OBJECTIVE: To determine if injury rates among female field hockey players differ before and after implementation of a national mandate for protective eyewear (MPE).
METHODS: We analyzed girls’ field hockey exposure and injury data collected from national (High School Reporting Information Online [RIO]) and regional (Fairfax County Public Schools) high school sports injury databases in 2 seasons before (2009/10 and 2010/11) and 2 seasons after (2011/12 and 2012/13) a national MPE.
RESULTS: The incidence of eye/orbital injuries was significantly higher in states without MPE (0.080 injuries per 1000 athletic exposures [AEs]) than in states with MPE (before the 2011/12 mandate) and the postmandate group (0.025 injuries per 1000 AEs) (odds ratio 3.20, 95% confidence interval 1.47–6.99, P = .003). There was no significant difference in concussion rates for the 2 groups (odds ratio 0.77, 95% confidence interval 0.58–1.02, P = .068). After the 2011/12 MPE, severe eye/orbital injuries (time loss >21 days) were reduced by 67%, and severe/medical disqualification head/face injuries were reduced by 70%. Concussion rates for field hockey (0.335 per 1000 AEs) rank third among girls’ sports included in the High School RIO surveillance program.
CONCLUSIONS: Among female high school field hockey players, MPE is associated with a reduced incidence of eye/orbital injuries and fewer severe eye/orbital and head/face injuries. Concussion rates did not change as a result of the national MPE. Concussion remains the most common injury involving the head and face among female field hockey players, prompting further inquiry into potential effects of adopting protective headgear/helmets.
- AE —
- athletic exposure
- AT —
- athletic trainer
- CI —
- confidence interval
- DQ —
- FCPS —
- Fairfax County Public Schools
- High School RIO —
- High School Reporting Information Online
- MPE —
- mandate for protective eyewear
- NCAA —
- National Collegiate Athletic Association
- NFHS —
- National Federation of State High School Associations
- NHL —
- National Hockey League
- OR —
- odds ratio
- TL —
- time loss
What’s Known on This Subject:
A previous national study conducted over 2 seasons by this group of authors demonstrated the effectiveness of mandated protective eyewear in reducing eye/orbital, concussive, and head/facial injuries in high school girls' field hockey.
What This Study Adds:
Data collected from regional/national high school sports injury surveillance databases by certified athletic trainers over 4 seasons has shown that nationally mandated protective eyewear results in a greater than 3-fold reduced risk of eye/orbital injuries in girls playing high school field hockey.
Field hockey remains a popular high school (HS) sport for girls in the United States, with participation rates increasing by 28% from 1990 to 2014.1 Although they are infrequent, serious eye injuries can occur, most commonly resulting from players being struck by the stick or ball.2–4 On occasion, eye injuries can be catastrophic, resulting in vision loss and permanent disability.5 In 2011, the National Federation of State High School Associations (NFHS) issued a protective eyewear mandate (MPE) requiring all HS field hockey players to wear protective eyewear in NFHS-sanctioned competitions.6 In contrast, protective eyewear remains voluntary in non-NFHS sanctioned competitions and other field hockey–related play, as USA Field Hockey, the National Collegiate Athletic Association (NCAA), and the International Hockey Federation have not yet endorsed eye protection among their players.7,8 Developmental, college, and national-level field hockey coaches and programs have voiced concern that MPEs will jeopardize international recruitment efforts (as no other country mandates eyewear protection) and the ability of the US national teams to remain competitive internationally.9 Previous studies have shown that MPE in female HS lacrosse players results in a virtual elimination of eye/orbital injuries.10
The primary objective of this study was to compare eye/orbital injuries during practices and games for US players of HS girls’ field hockey for 2 seasons before and 2 seasons after a national MPE. Secondary objectives included examining differences between cohorts for (1) all eye/orbital, concussive, and head/face injuries; (2) concussive injuries only; (3) head/face injuries only (excluding eye/orbital and concussive injury); and (4) head/face and eye/orbital injuries resulting in delayed return to activity (time loss [TL] >21 days and/or medical disqualification [DQ] for remainder of season). These secondary objectives were chosen because critics of protective eyewear have cited concerns that it obscures peripheral vision and can lead to more aggressive play, and thus may result in players sustaining more concussions or head/face injuries owing to increased player-player contact.
A prospective cohort study was conducted during 2 seasons of play immediately before (fall 2009 and fall 2010) and immediately after (fall 2011 and fall 2012) a national MPE in girls’ field hockey exercised by the NFHS (effective fall 2011). The study population was US players of HS girls’ field hockey. Before the national MPE, cohorts were defined by their participation in a state interscholastic league either with or without a protective eyewear mandate. As of fall 2011, all US girls’ HS field hockey players were mandated to wear protective eyewear. Inclusion criteria were HS field hockey; play occurring during HS-sanctioned seasons; and participating HS covered by a certified athletic trainer (AT). Exclusion criteria were injuries sustained during field hockey play unrelated to practice or competition; off-season field hockey practices or competitions; or activities unrelated to field hockey practices or games (eg, injury in recreational soccer, locker room horseplay).
Given the nature of the study design (retrospective data analysis captured by prospective longitudinal surveillance programs, no intervention performed, no personal data collected), informed consent was not obtained from study participants. Institutional review board approval was granted from Rhode Island Hospital.
Injury surveillance systems used in this study included (1) High School Reporting Information Online (RIO), a validated, Internet-based data collection tool developed and used by 1 author (RDC) for tracking sports injury epidemiologic data including athlete exposure and injury information, and (2) Fairfax County (Virginia) Public Schools (FCPS) Athletic Training Program, a large public school system with 25 member high schools. High School RIO’s quality measures are reported annually in on-line reports (http://www.ucdenver.edu/academics/colleges/PublicHealth/research/ResearchProjects/piper/projects/RIO/Pages/Study-Reports.aspx). The FCPS database, captured via a district-mandated electronic medical record-keeping program for injury surveillance, was maintained by 2 authors (JLA and JR).
ATs collected field hockey–related athletic exposure and injury information throughout the study. In addition to standard variables captured by the HS RIO and FCPS surveillance systems, a variable was added to the data collection: whether MPE was in effect in the injured player’s state of HS attendance (before fall 2011). An athletic exposure (AE) was defined as 1 athlete participating in 1 practice or competition. A reportable injury was defined as one that (1) occurred as a result of an organized HS athletic practice or competition, (2) required medical attention from a team AT or physician, and (3) resulted in restriction or alteration of the athlete’s participation status. For each injury, the AT completed a detailed report that included date of injury, exposure (eg, practice versus competition), injury characteristics (eg, body site, diagnosis, severity, TL), and circumstances leading to injury (eg, mechanism, specific activity at time of injury). Both databases were monitored regularly by the authors’ research teams (RDC, JLA, and JR) to maximize compliance and ensure data quality.
As the primary objective in this prospective cohort study was to ascertain whether athletes who have exposure to MPE are less likely to sustain eye/orbital injuries compared with those without MPE, incidence rates and odds ratios (ORs) were calculated, using the z-test to determine whether MPE led to a significantly reduced injury rate. Because the injury data represent rates per 1000 AEs, generalized Poisson log-linear regression modeling was used to compare incidence rates of total injuries and specific injury types between MPE and no-MPE groups, with the likelihood ratio test to assess significance and ORs and 95% confidence intervals (CIs) to estimate the effect of MPE on the risk of injury.11 Statistical analysis was performed using PROC GENMOD in SAS version 9.2 (SAS Institute, Cary, NC). Two-tailed values of P < .05 were considered statistically significant.
Overall, 206 high schools participated. HS field hockey players sustained 415 eye/orbital, concussion, and head/facial injuries during 624 803 athletic exposures (0.664 injuries per 1000 AEs). Table 1 summarizes the study population characteristics. Players from 16 of 19 states that sanction HS field hockey were represented. Of 206 participating high schools, 148 (72%) were large schools (≥1000 students).
Of 415 injuries, 234 (56%) were reported in the MPE group during 361 488 AEs, and 181 were reported in the no-MPE group in 263 315 AEs. Cohort-specific injury rates and corresponding ORs for total injuries (including eye/orbital and concussion), concussive injuries, head/face injuries (excluding eye/orbital and concussion), eye/orbital injuries only, and severe injuries are summarized in Table 2.
Eye/orbital injuries recorded during the study period included eyebrow/eyelid lacerations, periorbital contusions, and corneal abrasions. Eye/orbital injuries occurred 3 times more frequently in players from no-MPE states compared with MPE states (before the 2011/12 mandate) and the postmandate group (0.080 injuries vs. 0.025 injuries per 1000 AEs; OR 3.20, 95% CI 1.47–6.99, P = .003). The incidence of total injuries including eye/orbital and concussion was 0.687 injuries per 1000 AEs in the no-MPE group compared with 0.647 injuries per 1000 AEs in the MPE group (OR 1.06, 95% CI 0.87–1.29, P = .54).
Regarding concussion, 116 concussions were diagnosed during the 2 seasons after the national MPE mandate (2011/12 and 2012/13), compared with 93 in the 2 seasons preceding the mandate (2009/10 and 2010/11). The concussion incidence in the group without MPE was 23% lower than that of the group with MPE overall (OR 0.77, 95% CI 0.58–1.02, P = .068) during the 4-season study, but this result was not statistically significant, although it suggests a statistical trend. The concussion rate for field hockey players during the 4-season study was 0.335 injuries per 1000 AEs (Table 1), compared with 0.392 per 1000 AEs for the 2 seasons after the national MPE mandate and 0.282 injuries per 1000 AEs for the 2 premandate seasons. Concussions were the most common injury, representing 209 of 415 (50.4%) total eye, orbital, and head/facial injuries collected during the 4-season study. Head/face injuries (excluding eye/orbital and concussions) occurred >25% more frequently in the group without MPE compared with the group with MPE (0.323 vs 0.252 injuries per 1000 AEs; OR 1.28, 95% CI 0.95–1.72, P = .099). After the 2011/12 mandate, severe eye/orbital injuries (TL >21 days) were reduced by 67% (3 injuries during 2009/10 and 2010/11 vs 1 injury during 2011/12 and 2012/13), and severe/medical DQ head/face injuries were reduced by 70% (10 injuries during 2009/10 and 2010/11 vs 3 injuries during 2011/12 and 2012/13).
TL injuries were compared between the 2 seasons premandate, the 2 postmandate seasons, and the entire 4-season study period (Table 3). No statistically significant differences between the MPE and no-MPE groups were identified for each of the TL intervals. Compared with the premandate (2009–2011) results, there was a relative increase in TL injuries lasting 10 to 21 days and season-ending injuries in the postmandate (2011–2013) seasons, with the majority (86%) of these injuries resulting from concussion (Table 1). In comparison, concussive injuries made up only 52% of severe (TL >21 days) and medical DQ injuries in the 2 premandate seasons (2009–2011).
Table 4 compares injury mechanisms for eye/orbital, concussion, and head/face injuries for seasons 2009 to 2011 and 2011 to 2013, as well as the cumulative injuries for all 4 seasons. Contact with the ball and stick remained the most common injury mechanism among both the MPE and no-MPE groups, accounting for a collective 36% and 28% of eye/orbital, concussion, and head/face injuries, respectively. Overall, player-player contact injuries were similar between the MPE and no-MPE groups (25% vs 19% of total injuries, respectively). No statistical trends or statistically significant differences were identified for any injury mechanisms between the MPE and no-MPE groups.
Evidence from our study confirms that a national mandate for protective eyewear among girls participating in US HS field hockey is associated with a 3-fold reduction in the rate of eye/orbital injuries, without significantly increasing frequency of player-player contact head and facial injuries, including concussion. Head/face injuries (excluding eye/orbital and concussion) occurred >25% more frequently in the no-MPE group compared with the MPE group. Concussions were the most common injury, representing 50% of all injuries involving the head and face. Although concussion rates increased during the 4 seasons of data collection, concussion rates for MPE and no-MPE groups did not demonstrate a statistically significant difference. Additionally, the number of reported severe eye/orbital and head/face injuries decreased by 67% and 70%, respectively, when comparing data from a 2-season time period before and after a national MPE.
Mandated protective eyewear for HS field hockey players is an important injury prevention development. As in girls’ lacrosse,10,12 epidemiologic studies support the effectiveness of protective eyewear mandates in reducing eye/orbital injuries in HS field hockey. More than 64 000 HS athletes participate in NFHS-sanctioned field hockey.1 Additionally, >5000 athletes participate in NCAA women’s field hockey.13 In contrast, only 31 athletes are currently members of the US Women’s National Team.14 Despite the discrepancies in these numbers, there is 1 commonality among all 3 groups: they are all amateur athletes at risk for sports-related injury.
Micieli et al15 recently reported on the impact of visors on eye/orbital injuries in professional athletes, demonstrating an incidence of eye/orbital injuries in the National Hockey League (NHL) of 0.248 per 1000 AEs during 2002/13, 3 times higher than that among HS field hockey players in states without MPE. Unlike the reluctance to endorse eye protection in amateur elite field hockey, professional ice hockey at various levels including the NHL has made significant strides in implementing mandated visor use over the past decade.16–18 Another study showed that 73% of NHL players wore visors as of the 2012/13 season, and in a relatively short time, there will be 100% compliance with mandatory visor use among NHL players, based on the current NHL grandfathering rule.19
Although one could argue that the risk of eye/orbital injury in amateur field hockey is one-third the risk in professional men’s ice hockey, the financial burden to amateur athletes who sustain an eye/orbital injury and their families may be substantially higher compared with a professional athlete because an amateur player’s disability insurance policy (if she has one) is unlikely to provide much financial compensation for life- or career-altering loss of vision. Furthermore, because only 37% of US public secondary schools employ a full-time AT and only 47% of US public secondary school athletes have full-practice AT coverage every afternoon,20 timely access to medical care, as well as the level of medical care, available to HS athletes is in stark contrast to the tertiary levels of medical care that professional athletes commonly have at their disposal. Despite the significant strides made regarding protective eyewear mandates in US HS-sanctioned field hockey competitions, protective eyewear remains voluntary in practices, non–NFHS-sanctioned competitions, showcases, tournaments, and other field hockey–related play. This includes large numbers of middle school, high school, collegiate, and national team field hockey players in the United States. The eyesight of nearly 70 000 US players is currently at risk for serious injury, to allow a select few elite amateur field hockey players to remain competitive internationally or to allow collegiate field hockey teams to competitively recruit international players.
Although concussion assessment in US HS field hockey players was a secondary study objective, there were many significant findings and trends pertaining to concussive injury. It is important to note that in our 4-year study, there were no statistically significant differences in concussion rates between groups with and without MPE. Similarly, in the 2-year study performed before the national mandate, there were no significant differences in concussion rates between the 2 groups (OR 1.05 95% CI 0.63 to 1.75, P = .86).21
After the NFHS protective eyewear mandate in fall 2011, the incidence rate for concussions sustained in HS field hockey increased from 0.285 concussions per 1000 AEs (seasons 2009/10 and 2010/11) to 0.393 concussions per 1000 AEs (2011/12 and 2012/13). At first glance, one might infer that an eyewear protection mandate, and perhaps the accompanying criticisms of protective eyewear (eg, reduced peripheral vision), were responsible for this increase, but a closer examination of concussion epidemiology provides a more likely explanation. Rosenthal et al22 reported that during the time period 2005/06 through 2011/12, concussion rates reported by ATs for 9 HS sports increased from 0.23 to 0.51 concussions per 1000 AEs, with 5 sports having statistically significant increases over this period. The authors hypothesized that several factors potentially contributed to this trend: (1) concussion incidence actually increased; (2) increased athlete monitoring by coaches, medical personnel, parents, and athletes themselves occurred secondary to increased concussion awareness; and (3) increased coverage of games/practices by ATs occurred.22 Concussion legislation enacted in all US states between 2009 and 201423 has inevitably led to increased concussion education and reporting among student-athletes, coaches, parents, and school nurses: several authors in our study cited a significant increase in total number of concussions reported after concussion laws went into effect in their respective states. Similarly, with ever-growing numbers of primary care sports medicine fellowships nationally24 and a subsequent greater availability of sports medicine–trained physicians for game coverage and concussion clinic staffing, it is likely that physician reporting of sports-related concussion has also increased over the past few years. Echlin et al reported a significantly higher incidence of concussion with physician-observed games compared with games not covered by physicians in collegiate men’s and women’s varsity ice hockey, suggesting an underestimation of sports concussion in the scientific literature.25
Our study has some limitations. Randomization was not part of the study design, since enrollment in MPE and no-MPE groups was predetermined by established state mandates for protective eyewear in effect during the 2009/10 and 2010/11 seasons. Additionally, small event frequencies in specific injury subcategories (such as severe eye/orbital injuries [TL >21 days] and severe/medical DQ head/face injuries in the MPE and no-MPE groups) prevented attaining statistically significant results. However, clinical significance was achieved regarding reduction of these injury subcategories with implementation of MPE. Furthermore, no catastrophic injuries were recorded during our 4-season study period. Based on calculations performed during our prior publication,21 a catastrophic injury in HS field hockey occurs every 8.3 seasons, making the likelihood of capturing such an injury in a relatively small sample of the total number of national athletic exposures in HS field hockey exceedingly rare. Performing a prospective, longitudinal study that collects both injury and exposure data among all HS field hockey participants nationally in an effort to capture catastrophic eye/orbital, concussion, and head/facial injuries would be costly and resource prohibitive. Additionally, whereas we were able to capture injuries and determine which injuries occurred in states with and without MPE, incomplete data collection by ATs for the variable “was the athlete wearing eye protection at time of injury?” prevents us from determining whether players were wearing protective eyewear at the time of injury in MPE and no-MPE states. Finally, data on the number of fouls incurred during competition is not captured by High School RIO, FCPS Athletic Training Program, or any other national database. Although it is feasible that players were more aggressive when playing with eye protection, we saw no difference in athlete-athlete contact injury rates during our study period, which would have been expected if play became more aggressive over time.
Despite some limitations, our study was able to pool and analyze data from national and regional HS sport injury surveillance databases from 2 seasons before and 2 seasons after implementation of a national protective eyewear mandate in HS girls’ field hockey, resulting in the largest prospective national study examining the effectiveness of MPE in reducing eye/orbital, concussive, and head/facial injuries performed to date. Future research evaluating the performance of athletes wearing and not wearing protective eyewear (eg, goals, assists, fouls committed) may be warranted to determine the impact of protective eyewear on skill level and player development.
Among female US HS field hockey players, a national MPE is associated with a >3-fold reduced risk of eye/orbital injuries and a decreased incidence of severe eye/orbital and head/face injuries. Given the scientific evidence demonstrating that mandatory protective eyewear effectively reduces eye injuries in field hockey players without increasing concomitant injury such as concussion, research now exists to support a policy change regarding mandatory protective equipment in field hockey at all amateur levels.
We thank the ATs who assisted with data collection in this study and Vito Perriello, MD, for his lifelong contributions to the fields of pediatrics, sports medicine, and injury prevention before his unexpected death in 2009.
- Accepted June 1, 2015.
- Address correspondence to Peter Kriz, MD, 2 Dudley St, Ste 200, Providence, RI 02905. E-mail:
Dr Kriz conceptualized and designed the study; Drs d’Hemecourt and Comstock assisted with study design; Mr Almquist, Dr Collins, and Dr Comstock designed the data collection instruments; Mr Almquist, Mr Reynolds, Dr Collins, and Dr Comstock coordinated and supervised data collection at one of the two sites; Dr Kriz and Ms Ruggieri collected and analyzed data from the two databases and drafted the initial manuscript; Dr Zurakowski carried out the statistical analyses; Drs Kriz and Zurakowski contributed tables and figures; Drs Zurakowski, d’Hemecourt, and Comstock reviewed and revised the manuscript; and all authors approved the final manuscript as submitted.
The content of this report is solely the responsibility of the authors and does not necessarily reflect the official views of Prevent Blindness America or the Centers for Disease Control and Prevention.
FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.
FUNDING: Funded in part by Prevent Blindness America grant 701-5215 and Centers for Disease Control and Prevention grant R49/CE001172-01. The authors also acknowledge the generous research funding contributions of the National Operating Committee on Standards for Athletic Equipment.
POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.
- ↵National Federation of State High School Associations. Participation statistics. Available at: www.nfhs.org/ParticipationStatics/ParticipationStatics.aspx/. Accessed December 2014
- Dick R,
- Hootman JM,
- Agel J,
- Vela L,
- Marshall SW,
- Messina R
- Elliott AJ,
- Jones D
- ↵National Federation of State High School Associations. NFHS field hockey rules committee – eyewear ruling. Available at: www.longstreth.com/Field-Hockey-Press-Release/products/1952/. Accessed December 2014
- ↵International Hockey Federation. FIH Rules of Hockey 2015. Available at: www.fih.ch/files/Sport/Rules/FIH-Rules%20of%20Hockey%202015-interactif.pdf. Accessed December 2014
- ↵Field Hockey NCAA. NCAA field hockey rules modifications 2014: Divisions I, II, and III. Available at: www.ncaa.org/sites/default/files/2014%20NCAA%20Rules%20Modifications_FINAL.pdf. Accessed December 2014
- ↵Loh S. Going deep: opinions evenly split on the value of goggles in field hockey. Available at: blog.pennlive.com/patriotnewssports/2011/10/going_deep_opinions_evenly_spl.html. Accessed February 2015
- Lincoln AE,
- Caswell SV,
- Almquist JL,
- et al
- McCullagh P,
- Nelder JA
- Lincoln AE,
- Hinton RY,
- Almquist JL,
- Lager SL,
- Dick RW
- ↵National Collegiate Athletic Association. 1981-82 – 2012/13 NCAA sports sponsorship and participations rates report. Available at: www.ncaapublications.com/productdownloads/PR2014.pdf. Accessed December 2014
- ↵Field Hockey USA. U.S. women’s national team roster. Available at: www.teamusa.org/USA-Field-Hockey/USWNT/SENIOR-SQUAD. Accessed December 2014
- ↵Ontario Hockey League. Ontario Hockey League rule book 2014-15. Available at: www.ontariohockeyleague.com/uploads/assets/OHL_EN_SITE/2014_15/2014-2015%20OHL%20Rule%20Book.pdf. Accessed December 2014
- American Hockey League. American Hockey League official rules 2014-2015. Available at: cdn.rapidmanager.com/ahl/files/14_15_AHLRuleBook_rev.pdf. Accessed December 2014
- ↵National Hockey League. National Hockey League official rules 2014-2015. Available at: www.nhl.com/nhl/en/v3/ext/rules/2014-2015-rulebook.pdf. Accessed December 2014
- Rosenthal JA,
- Foraker RE,
- Collins CL,
- Comstock RD
- ↵National Conference of State Legislatures. Traumatic Brain Injury Legislation. Available at: www.ncsl.org/issues-research/health/traumatic-brain-injury-legislation.aspx. Accessed January 17, 2015
- ↵American Medical Society for Sports Medicine. Sports medicine fellowships in the USA and Canada. Available at: www.amssm.org/FellowshipsPositions.html. Accessed December 2014
- ↵Echlin PS, Skopelja EN, Worsley R, Dadachanji SB, Lloyd-Smith DR, Taunton JA, Forwell LA, Johnson AM. A prospective study of physician-observed concussion during a varsity university ice hockey season: incidence and neuropsychological changes. Part 2 of 4. Neurosurg Focus. 2012;33(6):E2:1–11
- Copyright © 2015 by the American Academy of Pediatrics