Injury Rate and Patterns Among CrossFit Athletes

Abstract

Background:
CrossFit is a type of competitive exercise program that has gained widespread recognition. To date, there have been no studies that have formally examined injury rates among CrossFit participants or factors that may contribute to injury rates.

Purpose:
To establish an injury rate among CrossFit participants and to identify trends and associations between injury rates and demographic categories, gym characteristics, and athletic abilities among CrossFit participants.

Study Design:
Descriptive epidemiology study.

Methods:
A survey was conducted, based on validated epidemiologic injury surveillance methods, to identify patterns of injury among CrossFit participants. It was sent to CrossFit gyms in Rochester, New York; New York City, New York; and Philadelphia, Pennsylvania, and made available via a posting on the main CrossFit website. Participants were encouraged to distribute it further, and as such, there were responses from a wide geographical location. Inclusion criteria included participating in CrossFit training at a CrossFit gym in the United States. Data were collected from October 2012 to February 2013. Data analysis was performed using Fisher exact tests and chi-square tests.

Results:
A total of 486 CrossFit participants completed the survey, and 386 met the inclusion criteria. The overall injury rate was determined to be 19.4% (75/386). Males (53/231) were injured more frequently than females (21/150; P = .03). Across all exercises, injury rates were significantly different (P < .001), with shoulder (21/84), low back (12/84), and knee (11/84) being the most commonly injured overall. The shoulder was most commonly injured in gymnastic movements, and the low back was most commonly injured in power lifting movements. Most participants did not report prior injury (72/89; P < .001) or discomfort in the area (58/88; P < .001). Last, the injury rate was significantly decreased with trainer involvement (P = .028).

Conclusion:
The injury rate in CrossFit was approximately 20%. Males were more likely to sustain an injury than females. The involvement of trainers in coaching participants on their form and guiding them through the workout correlates with a decreased injury rate. The shoulder and lower back were the most commonly injured in gymnastic and power lifting movements, respectively. Participants reported primarily acute and fairly mild injuries.

Full text

Injury Rate and Patterns
Among CrossFit Athletes
Benjamin M. Weisenthal,* BA, Christopher A. Beck,
†
MA, PhD, Michael D. Maloney,
‡
MD,
Kenneth E. DeHaven,
‡
MD, and Brian D. Giordano,
‡§
MD
Investigation performed at the University of Rochester School of Medicine and Dentistry,
Rochester, New York, USA
Background: CrossFit is a type of competitive exercise program that has gained widespread recognition. To date, there have been
no studies that have formally examined injury rates among CrossFit participants or factors that may contribute to injury rates.
Purpose: To establish an injury rate among CrossFit participants and to identify trends and associations between injury rates and
demographic categories, gym characteristics, and athletic abilities among CrossFit participants.
Study Design: Descriptive epidemiology study.
Methods: A survey was conducted, based on validated epidemiologic injury surveillance methods, to identify patterns of injury
among CrossFit participants. It was sent to CrossFit gyms in Rochester, New York; New York City, New York; and Philadelphia,
Pennsylvania, and made available via a posting on the main CrossFit website. Participants were encouraged to distribute it further,
and as such, there were responses from a wide geographical location. Inclusion criteria included participating in CrossFit training at
a CrossFit gym in the United States. Data were collected from October 2012 to February 2013. Data analysis was performed using
Fisher exact tests and chi-square tests.
Results: A total of 486 CrossFit participants completed the survey, and 386 met the inclusion criteria. The overall injury rate was
determined to be 19.4% (75/386). Males (53/231) were injured more frequently than females (21/150; P ¼ .03). Across all exercises,
injury rates were significantly different (P < .001), with shoulder (21/84), low back (12/84), and knee (11/84) being the most commonly
injured overall. The shoulder was most commonly injured in gymnastic movements, and the low back was most commonly injured in
power lifting movements. Most participants did not report prior injury (72/89; P < .001) or discomfort in the area (58/88; P < .001). Last,
the injury rate was significantly decreased with trainer involvement (P ¼ .028).
Conclusion: The injury rate in CrossFit was approximately 20%. Males were more likely to sustain an injury than females. The
involvement of trainers in coaching participants on their form and guiding them through the workout correlates with a decreased
injury rate. The shoulder and lower back were the most commonly injured in gymnastic and power lifting movements, respectively.
Participants reported primarily acute and fairly mild injuries.
Keywords: competitive exercise; CrossFit; Olympic lifting; power lifting; injury rate; cross-sectional pilot study
CrossFit is a conditioning program that has gained wide-
spread attention for its focus on successive ballistic
motions that build strength and endurance. It is charac-
terized by workouts that use a wide variety of exercises,
ranging from running and rowing to Olympic lifting
(snatch, clean, and jerk), power lifting (s quat, deadlift,
press/push press, bench press), and gymnastic movements
(pull-ups, toes-to -bar, knees-to-elbo ws, lunges, muscl e-
ups, burpees, dips, gluteus-hamstring developer sit-ups,
push-ups, rope climbs, handstand push-ups, pistols).
These exercises are often combined into high-intensity
workouts that are performed in rapid, successive repeti -
tion, with limited or no recovery time. It has been adopted
in both military and civilian populations with widespread
anecdotal reports of impressive fitness gains.
These gains are consistent with existing literature that
supports the contention that high-intensity, single modal
§
Address correspondence to Brian D. Giordano, MD, University of
Rochester School of Medicine and Dentistry, University of Rochester
Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642,
USA (e-mail: brian_giordano@urmc.rochester.edu).
*University of Rochester School of Medicine and Dentistry, Rochester,
New York, USA.
†
Department of Biostatistics and Computational Biology, University of
Rochester Medical Center, Rochester, New York, USA.
‡
Department of Orthopedics, University of Rochester Medical Center,
Rochester, New York, USA.
One or more of the authors has declared the following potential
conflict of interest or source of funding: Grant support from the Clinical
and Translational Science Institute (Grant No. UL1 RR024160 from the
National Institutes of Health) allowed access to REDCap via the University
of Rochester School of Medicine and Dentistry.
The Orthopaedic Journal of Sports Medicine, 2(4), 2325967114531177
DOI: 10.1177/2325967114531177
ª The Author(s) 2014
1
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licenses/by-nc-nd/3.0/), which permits the noncommercial use, distribution, and reproduction of the article in any medium, provided the original author and source are
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exercise is effective with relatively minimal time invest-
ment.
2,6,8,12,17,19,20
A recent study found that participation
in CrossFit improved metabolic capacity and resulted in
improvements in fitness based on maximal oxygen uptake
(VO
2
max) and body composition. These improvements
were noted among subjects of both sexes and across all lev-
els of fitness.
18
A study conducted by the US Army found
that implementation of CrossFit among soldiers led to sig-
nificant improvements in soldiers’ physical fitness.
14
A con-
sensus paper by the Consortium for Health and Military
Performance and the American College of Sports Medicine
acknowledged the beneficial effects of extreme conditioning
programs while addressing concerns over the possible
injury rate and rhabdomyolysis.
1
The primary purpose of this pilot study was to investi-
gate the injury rate among CrossFit participants. A second-
ary objective was to identify trends and associations
between injury rates and demographic categories, gym
characteristics, and athletic abilities among CrossFit parti-
cipants. We aimed to establish a baseline for further
research and investigation into CrossFit. With identifica-
tion of risk factors for injury, we can establish effective
means of preventing these injuries. Similar strategies have
been applied to handball and soccer to reduce injury
rates.
11,13
MATERIALS AND METHODS
General Design
This study utilized a cross-sectional design. Study data
were collected from October 2012 to February 2013 via
an electronic survey (see the Appendix, available at
http://ojsm.sagepub.com/supplemental). Data were col-
lected and managed using REDCap electronic data cap-
ture tools hosted at the University of Rochester.
7
REDCap (Research Electronic Data Capture) is a secure,
web-based application designed to supp ort data capture
for research studies, providing (1) an intuitive interface
for validated data entry, (2) audit trails for tracking data
manipulation and export procedures, (3) automated
export proced ures for seamless data downloads to com-
mon statistical packages, and (4) p rocedures for import-
ing data from external sources. To normalize data, we
chose to only use responses from CrossFit participants
who train at a CrossFit gym in the United States.
Responses from CrossFit athletes from outside the
United States or those who trained on their own were
excluded. The Institution al Review Board at th e Univer-
sity of Rochester approved this study.
Survey Development
The survey was developed from May 2012 to July 2012 via a
series of semistructured interviews with physicians and
CrossFit gym owners, coaches, and participants. It was
based on a survey developed to assess injury in track and
field participants.
9,10
Over the course of the interviews, the
survey was modified to reflect specific factors that should
be measured in CrossFit participants. The survey was then
piloted with multiple groups of CrossFit athletes (5 groups
of 3) and was adjusted according to feedback. From this we
established a 3-fold injury criterion that encompassed a
wide variety of injuries that can occur with CrossFit work-
outs. ‘‘Injury’’ encompassed any new musculoskeletal pain,
feeling, or injury that results from a CrossFit workout and
leads to 1 or more of the following options:
1. Total removal from CrossFit training and other out-
side routine physical activities for >1 week
2. Modification of normal training activities in dura-
tion, intensity, or mode for >2 weeks
3. Any physical complaint severe enough to warrant a
visit to a health professional
The argument for this definition and time requirement
is 3-fold. First, because of the constantly varied program-
ming of CrossFit workouts, athletes are often sore and
because of a particularly difficult workout may be unable
to exercise for several days. This soreness can often be con-
fused with injury. One week was the most commonly
reported time loss period among CrossFit athletes and
sports medicine physicians as to when suspected muscle
soreness was in reality a pathologic issue. Second, practice
in CrossFit consists of many different components, ranging
from gymnastics to power lifting. Therefore, when athletes
are unable to follow the original schedule, they can modify
it around their current injuries. This is defined as partial
time loss and enables them to continue training. Most ath-
letes reported that if they had to modify workouts for more
than 2 weeks they found that the injury was not going to
heal without medical attention. Last, any injury that
appeared to the athlete to require immediate medical atten-
tion from a health care professional should be reported.
This captures both acute injuries and transient injuries
that require the athlete to seek help from a medical profes-
sional but do not affect their training schedule.
We decided to use athlete-level data collection. While
CrossFit athletes regularly perform their workouts in gyms
under the supervision of coaches, often they do not consis-
tently train with the same coach, nor is the level of super-
vision similar to sports teams. CrossFit participants visit
a variety of health care professionals in the area, making
it impossible to use their care providers to gather this infor-
mation. Therefore, contacting the athletes directly is the
only means of assessing injury rate. To minimize recall bias
but maximize injury capture, we choose to survey the ath-
letes over a 6-month time period and created very specific
and concrete criteria for what constituted an injury.
Data Collection
A survey was electronically distributed to CrossFit gym
owners, coaches, and participants primarily in Rochester,
New York; New York City, New York; and Philadelphia,
Pennsylvania. Recipients of this survey were encouraged
to share the survey with members of their gym. Coaches,
owners, and participants were further encouraged to send
the survey to members of other gyms. In addition, the
2 Weisenthal et al The Orthopaedic Journal of Sports Medicine
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survey was made available to CrossFit participants via a
posting on the main CrossFit website. As a result, there
were a wide variety of responses from many distinct geogra-
phical locations, including athletes from outside the United
States. Additionally, many athletes responded who did not
train at CrossFit gyms but preferred to train on their own.
Exclusion criteria included training at a gym outside the
United States, training independently outside of a CrossFit
gym, and being younger than 18 years. Inclusion criteria
included being older than 18 years and training at a Cross-
Fit gym in the United States. This was in an effort to focus
our efforts primarily on CrossFit gyms and to limit geogra-
phical training bias. This was a single survey that recorded
demographic and participant characteristics (ie, sex, age,
experience, maximum lifts, and times) and the incidence
and characteristics of injuries incurred over the 6 months
prior to completing the survey. We specifically looked to
determine if there was any association between body part
injured and movement type and between injury rate and
age, sex, time of participation, training period for begin-
ners, trainer involvement, training time, rest days per
week, and length of time involved in CrossFit using chi-
square or Fisher exact tests. In addition, we investigated
the differences in rates of injury based on prior discomfort
in the injured area, prior injury to the injured area, and
final diagnosis of injury using the chi-square test for equal
proportions. All information, including diagnoses, obtained
for the study was from self-reports and was not indepen-
dently verified by a physician.
Data Analysis
Data analyses were performed using SAS software, version
9.3 (SAS Institute, Cary, North Carolina, USA). The use of
chi-square or Fisher exact tests and the chi-square test for
equal proportions were outlined in the previous paragraph.
All statistical tests were 2-sided, and a P value less than .05
was considered to be statistically significant.
RESULTS
Demographics/Gym Characteristics
There were a total of 468 responses, of which 386 met the
inclusion criteria of training at a CrossFit gym in the
United States (Figure 1). We focused our demographic data
collection on age, sex, and length of participation (Table 1).
The majority had been involved with CrossFit for 0 to
6 months (n ¼ 136; 35.2% ), trained for 30 to 60 minutes
at a time (n ¼ 319; 83.1%), took 2 to 3 rest days per
week (n ¼ 279; 72.8%), and exercised 4 to 5 days per week
Total responses
N = 468
Complete responses
n = 460
Incomplete responses
n = 8
Responses from US
n = 436
Responses from outside US
n = 24
Train at CrossFit gym in US
n = 386
Train outside CrossFit gym
n = 50
California - 29
(6.20%)
Illinois - 32
(6.84%)
Massachusetts - 18
(3.8%)
New York - 215
(45.94%)
Pennsylvania - 16
(3.42%)
Other - 76
(19.69%)
Figure 1. Study flowchart showing the methodology for inclusion criteria, the number of participants included, and where they
were from.
The Orthopaedic Journal of Sports Medicine Injury Rate Among CrossFit Athletes 3
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(n ¼ 279; 72.8%). Many gyms have a required training
period for beginners (n ¼ 325; 84.9%) and have trainers who
are present and actively correcting form during workouts
(n ¼ 219; 57.0%).
Injury Rate by Demographics/Gym Characteristics
Overall, we found that 75 participants (19.4%) had experi-
enced at least 1 injury resulting from a CrossFit workout in
the 6 months prior to filling out the survey that met the
defined injury criteria. Of this population, 63 participants
experienced 1 injury (84%), 10 experienced 2 injuries
(13.3%), and 2 experienced 3 injuries (2.7%).
We found no significant difference in injury rate across
age (n ¼ 381; P ¼ .56). We separated participants by the
amount of time they had been training in CrossFit. We
found no significant difference in injury rate based on
length of participation in CrossFit (n ¼ 386; P ¼ .099), but
athletes who had been participating in CrossFit for longer
periods of time tended to have longer training sessions
(n ¼ 384; P < .001) but not an increased number of sessions
per week (n ¼ 381; P ¼ .67). There was no significant differ-
ence in injury rate based on length of training session (n ¼
384; P ¼ .17). Days spent training per week did not show
any trends based on injury rate (n ¼ 383; P ¼ .16). Partici-
pants who attended a gym that required a training period
for beginners reported a lower injury rate (18.5%) than
training facilities that did not require a training period
(25.9%); however, this did not reach significance (n ¼ 383;
P ¼ .2). Injury rate was separated based on the maximum
weight participants could lift in various strength exercises
(deadlift, squat, press, clean and jerk), and there was no
significant difference between different groups. Five parti-
cipants failed to report their sex, so there were 381 partici-
pants included in the analysis of injury rate based on sex.
Males were significantly more likely to injure themselves
than females (n ¼ 381; P ¼ .03). A significant correlation
was noted between injury rate and level of coach supervi-
sion when men and women were considered together (Table
2). Females, however, were significantly more prone to seek
coach supervision as opposed to males (n ¼ 380; P ¼ .015).
When men and women were considered separately with
regard to injury rate and trainer involvement, the effect
of involvement of trainers had a decreasing effect on injury
rate for each sex, but neither subgroup reached significance
due to a reduced sample size. In subsequent analyses, the
effect of the involvement of trainers on injury rate was
found to be not significantly different for men versus
women, which justified analyzing the 2 groups
concurrently.
Injury Characteristics
CrossFit workouts often include a wide variety of exercises.
Across all exercises, the injury rates were significantly dif-
ferent across body parts (P < .001). The most common
injured parts were the shoulder (21/84), low back (12/84),
and knee (11/84). For gymnastic movements, injury rates
were significantly different across body parts (P ¼ .04),
with shoulder injured most often (7/17). For power lifting
movements, injury rates were significantly different across
body parts (P < .001), with lower back injured most often (9/
19) (Table 3). The majority had neither experienced any dis-
comfort in the injured area prior to the injury (n ¼ 88; P <
.001) nor had an injury to that same body part in the past
year (n ¼ 89; P < .001). The self-reported final diagnoses
were most co mmonly general inflammation and pain (n
¼ 25; 30.8%; P < .001), other (n ¼ 22; 27.2%), sprain/strain
(n ¼ 14; 17.2%), w hile rupture (n ¼ 3; 3.7%)anddislocation
(n ¼ 2; 2.5%) were relatively infrequent.
DISCUSSION
CrossFit is a blend of multiple synchronistic exercises, such
as gymnastics, power lifting, Olympic lifting, and endur-
ance activities. These movements are often performed at
a high intensity with little recovery time between exercises.
As such, some reports have predicted a high injury rate
among CrossFit participants because of repetitive use of
technical exercises at a high intensity.
1
We hypothesized
that this would not be true due to the level of supervision
at CrossFit gyms and an emphasis on instruction before
exercises are performed in a workout. In our study, we
found the overall injury rate in CrossFit was approximately
20%. This injury rate was gathered only from athlete-level
collection, and we depended on their reporting based on our
injury criteria to establish this injury rate. Although the
mechanism of injury would not be the same between run-
ning and CrossFit, running would be a reasonable logical
alternative for exercise in the recreational athlete. As a ref-
erence, epidemiological studies on runners have reported
injury incidence rates ranging from 19.4% to 79.3%.
21
Elite
TABLE 2
Injury Rate Versus Trainer Presence
a
No Injury, n
(Row %)
Injury, n
(Row %)
Total, n
(Column %)
Level of trainer involvement
All of the time 187 (85.4) 32 (14.6) 219 (57)
Most of the time 102 (75.6) 33 (24.4) 135 (35)
Some of the time 20 (69.0) 9 (31.0) 29 (8)
Never 1 (100) 0 (0) 1 (0.2)
Total no. of injuries 310 74 384
b
a
P ¼ .028 for injury rate versus trainer presence.
b
Two subjects did not report trainer presence data.
TABLE 1
Demographic Data by Age and Sex
Age Group, y Males, n (%)(n¼ 231) Females, n (%)(n¼ 150)
18-29 98 (42) 64 (42)
30-39 84 (36) 49 (32)
40-49 34 (15) 28 (18)
50-59 10 (4) 7 (5)
60-69 5 (2) 2 (1)
4 Weisenthal et al The Orthopaedic Journal of Sports Medicine
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track and field athletes, while a very different population
but with similar high-intensity ballistic mechanisms,
demonstrated a 42.8% 1-year retrospective injury preva-
lence, with gradual onset inflammation and pain being the
most common type of injury.
Participants reported injuring their shoulders, knees, and
low back most frequently. These were incurred most often
during power lifting and gymnastic movements. The
shoulder and lower back represented the most frequently
injured body areas during these exercises, respectively. This
finding is consistent with published injury rates among gym-
nasts, with athletes experiencing shoulder injuries most
commonly.
3
Similar trends have been reported for Olympic
and power lifters.
11
Separate studies of elite weight and
power lifters have demonstrated a predominance of
shoulder, low back, and knee injuries, consistent with the
findings of this study, albeit in a different population.
4,15
Demographically, male athletes tended to injure them-
selves more frequently than female athletes. Interestingly,
females were more likely to seek help from a trainer, and
therefore, this may account for their decreased injury rate.
There was no significant difference in injury rate across
age, which persisted in female- and male-only samples.
This indicates that CrossFit is a workout program that can
function safely for athletes across all represented age
groups if performed in a safe environment.
Most reported injuries in CrossFit appear to be of an
acute n ature, as participants generally reported no prior
history of discomfort or injury to the body area they sub-
sequently injured. The majority of those injuries were
fairly mild, with particip ants reporting some general
inflammation/pain or sprain/strain as a result of these
injuries as opposed to more severe problems s uch as dis-
location or f racture. This sugg ests that the majority of
injuries in CrossFit are minor and return to participa-
tion is likely. However, potential re call b ias cannot be
excluded from those results, a s other studies have
demonstrated a 61% accuracy of self-reported diagnosis
in participants reporting over 12 months.
5
Injury prevention programs have become a common
adjunct to a variety of athletic activities.
3,10
To design an
injury prevention program, it is important to be aware of
injury rate and factors associated with injury in a
sport.
11,13,16
This is especially important considering the
business model of CrossFit. To a certain extent, CrossFit
represents a unified organization. However, unlike other
large fitness corporations, it does not directly supervise
gyms but instead gives them freedom to develop and grow
on their own. It does not require them to perform the pro-
gramming that is produced each day by CrossFit headquar-
ters in Washington, DC. Each gym owner is required to
have a CrossFit L1 certification, but aside from that, no
TABLE 3
Injury Location Versus Movement Performed
Movement Type
a
Power Lifting
b
Olympic Lifting Gymnastics
c
Endurance Other Not Associated Total
d
Body part
Neck 0 2 0 0 0 0 2
Upper back 1 2 0 0 0 0 3
Middle back 0 0 0 0 1 0 1
Lower back 9 0 0 0 1 2 12
Shoulder 2 4 7 0 1 7 21
Upper arm 0 0 2 0 0 0 2
Elbow 0 2 1 0 0 1 4
Forearm 0 0 0 0 0 1 1
Wrist 1 2 0 0 1 0 4
Hand 0 0 1 0 0 0 1
Hip 1 1 1 1 2 0 6
Groin 0 0 1 0 1 1 3
Knee 4 1 2 2 1 1 11
Upper leg 1 0 0 0 1 1 3
Lower leg 0 0 0 2 1 0 3
Achilles/calf 0 1 1 0 3 0 4
Ankle 0 1 1 0 0 1 2
Foot/toe 0 0 0 0 0 1 1
Total
e
19 14 17 5 13 16 84
f
a
Power lifting ¼ squat, deadlift, press/push press, bench press; Olympic lifting ¼ snatch, clean, jerk, clean and jerk; gymnastics ¼ pull-ups,
toes-to-bar, knees-to-elbows, lunges, muscle-ups, burpees, dips, gluteus-hamstring developer sit-ups, push-ups, rope climbs, handstand push-
ups, pistols; endurance ¼ rowing, running, sprints; Other ¼ kettlebell swings, thrusters, Turkish get-ups, box jumps, double unders.
b
P ¼ .004 for testing equal injury rates across body parts for power lifting.
c
P ¼ .04 for testing equal injury rates across body parts for gymnastics.
d
P < .001 for testing equal injury rates across body parts overall.
e
P < .001 for testing equal injury rates across movement type.
f
Five subjects did not report a specific movement.
The Orthopaedic Journal of Sports Medicine Injury Rate Among CrossFit Athletes 5
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further training is necessary. Therefore, it is possible to be
faced with a wide variation in quality between CrossFit
gyms based on the experience of the owner and coaches.
CrossFit maintains that the market will select out the gyms
with poor management and trainers and that the excep-
tional gyms will succeed.
Findings from this study may be used to guide physi-
cians, CrossFit owners, and coaches as they implement pre-
ventive strategies in their gyms and practices. This study
identified a specific area of focus that may be used to opti-
mize injury rate reduction strategies based on gym quality.
Increased supervision by CrossFit coaches was directly
related to injury rate. This could be because of several fac-
tors. Coaches guide CrossFit athletes through their work-
outs, help organize the class, and correct form. In
addition, they aid athletes in choosing the correct weight
for the workout. Often, workouts are posted with a pre-
scribed weight and repetition scheme, which can prove to
be excessive for even more experienced members. An expe-
rienced coach can help an athlete choose the right weight
and modify the repetition scheme to minimize injury based
on the athlete’s personal limitations. Our results indicate
that athlete experience level and overall involvement of the
coaches had the most pronounced effect on the health of the
athletes. As such, we recommend that potential partici-
pants evaluate the skill and attentiveness of the trainers,
as that is crucial to creating a safe environment.
As well, we feel that it is crucial for participants to be per-
sonally aware of these risks and strive to maintain form
throughout a workout, with specific focus on elements of
the movement related to the risk area. For example, when
an athlete is performing a power lifting movement, they
should be aware that the lower back is most commonly
injured in that type of movement and strive to maintain
an appropriate lumbar curve to avoid injury. A secondary
preventative strategy is to encourage patients with preex-
isting shoulder or low back pathology to avoid provocative
exercises or very gradually build up to performing those
exercises in a workout.
This study has limitations. We distributed our survey
electronically to current participants who then chose
whether to complete it. This introduces sampling bias
because participants who have had injuries may be more
likely to complete the survey. Alternatively, because we
only surveyed active CrossFit members, it is possible that
athletes who were injured and subsequently dropped out
may have been missed. We defined an acute injury as one
in which the athlete did not experience prior pain or dis-
comfort in the injured area. As this concentrates primarily
on the pain aspect of the injury, it does not take into account
that the mechanism of the injury could have started in a
prior workout without the appearance of pain. We had ath-
letes group their injury into general categories in place of
listing specific injuries, as there was no independent physi-
cian validation of the injury and our goal was to primarily
differentiate between mild and severe injuries. Further-
more, the retrospective nature of the study design intro-
duces the possibility of recall bias. A study examined
injury rates over a 12-month time period.
5
There was a per-
fect recall of whether an injury had been sustained during
that period, with a decreasing percentage of athletes recal-
ling the exact number of injuries, body region, or diagnosis.
Therefore, it stands to reason that the injury rate is accu-
rate, with some decreasing accuracy in the reported num-
ber of injuries, location of injury, and diagnosis, as all this
information was obtained from self-report. There was a
small amount of reported injuries, which limits the conclu-
sions on injury location and type. Despite these limitations,
this study also has several advantages. Our injury criteria
were concrete, encompassed the wide range of injuries that
are seen in CrossFit, and were assembled with input from a
number of different sources, including physicians, CrossFit
owners, and coaches. Although not validated, it also piloted
a means of electronic delivery to athletes, and this could
easily be replicated on a much larger scale to reach partici-
pants throughout the world. Finally, we sampled athletes
from a variety of different gyms throughout the country.
We have determined that injury rate differs based on trai-
ner involvement, and therefore it stands to reason that cer-
tain gyms with more effective or less effective trainers
could skew the injury rate in the study. However, because
of our wide distribution, we believe that this injury rate
comes closer to representing an average for CrossFit gyms
throughout the country as opposed to reporting the values
from a single gym.
This was structured as a pilot study, which could provide
areas of focus for further studies. A larger, prospective
study with a validated survey and examination of injury
rate with direct comparison with other recreational sports
would be the logical next step. The factors we have identi-
fied to be associated with injury patterns may then be
explored in more detail to help design effective preventative
strategies to reduce injury rates and aid CrossFit in grow-
ing as a safe and effective exercise program.
CONCLUSION
CrossFit is emerging as a popular form of competitive
exercise. As participation in CrossFit continues to expand,
injuries associated with involvement will likely grow com-
mensurately. Sports medicine physicians should have an
awareness of the elements of this form of exercise and be
prepared to treat the various patterns of injury incurred
by its athletes. Injury rates in CrossFit are comparable
with established injury rates for other recreational or com-
petitive athletes, with an injury profile resembling that of
gymnasts, Olympic weight lifters, and power lifters. The
increasing involvement of CrossFit trainers in coaching
participants corresponds to a decreasing injury rate. The
shoulder and lower back areas were the most commonly
injured body regions and most frequently were injured dur-
ing gymnastic and power lifting movements. Most injuries
in CrossFit are of an acute nature, without history of previ-
ous injury or symptoms in that same body area. In sum-
mary, we identified a preliminary injury rate in CrossFit,
characteristics of a gym that correlate with injury rates, the
most common location of injuries, and trends among Cross-
Fit participants that correlate with injury rates. This infor-
mation can be used by physicians treating patients who
6 Weisenthal et al The Orthopaedic Journal of Sports Medicine
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participate in CrossFit as well as owners and coaches who
work with athletes on a daily basis.
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