Sports Special Issue Research article
INCIDENCE OF INJURY IN PROFESSIONAL MIXED MARTIAL ARTS COMPETITIONS
Johns Hopkins University School of Medicine, Department of Emergency Medicine,
Baltimore, Maryland, USA.
Journal of Sports Science and Medicine (2006) 5 (CSSI), 136
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Martial Arts (MMA) competitions were introduced in the United States
with the first Ultimate Fighting Championship (UFC) in 1993. In 2001,
Nevada and New Jersey sanctioned MMA events after requiring a series
of rule changes. The purpose of this study was to determine the incidence
of injury in professional MMA fighters. Data from all professional
MMA events that took place between September 2001 and December 2004
in the state of Nevada were obtained from the Nevada Athletic Commission.
Medical and outcome data from events were analyzed based on a pair-matched
case-control design. Both conditional and unconditional logistic regression
models were used to assess risk factors for injury. A total of 171
MMA matches involving 220 different fighters occurred during the study
period. There were a total of 96 injuries to 78 fighters. Of the 171
matches fought, 69 (40.3%) ended with at least one injured fighter.
The overall injury rate was 28.6 injuries per 100 fight participations
or 12.5 injuries per 100 competitor rounds. Facial laceration was
the most common injury accounting for 47.9% of all injuries, followed
by hand injury (13.5%), nose injury (10.4%), and eye injury (8.3%).
With adjustment for weight and match outcome, older age was associated
with significantly increased risk of injury. The most common conclusion
to a MMA fight was a technical knockout (TKO) followed by a tap out.
The injury rate in MMA competitions is compatible with other combat
sports involving striking. The lower knockout rates in MMA compared
to boxing may help prevent brain injury in MMA events.
WORDS: Brain injury, ultimate, boxing, jiu jitsu.
Martial Arts (MMA) competitions were introduced in the United States
with the first Ultimate Fighting Championship (UFC) in 1993 (Krauss
and Aita, 2002).
Styled after the popular Vale Tudo (Portugese for "anything
goes") matches in Brazil (Peligro, 2003),
these first UFC matches were marketed as brutal, no-holds-barred
tournaments with no time limits, no weight classes, and few rules
such as Senator John McCain of Arizona led the charge to ban these
competitions from cable television, describing the events as "human
cock fighting" (Krauss, 2004).
When their cable contracts were terminated in 1997, MMA events survived
underground through internet and word of mouth promotions until
their organizers agreed to a change of rules that allowed the Nevada
State Athletic Commission and the New Jersey State Athletic Control
Board to sanction the competitions
This study is the first report of the incidence of injury in MMA
competitions. No study has previously documented injuries in MMA
events either before or after the tightening of regulations. Fight
results and injury incidence from professional MMA bouts since their
sanctioning in 2001 in Nevada are compared to boxing data from the
same state. A discussion of MMA events and combat sports injuries
is also included.
Art (MMA) data from all professional MMA matches in the state of
Nevada from September 2001 until December 2004 (n = 171 matches)
was obtained from the Nevada State Athletic Commission. All professional
MMA matches occurring in the state during the study period were
included. Data obtained included gender, date of the match, date
of birth, weight, rounds scheduled, rounds fought, whether the fighter
won or lost, how the match ended (knockout, technical knockout,
decision, draw, disqualification, no decision, tap out, or choke)
and the injuries that occurred in the match and the type of injuries
sustained. Up to four injuries per fighter were recorded per competition.
These data are in the public domain and accessible on the website
of the Nevada State Athletic Commission (http://boxing.nv.gov,
last accessed January 2005).
Medical and outcome data for all professional MMA matches were analyzed
based on a pair-matched case-control design. Cases were fighters
who sustained an injury during the matches. Fighters who were not
injured served as controls. Matches in which both competitors were
injured or both were uninjured were excluded from the conditional
logistic regression. Both conditional and unconditional logistic
regression models were used to assess risk factors for injury.
Injuries were recorded based on the clinical report of the physician
at ringside. No follow-up study was done to confirm the accuracy
of the reported injury based on radiography or other diagnostic
testing. Injuries were divided into seventeen broad classifications:
eye injuries, facial lacerations, ear injuries, nose injuries, mouth
injuries, jaw injuries, hand injuries, shoulder injuries, elbow
injuries, ankle injuries, foot injuries, chest injuries, abdominal
injuries, knee injuries, back injuries, neck injuries, and arm injuries.
Lacerations to the eyelid and nose were counted as facial lacerations.
Only those injuries documented other than lacerations-such as possible
orbit fractures or a nose deformity- were listed as eye or nose
The Johns Hopkins University School of Medicine's Institutional
Review Board approved the study protocol via exemption.
total of 171 MMA matches involving 220 different fighters occurred
during the study period. All participants were male with an average
age of 28.5 years (SD = 4.7, range from 19 to 44 years old). The
average weight was 87.6 kg (SD= 16.3 kg, range from 60.4 to 166.4
kg). A total of 1,130 rounds were scheduled, of which 624 (55%)
were actually fought. These rounds were each 5 minutes for a total
of 3120 minutes of fighting. A total of 67 fighters fought in more
than one fight during the study period. The average number of competitions
for these 67 repeat fighters was 2.8 (SD = 1) with a range of 2
to 6 fights each.
There were a total of 96 injuries to 78 fighters. Of the 171 matches
fought, 69 (40.3%) ended with at least one injured fighter. The
overall injury rate was 28.6 injuries per 100 fight participations,
12.5 injuries per 100 competitor rounds, or 3.08 injuries per 100
fight minutes. The majority of recorded injuries were injuries to
the facial region with facial lacerations being the most common.
Hand injuries were the second most common injury, accounting for
13.5% of all injuries, followed by injuries to the nose (10.4%)
and eye (8.3%, Table 1).
Older fighters were at greater risk of injury as were those who
lost a match by knockout or technical knockout (Tables 2 and 3).
Those who lost their match under any circumstance-whether knockout,
technical knockout, decision, tap out, choke, or disqualification-were
significantly more likely to suffer an injury during the course
of the competition than those who won (p < 0.001). Also, the
incidence of injury increased with the length of the fight with
matches lasting 4 or 5 rounds being more likely to include a fighter
who suffered an injury (Tables
2 and 3). The most common
conclusion to a MMA fight was a technical knockout (TKO) followed
by a tap out (Table 4). The
proportion of fighters suffering a knockout during the competition
was 6.4% (n = 11).
initially promoted as brutal, no-holds-barred contests, Mixed Martial
Arts competitions in the United States have changed dramatically
and now have improved regulations to minimize injury. A total of
13 states now sanction MMA events, the first two being Nevada and
New Jersey in 2001. Since the sanctioning, MMA competitions have
followed much stricter regulations. Fighters are now forbidden to
headbutt, stomp or knee an opponent on the ground, strike the throat,
spine or back of the head, must fight within a predetermined weight
class, and are allowed only one fight per night-all important changes
that were implemented with sanctioning.
mandatory "grappling" gloves now used in MMA events weigh
between 4 to 8 ounces, thinner than the 8 to 10 ounce gloves worn
by professional boxers, and are designed with the fingers exposed
so a fighter can grasp his opponent. Fighters must pass the same
physical exam used to screen professional boxers including a cerebral
MRI, before being licensed. Referees and ringside physicians are
required to be present and have the authority to stop the match
at any time.
Fighters train in both the striking and grappling arts (Amtmann,
and become proficient in a number of means of "submitting"
or defeating their opponents (Figures
1 and 2). Fights can be
ended not only by the traditional knock out, technical knock out,
and decision of boxing, but also by "tap out"-where an
opponent either taps the mat or his opponent to signal his desire
to stop the match or verbally indicates to the referee his desire
to stop-and "choke"-where an opponent refuses to tap even
though caught in a choke hold and passes out.
events should be differentiated from the infamous "Toughman"
competitions held around the country. Toughman competitions feature
amateur fighters who often have little or no training experience,
wear "one-size-fits-all" protective gear, do not need
a thorough physical exam to compete, and often feature inexperienced
referees and ringside physicians (Branch, 2003).
While there have been no deaths in the United States in MMA competitions,
at least 12 participants have died during Toughman events-two of
whom were being supervised by ringside physicians who were chiropractors
Incidentally, both Nevada and New Jersey-the first two states to
sanction MMA competitions-are "among 10 states that have banned
or attempted to ban [Toughman] events." (Branch, 2003).
The relatively high incidence of injuries in combat sports has been
well documented. The giving and receiving of high velocity blows
seems to be the best correlation of whether a sport will have an
increased risk of injury.Styles that include striking-such as boxing
(Bledsoe et al., 2005;
Zazryn et al., 2003a),
kickboxing (Gartland et al., 2001;
Zazryn et al., 2003b),
karate (Zetaruk et al., 2005),
and taekwondo (Kazemi and Pieter, 2004)-have
been shown to have a higher incidence of injury than styles that
involve grappling alone, such as collegiate wrestling (Jarret et
Strikes from elite athletes, particularly professional boxers, can
generate a significant amount of force (Walilko et al., 2005)-equivalent
to "a padded wooden mallet with a mass of 6 kg (13 lbs) if
swung at 20 mph" (Atha et al., 1985)
according to one study. This seems to explain why many injuries
in the striking arts are prevalent not only in the target areas
of the face and torso, but also the extremities used for striking
such as the hands for boxing and the upper and lower extremities
in kickboxing and karate.
While no prior articles document the incidence of injury in MMA,
injury rates from boxing have been reported. In 2003, Zazryn and
reported an overall injury rate to professional boxers in Victoria,
Australia of 25 injuries per 100 fight participations. A recent
look at the injury rates of professional boxers in Nevada showed
17.1 injuries per 100 fight participations (Bledsoe et al., 2005).
With an overall injury rate of 28.6 injuries per 100 fight participations,
MMA competitions demonstrate a high rate of overall injury, but
a rate in keeping with other combat sports involving striking. By
contrast, sports involving grappling have demonstrated much lower
rates of injury. For example, collegiate wrestling has been documented
to have rates as low as 1 injury per 100 participations when analyzed
for participants in both practice and competition (Jarret et al.,
As opposed to professional boxing, MMA competitions have a mechanism
that enables the participant to stop the competition at any time.
The "tap out" is the second most common means of ending
a MMA competition (Table 4)
This unique characteristic, combined with more options of attack
when competing, is thought to help explain a knockout proportion
in MMA competitions that is almost half of the reported 11.3% of
professional boxing matches in Nevada (Bledsoe et al., 2005).
With the growing concern over repetitive head injuries and the risk
of dementia pugilistica among career boxers, decreasing the
number of head blows a fighter receives during a match has been
promoted as an important intervention (Mendez, 1995;
Unterharnscheidt, 1995). With MMA competitions, the opportunity to attack the
extremities with arm bars and leg locks and the possibility of extended
periods of grappling could serve to lessen the risk of traumatic
brain injury. When TKOs are compared, proportions between professional
boxing (38%)and MMA are similar (Bledsoe et al., 2005).
There are several limitations to this study. First, the injuries
reported were based on the physical exams performed at ringside
by the ringside physician. No labs or radiologic studies were ordered
and no diagnoses were confirmed. The incidence of injury in these
fighters may have been higher than reported. Second, although the
study included all MMA fights throughout a 40 month period, the
total number of matches was relatively small. Third, the fights
included in this study were all held in Nevada, the premiere site
for MMA events. How injury rates would change for events held under
different conditions with less supervision is a matter of concern.
Finally, for the purpose of discussion, knockouts and technical
knockouts were not defined as injuries although many would argue
that these represent the most serious of all boxing injuries. Due
to the sometimes subtle nature of traumatic brain injury-and since
there was no radiographic imaging available to verify whether an
injury had occurred-KOs and TKOs were discussed as separate entities
and not included in the overall injury data. Further research is
needed to determine the true nature of these injuries and their
cumulative effects upon the individual fighters.
Mixed Martial Arts competitions have changed dramatically
since the first Ultimate Fighting Championship in 1993. The overall
injury rate in MMA competitions is now similar to other combat sports,
including boxing. Knockout rates are lower in MMA competitions than
in boxing. This suggests a reduced risk of TBI in MMA competitions
when compared to other events involving striking.
MMA events must continue to be properly supervised by trained referees
and ringside physicians, and the rules implemented by state sanctioning-including
weight classes, limited rounds per match, proper safety gear, and
banning of the most devastating attacks- must be strictly enforced.
Further research is necessary to continue to improve safety in this
developing new sport.
The authors would like
to express their appreciation to Michael Johnson and Steve Lord
for permission to use their photographs to demonstrate the jiu jitsu
martial arts (MMA) has changed since the first MMA matches in
the United States and now has increased safety regulations and
competitions have an overall high rate of injury.
have been no MMA deaths in the United States.
knockout (KO) rate in MMA appears to be lower than the KO rate
of boxing matches.
must continue to be supervised by properly trained medical professionals
and referees to ensure fighter safety in the future.
Gregory H. BLEDSOE
Professor, Department of Emergency Medicine, The Johns Hopkins
University School of Medicine.
Degrees: MD, MPH
Research interests: Injury prevention, combat sports
injuries, expedition medicine
Edbert B. HSU
Professor, Department of Emergency Medicine and Office of Critical
Event Preparedness and Response (CEPAR), The Johns Hopkins University
School of Medicine.
Degrees: MD, MPH
Research interests: Disaster preparedness and response
Jurek George GRABOWSKI
Department of Emergency Medicine, The Johns Hopkins University
School of Medicine.
Research interests: JOccupational and recreational injury
prevention, spatial data analysis, and Geographic Information
Justin D. BRILL
Coordinator, Department of Emergency Medicine. The Johns Hopkins
University School of Medicine.
Research interests: Disaster response and emergency department
and Director of Research, Department of Emergency Medicine,
The Johns Hopkins University School of Medicine.
Degrees: MD, DrPH
Research interests: Injury epidemiology and prevention