Central Annals of Sports Medicine and Research

Research Article *Corresponding author Roderick S. Hooker, Email: Submitted: 14 July 2015 Sudden Impact: Concussion in Accepted: 11 August 2015 Published: 13 August 2015 Female Roller Derby Athletes Copyright © 2015 Hooker et al. Anna L. Hoskins and Roderick S. Hooker* Division of Family Medicine, University of Washington, USA OPEN ACCESS

Abstract Objectives: Roller derby is one of the fastest-growing women’s sports in America. Keywords Known for its aggressive nature as a full-contact sport, no concussion studies have been undertaken on these athletes. Increasing awareness of head injury in all sports • Roller derby has drawn attention that brain trauma in roller derby athletes needs evaluating. An • Sports athletes exploratory study was undertaken to assess the occurrence of concussion to enable • Leagues further preventive research of brain trauma in this sport. Methods: Adult female athletes attending the 2014 Roller Con international roller derby conference were surveyed about roller derby related concussion rates. Additional information included league protocols, competition level, and demographics. A sample of 75 participants, stratified by age and sex, was theorized to reach information saturation as an explorative study. Results: In total, 75 out of 97 randomly approached athletes consented (response rate 77.3%). Mean age of athletes surveyed was 32, with over 3 years’ experience playing roller derby and represented four countries. On interview 58% self-reported a concussion history. Twenty-two athletes changed their concussion history after reading medical concussion criteria (29.7%). The mean concussion history was 1.5 (range 1-5) per player. Conclusion: Concussion occurrences in adult female roller derby athletes represent a serious risk when playing this sport. Pre-season head trauma evaluation for leagues is recommended to raise awareness of properly identifying and treating concussion. More in-depth studies are needed to correlate if on-track observations agree with recall.

INTRODUCTION The blockers’ objective is to block the opposing jammer while assisting their own jammer through the pack (Figure 1). Blockers Roller Derby is described as the fastest-growing women’s can do this by passive blocking or direct hits delivered with the sport in America and boasts over 1,500 leagues world-wide [1,2]. hips, shoulders, or chest targeting a legal blocking zone. The legal The sport attracts athletes of all ages and abilities, from those who blocking zone extends from above the knees to the shoulders, have never skated or participated in team sports to Olympic gold excluding the back. An illegal block is if the blocker targets an illegal blocking zone, or utilizes forearms, elbows, or head to make organization is the Women’s Flat Track Derby Association. By medalists [3,4]. The first and largest competitive international contact (Figure 2). League members skate under a set of rules 2015, WFTDA had grown to 316 full member leagues and 98 and adhere to a safety protocol developed by a risk management apprentice leagues [1]. WFTDA is divided into three competitive divisions and holds an international bracketed tournament and are online at www.wftda.com) [5,6]. WFTDA acknowledges annually for the top two divisions. This fast-paced, full-contact committeethe importance (composed of concussion of skaters, safety officials, and and awareness team physicians through articles addressing concussion in their magazine, Five on Five, speed skates. A bout consists of two 30-minute halves broken sport takes place on a flat-track court with athletes on quad and an extensive concussion protocol is documented that includes removal from play and a graded return-to-play protocol the track for each jam, which consists of 4 blockers – collectively up into multiple 2-minute “jams”. Each team fields 5 players on in the WFTDA safety manual [7-12]. For additional safety of the athlete, in order to be eligible to participate in sanctioned on her helmet. The jammer is the athlete who scores points. In referred to as “the pack” – and one jammer, identified by a star order to be eligible to score, she must legally pass through the 180-degree turns, skating on one foot, and be deemed to be safe pack once, and then she enters scoring laps. On a scoring lap, for forgames, full-contact new skaters (able must to safelypass a acceptminimum and required deliver skill hits). set, While e.g., each opposing athlete’s hips she passes, she receives one point. these important safety measures were put in place to protect

Cite this article: Hoskins AL, Hooker RS (2015) Sudden Impact: Concussion in Female Roller Derby Athletes. Ann Sports Med Res 2(7): 1041. Hooker et al. (2015) Email: Central

concussion [18]. When compared to sports with the same rules as males (e.g., lacrose), females had a higher concussion incidence an males [15,19]. In sports such as ice hockey and soccer the concussion rates are higher in female athletes compared to their male counterparts [20-22]. This higher risk is especially pertinent to roller derby because it is a predominantly female sport and is full-contact – high risk factors for concussion [22,23]. Another issue surrounding concussion is the underreporting of symptoms – from not recognizing concussion symptoms to believing that it was still safe to play [24-26]. In a survey of rugby teams, 38.5% of male players were unaware of the symptoms of concussion and 10% thought it was safe to return to play after sustaining a concussion [27]. Even the small percentage of individuals believing it is safe to play with a concussion is considered too Figure 1 Athlete from Team USA jumping the apex in a bout against Team England in the 2nd Roller Derby World Cup 2014 in Dallas, TX.. tomuch female because athlete of theinjuries severe is consequences,emerging, but assuch of as2015 second there impact were nosyndrome, published which studies can assessingresult in deathany form [28, of 29]. injury Literature in the sportspecific of roller derby. With the absence of literature on roller derby injury epidemiology, and an increased focus on concussion awareness and education in sports, this study was undertaken to explore the knowledge of roller derby athletes on concussion and to identify the occurrence of concussion by the athletes in the sport. METHODS Study Population Adult female athletes attending the 2014 International RollerCon roller derby convention in Las Vegas, NV. Survey Design Based on discussions with coaches and roller derby athletes an exploratory survey using a convenience sample random Figure 2 Athlete from Denver Roller Dolls caught in mid-air during game 5 of the 2014 WFTDA Division 1 Tournament against B.ay A.rea D.erby. explore concussion occurrence in female roller derby competition. encounter technique was selected as an efficient strategy to research “information saturation” (the point in data collection roller derby athletes, research about concussion incidence and whenSeventy-five no new athletes or relevant were information estimated as emerges the number with respect needed to awareness in the roller derby community is lacking. a newly constructed theory) [30]. Athlete participant encounter The Centers for Disease Control (CDC) estimates that between 1.6 and 3.8 million sports-related concussions occur walking by the researcher in the convention hallway, female andoccurred over over18, was a five-day invited period. to take Every the mobile tenth roller survey. derby To controlathlete complex pathophysiological process affecting the brain, induced some of the variables while collecting data, the researcher wore byin the biomechanical United States forces.” each year [14]. [13]. This Concussion can result is from defined a direct as “a the same professional attire, was located in the same area of the impact to the head, neck, or elsewhere on the body where the convention center, and approached volunteers with a scripted force can transfer to the head. The symptoms of concussion can greeting [31]. The survey was administered on an iPad. Approval be broad and can include somatic (e.g., headache), cognitive of research was granted through the University of Washington’s (memory loss), emotional (inappropriate laughing or crying), Institutional Board Review Human Subjects Division. physical (in coordination), behavioral (aggression or irritation), or manifest as sleep disturbances [14]. Questionnaire Variables Several studies suggest that female athletes are at higher risk The survey collected concussion history regarding self- of sustaining concussions and exhibiting more severe symptoms reported roller derby related injury rates before and after the than males [15,16]. One contributing factor that Tierney et al. found is that, when compared to males, females are more susceptible to head displacement and higher speeds of acceleration when derbyprovision league of had a medicalan existing definition concussion of protocol concussion and [13,14,32].if they had an external force is applied [17]. This may be due in part to readAdditional the Women’s questions Flat centered Track Derby on whetherAssociation’s the athletes’Safety Manual roller. weaker neck muscles. Another study reported that adult females If answering “yes” to their league having an existing concussion were more likely to suffer from headaches, dizziness, fatigue, protocol, the athlete was asked if that protocol included baseline irritability, and concentration problems at three months post- concussion testing administered by a trained healthcare

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risk factors (e.g. age, time playing derby, competitive division) to concussion incidence produced no additional statistical followed.professional. Other information reflected the individual’s affiliation with a specific derby association and the rule set To determine the level of play, athletes disclosed the significantDISCUSSION risk factors (Table 3). competitive division (Division 1, 2, 3, or Apprentice) and the league structure they skated on. General demographics such as in the sport of roller derby – a high impact, primarily female age, state/province, and country were collected so that the study sport.This As is withthe first any exploratory full-contact study sport, into understanding concussion occurrences the injury is in the Appendix. safety. This survey revealed a high occurrence of brain trauma: population could be accurately described. The full questionnaire 54.1%implications reporting and onefilling or inmore knowledge concussions gaps overis essential their roller for athlete derby Data Analysis Descriptive analysis was performed on the survey variables Table 1: rank test determined difference in self-reported concussion Mean ageMean at time player of survey profile. 31.7±6.42 and percentages on quantifiable data points. A Wilcoxon signed Mean years played roller derby 3.6±2.20 Logistic regression models incorporating risk factors (e.g. age, Uses WFTDA rule set 98.7% timehistory playing based derby, on pre- competitive and post-medical division) concussion to concussion definition. were WFTDA Division: D1 35.1% assessed using the generalized linear model in R (an open source statistical package) [33]. WFTDA Division: D2 10.8% WFTDA Division: D3 21.6% RESULTS WFTDA Division: Apprentice 12.2% A total of 97 roller derby athletes were approached at the Non-WFTDA 20.2% convention. Of the athletes approached, 75 agreed to participate in the survey with a response rate of 77.3%. Seventy-four of the 75 surveys were included in the analysis (the excluded was Table 2: Concussion Protocols and Safety. under 18 years age). The mean age was 31.7 (±6.4) yrs., had Concussion protocol 58.1% (43/74) been in competitive roller derby 3.6 (±2.2) yrs., and almost No concussion protocol 17.6% (13/74) exclusively (98.7%) played under the WFTDA rule set (Table 1). Unsure of concussion protocol 24.3% (18/74) concussion occurrence screening found 35.1% of the athletes met Concussion protocol baseline testing 62.8% (27/43) rollerBefore derby reading related a medical concussion definition criteria. of concussion,This increased the tobaseline 54.1% Players who have read WFTDA safety 44.6% (33/74) Players who have not read WFTDA safety 55.4% (41/74) rollerafter providing derby related a medical concussions, definition and of the concussion mean increased (Table 2).to 0.96The mean baseline concussion occurrence (pre-definition) was 0.53 70 57.5 total, 22 (29.7%) athletes changed their self-reported concussion 60 after providing a medical definition of concussion (P <0.001). In 54.1 50 45.9 number. Of the 22 athletes who changed their self-reported 40 history post-definition with only one athlete decreasing her 31.1 30 with a range of 1 to 5. Of the 74 athletes playing under the WFTDA 20 concussion history post-definition, the mean increased to 1.5 20 rules set, 79.9% were part of leagues that were members of 10.8 12.5 8.8 7.5 10 4.1 1.4 2.5 at the time of the survey for acceptance into WFTDA’s apprentice 0 programWFTDA, andor played the remaining by their fifteenrule set. (20.3%) One-third were (26/74) either applying athletes 0 ≥1 1 2 3 4 5 Concussion were members of D1 leagues, 10.8% (8/74) athletes in D2, 21.6% incidence (16/74) in D3, and the remainder, 12.2% (9/74), in apprentice leagues. Some athletes were involved in multiple teams within Percentage of all athletes Percentage of concussed athletes their league. When asked if the athletes’ league had a concussion Figure 3 atheletes. concussion protocol, and 24.3% (18/74) were uncertain about Post definition concussion occurrence in roller derby aprotocol, league concussion 58.1% (43/74) protocol. affirmed, Of the athletes 17.6% whose (13/74) leagues denied had concussion protocols, 62.8% (27/43) included baseline testing had sustained three or more concussions, and four had sustained administered by a trained healthcare professional. WFTDA’s four or more (Figure 3). safety manual had not been read by half (55.4%) of the athletes. Concussion incidence was the highest among the D2 athletes (mean 1.8) – the smallest number of athletes surveyed – but is also athletes reported having one or more concussion. The majority the smallest division of WFTDA, comprised of only 20 teams. The After having read the medical definition of concussion, 54% of athletes had sustained one concussion at the time of the survey mean concussion incidence by division level was 1.0 and 0.4 (D1 (23/40, 57.5%) and (8/40, 20%) had sustained two. Nine athletes and D3 respectively). Logistic regression models incorporating

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Table 3: Concussion risk regression against risk factors. “Heads up Concussion” which has modules geared toward coaches and clinicians [36]. Standard Estimate Z value Pr(>|z|) Error LIMITATIONS Concussion protocol 0.88 0.58 1.52 0.13 The nature of this study is based on individual recall. As an Players who have read exploratory study, it drew on a convenience sample to maximize WFTDA safety 0.04 0.47 0.08 0.94 accessibility and concentration of athletes. Almost all of the skaters surveyed were associated with WFTDA teams providing Age -0.06 0.04 -1.55 0.12 some uniformity of attendees. A survey that would go out to all Years playing -0.02 0.11 -0.14 0.89 WFTDA teams and registered athletes could capture a broader Competitive Division measure of concussion occurrences in roller derby athletes, but it would remain a retrospective study of contributing risk factors to D1 -0.15 1.47 -0.11 0.92 concussion and survey participation rates tend to be low. The fact Competitive Division that no correlation was seen with any of the surveyed factors and D2 1.95 1.77 1.10 0.27 concussion awareness in this study suggests a high variability between leagues and concussion practices. Competitive Division

D3 -0.79 1.51 -0.52 0.60 A larger sample size may reveal a correlation between the leagues’ concussion policies and concussion awareness and career. Yet half of these athletes play under a concussion protocol history. Additional information gathered about these participants’ and had read the WFTDA safety protocol. Robbins et al. evaluated concussions and whether they were removed from a game or practice, followed a graded return-to-play protocol, or were reported concussion to athletes in any sport and found that 73% evaluated by a health care professional would evaluate if leagues ofthe their effect sample of providing population a definition (n=459) of concussion increased on the lifetime number self- of are properly managing concussed athletes. Furthermore, because self-reported concussions from baseline [32]. This suggests that this was exploratory in nature, this study did not categorize the concussion awareness among roller derby athletes is meaningful, setting in which concussions occurred (e.g. practice, bout, or tournament play). The time interval between concussions of of concussion. However, 30% of athletes changed their self- those athletes who reported more than one concussion could also and the majority of athletes are aware of the medical definition help evaluate a protocol for an acceptable number of sustained opportunities for improvement in concussion education. concussions within a season or career. This study was unable reported concussion history post-definition showing there are to evaluate true competitive level due to the complex nature of Overall occurrence was one concussion per player over a rankings and league structure. However, prospective research mean of 3.6 years of sport participation. That observation, with over 10% reporting three or more concussions, is concerning and limb injury, health injury, and minutes of game event and how many concussions are too participationcould film track per events, injury. record contacts per unit time, falls, axial many? Having had a concussion increases an athlete’s chance becauseof incurring it raises additional the question, head trauma, prolonging recovery, CONCLUSION and increases the chance of long-term effects [19, 23, 34]. No Concussions are one of the serious risks of playing full- statistical differences emerged in concussion reporting between contact sports, and the importance of having a concussion protocol is fundamental to educate and protect athletes. Female if an athlete’s league had a concussion protocol compared to roller derby athletes attending an international conference were thosepre- and athletes post-concussion who were unsure definition if their (or league higher had self-reporting a protocol or reported no protocol). Nor was there meaningful differences surveyed about concussion history. Over half reported at least one concussion in their roller derby careers and some as many as whose leagues performed baseline testing as part of their concussionbetween athletes’ protocol pre- compared and post-definition to leagues concussion that did not. reporting While protocol and graduated return to play, the concussion awareness ratefive occurrences.by half of those While surveyed WFTDA’s suggests safety thatmanual leagues has acould concussion better evidence does not support the widespread use, pre-season educate their athletes. Additional research is needed to better medicalbaseline testingevaluation is not which required includes for adequate concussion assessment history and understand the incidence, prevalence, severity, and long-term education is data supported [14]. Advocates of baseline testing effect this growing sport has on its athletes. maintain that it allows for consideration of demographic factors, ACKNOWLEDGEMENTS such as gender and age, considers individual strengths and weaknesses, and aides in determining concussion severity [35]. The authors are grateful to the 2014 leadership and Pre-season baseline testing, much like concussion evaluation, administrators of RollerCon for authorizing and enabling access presents an opportunity to educate athletes on the prevention, to the athletes at their annual conference. A special thanks is symptoms, and management of concussion while providing extended to Masonite Burn Photography for authorizing the use a comparison should an athlete become concussed [14]. An of images. All athlete photographs are accompanied with signed additional educational resource is the CDC’s free online training permission for reproduction.

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Cite this article Hoskins AL, Hooker RS (2015) Sudden Impact: Concussion in Female Roller Derby Athletes. Ann Sports Med Res 2(7): 1041.

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