frequent training sessions primarily
reduced head impacts during games at midseason time
points.
38
Although more examination is warranted, this
training method holds promise as an intervention for
reducing head-impact behavior and cumulative exposure.
Details on these interventions published in the research thus
far can be found in Table 2.
Rules and Regulations (Recommendations 8–10)
Historically, the first measures taken to influence player
behavior were updating policies and rules. The landmark
1976 rule change to eliminate intentional spear tackling or
using the head as a weapon is one such example. Even
though this change decreased catastrophic head and spine
injuries, nearly 80% of high-magnitude head impacts
resulted from leading with the head.
66
This indicates a
continuing need to empha size policies and d evelop
innovative health and safety interventions to further reduce
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Table 2. Characteristics of Intervention Studies for Reducing Head-Impact Exposure in American Football Players Continued on Next Page
Research Study
Study
Design
Strength of
Recommendation
Taxonomy
Study Quality
30
Sample, n Intervention Relevant Findings
Kerr et al (2015), ‘‘ Comprehensive
Coach Education Reduces Head
Impact Exposure in American Youth
Football’’
60
Cohort 2 70 (HU ¼ 38, NHU ¼ 32) Educational: preseason, HU
teams received didactic and
demonstration instruction in
tackling techniques, drill
development, and player
contact. Top-down instruction
provided by ‘‘ master trainers’’
to PSCs and then team
coaches and players.
Impacts in NHU (62%, n ¼ 4637) vs HU
(38%, n ¼ 2841) group
6 concussions, all in NHU, but no difference
between HU and NHU
Age 8 to 11 y: practice impacts/individual in
NHU (9.1 6 3.3) vs HU (5.5 6 3.2;
difference ¼ 3.6; 95% CI ¼ 2.9, 4.3)
Age 12 to 15 y: practice impacts/individual
in NHU (8.7 6 2.9) vs HU (5.7 6 2.5;
difference ¼ 3.0; 95% CI ¼ 2.3, 3.7)
At 10g,20g thresholds: no difference
between game impacts/individual
10g threshold: practice impacts/individual in
HU (5.6 6 2.9) vs NHU (8.9 6 3.1;
difference ¼ 3.4; 95% CI ¼ 0.9, 3.9);
difference varied at 20g threshold but
remained significant (difference ¼ 1.0; 95%
CI ¼ 0.7, 1.3)
Schussler et al (2018), ‘‘ The Effect of
Tackling Training on Head
Accelerations in Youth American
Football’’
37
Controlled
laboratory
324(age¼ 11.5 6 0.6 y) Behavioral: 1-d training on
tackling technique using
tackling dummy. Subgroup
completed additional 2 d of
training and 48-h retention test.
Peak linear head accelerations .10g and
peak rotational head accelerations .18858/s
2
in dummy tackling after 1- and 3-d training
regimens; tackling form score changed
between pretest and posttest (P ¼ .004).
Shanley et al (2019), ‘‘ Heads Up
Football Training Decreases
Concussion Rates in High School
Football Players’’
36
Prospective
cohort
2 2514 (HU ¼ 1818, NHU
¼ 696)
Behavioral: preseason, 1
coach/team received HU
training from USA Football.
Coaching technique, player
instruction monitored randomly
33 during season to ensure
program compliance.
Risk of SRC ¼ 1.53 (95% CI ¼ 1.1, 2.1) or
32% for HU vs NHU (4.1 vs 6.0/100
players)
Entire cohort: game (61) vs practice (56) rate
ratio difference not significant (1.1; 95% CI
¼ 0.73, 1.5)
Practice SRCs in NHU vs HU (RR ¼ 1.9;
95% CI ¼ 1.1. 3.2)
Swartz et al (2015), ‘‘ Early Results of a
Helmetless-Tackling Intervention to
Decrease Head Impacts in Football
Players’’
33
RCT 2 50 (intervention ¼ 25,
control ¼ 25)
Behavioral: progressive tackling
instruction, drills (HuTT)
without shoulder pads and
helmet 23/wk preseason, 13/
wk in-season
End of season 1: intervention 28% in
head-impacts/AE (9.99 6 6.10); control
unchanged (13.84 6 7.27. P ¼ .009)
Intervention: 30% impacts/AE (9.99 6 6.10)
vs control (14.32 6 8.45, P ¼ .045)
Swartz et al (2019), ‘‘ A Helmetless-
Tackling Intervention in American
Football for Decreasing Head Impact
Exposure: A Randomized Controlled
Trial’’
38
RCT 1 180 enrolled, 115 completed
study (WoH ¼ 59, control
¼ 56)
Behavioral: progressive tackling,
blocking instruction and drills
without shoulder pads and
helmet; 43/wk preseason, 23/
wk in-season over 2 y
WoH: 26%–33% game ImpAEs at 2
identical time points across seasons; also
game ImpAEs vs control at wk 4 (season 1
P ¼ .0001, season 2 P ¼ .0005) and 7 in
both seasons (P ¼ .0001) and ImpAEs in
wk 7 during training vs control in-season 1
(P ¼ .015)
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Table 2. Continued From Previous Page
Research Study
Study
Design
Strength of
Recommendation
Taxonomy
Study Quality
30
Sample, n Intervention Relevant Findings
Kerr et al (2016), ‘‘ Comparison of
Indiana High School Football Injury
Rates by inclusion of the USA
Football ‘Heads Up Football’ Player
Safety Coach’’
97
Cohort 2 390 (PSC ¼ 204, EDU
¼ 186)
Educational: players supervised
by PSC certified in concussion
program modules (‘‘ Heads-
Up’’ ), heat and hydration,
cardiac arrest, and proper
tackling, blocking, and
equipment fit
17 SRCs ¼ 11.4% of all injuries
Educational ¼ 88.2% (n ¼ 15/17) vs PSC
group (11.8%, n ¼ 2/17)
SRCs in practice: IRR in PSC group (0.09
vs 0.73/1000 AEs; IRR ¼ 0.12; 95% CI ¼
0.01, 0.94)
SRCs in games: IRR not different in PSC
group vs EDU (0.60 vs 4.39/1000 AEs; IRR
¼ 0.14; 95% CI ¼ 0.02, 1.11)
Champagne et al (2019), ‘‘ Data-
Informed Intervention Improves
Football Technique and Reduces
Head Impacts’’
35
Experimental 2 70 (baseline and postinter-
vention measurements),
19 wore helmet
accelerometers
Behavioral: players completed
prepractice tackling and
blocking drills simulating game-
like situations 23/wk
30% total frequency of practice impacts
session in practice 1 mo postintervention
No difference in cumulative rotational velocity
(g): preintervention ¼ 4047.46 6 1838.71,
postintervention ¼ 3789.98 6 2170.24 (P ¼
.6378)
Average cumulative linear acceleration (g) :
preintervention ¼ 272.19 6 112.78,
postintervention ¼ 186.10 6 80.98 (P ¼
.0037)
Abbreviations: AE, athlete-exposure; EDU, education-only group; HU, ‘‘ Heads-Up’’ participants; HuTT, helmetless-tackling training; ImpAE, impacts per athlete-exposure; IRR, injury rate
ratio; NHU, non–‘‘ Heads-Up’’ participants; PSC, player safety coach; RCT, randomized controlled trial; RR, rate ratio; SRC, sport-related concussion; WoH, without-helmet group.
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head-first contact behavior, whether via tackling, blocking,
or carrying the ball.
Limiting contac t practice s and modifying practice
structures may be beneficial in reducing the magnitude
and frequency of head impacts. In 2011, the NFL Players’
Association collective bargaining agreement restricted full-
contact practices by limiting the total to 14 per year, with
11 allowable in the first 11 weeks of the season (1 per
week). The agreement influenced the 2016 Na tional
Collegiate Athletic Association (NCAA) policy change
that limited full-contact practices to 1 per week with
players dressed in full equipment or shells (helmet and
shoulder pads only). The Ivy League schools went so far as
to ban tackling from practice altogether.
84
Youth football participants can experience an average of
100 to 200 head impacts in a season,
10,11,85
whereas hi gh
school players may sus tain more than 400 impacts.
86,87
The increase in hea d-impact frequency with age contra-
dicts the typical improvement in skill that cor relates with
increased experience. To mitigate head-impact exposure ,
some states and leagues have limited the number of
allowable full-co ntact prac tic e days per week or, as in
youth f ootball, prohibited tackling in practice. Pop Warner
practice guidelines eliminate drills in which players are
more tha n 2.7 m (3 yd) apart,
88
though t hese efforts have
been driven primarily by the risk for concussion. When
full-contact high school football practices we re reduced
from 3 to 2 per week, head-impa ct instrumentat ion
captured a 42% overall reduction in head-impact expo-
sure, with a greater decre ase during practices than during
games.
40
However, too few concussions occurred to
evaluate a change in that risk. Similar findings were noted
among youth athletes when contact practices were
restricted.
89
In addition, eliminating certain drills known
to encourage head-first contac t behavior (eg, th e Okl aho-
ma Drill) or limiting full-contact practice sessions
decreased the risk of sustaining a c atastrophic spine injury
or concussion.
40
Yet adopting changes that restr ict
practice in a full-contact environment prompts questions
about how these measures might inhi bit skill devel opment
or reduce a team’s competitive edge. In other words,
because the game requires full contact, how much of the
introduction, rehearsal, and mastery of these skills can be
suppressed before the participant’s safety i s a ffected? Thi s
conundrum has been studied in ice hockey regarding the
risk of injury due to body checking,
90
a collision-specific
skill that is similar to tackling or blocking in football.
Compared with youth hockey players who lacked body-
checking experience , those who had 2 years of such
experience displayed a 33% decrease in overall severe
injuries (more than 7 days of time loss) but no differences
in concussion rates or severity.
91
Nevertheless, the authors
pointed out that this finding needs to be consi dered i n the
context of the 70% reduction in severe injuries among P ee
Wee players in leagues that prohibited body checking.
90
In
other words, the benefits and consequences of rule
changes for tackling must be assessed in totality to
determine t he best over all preventive model for decreasing
head-impact exposure in American football players. To
our knowledge, this work has not yet been done.
At higher levels of play, leagues have changed rules for
game play, particularly kickoffs, which had the highest
incidence of concussions and severe injuries.
92,93
Notable
changes by the NFL were the ban on wedge-formation
blocking by the receiving team (2004, 2018), moving the
line of scrimmage from the 30- to the 35-yard line and
minimizing the running start of the kicking team to 4.57 m
(5 yd [2011]), restricting contact to within 13.72 m (15 yd)
of the kickoff spot (2018), and eventually eliminating the
running start by the kicking team (2018). The NCAA
followed suit with wedge and line-of-scrimmage changes
and added a fair-catch option for the receiving team (2018).
These rule changes resulted in a reduction in concussions of
8.88/1000 plays during kickoffs at the collegiate level.
93–95
Updates to the National Federation of State High School
Associations (NFHS) rules include infractions for blind-
side blocking (ie, contact with an opponent other than the
runner who does not see the block coming) and banning
pop-up kicks (a form of onside kick in which the ball is
kicked so that it pops it up in the air; 2018). The receiving
player’s upward gaze and concentration during the pop-up
kick leaves him vulnerable to injury. Pop Warner Youth
Football was the first league to ban kick-offs for its
youngest divisions (2016).
In addition, the NCAA and NFHS have elevated the
consequences for head-down tackling in situations deemed
to be targeting. Specifically, targeting and making forcible
contact with the crown of the helmet (NCAA Rule 9-1-3) or
the head or neck area of a defenseless player (NCAA Rule
9-1-4) both result in immediate disqualification from
competition.
2
The NCAA describes targeting as an
infraction stemming from a player ‘‘ taking aim at an
opponent for the purposes of attacking with forcible contact
going beyond that which is required to make a legal tackle
or a legal block.’’
2
The NFHS uses similar language and
punitive results.
96
Ultimately, although policies aimed at reducing full-
contact time or practices have merit for lowering the
general head-impact risk,
8,89
they fall short in addressing
head-first contac t behavior. Use of t he ‘‘ Heads-Up’’
coaching strategy and limiting contact in practice decreased
both head-impact exposures and concussions in youth
football.
97
However, further study is needed to understand
when introducing tackling and blocking is appropriate. For
example, researchers
98
attempted to address a similar
question about the injury risk from body checking among
youth ice hockey t eams, considering rule and policy
changes, and thi s work could serve as a model for
American football.
Rule and policy changes may c reate controversies due to
social pressures in the sport (eg, f ootball highlights oft en
center on ‘‘ big hits’’ ). These changes may put pressure on
coaches and players to modify training techniques,
develop new ski lls whi le eliminating high-risk maneuvers,
and limit the amount of contact exposure and potentially
the opportunities f or skill rehearsal. Greater still is the
pressure on game officials. Consistent and vigorous
enforcement of rules for protecting players’ safety,
especially the use of the head and helmet when making
contact, is subjective a t best and may influence the
outcome of a game. Despite these concerns and pr essures,
rule c hanges have been demonstrated to improve athlete
safety. As more evidence becomes available, they should
be implemented to enha nce the health and safety of
athletes.
Journal of Athletic Training 119
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Technology and Scientific Research
(Recommendations 11–14)
Helmets remain the best—and yet still incomplete—
solution for mitigating forces generated by single or
multiple direct head impacts. As a result, attention has
focused on designing better protective headgear and the
emergence of independent quality assessments to validate
these enhancements (eg, Virginia Tech’s Summation of
Tests for the Analysis of Risk [STAR] rating,
99
National
Football League helmet testing
100
). At its outset, the STAR
system identified a single helmet as qualifying for 5 stars
(the highest rating); more recently, 16 helmets spread over
5 brand labels have received top ratings.
101
Given these
independent appraisals, which exceed the minimum
certifying standards set forth by NOCSAE, manufacturers
have developed helmets that are better able to mitigate
head-impact forces. Despite persistent concussion rates,
102
the football helmet has likely never been better able to
absorb deleterious contact forces and protect the head from
acute trauma (eg, skull fracture, hemorrhage), its original
intention.
103
Helmets are not designed to reduce head-first contact
behavior, so ATs and other key stakeholders should remain
vigilant in their efforts to do so. This vigilance may include
ATs educating other stakeholders about recent evidence, as
unintended behavioral changes a nd subsequent injury
outcomes follow a pattern associated with the use of
protective equipment.
80,104,105
Risk compensation theory
explains similar consequences for behavioral changes in
other sport or physical activities (eg, helmet use in alpine
skiing and cycling) and activities of daily living (eg,
seatbelt use and motor vehicle crashes).
80
History informs
us that as helmets evolved, from a leather cover to a solid
outer shell in the 1950s to 1960s and the inclusion of a face
mask and various iterations of interior padding or air
bladders in the 1970s to 1980s,
103
a documented change in
player behavior took place. Alarmingly and at a time
coinciding with helmet innovation,
44
head and neck injuries
in American football at all levels of play resulted in 204
deaths between 1965 and 1974, with 36 deaths in the 1968
football season alone
3
and 99 permanent cervical cord
injuries in a 4-year span from 1971 to 1975.
83
To mitigate the unintended consequence of head-first
contact be havior associated w ith helmet usage, head-
impact monitoring systems may be useful. These instru-
ments are commercially available as research-grade
equipment (most expensive) a nd more consumer-friendly
models (least expensive). The devices are primarily
intended to detect head accelerations resulting from
impacts during sport participation. Head-impact biome-
chanical data are computed as linear acceler ation (g),
rotational velocity (rad/s), rotational accel eration (rad/s
2
),
Head Injury Criterion, Gadd Severi ty Index (GSI), or other
measures of interest. Some a lso triangulat e the he ad-
impact location. Thes e data may be min imally u seful as a
means of biofeedback or, more importantly, a s t rackable
outputs in the study of behavioral interventions. With
recent advance s in technology (eg, sm aller equipment a t
lower costs), a growing market of head-impact monitors is
available. These monitoring systems may be beneficial for
obtaining real-time head-impact data, but their clinical
utility has been questioned.
50,106
The science surrounding
head-impact bi omechanics continues t o evolve a nd, thus,
thedataprovidedbythesesystemsarelikelyaffectedby
external (eg, s port) and internal (eg, age, behavioral)
factors. Devising a produc t that performs perfectly in the
field is not tenable, even when the product demonstrates
good performance in c ontrolled laboratory envi ronments.
The literature is divided on this topic: some researchers
107
noted system inaccuracies, whereas others
108
supported
these tools as useful in furthe ring our knowledge of
concussion and head-impact biomechanics. Notwithstand-
ing the known limitations of these devi ces, accelerometer-
based head-impact monitoring is useful for charact erizing
the head kinematics and kinetics associated with concus-
sion
50
and the play-related circumsta nces believe d to
increase the concussion risk (eg, anticipating collisions,
109
special teams p lays
110
). Although these systems may
provide a dditional information for identifying a nd cor-
recting drills or practice strategies that result in leading
with the he ad, it is important to point out that impa ct-
monitoring systems a nd vide o c apture are not appropriate
clinical tools for diagnosing a concussion,
56,106,111
nor
should the y be used in place of an on-site health car e
professional for football.
Several commercially available produc ts attempt to
address the safety-related needs of players, and many are
advertised as after-market add-ons to footbal l helmets for
impact-force m itigation. Such products often take the
form of more soft or conforming exterior padding and
come with little to no independent scientific evidence to
support their efficacy in reducing impact forces during
play. The current evidence describes no benefit. For
example, investigat ors
45
assessed the ability of the
Guardian Cap helmet cover t o r educe linear accelera tion
andtheGSIscore.Using2stylesofhelmetsandthe
NOCSAE drop-testing method, they found that the
Guardian Cap failed to improve the helmets’ ability to
mitigate impact forces at a ll but 2 re ar helmet l ocations.
Football helmets must meet an i ndustry standardization
process. Though several processes exist, NOCSAE
certification is required of all helmets worn in professional
and amateur football. No standards or certifications are
required for after-market helmet add-ons. Bec ause of t his
limited product oversight, stake holders are encouraged to
use due diligence before i nvesting in ma rketed produc ts.
In most cases, after-market helmet add-ons will compro-
mise the NOCSAE certification obtained by protective
equipment manufacturers.
112
Finally, an overarching prima ry injury-prevention rec-
ommendation is to c ontinue rigorous epidemiologic
monitoring a nd experimental research where possible to
provide evidence-informed strate gies re lated to head-safe
behaviors. It is paramount that American football
stakehold ers use o bser vation al a nd empir ical da ta to
evaluate, propose, and direct head-safe behavior s. Ideally,
head and cer vical spine trauma in foot ball players should
be more fully understood before rules and policies are
proposed t o further mitigate the injury risk. Athletic
trainers who already work closely with coaches and
strength specialists can reinforce the importance of
teaching appropriate skills and monitoring practice
structures in a way that reduces head-first contact
behavior.
26
Athletic trainers should be primary stakehold-
ers on committees that a ssess and direct policy. For
example, identifying and then eliminating or modifying
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February 2022
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specific drills or pract ice maneuve rs that increase the
concussion ri sk is one such approach.
113
The benefit of
this approach is eliminating injuries, allowing for greater
participation by all involved athletes.
CONCLUSIONS
The recommendations outlined in this position statement
and discussed in the existing literature are aimed at
decreasing the prevalence of head-first contact behavior
and the associated risk for serious head and cervical spine
injury, in addition to reducing the accumulation of head
impacts over time. Although these recommendations
provide a host of potentially effe ctive st rategies for
reducing head impacts in football, it is concerning that
the scientific-medical community has little to no high-level
(SOR A) ev idence for a mechanism that ent ails a
potentially catastrophic outcome. Critically needed are
rigorous studies (ie, RCTs) and validation of existing and
future strategies intended to address head-first contact
behavior in American football players. It is worth noting
that participation in any sport comes with an inherent risk
of injury, and our profession should take collective action
to reduce the injury risks for athletes participating in all
sports. The potential risks of participation should be
mitigated by options that enable young athletes to develop
skills and sustain physically active lifestyles. With respect
to American football, we must continue to identify
strategies that decrease football-related head, neck, and
spine injuries and the associated behaviors that increase the
injury incidence, given the very high level of interest in
participating in the sport.
ACKNOWLEDGMENTS
We gratefully acknowledge the efforts of Javier F. Cardenas,
MD; Gianluca Del Rossi, PhD, ATC; Robert C. Lynall, PhD,
ATC; Kelli Pugh, MS, ATC; Joel D. Stitzel, PhD; and the
Pronouncements Committee in the preparation of this document.
DISCLAIMER
The NATA and NATA Foundation publish position statements
as a service to promote the awareness of certain issues to their
members. The information contained in the position statement is
neither exhaustive nor exclusive to all circumstances or
individuals. Var iables such as institutional human resource
guidelines, state or federal statutes, rules, or regulations, as well
as regional environmental conditions, may impact the relevance
and implementation of these recommendations. The NATA and
NATA Foundation advise members and others to consider
carefully and independently each of the recommendations
(including the applicability of same to any particular circum-
stance or individual). The position statement should not be relied
upon as an independent basis for care but rather as a resource
available to NATA members or others. Moreover, no opinion is
expressed herein regarding the quality of care that adheres to or
differs from the NATA and NATA Foundation position
statements. The NATA and NATA Foundation reserve the right
to rescind or modify its position statements at any time.
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Address correspondence to Erik E. Swartz, PhD, ATC, Department of Physical Therapy and Kinesiology, University of Massachusetts,
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