Thesis-FINAL

i
Injury Epidemiology in Competitive
Powerlifting
by
Ong Pang Wee
U1280034F
Sport Science and Management
Nanyang Technological University
A final year report submitted to Nanyang Technological
University in partial fulfilment of the requirements for the
degree of Bachelor of Science.
YEAR

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STATEMENT OF ORIGINALITY
I have read and understood the guidelines on academic dishonesty as found at
and the penalties for academic integrity
(http://academicintegrity.ntu.edu.sg/a-guide-to-academic-
integrity/ ) and declare that this assignment is my own work and does not
involve plagiarism or collusion according to the University’s honour code and
pledge (http://www.ntu.edu.sg/home/yclai/). The sources of other
people’s work have been appropriately referenced. I have also not submitted
any part of this assignment for another course.
.......................................... (Signed)
.......................................... (Date)

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ABSTRACT
Powerlifting is a rapidly growing sport in the world. It requires repetitive activities, especially
during training that generates large amounts of strength and power. As powerlifters must
generate exceedingly large internal forces and torques, they are susceptible to a range of
musculoskeletal injuries. With the current information available, it is understood that
powerlifters may suffer a range of injury types, with the majority of these being symptomatic
for moderately short periods of time. However, the extent to which these injuries affect training
and competitive participation is unclear. This becomes even more critical when considering
adolescent athletes competing in the Sub-Junior (14-18 years of age) and Junior (19-23 years
of age), as some injuries may become chronic, leading to long-term adverse effects and putting
them at risk of dropping out.
The proposed study aims to investigate the descriptive injury epidemiology in powerlifting. It
will determine the injury incidence rates, type and nature of injury, injury localisation and also
common risk factors and possible mechanisms involved in powerlifting injuries. The results of
this research will also contribute to the existing body of knowledge and pave the way for future
research in other aspects such as injury management, rehabilitation and prevention.

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ACKNOWLEDGEMENTS
I would like to thank Dr Swarup Mukherjee (National Institute of Education) for providing
guidance and mentorship in the forming of this thesis.
I would also like to extend my gratitude to Powerlifting (Singapore), The Gym Nation, Anytime
Fitness NEX and Elevate Strength & Conditioning for being responsive and willing to aid this
research and provide points of contact so as to fulfill sample population requirements. It is also
necessary that I express my gratefulness to the participants of this study who have been more
than willing to assist me in providing necessary data in this pursuit of greater knowledge and
understanding of powerlifting injuries.
Lastly, I would like to thank my girlfriend for her love, understanding, care and support. Her
unending encouragement and motivation was crucial to my perseverance in the final semester
of my undergraduate life.

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TABLE OF CONTENTS
Abstract i
Acknowledgements ii
Table of contents iii
List of tables iv
List of figures v
List of abbreviations vi
List of symbols vii
CHAPTER 1 - INTRODUCTION 1
1.1. Literature Review 1
1.2. Biomechanics and Influence on Injury 4
1.3. Hypothesis and Aim of Study 6
CHAPTER 2 – METHODS 7
2.1. Experimental Approach 7
2.2. Participants 7
2.3. Survey and Procedure 7
2.4. Data Analysis 9
CHAPTER 3 – RESULTS 11
CHAPTER 4 – DISCUSSION 20
4.1. Powerlifting Safety xand Injury Statistics 20
4.2. Commonly Injured Body Parts 21
4.3. Differences across Sub-groups 22
4.4. Onset and Nature of Injuries 24
4.5. Limitations 25
4.6. Conclusion and Practical Implications 26
REFERENCES 27
APPENDICES
APPENDIX A: IRB Approval Letter
APPENDIX B: Parent/Coach Information and Consent Form
APPENDIX C: Athlete Assent Form
APPENDIX D: Athlete Questionnaire

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LIST OF TABLES
Table 1. Summary of existing literature on powerlifting injury epidemiology 3
Table 2. Demographic characteristics of powerlifters 12
Table 3. Injury incidence rate of powerlifters 12
Table 4.1. Injured body regions of powerlifters 15
Table 4.2. Event of injury acquisition 16
Table 4.3. Causative activity 16
Table 4.4. Form of injury treatment utilised 17
Table 4.5. Injury onset 17
Table 4.6. Injury severity 18
Table 4.7. Injury type 18

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LIST OF FIGURES
Figure 1.1. High-bar squat (left), low-bar squat (right) 2
Figure 1.2. Conventional deadlift (left), Sumo deadlift (right) 4
Figure 1.3. Bench press moderate/narrow-grip (left), wide-grip (right) 5
Figure 2. Outline sketch of human body 8

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LIST OF ABBREVIATIONS
%MVIC Percentages of maximum volitional isometric contractions
kg Kilograms
injuries/y Injuries per lifter per year
injuries/1000hr Injuries per lifter per 1000 training hours
SPO Singapore Powerlifting Open
PR Personal record

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LIST OF SYMBOLS
M Mean
SD Standard Deviation
CI Confidence interval
< Less than
≤ Less than or equal to
yr Year
wk Week
hr Hour
* Significantly different to other level of variable
┼ Normally distributed data

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CHAPTER 1 – INTRODUCTION
A sport housing some of the strongest people in the world (Vandenburgh & Dooman,
2000), powerlifting is a strength sport, conducted in a similar fashion to Olympic
weightlifting. Athletes compete in different divisions specifically defined by age, gender and
body mass. A full competition, known as a meet, requires powerlifters to perform three
maximal attempts in each of the three disciplines – squat, bench press and deadlift. It is a
sport requiring maximal strength and force generation in competition and even during
training. When done repeatedly, powerlifters are exposed to high risk of injuries.
In 2011, the first powerlifting meet was conducted with only 13 participants before
Powerlifting (Singapore) became an official registered society. In the Singapore Powerlifting
Open (SPO) 2014, this number grew to 70 male and 11 female competitors. In the SPO 2015,
this number further increased to a grand total of 106. This nearly nine-fold growth signifies
the increasing reach and popularity of powerlifting as a sport. However, despite rising
popularity and participation, there remains limited research with regards to powerlifting
injury epidemiology. Consequently, the primary aim of this study was to investigate the
descriptive injury epidemiology in competitive powerlifting.
1.1. Literature Review
Powerlifting requires repetitive activities especially during training that generates
large amounts of strength and power. As powerlifters generate exceedingly large internal
forces and torques, they are susceptible to a range of musculoskeletal injuries (Brown &
Kimball, 1983). With the current information available, it is understood that powerlifters may
suffer a range of injury types, with majority of these being symptomatic for moderately short
periods of time (Keogh et al., 2006). The work of Siewe et al. (2011) showed that the daily

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workout of a large proportion of powerlifters was affected by disorders that do not require an
interruption of training. This suggests that powerlifters may persist through their training
even with injuries present, exposing themselves to possible deterioration of their conditions.
Based on the existing studies (Table 1), powerlifting has a relatively low rate of
injury, averaging on 2 per year. However, the extent to which these injuries affect athletes’
training and competitive participation is unclear. This becomes even more critical when
considering adolescent athletes competing in the Sub-Junior (14-18 years of age) and Junior
(19-23 years of age), as some injuries may become chronic, leading to long-term adverse
effects and putting them at risk of dropping out of the sport.
Table 1. Summary of existing literature on powerlifting injury epidemiology
Study Sample characteristics Injury rate Most frequently injured
body parts
Injury severity
Brown & Kimball,
1983
71 Junior men 1.4 injuries/lifter/yr Lower back (50%),
shoulder (11.9%) and
knee (8%)
11.5 days/injury
Keogh et al., 2006 101 Oceania
powerlifters
1.2 injuries/lifter/yr Shoulder (36%), lower
back (23.7%)
Mild (39%), moderate
(39%), major (22%)
Siewe et al., 2011 245 competitive and
elite powerlifters
0.3 injuries/lifter/yr
1 injury/1000hr
Shoulder (53.1%),
lumbar spine (40.8%)
43.3% complained of
pain during workouts
Raske & Norlin, 2002 55 elite powerlifters, 55
elite weightlifters
2.6 injuries/1000hr Shoulder (powerlifters),
knee and low back
(weightlifters)
93% of shoulder
injuries and 85% of
low back injuries were
major
Haykowsky et al.,
1999
11 elite visually
impaired athletes, 9
men, 2 women
1.1 injuries/1000hr Shoulder (25%), lower
back (25%)
12 days/injury
Inspecting existing literature, it becomes obvious that the shoulder and lower back are
the most commonly affected body parts. Knee injuries were briefly mentioned by Brown and
Kimball (1983) and Raske and Norlin (2002).
Siewe et al. (2011) noted that both deadlifts and squats aggravate back pain. However,
squats led to more problems in the upper and lower extremities. The bench press was

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correlated with pain predominantly in the upper body. Furthermore, most injuries across
studies were muscular in nature. Participants in these studies were able to train albeit
complaints of pain or discomfort during their training.
When comparing studies, there was no definite pattern between age and injury
incidence. Moreover, in Brown and Kimball’s (1983) study, the injury rate of adolescent
powerlifters was not very different from those of older lifters in the other studies. In fact, it
was suggested that training experience, more than age, is an important predictor of injury
risk. In Keogh et al.’s (2002) paper, it was noted that despite powerlifters in the Master age
categories having higher injury risk as a result of ageing, their training experience
accumulated over the years may have offset this intrinsic risk. This was further reinforced by
the fact that international lifters sustained less injuries than national lifters.
There are also certain aspects of injury documentation that could have been beneficial
but were not covered in the existing studies. For example, there was no profiling of when the
participants sustained their injuries. While overuse injuries may be common due to the
repetitive nature of this sport, it useful to understand whether these injuries are acquired
during the off-season, competition preparation or during the competition itself. Furthermore,
there was no classification in some of the papers as to whether the injury is acute traumatic or
chronic. There was also little documentation of injury mechanisms. These studies were
conducted largely in Western populations. There have yet to be studies conducted on the
Asian population. This is a huge gap in research as there are anthropometric and
physiological differences across races and ethnicities that might be significant when
considering factors that can influence injury risk, patterns and incidence.

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1.2. Biomechanics and Influence on Injury
A common limitation of existing studies is that the influence of biomechanical factors on
injury acquisition in powerlifting has not been elucidated. They have not accounted for the
styles of squatting, bench pressing and deadlifting and analyse their effects on injury patterns.
Hence, in order to fill this gap, this research also investigated the relationship between the
style of lift and how they affect the injury profile of powerlifters.
In the powerlifting squat, many elect a low-bar position as opposed to a high-bar
position (Figure 1.1). In the low-bar squat, the barbell is placed on the back, across the
superior surface of the posterior deltoid with a slight degree of variation based on individual
lifter’s anthropometry and body structure. This changes the combined center of gravity of the
athlete and barbell, leading to greater forward lean. This results in greater hip flexion, and
reduced knee flexion and dorsiflexion angles. Relative to a high-bar squat, this causes greater
posterior excursion of the hips, reducing the moment arm of the load and extensor torque
about the knee while increasing them about the hip (Keogh et al., 2006; Escamilla et al.,
2001; Wretenberg et al., 1996). This could account for relatively low knee injuries despite the
heavy loads exerted on the knee’s musculoskeletal structure. Additionally, the increased
extensor torque about the hip and thus increased stress on the muscular structures adjacent to
the hip could account for the relatively high lower back injury rate.
Figure 1.1. High-bar squat (left), low-
bar squat (right)
Figure 1.2. Conventional deadlift (left),
Sumo deadlift (right)

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Furthermore, some studies conducted on competitive powerlifters (Cholewicki et al.,
1991; Granhed et al., 1987) have shown that compressive and shear forces acting on the spine
are substantially large, especially for lifters who opt to perform the conventional deadlift, as
shown in Figure 1.2. Compressive load can measure more than 17192N, while average L4/L5
and hip moments can be around 1000Nm (Siewe et al., 2011). This suggests that lumbar
extensors are under immense mechanical stress that, accumulated over time, may contribute
to physiological and mechanical strain, resulting in the prevalence of low back injuries.
Figure 1.3. Bench press moderate/narrow-grip (left), wide-grip (right)
Another interesting observation was found in a study on injury prevalence and
incidence among elite weightlifters and powerlifters (Raske & Norlin, 2002). In this study,
one of the aims was to investigate exercises that provoke shoulder injury. Hence, a list of
exercises performed weekly were collected based on participant training regimes. Lifters who
had the bench press in their programmes were more likely to have shoulder injuries. This
observation may be correlated to the higher percentages of maximum volitional isometric
contractions (%MVIC) by the anterior deltoid during the concentric portion of the bench
press compared to pectoralis major and biceps brachii (Clemons & Aaron, 1997). Moreover,
the total %MVIC of the prime movers were greater as grip width of the bench press
increased. As greater values %MVIC suggests higher force production and thus tension
experienced by the muscle, it may explain why shoulder injuries were common, as more

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experienced competitive powerlifters tend to use a relatively wider grip width (Madsen &
McLaughlin, 1984), as demonstrated in Figure 1.3. This is done to reduce range of motion in
competition and training. This in turn brings about higher percentages of %MVIC in the
anterior deltoid muscle, exposing it to greater stress.
Hence, in order to better understand how the elected competition stance in each lift
affects injury mechanisms and risk factors, this study seeks to investigate and determine if
such relationships exist. The information and knowledge derived from this study will be
useful for coaches, athletes and other relevant individuals and professionals in injury
prevention and/or risk minimisation during training and when preparing for competition.
1.3. Hypothesis and Aim of Study
Understanding that powerlifting is a sport that involves explosive and repetitive training,
this study hypothesises that most injuries will be overuse in nature. This study also maintains
the stand that powerlifting has low injury rates and is a relatively safe sport.
This paper aims to investigate the descriptive injury epidemiology in powerlifting. It
will determine the injury incidence rates, type and nature of injury, injury localisation and
also common risk factors and possible mechanisms involved in powerlifting injuries. The
results of this research will also add on to the existing body of knowledge and pave the way
for future research in other aspects such as injury management, rehabilitation and prevention.
One major outcome of this research would be to provide a more detailed description
of the injury statistics of powerlifters and ultimately determine the relative safety of this sport
based on data collected.

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CHAPTER 2 – METHODS
2.1. Experimental Approach
The study employed a retrospective approach. Questionnaires with categorical and
open-ended questions were used to elicit the injury information in athletes. This provided
insights into injury incidence and severity leading up to competitions especially.
2.2. Participants
91 participants recruited were competitive powerlifters who have competed in meets
approved and/or sanctioned by Powerlifting (Singapore). They have entered at least 1
competition, with exception to those who were injured in the midst of competition
preparation.
2.3. Survey and Procedure
Questionnaires were distributed physically and completed in the presence of the
researcher. The researcher was present to help clarify doubts in responding to the
questionnaires in order to increase validity of participant responses.
As per the guidelines written in the questionnaire used for data-gathering purposes, a
reportable injury is defined by the following criteria:
 Occurred during time of powerlifting participation
 Resulted in functional or performance limitations, i.e. inability to maintain training
volume/intensity/frequency
 May or may not require medical attention or involves time loss in terms of training
 Led to modifications in one or more training sessions and/or missing a competition
The questionnaire contained questions on anthropometric, demographic, training and
injury characteristics of subjects. It also included an outline sketch of the human body to

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allow indication of injuries localisation and also to validate the locations. Only one injury
will be documented in a single form. Participants with multiple injuries were asked to
complete multiple forms.
Figure 2. Outline sketch of human body
Injuries were classified as acute traumatic, recurrent, exacerbation and overuse.
Questionnaires provided the criteria for new/acute, recurrent, aggravation and overuse
injuries. Severity was determined based on whether medical attention was sought or if the
injury led to time loss from training and competition. A mild injury would be one where no
medical attention was sought and no time was lost in training. A moderate injury would be
one where the subject had approached a professional, such as a trained medical specialist, for
advice and help with the injury and/or stopped performing a certain exercise(s). A severe
injury would be one where the subject had sought medical attention for an extended duration
and/or cancelled training for 3 weeks or more. A similar approach was used by Keogh et al.
(2006) in their study.

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Injuries were categorised according to being a consequence of either training,
competition or other activities. Participants were asked to specify whether injuries occurred
as a result of either of the 3 disciplines or other exercises and activities.
Several measures were taken to minimise the extent of recall bias. A clear and
specific injury definition was provided for the participants to recall the events through
specific prompts. This paper argues that powerlifters are in the sport by choice and are
generally meticulous in recording their daily training sessions in diaries and logs (Keogh et
al., 2006). The injury registration form also had clear and specific indications of body parts
and the type of injury thus, reducing recall-related challenges. Furthermore, the injury
registration form required participants provide a short description of the injury, its occurrence
and progress, thus providing a clearer picture of the injury.
2.4. Data Analysis
Means (M) and standard deviations (SD) were calculated for participant characteristics
and injury rates. Injury rates were quantified in two ways – number of injuries per lifter per
year (injuries/yr) and number of injuries per lifter per 1000 training hours (injuries/1000hr).
To calculate injuries/1000hr, annual training time was estimated by multiplying each lifter’s
reported average weekly training time by the number of weeks in a year.
For other dependent variables, such as onset of injury and causative activity, the
frequency and percentage of total occurrences were calculated. Results were calculated for
the entire sample as well as for the various sub-groups of competitive age category,
bodyweight category and gender. Competitive age categories used for the purpose of this
study were Junior (≤23 years) and Open (>23 years), with participant age being recorded
based on the calendar year. As male and female athletes compete in 9 and 8 bodyweight
classes respectively, participants were assigned to lightweight or heavyweight sub-groups

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based on their competition bodyweight classes. For men, bodyweight classes in 83kg and
below were considered lightweight, while women in 63kg class and below were considered
lightweight.
Data was analysed using IBM Statistical Package for the Social Sciences (SPSS)
Statistics 22. A 2-tailed Mann-Whitney test was used to determine if any significant
differences exist in the demographics or injury epidemiology as a function of age,
bodyweight or gender. Pearson’s chi-square test was used to determine if the style of lift used
had any relation with acquisition of injuries. Pearson Correlation tests were used to determine
if there was any relationship between training experience and injury rates. Statistical
significance was set at p ≤ 0.05.

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CHAPTER 3 – RESULTS
91 competitive powerlifters, 74 male and 17 female, were recruited for this study. The
average age was 24.73 years, SD = 0.56, 95% CI [23.61, 25.84]. Average training experience
was 2.42 years, SD = 0.17, 95% CI [2.08, 2.76]. Complete demographic data is shown in
Table 2. A total number of 162 injuries were documented. The Shapiro-Wilk test was used to
assess normality of data. Data that was normally distributed were marked on the tables that
follow.
The average injury rate was 0.91 injuries/yr, (SD = 0.09, 95% CI [0.74, 1.09]). Mean
injuries/1000hr was 2.11 (SD = 0.19) at 95% CI [1.73, 2.50]. This is reflected in Table 3.

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Table 2. Demographic characteristics of powerlifters. Results are presented as M ± SD.
Age Gender Body Mass
All lifters (n= 91) Junior (n = 35) Open (n = 56) Male (n = 74) Female (n = 17) Lightweight (n = 65) Heavyweight (n = 26)
Age (yr) 24.73 ± 0.56 20.11 ± 0.32*┼ 27.61 ± 0.63 24.76 ± 0.67 24.59 ± 0.74┼ 23.57 ± 0.56* 27.62 ± 1.22
Training Experience
(yr) 2.42 ± 0.17 1.53 ± 0.12*┼ 2.98 ± 0.24 2.35 ± 0.19 2.73 ± 0.38┼ 2.16 ± 0.13 3.13 ± 0.47
Amount of training
(hr/wk) 8.58 ± 0.30┼ 9.56 ± 0.44* ┼ 7.96 ± 0.39 8.84 ± 0.34 ┼ 7.44 ± 0.67┼ 8.44 ± 0.31┼ 8.92 ± 0.73┼
Body mass (kg) 78.43 ± 1.58 74.93 ± 2.25 80.61 ± 2.11┼ 82.07 ± 1.64* 62.56 ± 1.66┼ 72.36 ± 1.12*┼ 93.59 ± 3.27┼
Personal record (PR)
total (kg) 476.77 ± 12.99┼ 452.35 ± 19.54┼ 492.03 ± 17.03┼ 523.32 ± 9.53*┼ 274.15 ± 10.82┼ 450.61 ± 14.13*┼ 542.17 ± 24.63
*Significantly different (p < 0.05) to other level of variable -
┼Normally distributed data
Table 3. Injury incidence rate of powerlifters. Results are presented as M with 95% CI within parentheses.
*Significantly different (p < 0.05) to other level of variable -
All lifters (n= 91) Junior (n = 35) Open (n = 56) Male (n = 74) Female (n = 17) Lightweight (n = 65) Heavyweight (n = 26)
Inury rate
Injuries/yr 0.91 (0.73, 1.10) 1.34 (0.95, 1.72)* 0.64 (0.53, 0.76) 0.96 (0.75, 1.16) 0.71 (0.39, 1.03) 1.00 (0.78, 1.23) 0.68 (0.46, 0.90)
Injuries/1000hr 2.11 (1.73, 2.50) 2.78 (2.06, 3.50)* 1.77 (1.36, 2.17) 2.17 (1.74, 2.59) 2.11 (1.19, 3.04) 2.38 (1.91, 2.85)* 1.60 (1.02, 2.17)

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The Mann-Whitney test indicated the following results (reflected in Table 2) when
comparing Junior and Open powerlifters. Mean age of Open powerlifters (M =27.61 , SD =
0.63) was significantly greater than Junior powerlifters (M = 20.11, SD = 0.32), U = 0, p <
0.05. Mean training experience of Open powerlifters (M = 2.98, SD = 0.24) was significantly
greater than Junior powerlifters (M = 1.53, SD = 0.12), U = 339.50, p < 0.05. Mean weekly
training hours of Junior powerlifters (M = 9.56, SD = 0.44) was significantly greater than
Open powerlifters (M = 7.96, SD = 0.39), U = 611.00, p < 0.05.
comparing male and female powerlifters. Mean body mass of male powerlifters (M =82.07 ,
SD = 1.64) was significantly greater than female powerlifters (M = 62.56, SD = 1.66), U =
85.00, p < 0.05. Mean personal record (PR) total of male powerlifters (M = 523.32, SD =
9.53) was significantly greater than female powerlifters (M = 274.15, SD = 10.82), U = 2.00,
p < 0.05.
comparing lightweight and heavyweight powerlifters. Mean age of heavyweight powerlifters
(M =27.62, SD = 1.22) was significantly greater than lightweight powerlifters (M = 23.57, SD
= 0.56), U = 467.50, p < 0.05. Mean body mass of heavyweight powerlifters (M =93.59, SD =
3.27) was significantly greater than lightweight powerlifters (M = 72.36, SD = 1.12), U =
206.00, p < 0.05. Mean PR total of heavyweight powerlifters (M = 542.17, SD = 24.63) was
significantly greater than lightweight powerlifters (M = 450.61, SD = 14.13), U = 385.00, p <
0.05.
comparing injury rates across sub-groups. Mean injuries/yr for Junior powerlifters (M = 1.34,
SD = 0.19) was significantly greater than that of Open powerlifters (M = 0.64, SD = 0.06), U
= 464.50, p < 0.05. Mean injuries/1000hr for Junior powerlifters (M = 2.78, SD = 0.35) was

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significantly greater than the mean injuries per 1000 hour of exposure for Open powerlifters
(M = 1.77, SD = 0.20), U = 617, p < 0.05. Mean injuries/1000hr for lightweight powerlifters
(M = 2.38, SD = 0.24) was significantly greater than that of heavyweight powerlifters (M =
1.60, SD = 0.28), U = 617.50, p < 0.05.

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Table 4.1. Injured body regions of powerlifters. Results for body region injured are expressed with two values –
first value being frequency of occurrences and second number in parentheses the percentage of total occurences.
All lifters
(n= 91)
Junior
(n = 35)
Open
(n = 56)
Male
(n = 74)
Female
(n = 17)
Lightweight
(n = 65)
Heavyweight
(n = 26)
Body region
Neck 5 (3.09%) 2 (3.08%) 3 (3.09%) 3 (2.16%) 2 (8.00%) 3 (2.61%) 2 (4.26%)
Shoulder 21 (12.96%) 10 (15.38%) 11 (11.34%) 16 (11.51%) 5 (20.00%) 17 (14.78%) 4 (8.51%)
Upper arm 2 (1.23%) - 2 (2.06%) 2 (1.44%) - 1 (0.87%) 1 (2.13%)
Chest 5 (3.09%) - 5 (5.15%) 4 (2.88%) - 2 (1.74%) 3 (6.38%)
Spine 1 (0.62%) - 1 (1.03%) 1 (0.72%) - - 1 (2.13%)
Upper back 4 (2.47%) 1 (1.54%) 3 (3.09%) 4 (2.88%) - 3 (2.61%) 1 (2.13%)
Lower back 37 (22.84%) 18 (27.69%) 19 (19.59%) 26 (18.71%) 11 (44.00%) 29 (25.22%) 8 (17.02%)
Hip flexor 11 (6.79%) 3 (4.62%) 8 (8.25%) 10 (7.19%) 1 (4.00%) 10 (8.70%) 1 (2.13%)
Pelvis/Hip/Groin 11 (6.79%) 2 (3.08%) 9 (9.28%) 9 (6.47%) 2 (8.00%) 4 (3.48%) 7 (14.89%)
Gluteal region 7 (4.32%) 5 (7.69%) 2 (2.06%) 7 (5.04%) - 5 (4.35%) 2 (4.26%)
Quadriceps 6 (3.70%) 1 (1.54%) 5 (5.16%) 5 (3.60%) 1 (4.00%) 6 (5.22%) -
Hamstrings 9 (5.56%) 3 (4.62%) 6 (6.19%) 8 (5.76%) 1 (4.00%) 6 (5.22%) 3 (6.38%)
Knee 18 (11.10%) 9 (13.80%) 9 (9.28%) 17 (12.2%) 1 (4.00%) 11 (9.57%) 7 (14.89%)
Calf 1 (0.62%) - 1 (1.03%) 1 (0.72%) - - 1 (2.13%)
Shin 1 (0.62%) - 1 (1.03%) 1 (0.72%) - - 1 (2.13%)
Ankle 5 (3.09%) 5 (7.69%) - 5 (3.60%) - 5 (0.87%) -
Foot 1 (0.62%) - 1 (1.03%) 1 (0.72%) - 1 (0.87%) -
Elbow 6 (3.70%) 1 (1.54%) 5 (5.16%) 6 (4.32%) - 3 (2.61%) 3 (6.38%)
Forearm 3 (1.85%) - 3 (3.09%) 2 (1.44%) 1 (4.00%) 3 (2.61%) -
Wrist 6 (3.70%) 4 (6.15%) 2 (2.06%) 6 (4.32%) - 5 (4.35%) 1 (2.13%)
Hand 2 (1.23%) 1 (1.54%) 1 (1.03%) 2 (1.44%) - 1 (0.87%) 1 (2.13%)
The most commonly injured part of the body was the lower back (22.84%), followed
by the shoulder (12.96%) and the knee (11.10%). This trend is consistent across all subgroups
except males and heavyweights, who had greater occurrences of knee and pelvis/hip/groin
injuries (14.89%) compared to shoulder injuries (8.51%).

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Table 4.2. Event of injury acquisition. Results are expressed with two values – first value being frequency of
occurrences and second number in parentheses the percentage of total occurences.
All lifters
(n= 91)
Junior
(n = 35)
Open
(n = 56)
Male
(n = 74)
Female
(n = 17)
Lightweight
(n = 65)
Heavyweight
(n = 26)
Event of injury
Training 133 (83.13%) 52 (80.00 %) 81 (83.51%) 109 (79.56%) 24 (96.00%) 95 (82.61%) 38 (80.85%)
Competition 4 (2.5%) 1 (1.54%) 3 (3.09%) 4 (2.92%) - 3 (2.61%) 1 (2.13%)
Others 25 (15.63%) 12 (18.46%) 13 (13.40%) 24 (17.52%) 1 (4.00%) 17 (14.78%) 8 (17.02%)
As observed from the results in Table 4.2, a large proportion of injuries were acquired
through training (83.13%)
Table 4.3. Causative activity. Results are expressed with two values – first value being frequency of occurrences
and second number in parentheses the percentage of total occurences.
All lifters
(n= 91)
Junior
(n = 35)
Open
(n = 56)
Male
(n = 74)
Female
(n = 17)
Lightweight
(n = 65)
Heavyweight
(n = 26)
Causative activity
Squat 73 (45.06%) 30 (46.15%) 43 (44.33%) 59 (43.07%) 14 (56.00%) 55 (47.83%) 18 (38.30%)
Bench 26 (16.05%) 8 (12.31%) 18 (18.56%) 25 (18.25%) 1 (4.00%) 18 (15.65%) 8 (17.02%)
Deadlift 36 (22.22%) 18 (27.69%) 18 (18.56%) 26 (18.98%) 10 (40.00%) 26 (22.61%) 10 (21.28%)
Assistance 9 (5.56%) 1 (1.54%) 8 (8.25%) 6 (4.38%) 3 (12.00%) 5 (4.35%) 4 (8.51%)
Others 25 (15.63%) 12 (18.46%) 13 (13.40%) 24 (17.52%) 1 (4.00%) 17 (14.78%) 8 (17.02%)
Table 4.3 shows that the most common causative activity was the squat (45.06%),
followed by the deadlift (22.22%). This trend is observed in all sub-groups excluding
powerlifters belonging to the Open and Male sub-group, who seem to be equally affected by
the deadlift and the bench press as the second most causative activity.

17
Table 4.4. Form of injury treatment utilised. Results are expressed with two values – first value being frequency
of occurrences and second number in parentheses the percentage of total occurences.
All lifters
(n= 91)
Junior
(n = 35)
Open
(n = 56)
Male
(n = 74)
Female
(n = 17)
Lightweight
(n = 65)
Heavyweight
(n = 26)
Injury treatment
None 44 (27.16%) 15 (23.08%) 29 (29.90%) 40 (29.20%) 4 (16.00%) 28 (24.35%) 16 (34.04%)
Self 24 (14.81%) 7 (10.77%) 17 (17.53%) 24 (17.52%) 0 (0%) 16 (13.91%) 8 (17.02%)
Medical 94 (58.02%) 43 (66.15%) 51 (52.58%) 73 (53.28%) 21 (84.00%) 71 (61.74%) 23 (48.94%)
From the results in Table 4.4, most powerlifters sought medical treatment (58.02%)
for their injuries. This was observed across each sub-group.
Table 4.5. Injury onset. Results are expressed with two values – first value being frequency of occurrences and
second number in parentheses the percentage of total occurences.
All lifters
(n= 91)
Junior
(n = 35)
Open
(n = 56)
Male
(n = 74)
Female
(n = 17)
Lightweight
(n = 65)
Heavyweight
(n = 26)
Injury onset
Acute 101 (63.10%) 46 (70.80%) 55 (56.7%) 88 (64.2%) 13 (52.00%) 71 (61.74%) 30 (63.83%)
Chronic 61 (38.13%) 19 (29.23%) 42 (43.30%) 49 (35.77%) 12 (48.00%) 44 (38.26%) 17 (36.17%)
New 93 (58.00%) 38 (58%) 55 (57%) 82 (60%) 11 (44.00%) 63 (54.80%) 30 (63.80%)
Recurring 12 (7.50%) 11 (16.90%) 1 (1%) 11 (8%) 1 (4.00%) 11 (9.57%) 1 (2.13%)
Exacerbation 1 (0.63%) 1 (1.54%) - - 1 (4.00%) 1 (0.87%) -
Overuse 56 (35.00%) 15 (23.08%) 41 (42.27%) 44 (32/11%) 12 (48.00%) 40 (34.78%) 16 (34.04%)
According to Table 4.5, most injuries were of an acute nature (63.10%). Furthermore,
according to the participant feedback, most of these injuries were either new (58.00%) or
overuse (35.00%) injuries.

18
Table 4.6. Injury severity. Results are expressed with two values – first value being frequency of occurrences and
All lifters
(n= 91)
23 and below
(n = 35)
Above 23
(n = 56)
Male
(n = 74)
Female
(n = 17)
Lightweight
(n = 65)
Heavyweight
(n = 26)
Injury severity
Mild 34 (20.99%) 10 (15.38%) 24 (24.74%) 32 (23.56%) 2 (8.00%) 22 (19.13%) 12 (25.53%)
Moderate 106 (65.43%) 44 (67.69%) 62 (63.92%) 86 (62.77%) 20 (80.00%) 77 (66.96%) 29 (61.70%)
Major 22 (13.58%) 11 (16.92%) 11 (11.34%) 19 (13.87%) 3 (12.00%) 16 (13.91%) 6 (12.77%)
Upon inspecting the values in Table 4.4, most injuries acquired had a mild (20.99%)
to moderate effect (65.43%). Only a small proportion of injuries were major (13.58%) and
required stoppage of training for 3 weeks or more.
Table 4.7. Injury type. Results are expressed with two values – first value being frequency of occurrences and
All lifters
(n= 91)
23 and below
(n = 35)
Above 23
(n = 56)
Male
(n = 74)
Female
(n = 17)
Lightweight
(n = 65)
Heavyweight
(n = 26)
Type of injury
Contusion 1 (0.63%) - 1 (1.03%) 1 (0.73%) - 1 (0.87%) -
Bursitis 1 (0.63%) - 1 (1.03%) 1 (0.73%) - 1 (0.87%) -
Tendonitis 42 (26.25%) 16 (24.62%) 26 (26.80%) 37 (27.01%) 5 (20.00%) 32 (27.83%) 10 (21.28%)
Ligament
sprain (incomplete
tear) 5 (3.13%) 3 (4.62%) 2 (2.06%) 4 (2.92%) 1 (4.00%) 3 (2.61%) 2 (4.26%)
Ligament
sprain (complete
tear) 9 (5.63%) 7 (10.77%) 2 (2.06%) 8 (5.84%) 1 (4.00%) 9 (7.83%) -
Muscle-tendon
strain (incomplete
tear) 83 (51.88%) 32 (49.23%) 51 (52.58%) 67 (48.91%) 16 (64.00%) 57 (49.57%) 26 (55.32%)
Dislocation
(complete) 1 (0.63%) 1 (1.54%) - 1 (0.73%) - 1 (0.87%) -
Fracture 2 (1.25%) - 2 (2.06%) 2 (1.46%) - - 2 (4.26%)
Nerve 11 (6.88%) 2 (3.08%) 9 (9.28%) 10 (7.30%) 1 (4.00%) 7 (6.09%) 4 (8.51%)
Others 7 (4.38%) 4 (6.15%) 3 (3.09%) 6 (4.38%) 1 (4.00%) 4 (3.48%) 3 (6.38%)
Table 4.7 describes injury type. More than half of injuries acquired were minor
muscular-tendinous strains (51.88%) and tendonitis (26.25%).

19
A Pearson Correlation test was used to determine if there was any correlation between
training experience and injury rates. Based on the results of the Pearson Correlation test,
training experience and injuries/yr were significantly correlated, r = -0.32, p < 0.05. The
Pearson Correlation test also indicated that training experience and injuries/1000hr were
significantly correlated, r = -0.26, p < 0.05.
Pearson’s chi-square test revealed no significant relationship between deadlift stance
and lower back injury acquisition. The test also revealed no significant relationship between
grip width for the bench press and shoulder injury acquisition.

20
CHAPTER 4 – DISCUSSION
4.1. Powerlifting Safety and Injury Statistics
From the injury rates described in Table 3, this study indicates that powerlifters suffer
a relatively low rate of injury. Furthermore, with reference to Table 4.7, a significant
proportion of these injuries were minor (20.99%) to moderate (65.43%) in severity with
regards to their effect training and the subsequent medical attention required.
The rate of injury observed in this research was relatively consistent with other
studies (Keogh et al., 2006; Haykowsky et al., 1999; Raske & Norlin, 2002; Brown &
Kimball, 1983; Siewe et al., 2011). Based on these results, it would seem that powerlifting
has relatively lower rates of injuries compared to other sports. While powerlifters experience
about 1 to 2 injuries per year and on average 2 injuries/1000hr, athletes in other sports, such
as football (Ekstrand et al., 2009), basketball (Dick et al., 2007) and rugby (Gissane et al.,
2002), are exposed to at least twice the risk of injury. For example, the work of Gissane et al.
(2002) showed that in rugby league football, the overall injury rate was 40.3 injuries per 1000
hours. This shows the stark contrast in injury risk when comparing powerlifting to other more
popular sports. While there may be inter-study variances in injury definition and data
collection procedures, the results of this study shows that powerlifting is a sport with
relatively low injury rates, as supported by other powerlifting literature.
While the aim of this study is to provide a clearer picture of injury epidemiology in
the powerlifting population, there was also a notable degree of interindividual variance in
injury rate. Of the 91 participants in this study, 10 had experienced no injuries in their
powerlifting experience, while 2 sustained 5 and 6 injuries respectively. Interestingly, the
participant that sustained 6 injuries had only 11 months of training experience, resulting in a
values of 6.55 injuries/yr and 10.49 injuries/1000hr. This variability did not appear to be

21
related to age, body mass or gender, which was an observation similar to that of the study
done by Keogh et al. (2002). This would suggest that intrinsic factors such as anthropometry,
muscle imbalance and training practices and methodology, had a significant influence on
injury risk. Extrinsic factors including use of safety equipment, time of day of training and
environmental conditions may have also contributed to these differences (van Mechelen et
al., 1992).
However, based on the results of the Pearson Correlation tests used in analysing the
relationship between training experience and injury rates, it can be said that there was a
certain degree of inverse correlation between these parameters. The results obtained from
both tests suggest that with greater training experience, injury rates tend to be lower. This
would seem logical – with accumulated experience, powerlifters are better able to pace
themselves in training and in competition and ensure that they do not incur debilitative
injuries that affect their progress in the long run. This observation reinforced by the fact that
Open category powerlifters had significantly lower injury rates compared to their Junior
counterparts. Furthermore, as described in Table 3, Open powerlifters had greater training
experience than Junior powerlifters. Hence, as training experience increases, the likelihood of
injury for powerlifters would seemingly decrease.
4.2. Commonly Injured Body Parts
Upon inspection of Table 4.1, the most commonly injured body parts were the lower
back and shoulder. This is consistent with other powerlifting literature (Keogh et al., 2006;
Haykowsky et al., 1999; Raske & Norlin, 2002; Brown & Kimball, 1983; Siewe et al., 2011).
There was little difference in this trend across the different sub-groups. The occurrence of
lower back injuries could be due to the large hip extensor torques and compressive or shear
lumbar forces documented in the execution of the squat and the deadlift (Keogh et al., 2006;

22
Escamilla et al., 2001; Wretenberg et al., 1996; Siewe et al., 2011, Brown & Abani, 1985;
Cholewicki et al., 1991; Granhed et al., 1987). This could also be related to the squat and
deadlift being the most prominent causes of injury as shown in Table 4.3. Shoulder injuries
could be attributed to the stress placed on the shoulder musculature by the bench press
(Bhatia et al., 2007; Clemons & Aaron, 1997; Raske & Norlin, 2002).
One important observation in this study was that the occurrence of knee injuries was
close to that of shoulders, with only a 1.86% difference. This was in contrast to other studies
done (Keogh et al., 2006; Haykowsky et al., 1999; Raske & Norlin, 2002; Brown & Kimball,
1983; Siewe et al., 2011). While these studies maintained that powerlifters had lower
occurrence of knee injuries compared to Olympic weightlifting and bodybuilding, the present
study finds that knee injuries were almost as common as shoulder injuries. Contrary to the
claim that the low-bar squat significantly reduces torque and mechanical stress about the
knee, adopting such a position may not necessarily correlate to lower acquisition of knee
injuries. With 83 of the 91 participants training and competing with a low-bar position, it
would seem that there are other factors to be considered. This difference in injury patterns
between studies could be due to factors such as technique. Furthermore, as existing studies
were mostly conducted on Western or European populations while the present study was
carried out on a predominantly Asian population, there may be other physiological or
anatomical factors underlying this difference in injury pattern.
4.3. Differences across Sub-groups
Junior powerlifters and those in the lightweight sub-group had higher rates of lower
back and shoulder injuries. This was also likewise for females. This phenomenon has a few
implications.

23
It brings about the consideration that muscular strength and development in the upper
body play a considerable role in determining injury predisposition. As females have relatively
smaller muscle fibres and lower proportion of their lean tissue distributed in the upper body
(Abe et al., 1998; Miller et al., 1993), one can deduce that they have less muscular size and
strength when compared to male powerlifters. While this gender-related physiological
difference has yet to be expanded upon within the context of barbell sports, current literature
would suggest that even amongst powerlifters, there is a likelihood of such gender-related
differences in terms of muscular size and strength. Hence, it brings forward the possibility of
muscular strength and development being a strong determinant and indicator of upper-body
injury risk.
Also, heavyweight powerlifters have greater body mass than lightweight competitors.
While it is difficult to determine within whether this was contributed largely by differences in
lean body mass or bodyweight in general, it would seem that individuals with greater body
mass were at lower risk of upper body injuries. This is further bolstered by the fact that there
was a statistically significant difference in injuries/1000hr between heavyweight and
lightweight powerlifters. Therefore, heavyweight powerlifters are likely to be at less risk of
not only lower back and shoulder injuries, but also injury in general.
Lastly, as it was already established previously that there was some form of
relationship between training experience and injury risk, Junior powerlifters may be more
exposed to injury than Open powerlifters. With greater training experience, it is possible for
Open powerlifters to have developed stronger musculature as a result of adaptation. Thus, it
could be possible for Junior powerlifters to be more predisposed to injury as a result of their
relatively less developed muscular system.
Heavyweight powerlifters displayed relatively greater rates of injury in the lower
body than other sub-groups. In fact, they have a notable frequency of pelvis/hip/groin injuries

24
(14.89%) while other sub-groups had lower frequencies. This value was the same as for knee
injuries (14.89%). This suggests that heavyweight powerlifters may be more predisposed to
hip and knee injuries. However, it is still unclear what intrinsic factors would contribute to
this pattern of injury and therefore requires further research in future studies.
4.4. Onset and Nature of Injuries
More than half of injuries documented were acute (63.10%) in nature. This rejects the
hypothesis that most injuries would be of overuse nature. However, there were injuries that
reflect chronic degeneration despite acute onset (Caine et al., 1996). Due to the design of this
study and lack of medical confirmation, there was difficulty in determining this other type of
injury onset. Hence, the true rate of acute injuries may be lower than what was reported.
Furthermore, most injuries were new cases (58.00%), indicating that many of the participants
reported injuries that were novel during the course of their training career. 35.00% of injuries
were classified as overuse. This disparity in injury classification emphasises the need for
medical professionals in documenting and recording injuries to provide a more accurate
picture of injury acquisition.
Despite the large proportion of acute injuries reported, many of these injuries had only
a mild (20.99%) to moderate (65.43%) effect on training. Furthermore, participants were
diligent in managing their injuries, as most of these injuries were treated via medical attention
(58.02%), self-management and rehabilitation (14.81%). This meant that most injuries were
kept under control and had little debilitative influence on training and therefore minimal loss
of training time (Siewe et al., 2011). This is strongly evident when taking into consideration
the low recurrence rate of injuries (7.50%).
Upon inspecting Table 2.4, it becomes clear that a significant percentage of the total
injuries were muscular in nature (78.13%). As mentioned in the initial part of this paper,

25
powerlifters are susceptible to musculoskeletal injuries, thus resulting in the high proportion
of tendonitis (26.25%) and muscle-tendon strain injuries (51.88%). In fact, most ligamentous
injuries displayed in Table 4.4 were largely due to activities outside of powerlifting. This
included ankle sprains and anterior-cruciate ligament (ACL) tears from dynamic activities
involving torsion such as jumping and changing direction in sports such as football. Also,
many of the nerve injuries can be attributed to compressions brought about by physiological
changes in muscle structure due to injury. For example, spinal disc protrusions that lead to
nerve compression may result from uneven forces acting on the lumbar spine arising from
muscular imbalance. Thus, the actual percentage of muscular-tendinous injuries resulting
from powerlifting activities may be higher than what was reported.
4.5. Limitations
While the sample size was relatively large, a bigger sample with normally distributed
data may be more representative of the powerlifting population and also provide more data
for meaningful comparisons. This would also allow more observations and trends to be
drawn.
The lack of assistance from medical professionals made it difficult to determine some
injury types and onsets. While this study expanded on the categorical injury types that other
studies have used, it may not be sufficient to provide a precise picture of epidemiology in
powerlifting. Hence, if future studies were to be conducted, it would be beneficial to enlist
the help of medical professionals to accurately analyse and classify injuries.

26
4.6. Conclusion and Practical Implications
Considering the findings of this research, powerlifting is a relatively safe sport with
low injury rates. However, it is not without its own share of concerns. As described by the
above results and discussion, most injuries suffered by powerlifters are of musculotendinous
nature. While most of these injuries do not directly lead to significant losses of training hours,
it is still imperative that coaches and athletes take precautionary measures to ensure minimal
risk of injury to prolong longevity and consistent progress.
Populations at slightly greater risk are Junior category powerlifters and lightweight
competitors. Female powerlifters may also be at greater predisposition towards lower back
and shoulder injuries. Athletes and coaches in charge of those belonging to these sub-groups
can spend more time working on general physical preparedness and muscular conditioning.
While the competitive lifts of the sport itself are exercises that are often used for strength and
conditioning in other sports, coaches and athletes may use variations of these lifts along with
other assistance exercises to enhance muscular size and strength in order to minimise injury
risks. This includes key musculature about the shoulder joint, lumbar spine and also the knee
joint, as powerlifters are more prone to shoulder, lower back and knee injuries as evidenced
by the findings in this research.
4,997 words

27
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Vanderburgh, P. M., & Dooman, C. (2000). Considering body mass differences, who are the
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33
APPENDIX B
Coach/Parent Consent Form

37
APPENDIX C
Athlete Assent Form

39
APPENDIX D
Athlete Consent Form

41
APPENDIX E
Survey Questionnaire

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