The American Journal of Sports Medicine http://ajs.sagepub.com/
Head, Face, and Eye Injuries in Collegiate Women's Field Hockey Elizabeth C. Gardner Am J Sports Med 2015 43: 2027 originally published online June 19, 2015 DOI: 10.1177/0363546515588175 The online version of this article can be found at: http://ajs.sagepub.com/content/43/8/2027
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Head, Face, and Eye Injuries in Collegiate Women’s Field Hockey
5-in-5
Elizabeth C. Gardner,*y MD Investigation performed at the Department of Orthopaedic Surgery and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut, USA Background: While there is concern regarding head, face, and eye injuries in field hockey, prompting some to recommend the use of protective equipment such as goggles and helmets, little has been written about their incidence and mechanism of injury in the modern game of field hockey. The elucidation of this information will better inform the development of maximally effective injury prevention schemes to protect the athlete while maintaining the integrity of the game. Purpose: To determine the incidence and epidemiology of head, face, and eye injuries in United States collegiate women’s field hockey players from 2004-2005 to 2008-2009. Study Design: Descriptive epidemiological study. Methods: All head, face, and eye injuries reported to the National Collegiate Athletic Association Injury Surveillance System for collegiate women’s field hockey athletes from the 2004-2005 through 2008-2009 seasons were analyzed. Data regarding the event type, injury mechanism, body part injured, type of injury, outcome, and time lost were reviewed. The weighted injury incidence per 1000 athlete-exposures (AEs) was calculated using the exposure data set for the same years; 95% CIs were calculated based on a normal approximation to the Poisson distribution. Results: There were 150 reported traumatic injuries during this time period, with a weighted occurrence of 1587.3 injuries. The overall incidence of head, face, and eye injuries in collegiate women’s field hockey was 0.94 per 1000 AEs (95% CI, 0.86-1.19). Injuries to the head or face, other than the mouth, nose, and eye, accounted for 75.3% of these injuries. The incidence of eye injuries was 0.07 per 1000 AEs (95% CI, 0.03-0.12); nose injuries occurred at a rate of 0.10 per 1000 AEs (95% CI, 0.05-0.15). The rate of traumatic dental injuries was 0.06 per 1000 AEs (95% CI, 0.04-0.14). Contact with an apparatus caused 72.9% of all injuries; specifically, contact with an elevated ball accounted for 47.9% of all injuries, and contact with an elevated stick caused 21.7% of all injuries. While the majority of players suffering a head, face, or eye injury were able to return to sport that season (90.0%), the remaining athletes suffered season-ending injuries (10%). Concussions accounted for 42.8% of all head, face, and eye injuries reported (0.40 per 1000 AEs; 95% CI, 0.32-0.53). Conclusion: Head, face, and eye injuries occur regularly in women’s field hockey. This description of the injury profile and mechanisms of injury may be used to design appropriate injury prevention schemes for the sport. Keywords: head, eye, and face injuries; women’s field hockey; collegiate
popularity internationally is second only to soccer.10 Traditionally played by women in the United States (US), the game is one of the most popular sports in both high schools and universities. In field hockey, the struck plastic ball may reach up to 80 km/h.9 Sticks are 36 to 38 inches in length and are typically made of a carbon composite, often containing Kevlar. The stick, ball, and contact with other players may all be implicated in causing head, face, and eye (HFE) injuries in field hockey. Although the game is played primarily on the ground, the ball and stick are frequently raised above shoulder height, intentionally or not, during the game. Recent alterations to the game aimed to increase goal scoring opportunities, including rule changes, advances in stick and playing surface technologies, the development of powerful shots such as the reverse-stick (left-sided) chip shot in the shooting circle, and an increased dedication to physical conditioning and strength, have all made
Played by men and women on 6 continents and in at least 134 nations for more than 4000 years, field hockey’s
*Address correspondence to Elizabeth C. Gardner, MD, Department of Orthopaedic Surgery and Rehabilitation, Yale University School of Medicine, 800 Howard Avenue, 1st Floor, New Haven, CT 06519, USA (email: [email protected]). y Department of Orthopaedic Surgery and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut, USA. The author has declared the following potential conflict of interest or source of funding: The National Collegiate Athletic Association (NCAA) Injury Surveillance System data were provided by the Datalys Center for Sports Injury Research and Prevention. The Injury Surveillance System was funded by the NCAA. The content of this article is solely the responsibility of the author and does not necessarily represent the official view of the Datalys Center or the NCAA. The American Journal of Sports Medicine, Vol. 43, No. 8 DOI: 10.1177/0363546515588175 Ó 2015 The Author(s)
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TABLE 1 Athlete Population Dataa
Year 2004-2005 2005-2006 2006-2007 2007-2008 2008-2009 Average/total
NCAA Schools Sponsoring Women’s Field Hockey, n 257 258 259 258 250 256
Schools Reporting to ISS, n (% of Total Schools) 23 22 20 24 22 22
(9) (9) (8) (9) (9) (9)
Exposures (Competitions and Practices), n
AEs, n
Estimated Population AEs, n
1562 1486 1401 1777 1718 7944
28,834 26,910 26,604 33,570 32,787 148,705
327,157 313,962 335,619 361,660 371,837 1,710,235
a
AE, athlete-exposure; ISS, Injury Surveillance System; NCAA, National Collegiate Athletic Association.
the modern game faster and more exciting than ever. Certainly, the game is markedly different from that of even just the past decade. The advancement of the game must be balanced with an appropriate effort to protect the athlete. Recently, there has been much discussion regarding the use of additional personal protective equipment in field hockey, most importantly the use of goggles. Thus, the purpose of this study was to provide an updated assessment of the epidemiology of HFE injuries in the sport that reflects the current American collegiate game to better inform decisions regarding maximally effective safety interventions and monitor for their efficacy.
METHODS The National Collegiate Athletic Association (NCAA) maintains an Injury Surveillance System (ISS), which collects data regarding athlete-exposures (AEs) and subsequent injuries. The details of this system have been previously described by Dick et al4 and Kerr et al.12 Briefly, these ‘‘convenience sample’’ data are reported on a volunteer basis by certified athletic trainers from any of the 3 NCAA divisions via a web-based injury tracking system that allows the entry of information related to the injury mechanism, body part injured, type of injury, measures of severity (time loss, need for surgery), when and where in play the injury occurred, and sport-specific questions related to the mechanism of injury and player position. As shown in Table 1, over the 5-year period from 2004-2005 through 20082009, the NCAA ISS collected data from an average of 9% of all Division I and III schools sponsoring women’s field hockey (although field hockey is played in Division II, no schools were sampled during this period). Of the 25 NCAA sports monitored by the ISS, field hockey ranks as the fifth highest percentage of participating programs from 20042005 through 2008-2009.12 To help provide national estimates of injuries from the sampled data, the NCAA ISS provides poststratification sample weights, based on sport and division. These weights are modified every academic year to account for year-to-year variations in reporting and sampling. While truly a deterministic sample, it has been found to be useful
for the purposes of calculating incidence and epidemiology. A recent study from Kucera et al14 found that the NCAA ISS captured 88.3% of all time-loss injuries in men’s and women’s soccer. The NCAA took this underreporting into account when calculating its sample weights. Data were obtained from the Datalys Center for Sports Injury Research and Prevention, the nonprofit organization responsible for the collection and maintenance of NCAA ISS data. Approval (exemption) was confirmed with our Institutional Review Board. Exposure data were calculated using the Women’s Field Hockey Exposure Data Set. A reportable AE is defined as 1 student-athlete participating in 1 practice or game during which there was the possibility of an injury. The duration of the exposure is not recorded. During these 5 years, data from a total sample of 7944 events (practices and games) were reported for between 5 and 35 athletes per session. There were 111,669 athlete-practice sample exposures and 37,036 athlete-game exposures, for a total number of athlete sample exposures of 148,705. When exposure weights were taken into account, there were a total of 1,710,235 population exposures; 430,674 of these were game exposures, whereas 1,279,561 were population practice exposures. It should be noted that intrasquad scrimmages are classified as practices. Data collection began on the first day of preseason and concluded on the final day of competition, including postseason play if applicable. A reportable injury in the ISS is ‘‘one that (1) occurred as a result of participation in an organized intercollegiate practice or contest, (2) required medical attention by certified athletic trainers or physicians, and (3) resulted in restriction of the student-athlete’s participation for one or more days beyond the day of injury.’’3(p3) Per the NCAA ISS guidelines, all dental injuries are included, regardless of time lost. The Women’s Field Hockey Injury Data Set for 20042005 to 2008-2009 was examined using the ‘‘body part’’ codes ‘‘head/face,’’ ‘‘nose,’’ ‘‘eye,’’ and ‘‘mouth.’’ All injuries affecting these locations were included in the analysis. Specific injury codes, such as ‘‘concussion,’’ ‘‘nasal contusion,’’ or ‘‘jaw fracture,’’ provided further information regarding the nature of the injury. Of note, there is no free-text area in the injury report to allow a more descriptive account of the injury.
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Head Injuries in Field Hockey 2029
TABLE 2 Injuries by Body Locationa
100% 90%
Injury Incidence Body Part Eye Head/face Mouth Nose Total
Reported Injuries, n (% of All Injuries) 9 113 13 15 150
(6.0) (75.3) (8.7) (10.0) (100.0)
Weighted Population 113.4 1204.9 100.2 168.8 1587.3
Per 1000 AEs (95% CI) 0.07 0.71 0.06 0.10 0.94
(0.03-0.12) (0.62-0.90) (0.04-0.14) (0.05-0.15) (0.86-1.19)
80% 70% 60% 50%
47.9%
40% 24.6%
30% 21.7% 20% 10%
3.5%
2.3%
a
AE, athlete-exposure.
0% Contact with elevated ball
The weighted estimate of the population incidence of injuries is defined as the weighted number of injuries divided by the weighted number of population AEs. Generally, this is reported as injuries per 1000 AEs, which allows a comparison with previously published reports.5 As there is no information available regarding the severity of specific injuries, the variable of ‘‘time loss’’ was used as a surrogate to help describe the seriousness of injuries. Time loss is defined as the duration of time from the index injury to return to play at a level that allows participation in either a game or practice. As discussed by Dick et al,4 this measure is subject to great variability at the hands of the individual athlete and medical staff. Thus, the analysis of time loss was limited to only grouping injuries into those that restricted participation for 10 days, as a marker of high injury severity, as suggested by Dick et al.5 Even still, there is potential for variability, especially for those injuries that occurred near the end of the year when additional time loss may have been projected but not captured.
RESULTS There were 150 traumatic HFE injuries reported within the NCAA ISS sample from 2004-2005 through 20082009, with an estimated overall population incidence of 1587.3 injuries. Thus, the overall rate of HFE injuries in women’s collegiate field hockey from 2004-2005 through 2008-2009 was 0.94 per 1000 AEs (95% CI, 0.86-1.19). Specifically, the incidences of head/face injuries and eye injuries were 0.71 (95% CI, 0.62-0.90) and 0.07 (95% CI, 0.030.12) per 1000 AEs, respectively. Nose injuries occurred at a rate of 0.10 per 1000 AEs (95% CI, 0.05-0.15), whereas mouth injuries occurred at a rate of 0.06 per 1000 AEs (95% CI, 0.04-0.14). These are presented in Table 2. The most common specific type of injury was a concussion, occurring at a rate of 0.40 per 1000 AEs (95% CI, 0.32-0.53) and accounting for 42.8% of all injuries. Contusions (0.21 per 1000 AEs; 95% CI, 0.15-0.31) and lacerations (0.18 per 1000 AEs; 95% CI, 0.13-0.27) were also common. The specific details of these injuries are presented in Table 3. Details regarding the mechanism of injury are reported in Figure 1. Player contact with an elevated ball was the
Contact with ground ball
Contact with stick
Direct contact with player
Other/ unknown
Figure 1. Mechanism of all injuries.
most common mechanism of injury in both the game and practice situation, accounting for 47.9% of all HFE injuries. There are no data regarding whether the elevated ball was deemed to be legal or illegal by the referees. Direct contact with another player caused 24.6% of injuries. Contact with a stick caused 21.7% of injuries.
Time Loss Overall, 90.0% of athletes suffering HFE injuries during this time period were able to return to sport within the same season. There were 12.6% of injuries that resulted in 10 days away from play, although the player was eventually able to return to play that season. Of these injuries, .50% were concussions. Of all injuries suffered, 10.0% were so severe that the athlete did not return to play during that same season. The details of these injuries are presented in Table 4. This group included 3 concussions. It also included 5 eye/ cheek injuries: 1 corneal abrasion, 1 orbital fracture, 2 cheekbone fractures, and 1 eyelid laceration. Finally, there was 1 concussed player who was released from the team before the end of the season; whether this was related to her injury is unclear in the data.
Head/Facial Injuries An injury to the head or face, other than the mouth, nose, and eye, was the most common location of injury, accounting for 75.3% of all HFE injuries. A concussion was the most common injury to the head or face, occurring at a rate of 0.40 per 1000 AEs (95% CI, 0.32-0.53). Facial contusions and facial lacerations were also common, with incidences of 0.13 (95% CI, 0.07-0.19) and 0.12 (95% CI, 0.080.20) per 1000 AEs, respectively. The most common mechanism of injury for both facial contusions and lacerations was contact with an elevated ball (58.0%), although contact with a stick also caused a significant number of injuries as well (27.3%). Of the athletes suffering from facial lacerations and contusions, 6.1% lost 10 days of play before their return. There were also incidents of cheekbone
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TABLE 3 Specific Injury Dataa Injury Cheekbone fracture Concussion Corneal abrasion Dental work Epistaxis Eyelid laceration Facial contusion Facial laceration Head (not face) contusion Jaw contusion Jaw fracture Mouth laceration Nasal contusion Nasal fracture Nasal laceration Orbital fracture Other eye injury Other nose injury Skull fracture Eye soft tissue contusion Tooth fracture/avulsion
Reported Injuries, n (% of All Injuries) 2 63 1 2 1 5 19 21 7 3 1 2 4 7 2 1 2 1 1 1 4
Weighted Estimate of Injuries
(1.5) (42.8) (1.1) (1.1) (0.9) (4.2) (14.0) (12.7) (4.1) (1.3) (0.5) (0.9) (2.7) (5.2) (1.20 (0.6) (0.7) (0.6) (0.8) (0.5) (2.6)
Injury Incidence per 1000 AEs (95% CI)
23.2 679.5 17.6 17.6 14.6 67.1 222.1 201.9 64.7 20.2 17.4 14.5 42.5 88.4 18.5 9.7 11.6 9.7 13.4 7.4 40.6
0.01 0.40 0.01 0.01 0.01 0.04 0.13 0.12 0.04 0.01 \0.01 0.01 0.03 0.05 0.01 0.01 0.01 0.01 0.01 \0.01 0.02
(0.05-0.15) (0.32-0.53) (\0.0001-0.02) (\0.0001-0.03) (\0.0001-0.02) (0.004-0.06) (0.07-0.19) (0.08-0.20) (0.01-0.08) (\0.0001-0.04) (\0.0001-0.02) (\0.0001-0.03) (0.0005-0.05) (0.01-0.08) (\0.0001-0.03) (\0.0001-0.02) (\0.0001-0.03) (\0.0001-0.02) (\0.0001-0.02) (\0.0001-0.02) (0.0005-0.05)
a
AE, athlete-exposure.
fractures and 1 skull fracture, although, fortunately, these were uncommon. Although rare, the athletes suffering these injuries were unable to return to play that season, verifying the severity of the injuries. Each of these fractures resulted from contact with an elevated ball.
Concussions A further subset analysis of concussions is necessary to help prevent these potentially devastating injuries. As stated above, a concussion was the most common HFE injury occurring in women’s collegiate field hockey during this time period, occurring at a rate of 0.40 per 1000 AEs (95% CI, 0.32-0.53). The most common specific mechanism of injury was direct player contact, accounting for 39.3% of all concussions. There is no notation as to whether the contact was deemed illegal or not. Additionally, head contact with either a raised ball or stick combined to cause 45.8% of all concussions. The specific mechanisms of concussions are shown in Figure 2. Nearly all of the players suffering a concussion were eventually able to return to play within the same season (92.8%). Of these, 77.3% returned in \10 days from the time of injury, while the other 22.7% needed up to 20 days.
Mouth Injuries During the time period of observation, the overall weighted incidence of mouth injuries, including fractures/avulsions, was 0.06 per 1000 AEs. Data regarding the actual use of
TABLE 4 Season-Ending Injuriesa Injury
n
Incidence per 1000 AEs
Concussion Facial laceration Cheekbone fracture Corneal abrasion Eyelid laceration Nasal fracture Skull fracture Orbital fracture Head contusion Jaw fracture
3 3 2 1 1 1 1 1 1 1
35.3 32.5 23.2 17.6 17.6 17.6 13.4 9.7 7.4 7.4
a
AE, athlete-exposure.
mouthguards in these situations were not available. Contact with a stick or an elevated ball caused 52.9% and 29.6% of all mouth injuries, respectively.
Eye Injuries The overall rate of eye injuries during the 5 years of this study was 0.07 per 1000 AEs (95% CI, 0.03-0.12), resulting in a weighted total of 113.4 injuries. Of these traumatic eye injuries, 39.5% of the athletes were unable to return to play during that season. All of the traumatic injuries were caused by contact with a piece of apparatus, with 89.7% caused by an elevated ball and 10.3% caused by a raised stick.
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Head Injuries in Field Hockey 2031
Nasal Injuries The rate of injuries to the nose during this data collection period was 0.10 per 1000 AEs (95% CI, 0.05-0.15), accounting for 10.0% of all HFE injuries. A fracture was the most common nose injury, occurring at a rate of 0.05 per 1000 AEs (95% CI, 0.01-0.08). Contact with an elevated ball caused the majority of these injuries (71.7%), while direct contact with another player caused 14.3%.
Direct player contact 39.3%
Contact with elevated ball 24.8%
Other 14.9%
DISCUSSION Sport-related HFE injuries can be serious. While fortunately uncommon, injuries resulting in airway obstruction or neurological compromise may be life threatening. Others, such as globe injuries, dental injuries, facial fractures, and lacerations, are potentially disabling and disfiguring. Reports of such injuries in field hockey players have fortunately been rare. In their 24th Annual Report, the National Center for Catastrophic Sport Injury Research17 reported that from fall 1982 through spring 2006, there were 2 catastrophic eye injuries and 2 skull fractures suffered by field hockey players. Elliot and Jones7 reported 3 cases of severe eye injuries to young female field hockey players; all 3 resulted in blindness in the injured eye. In a review of all sport-related orbital blowout fractures over a 6-year period at a large British eye hospital, Jones11 found only 1 field hockey–related fracture; interestingly, this injury was caused by an intentional assault with a field hockey stick and was not incurred during regular match play. This review confirms that while reports of catastrophic injuries are rare, less-devastating HFE injuries do commonly occur in field hockey. A further analysis of current rules, as well as an understanding of the history and use of protective equipment, is necessary to develop maximally effective injury prevention schemes to decrease the incidence of all HFE injuries.
Head and Face Injuries Our finding that face and head injuries, not including those to the nose, eye, and mouth, were the most common location of HFE injuries is in line with that in prior studies from Yard and Comstock,27 Dick et al,5 and Murtaugh.16 Overall, a concussion was the most commonly reported injury to the head and face; it will be discussed separately. The incidence of facial lacerations, found to be 0.12 per 1000 AEs (95% CI, 0.08-0.20) in our study, is lower than the 0.23 per 1000 AEs reported by Dick et al.5 The incidence of facial contusions, 0.13 per 1000 AEs (95% CI, 0.07-0.19) in our group, is also similar to the 0.10 per 1000 AEs reported by Dick et al.5 Although permissible since 2007, face masks are not routinely worn in US high school and collegiate field hockey. They are most commonly encountered on players playing while recovering from a soft tissue injury or fracture to the face or nose. They are not allowed to be worn in international competition unless medically required.10
Contact with stick 21.0%
Figure 2. Specific mechanism of a concussion. ‘‘Other’’ includes contact with a ground ball, the goal cage, and the field surface. Currently, defensive players at all levels of play are allowed to wear plastic face shields while defending short corners, although these are typically removed once the immediate play has ended.10 Providing protection to the soft tissues of the face and nose, as well as perhaps the eye, these were introduced to decrease the rate of facial injuries during short corners, a play in which a direct and powerful shot is directed at several defenders running toward the ball. To this point, there has not been a study to demonstrate the effect of these masks.
Concussions We found that a concussion was the most common specific HFE injury in this population, with an incidence of 0.40 per 1000 AEs (95% CI, 0.32-0.53). This is concerning as we continue to learn more about the long-term consequences of this injury. This rate is significantly less than the 0.81 per 1000 AEs reported by Hendrickson et al.8 However, in their report of NCAA women’s field hockey players from 1988-1989 through 2002-2003, Dick et al5 reported an incidence of 0.09 per 1000 AEs. The reason for this observed increased incidence in the 2 more recent studies is unclear. Certainly, there is far more vigilance regarding head injuries today than during the time of the Dick et al5 study, leading to the reporting of concussions now that may have been missed years ago. It is also possible that as the game becomes faster and there is more dedication to the development of physical athletes, the injury pattern of the sport may be changing as a result. More surprising than the incidence of concussions is the fact that direct contact with another player was the most common cause for concussions in this essentially noncontact sport, consistent with the findings of Murtaugh.16 The 2 other common mechanisms, head contact with an
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elevated ball and contact with a stick, are both illegal in most play. This suggests that the stricter enforcement of rules regarding player contact and elevated game equipment may be a vital step in a multimodal approach to decrease the incidence of concussions in field hockey. The USA Field Hockey organization currently permits the use of soft protective headgear for all field players for the prevention of head injuries; to our knowledge, there are no data regarding the efficacy of this equipment. However, the International Hockey Federation (FIH), the governing body for international games, prohibits the use of such equipment in all international play. At all levels of play, the goalkeeper is required to wear a hard protective helmet that incorporates fixed full-face protection and covering for the entire head.10,18 Interestingly, in this study, the traumatic injuries known to be suffered by goalkeepers were both concussions. This illustrates that even a maximal level of protection such as a helmet cannot completely prevent injuries.
Mouth Injuries Since the 1960s and 1970s, mouthguards have been mandated by US and Canadian sporting associations for field hockey; however, in international games, its use is still only ‘‘recommended.’’10 The initial premise was to decrease the incidence and severity of both dental injuries as well as concussions.2 A recent meta-analysis found that the overall risk of an orofacial injury is 1.6 to 1.9 times higher if a mouthguard is not worn during a sport with a risk of facial injuries.13 However, a protective effect for concussions has never been clearly established.2 Despite the long-standing rule that players wear a mouthguard at all times during play, there was a weighted occurrence of 100.2 injuries classified to the mouth during the observed time period, including 20.2 jaw contusions and 17.4 jaw fractures, which may or may not be preventable with mouthguard use. Again, the majority of these injuries, 82.5%, were caused by contact with an elevated ball or stick. This again suggests that stricter rule enforcement may help to decrease the incidence of these injuries. It also highlights the fact that while new protective equipment is being developed, traditional equipment such as mouthguards should continue to be optimized to offer the best possible protection to the athlete. For example, most literature agrees that custom-fitted mouthguards offer better protection than the stock ‘‘over-thecounter’’ or ‘‘boil and bite’’ models that most collegiate athletes use.6 Current US and international rules do not specify the type of mouthguard worn, thus potentially missing an opportunity to enhance player protection.
Nose Injuries This study reported an incidence of nose injuries to be 0.10 per 1000 AEs overall (95% CI, 0.05-0.15). The incidence of fractures, 0.05 per 1000 AEs (95% CI, 0.01-0.08) in our study, was significantly lower than the 0.29 per 1000 AEs reported by Dick et al.5 As with injuries to other parts of
the head and face, the most common mechanism of injury was contact with an elevated ball. While potentially disfiguring, generally, injuries to the nose are less severe than other HFE injuries. This is supported by the fact that only 6.3% of nose injuries in our group were season ending. As mentioned above, plastic face masks, which provide some protection to the nose, are now allowed in American high school and college field hockey. Use of these masks internationally is limited to medical necessity and on shortcorner plays. Current field hockey goggles, as regulated by the American Society for Testing and Materials (ASTM), do not provide protection to the soft tissues or bones of the nose.
Eye Injuries Nationally, 40,000 to 100,000 sport- or recreation-related eye injuries occur annually in the US.20 The most common age-related causes of North American sport-related eye injuries are baseball (leading cause of eye injuries in 5to 14-year-old athletes), basketball (leading cause of injuries in 15- to 24-year-old athletes), and racquet sports (leading cause in 25- to 65-year-old athletes).1 Although fortunately rare, the incidence of eye injuries in field hockey remains a concern. In our population, these injuries included eyelid lacerations, a corneal abrasion, an orbital fracture, and a soft tissue contusion. Of the traumatic eye injuries in this study, 39.5% were season ending for the athlete, attesting to their severity. The other athletes were able to return to play within 4 days of the incident. Similar to other injuries, the most common mechanism of injury was contact with an elevated ball, accounting for 89.7% of the injuries. Once again, this suggests that rule enforcement could help to decrease their occurrence. Proponents of HFE protection in field hockey have cited the evolution of equipment worn traditionally by ice hockey players and more recently by women’s lacrosse players. Helmets were first mandated in ice hockey in 1963 in Swedish amateur players. By the late 1960s, both the American and Canadian Amateur Hockey Associations had followed suit, requiring all players to wear protection. However, a disturbing number of eye and facial injuries still occurred. This led to the introduction of face masks, both partial and full, attached to the helmet. Finally, there was a decrease in soft tissue injuries around the face and mouth, from 38% of players per year to 9% from 1975 to 1988.23 In 2003, US Lacrosse voted to ‘‘highly recommend’’ the use of protective eyewear for all women’s lacrosse players. It became required on January 1, 2005. The delay was aimed to allow the development of appropriate equipment. This mandate came after a detailed analysis of the risk of catastrophic eye injuries as well as less severe head and face injuries. As well, the US Lacrosse Sports Science and Safety Committee worked to develop eyewear designed specifically for women’s lacrosse to offer maximal benefit while still respecting the traditions of the game. Webster et al25 published a prospective analysis of the incidence of head and face injuries in New York scholastic women’s lacrosse during a transition from sparse to almost complete eyewear use. In all play, that is, both practice and game situations, the incidence of head and eye injuries was
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Head Injuries in Field Hockey 2033
16% less in goggle wearers. However, in games alone where more aggressive play predominates, the rate associated with eyewear use was 51% less, which reached statistical significance. There were no injuries to the eye (orbit) reported in the 77,947 AEs. Cheek and scalp injury rates tended to be higher in goggle wearers, although not significantly. In another comparative study, Lincoln et al15 found no change in the rate ratio of total injuries involving all body parts, but they did find a statistically increased rate of concussions (incidence rate ratio, 1.6; 95% CI, 1.1-2.3). There is some concern that players wearing enhanced protective equipment may consider themselves to be safer and thus will play more aggressively or recklessly to assume the preprotection level of risk.26 This emphasizes the importance of the careful consideration of and monitoring for unintended consequences of injury prevention protocols. Recently, the debate over eyewear in women’s lacrosse has segued into a similar discussion regarding the use of helmets.21,24 To this point, the sport’s governing body and its supporters have argued against the use of hard helmets,24 concerned about maintaining the ‘‘integrity’’ of the game as well as preventing a false sense of protection from injuries. They do, however, continue to allow the use of soft headgear. Current NCAA field hockey rules allow the use of either full face masks or goggles if desired by individual players.18 In international games, the use of eye protection for field players (nongoalies) is allowed only with written medical permission.10 Additionally, as discussed above, defensive players at all levels of play are allowed to wear plastic face shields while defending short corners, although these must be removed once the immediate play has ended.10 While a small group has advocated for the use of soft helmets,22 there have been no significant discussions about the use of hard helmets in the game of field hockey. While they may have the ability to prevent injuries due to direct impact of the stick and ball, more research on the mechanism of injury and product development is needed to recommend their use because of the potential effect on the game. As mentioned in the introduction, US high school field hockey players must now wear protective eyewear that conforms to the standards of the ASTM.19 This mandate followed on not only the implementation of goggles in women’s lacrosse but also the 2003 joint advice of the American Academy of Ophthalmology (AAO) and American Academy of Pediatrics (AAP), who issued a statement recommending eyewear protection for participants in all sports in which there is a risk of eye injuries. They stated that properly fitting appropriate eye protectors reduce the risk of eye injuries by 90%.1
found that the NCAA ISS captured 88.2% of all time-loss injuries in men’s and women’s soccer, attesting to the reliability of the instrument. A further limitation is that all injury data are reported by athletic trainers and are not otherwise verifiable. Certainly, there is room for error in data reporting, although the conversion to a computerized reporting system has likely helped to minimize this. Additionally, as noted above, there were no NCAA Division II program participants in the NCAA ISS during this period. While this may limit the extrapolation of these data to this division, there is no known reason to suspect that these players have a different injury profile or risk than their Division I or III counterparts. Finally, the NCAA ISS only captures those injuries that necessitate time loss from play. In a study very similar to ours, Hendrickson et al8 found that 65% of HFE injuries in their field hockey population resulted in less than 1day time loss and, as such, would be missed by the NCAA ISS. This could lead to significant underreporting of all injuries. It should be noted that the NCAA mandates reporting of all dental injuries, regardless of time loss. As such, the incidence of dental injuries is less subject to the underreporting that has been found elsewhere within the ISS. However, this does limit the ability to compare the rate of dental injuries with that of other injuries.
CONCLUSION Every sport, in fact, every activity, carries some inherent risk of an injury. This study, as well as the others presented here, suggests that while the incidence of catastrophic eye injuries in field hockey is very low, the incidence of other injuries to the head and face is substantially higher. In this study, a concussion was the most common overall injury, which is concerning. Contact with an elevated ball is the most common mechanism of injury, with contact with a stick also a significant cause of morbidity. This information may now be used to help guide a multifaceted approach to injury prevention within the sport of field hockey. Involving diligent research and collaboration between medical professionals, sport leaders, and equipment manufacturers to develop effective interventions, the ultimate goal is maximal protection of the athlete balanced with a respect for the traditions of the game.
ACKNOWLEDGMENT Limitations There are several limitations inherent in the use of injury surveillance databases such as the NCAA ISS. The primary limitation of this study is that it is only a convenience sample of all injuries incurred throughout the average 250 schools sponsoring women’s collegiate field hockey. Certainly, this introduces the possibility for either overestimation or underestimation of the incidence of injuries when extrapolating to the entire population. A validation study from Kucera et al14
The author acknowledges and appreciates the support of Dr Tej Singh and the statistical assistance of Daniel Bohl, BA. Additionally, the author thanks the staff at the Datalys Center for Sports Injury Research and Prevention for their assistance. Thanks also to the many athletic trainers who have volunteered their time and effort to submit data to the NCAA ISS. Their efforts are greatly appreciated and have a tremendously positive effect on the safety of collegiate athletes.
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REFERENCES
15. Lincoln AE, Casewell SV, Almquist JL, et al. Effectiveness of the women’s lacrosse protective eyewear mandate for reduction of injuries. Am J Sports Med. 2012;40(3):611-614. 16. Murtaugh K. Injury patterns among female field hockey players. Med Sci Sports Exerc. 2001;33:201-207. 17. National Center for Catastrophic Sport Injury Research. 24th annual report: fall 1982-spring 2006. Available at: http://www.unc.edu/ depts/nccsi/AllSport.htm. Accessed February 26, 2012. 18. National Collegiate Athletic Association. Field hockey rules modifications 2012: Divisions I, II and III. Available at: http://www.ncaa .org/championships/playing-rules/field-hockey-rules-game. Accessed June 3, 2015. 19. National Federation of High Schools. NFHS field hockey: field hockey eyewear press release. Available at: http://old.nfhs.org/content .aspx?id=5117. Accessed April 31, 2012. 20. Protective eyewear for young athletes: American Academy of Pediatrics Committee on Sports Medicine and Fitness and American Academy of Ophthalmology Committee on Eye Safety and Sports Ophthalmology. Pediatrics. 1996;98(2 Pt 1):311-313. 21. Schwartz A. A case against helmets in lacrosse. The New York Times. February 17, 2011; B13. 22. Smith C. New Jersey school district mandates soft helmets for all soccer, field hockey and lacrosse players to widespread controversy. Available at: http://sports.yahoo.com/blogs/highschool-prep-rally/ jersey-school-district-mandates-soft-helmets-soccer-field-1025268 52.html. Accessed February 4, 2015. 23. Stoner J, Kreating M. Hockey equipment: safety or an illusion? In:Castaldi CR, Bishop PJ, Hoerner EF, ed. Safety in Ice Hockey: ASTM STP 1212. Vol 2. Philadelphia: American Society for Testing and Materials; 1993:183-191. 24. US Lacrosse. Comment on Florida helmet ruling. Available at: http:// www.uslacrosse.org/multimedia-center/press-releases-news/ postid/650/us-lacrosse-comment-on-florida-helmet-ruling.aspx. Accessed February 4, 2015. 25. Webster DA, Bayliss GV, Spadaro JA. Head and face injuries in scholastic women’s lacrosse with and without eyewear. Med Sci Sports Exerc. 1999;31(7):938-941. 26. Wilde G. Notes on the interpretation of traffic accident data and of homeostasis theory: a reply to L Evans. Risk Anal. 1986;6:95-107. 27. Yard EE, Comstock RD. Injuries sustained by pediatric ice hockey, lacrosse and field hockey athletes presenting to United States emergency departments, 1990-2003. J Athl Train. 2006;41(4):441-449.
1. American Academy of Pediatrics Committee on Sports Medicine and Fitness. Protective eyewear for young athletes. Pediatrics. 2004;113(3 Pt 1):619-622. 2. Benson B. Is protective equipment useful in preventing concussion? A systematic review of the literature. Br J Sports Med. 2009;43:i56i67. 3. Datalys Center Inc. NCAA 2004/05 to 2008/09 Surveillance System Data Sets. Indianapolis, Indiana: Datalys Center Inc; 2012. 4. Dick R, Agel J, Marshall SW. National Collegiate Athletic Association Injury Surveillance System commentaries: introduction and methods. J Athl Train. 2007;42(2):173-182. 5. Dick R, Hootman JM, Agel J, Vela L, Marshall SW, Messina R. Descriptive epidemiology of collegiate women’s field hockey injuries: National Collegiate Athletic Association Injury Surveillance System, 1988-1989 through 2002-2003. J Athl Train. 2007;42(2):211-220. 6. Echlin PS, Upshur REG, Peck DM, Skopelja EN. Craniomaxillofacial injury in sport: a review of prevention research. Br J Sports Med. 2005;39:254-263. 7. Elliot A, Jones D. Major ocular trauma: a disturbing trend in field hockey injuries. Br Med J. 1984;289:21-22. 8. Hendrickson CD, Hill K, Carpenter JE. Injuries to the head and face in women’s collegiate field hockey. Clin J Sport Med. 2008;18(5):399402. 9. International Hockey Federation. International rules. Available at: http://www.fih.ch/files/Sport/Rules/Rulebook Outdoor 2011.pdf. Accessed February 31, 2012. 10. International Hockey Federation. Member national federations. Available at: http://www.fih.ch/en/fih/members. Accessed April 31, 2012. 11. Jones N. Orbital blowout fractures in sport. Br J Sports Med. 1994;28(4):272-275. 12. Kerr Z, Dompier T, Snook E, et al. National Collegiate Athletic Association Injury Surveillance System: review of methods for 2004-05 through 2013-2014 data collection. J Athl Train. 2014;49(4):552-560. 13. Knapik JJ, Marshall SW, Lee RB, et al. Mouthguards in sport activities: history, physical properties and injury prevention effectiveness. Sports Med. 2007;37:117-144. 14. Kucera KL, Marshall SW, Dbell DR, DiStefano MJ, Goerger CP, Oyama S. Validity of soccer injury data from the National Collegiate Athletic Association’s Injury Surveillance System. J Athl Train. 2011;46(5):489-499.
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Head, Face, and Eye Injuries in Collegiate Women's Field Hockey Elizabeth C. Gardner Am J Sports Med 2015 43: 2027 originally published online June 19, 2015 DOI: 10.1177/0363546515588175 The online version of this article can be found at: http://ajs.sagepub.com/content/43/8/2027
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Head, Face, and Eye Injuries in Collegiate Women’s Field Hockey
5-in-5
Elizabeth C. Gardner,*y MD Investigation performed at the Department of Orthopaedic Surgery and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut, USA Background: While there is concern regarding head, face, and eye injuries in field hockey, prompting some to recommend the use of protective equipment such as goggles and helmets, little has been written about their incidence and mechanism of injury in the modern game of field hockey. The elucidation of this information will better inform the development of maximally effective injury prevention schemes to protect the athlete while maintaining the integrity of the game. Purpose: To determine the incidence and epidemiology of head, face, and eye injuries in United States collegiate women’s field hockey players from 2004-2005 to 2008-2009. Study Design: Descriptive epidemiological study. Methods: All head, face, and eye injuries reported to the National Collegiate Athletic Association Injury Surveillance System for collegiate women’s field hockey athletes from the 2004-2005 through 2008-2009 seasons were analyzed. Data regarding the event type, injury mechanism, body part injured, type of injury, outcome, and time lost were reviewed. The weighted injury incidence per 1000 athlete-exposures (AEs) was calculated using the exposure data set for the same years; 95% CIs were calculated based on a normal approximation to the Poisson distribution. Results: There were 150 reported traumatic injuries during this time period, with a weighted occurrence of 1587.3 injuries. The overall incidence of head, face, and eye injuries in collegiate women’s field hockey was 0.94 per 1000 AEs (95% CI, 0.86-1.19). Injuries to the head or face, other than the mouth, nose, and eye, accounted for 75.3% of these injuries. The incidence of eye injuries was 0.07 per 1000 AEs (95% CI, 0.03-0.12); nose injuries occurred at a rate of 0.10 per 1000 AEs (95% CI, 0.05-0.15). The rate of traumatic dental injuries was 0.06 per 1000 AEs (95% CI, 0.04-0.14). Contact with an apparatus caused 72.9% of all injuries; specifically, contact with an elevated ball accounted for 47.9% of all injuries, and contact with an elevated stick caused 21.7% of all injuries. While the majority of players suffering a head, face, or eye injury were able to return to sport that season (90.0%), the remaining athletes suffered season-ending injuries (10%). Concussions accounted for 42.8% of all head, face, and eye injuries reported (0.40 per 1000 AEs; 95% CI, 0.32-0.53). Conclusion: Head, face, and eye injuries occur regularly in women’s field hockey. This description of the injury profile and mechanisms of injury may be used to design appropriate injury prevention schemes for the sport. Keywords: head, eye, and face injuries; women’s field hockey; collegiate
popularity internationally is second only to soccer.10 Traditionally played by women in the United States (US), the game is one of the most popular sports in both high schools and universities. In field hockey, the struck plastic ball may reach up to 80 km/h.9 Sticks are 36 to 38 inches in length and are typically made of a carbon composite, often containing Kevlar. The stick, ball, and contact with other players may all be implicated in causing head, face, and eye (HFE) injuries in field hockey. Although the game is played primarily on the ground, the ball and stick are frequently raised above shoulder height, intentionally or not, during the game. Recent alterations to the game aimed to increase goal scoring opportunities, including rule changes, advances in stick and playing surface technologies, the development of powerful shots such as the reverse-stick (left-sided) chip shot in the shooting circle, and an increased dedication to physical conditioning and strength, have all made
Played by men and women on 6 continents and in at least 134 nations for more than 4000 years, field hockey’s
*Address correspondence to Elizabeth C. Gardner, MD, Department of Orthopaedic Surgery and Rehabilitation, Yale University School of Medicine, 800 Howard Avenue, 1st Floor, New Haven, CT 06519, USA (email: [email protected]). y Department of Orthopaedic Surgery and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut, USA. The author has declared the following potential conflict of interest or source of funding: The National Collegiate Athletic Association (NCAA) Injury Surveillance System data were provided by the Datalys Center for Sports Injury Research and Prevention. The Injury Surveillance System was funded by the NCAA. The content of this article is solely the responsibility of the author and does not necessarily represent the official view of the Datalys Center or the NCAA. The American Journal of Sports Medicine, Vol. 43, No. 8 DOI: 10.1177/0363546515588175 Ó 2015 The Author(s)
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TABLE 1 Athlete Population Dataa
Year 2004-2005 2005-2006 2006-2007 2007-2008 2008-2009 Average/total
NCAA Schools Sponsoring Women’s Field Hockey, n 257 258 259 258 250 256
Schools Reporting to ISS, n (% of Total Schools) 23 22 20 24 22 22
(9) (9) (8) (9) (9) (9)
Exposures (Competitions and Practices), n
AEs, n
Estimated Population AEs, n
1562 1486 1401 1777 1718 7944
28,834 26,910 26,604 33,570 32,787 148,705
327,157 313,962 335,619 361,660 371,837 1,710,235
a
AE, athlete-exposure; ISS, Injury Surveillance System; NCAA, National Collegiate Athletic Association.
the modern game faster and more exciting than ever. Certainly, the game is markedly different from that of even just the past decade. The advancement of the game must be balanced with an appropriate effort to protect the athlete. Recently, there has been much discussion regarding the use of additional personal protective equipment in field hockey, most importantly the use of goggles. Thus, the purpose of this study was to provide an updated assessment of the epidemiology of HFE injuries in the sport that reflects the current American collegiate game to better inform decisions regarding maximally effective safety interventions and monitor for their efficacy.
METHODS The National Collegiate Athletic Association (NCAA) maintains an Injury Surveillance System (ISS), which collects data regarding athlete-exposures (AEs) and subsequent injuries. The details of this system have been previously described by Dick et al4 and Kerr et al.12 Briefly, these ‘‘convenience sample’’ data are reported on a volunteer basis by certified athletic trainers from any of the 3 NCAA divisions via a web-based injury tracking system that allows the entry of information related to the injury mechanism, body part injured, type of injury, measures of severity (time loss, need for surgery), when and where in play the injury occurred, and sport-specific questions related to the mechanism of injury and player position. As shown in Table 1, over the 5-year period from 2004-2005 through 20082009, the NCAA ISS collected data from an average of 9% of all Division I and III schools sponsoring women’s field hockey (although field hockey is played in Division II, no schools were sampled during this period). Of the 25 NCAA sports monitored by the ISS, field hockey ranks as the fifth highest percentage of participating programs from 20042005 through 2008-2009.12 To help provide national estimates of injuries from the sampled data, the NCAA ISS provides poststratification sample weights, based on sport and division. These weights are modified every academic year to account for year-to-year variations in reporting and sampling. While truly a deterministic sample, it has been found to be useful
for the purposes of calculating incidence and epidemiology. A recent study from Kucera et al14 found that the NCAA ISS captured 88.3% of all time-loss injuries in men’s and women’s soccer. The NCAA took this underreporting into account when calculating its sample weights. Data were obtained from the Datalys Center for Sports Injury Research and Prevention, the nonprofit organization responsible for the collection and maintenance of NCAA ISS data. Approval (exemption) was confirmed with our Institutional Review Board. Exposure data were calculated using the Women’s Field Hockey Exposure Data Set. A reportable AE is defined as 1 student-athlete participating in 1 practice or game during which there was the possibility of an injury. The duration of the exposure is not recorded. During these 5 years, data from a total sample of 7944 events (practices and games) were reported for between 5 and 35 athletes per session. There were 111,669 athlete-practice sample exposures and 37,036 athlete-game exposures, for a total number of athlete sample exposures of 148,705. When exposure weights were taken into account, there were a total of 1,710,235 population exposures; 430,674 of these were game exposures, whereas 1,279,561 were population practice exposures. It should be noted that intrasquad scrimmages are classified as practices. Data collection began on the first day of preseason and concluded on the final day of competition, including postseason play if applicable. A reportable injury in the ISS is ‘‘one that (1) occurred as a result of participation in an organized intercollegiate practice or contest, (2) required medical attention by certified athletic trainers or physicians, and (3) resulted in restriction of the student-athlete’s participation for one or more days beyond the day of injury.’’3(p3) Per the NCAA ISS guidelines, all dental injuries are included, regardless of time lost. The Women’s Field Hockey Injury Data Set for 20042005 to 2008-2009 was examined using the ‘‘body part’’ codes ‘‘head/face,’’ ‘‘nose,’’ ‘‘eye,’’ and ‘‘mouth.’’ All injuries affecting these locations were included in the analysis. Specific injury codes, such as ‘‘concussion,’’ ‘‘nasal contusion,’’ or ‘‘jaw fracture,’’ provided further information regarding the nature of the injury. Of note, there is no free-text area in the injury report to allow a more descriptive account of the injury.
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Head Injuries in Field Hockey 2029
TABLE 2 Injuries by Body Locationa
100% 90%
Injury Incidence Body Part Eye Head/face Mouth Nose Total
Reported Injuries, n (% of All Injuries) 9 113 13 15 150
(6.0) (75.3) (8.7) (10.0) (100.0)
Weighted Population 113.4 1204.9 100.2 168.8 1587.3
Per 1000 AEs (95% CI) 0.07 0.71 0.06 0.10 0.94
(0.03-0.12) (0.62-0.90) (0.04-0.14) (0.05-0.15) (0.86-1.19)
80% 70% 60% 50%
47.9%
40% 24.6%
30% 21.7% 20% 10%
3.5%
2.3%
a
AE, athlete-exposure.
0% Contact with elevated ball
The weighted estimate of the population incidence of injuries is defined as the weighted number of injuries divided by the weighted number of population AEs. Generally, this is reported as injuries per 1000 AEs, which allows a comparison with previously published reports.5 As there is no information available regarding the severity of specific injuries, the variable of ‘‘time loss’’ was used as a surrogate to help describe the seriousness of injuries. Time loss is defined as the duration of time from the index injury to return to play at a level that allows participation in either a game or practice. As discussed by Dick et al,4 this measure is subject to great variability at the hands of the individual athlete and medical staff. Thus, the analysis of time loss was limited to only grouping injuries into those that restricted participation for 10 days, as a marker of high injury severity, as suggested by Dick et al.5 Even still, there is potential for variability, especially for those injuries that occurred near the end of the year when additional time loss may have been projected but not captured.
RESULTS There were 150 traumatic HFE injuries reported within the NCAA ISS sample from 2004-2005 through 20082009, with an estimated overall population incidence of 1587.3 injuries. Thus, the overall rate of HFE injuries in women’s collegiate field hockey from 2004-2005 through 2008-2009 was 0.94 per 1000 AEs (95% CI, 0.86-1.19). Specifically, the incidences of head/face injuries and eye injuries were 0.71 (95% CI, 0.62-0.90) and 0.07 (95% CI, 0.030.12) per 1000 AEs, respectively. Nose injuries occurred at a rate of 0.10 per 1000 AEs (95% CI, 0.05-0.15), whereas mouth injuries occurred at a rate of 0.06 per 1000 AEs (95% CI, 0.04-0.14). These are presented in Table 2. The most common specific type of injury was a concussion, occurring at a rate of 0.40 per 1000 AEs (95% CI, 0.32-0.53) and accounting for 42.8% of all injuries. Contusions (0.21 per 1000 AEs; 95% CI, 0.15-0.31) and lacerations (0.18 per 1000 AEs; 95% CI, 0.13-0.27) were also common. The specific details of these injuries are presented in Table 3. Details regarding the mechanism of injury are reported in Figure 1. Player contact with an elevated ball was the
Contact with ground ball
Contact with stick
Direct contact with player
Other/ unknown
Figure 1. Mechanism of all injuries.
most common mechanism of injury in both the game and practice situation, accounting for 47.9% of all HFE injuries. There are no data regarding whether the elevated ball was deemed to be legal or illegal by the referees. Direct contact with another player caused 24.6% of injuries. Contact with a stick caused 21.7% of injuries.
Time Loss Overall, 90.0% of athletes suffering HFE injuries during this time period were able to return to sport within the same season. There were 12.6% of injuries that resulted in 10 days away from play, although the player was eventually able to return to play that season. Of these injuries, .50% were concussions. Of all injuries suffered, 10.0% were so severe that the athlete did not return to play during that same season. The details of these injuries are presented in Table 4. This group included 3 concussions. It also included 5 eye/ cheek injuries: 1 corneal abrasion, 1 orbital fracture, 2 cheekbone fractures, and 1 eyelid laceration. Finally, there was 1 concussed player who was released from the team before the end of the season; whether this was related to her injury is unclear in the data.
Head/Facial Injuries An injury to the head or face, other than the mouth, nose, and eye, was the most common location of injury, accounting for 75.3% of all HFE injuries. A concussion was the most common injury to the head or face, occurring at a rate of 0.40 per 1000 AEs (95% CI, 0.32-0.53). Facial contusions and facial lacerations were also common, with incidences of 0.13 (95% CI, 0.07-0.19) and 0.12 (95% CI, 0.080.20) per 1000 AEs, respectively. The most common mechanism of injury for both facial contusions and lacerations was contact with an elevated ball (58.0%), although contact with a stick also caused a significant number of injuries as well (27.3%). Of the athletes suffering from facial lacerations and contusions, 6.1% lost 10 days of play before their return. There were also incidents of cheekbone
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The American Journal of Sports Medicine
TABLE 3 Specific Injury Dataa Injury Cheekbone fracture Concussion Corneal abrasion Dental work Epistaxis Eyelid laceration Facial contusion Facial laceration Head (not face) contusion Jaw contusion Jaw fracture Mouth laceration Nasal contusion Nasal fracture Nasal laceration Orbital fracture Other eye injury Other nose injury Skull fracture Eye soft tissue contusion Tooth fracture/avulsion
Reported Injuries, n (% of All Injuries) 2 63 1 2 1 5 19 21 7 3 1 2 4 7 2 1 2 1 1 1 4
Weighted Estimate of Injuries
(1.5) (42.8) (1.1) (1.1) (0.9) (4.2) (14.0) (12.7) (4.1) (1.3) (0.5) (0.9) (2.7) (5.2) (1.20 (0.6) (0.7) (0.6) (0.8) (0.5) (2.6)
Injury Incidence per 1000 AEs (95% CI)
23.2 679.5 17.6 17.6 14.6 67.1 222.1 201.9 64.7 20.2 17.4 14.5 42.5 88.4 18.5 9.7 11.6 9.7 13.4 7.4 40.6
0.01 0.40 0.01 0.01 0.01 0.04 0.13 0.12 0.04 0.01 \0.01 0.01 0.03 0.05 0.01 0.01 0.01 0.01 0.01 \0.01 0.02
(0.05-0.15) (0.32-0.53) (\0.0001-0.02) (\0.0001-0.03) (\0.0001-0.02) (0.004-0.06) (0.07-0.19) (0.08-0.20) (0.01-0.08) (\0.0001-0.04) (\0.0001-0.02) (\0.0001-0.03) (0.0005-0.05) (0.01-0.08) (\0.0001-0.03) (\0.0001-0.02) (\0.0001-0.03) (\0.0001-0.02) (\0.0001-0.02) (\0.0001-0.02) (0.0005-0.05)
a
AE, athlete-exposure.
fractures and 1 skull fracture, although, fortunately, these were uncommon. Although rare, the athletes suffering these injuries were unable to return to play that season, verifying the severity of the injuries. Each of these fractures resulted from contact with an elevated ball.
Concussions A further subset analysis of concussions is necessary to help prevent these potentially devastating injuries. As stated above, a concussion was the most common HFE injury occurring in women’s collegiate field hockey during this time period, occurring at a rate of 0.40 per 1000 AEs (95% CI, 0.32-0.53). The most common specific mechanism of injury was direct player contact, accounting for 39.3% of all concussions. There is no notation as to whether the contact was deemed illegal or not. Additionally, head contact with either a raised ball or stick combined to cause 45.8% of all concussions. The specific mechanisms of concussions are shown in Figure 2. Nearly all of the players suffering a concussion were eventually able to return to play within the same season (92.8%). Of these, 77.3% returned in \10 days from the time of injury, while the other 22.7% needed up to 20 days.
Mouth Injuries During the time period of observation, the overall weighted incidence of mouth injuries, including fractures/avulsions, was 0.06 per 1000 AEs. Data regarding the actual use of
TABLE 4 Season-Ending Injuriesa Injury
n
Incidence per 1000 AEs
Concussion Facial laceration Cheekbone fracture Corneal abrasion Eyelid laceration Nasal fracture Skull fracture Orbital fracture Head contusion Jaw fracture
3 3 2 1 1 1 1 1 1 1
35.3 32.5 23.2 17.6 17.6 17.6 13.4 9.7 7.4 7.4
a
AE, athlete-exposure.
mouthguards in these situations were not available. Contact with a stick or an elevated ball caused 52.9% and 29.6% of all mouth injuries, respectively.
Eye Injuries The overall rate of eye injuries during the 5 years of this study was 0.07 per 1000 AEs (95% CI, 0.03-0.12), resulting in a weighted total of 113.4 injuries. Of these traumatic eye injuries, 39.5% of the athletes were unable to return to play during that season. All of the traumatic injuries were caused by contact with a piece of apparatus, with 89.7% caused by an elevated ball and 10.3% caused by a raised stick.
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Head Injuries in Field Hockey 2031
Nasal Injuries The rate of injuries to the nose during this data collection period was 0.10 per 1000 AEs (95% CI, 0.05-0.15), accounting for 10.0% of all HFE injuries. A fracture was the most common nose injury, occurring at a rate of 0.05 per 1000 AEs (95% CI, 0.01-0.08). Contact with an elevated ball caused the majority of these injuries (71.7%), while direct contact with another player caused 14.3%.
Direct player contact 39.3%
Contact with elevated ball 24.8%
Other 14.9%
DISCUSSION Sport-related HFE injuries can be serious. While fortunately uncommon, injuries resulting in airway obstruction or neurological compromise may be life threatening. Others, such as globe injuries, dental injuries, facial fractures, and lacerations, are potentially disabling and disfiguring. Reports of such injuries in field hockey players have fortunately been rare. In their 24th Annual Report, the National Center for Catastrophic Sport Injury Research17 reported that from fall 1982 through spring 2006, there were 2 catastrophic eye injuries and 2 skull fractures suffered by field hockey players. Elliot and Jones7 reported 3 cases of severe eye injuries to young female field hockey players; all 3 resulted in blindness in the injured eye. In a review of all sport-related orbital blowout fractures over a 6-year period at a large British eye hospital, Jones11 found only 1 field hockey–related fracture; interestingly, this injury was caused by an intentional assault with a field hockey stick and was not incurred during regular match play. This review confirms that while reports of catastrophic injuries are rare, less-devastating HFE injuries do commonly occur in field hockey. A further analysis of current rules, as well as an understanding of the history and use of protective equipment, is necessary to develop maximally effective injury prevention schemes to decrease the incidence of all HFE injuries.
Head and Face Injuries Our finding that face and head injuries, not including those to the nose, eye, and mouth, were the most common location of HFE injuries is in line with that in prior studies from Yard and Comstock,27 Dick et al,5 and Murtaugh.16 Overall, a concussion was the most commonly reported injury to the head and face; it will be discussed separately. The incidence of facial lacerations, found to be 0.12 per 1000 AEs (95% CI, 0.08-0.20) in our study, is lower than the 0.23 per 1000 AEs reported by Dick et al.5 The incidence of facial contusions, 0.13 per 1000 AEs (95% CI, 0.07-0.19) in our group, is also similar to the 0.10 per 1000 AEs reported by Dick et al.5 Although permissible since 2007, face masks are not routinely worn in US high school and collegiate field hockey. They are most commonly encountered on players playing while recovering from a soft tissue injury or fracture to the face or nose. They are not allowed to be worn in international competition unless medically required.10
Contact with stick 21.0%
Figure 2. Specific mechanism of a concussion. ‘‘Other’’ includes contact with a ground ball, the goal cage, and the field surface. Currently, defensive players at all levels of play are allowed to wear plastic face shields while defending short corners, although these are typically removed once the immediate play has ended.10 Providing protection to the soft tissues of the face and nose, as well as perhaps the eye, these were introduced to decrease the rate of facial injuries during short corners, a play in which a direct and powerful shot is directed at several defenders running toward the ball. To this point, there has not been a study to demonstrate the effect of these masks.
Concussions We found that a concussion was the most common specific HFE injury in this population, with an incidence of 0.40 per 1000 AEs (95% CI, 0.32-0.53). This is concerning as we continue to learn more about the long-term consequences of this injury. This rate is significantly less than the 0.81 per 1000 AEs reported by Hendrickson et al.8 However, in their report of NCAA women’s field hockey players from 1988-1989 through 2002-2003, Dick et al5 reported an incidence of 0.09 per 1000 AEs. The reason for this observed increased incidence in the 2 more recent studies is unclear. Certainly, there is far more vigilance regarding head injuries today than during the time of the Dick et al5 study, leading to the reporting of concussions now that may have been missed years ago. It is also possible that as the game becomes faster and there is more dedication to the development of physical athletes, the injury pattern of the sport may be changing as a result. More surprising than the incidence of concussions is the fact that direct contact with another player was the most common cause for concussions in this essentially noncontact sport, consistent with the findings of Murtaugh.16 The 2 other common mechanisms, head contact with an
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elevated ball and contact with a stick, are both illegal in most play. This suggests that the stricter enforcement of rules regarding player contact and elevated game equipment may be a vital step in a multimodal approach to decrease the incidence of concussions in field hockey. The USA Field Hockey organization currently permits the use of soft protective headgear for all field players for the prevention of head injuries; to our knowledge, there are no data regarding the efficacy of this equipment. However, the International Hockey Federation (FIH), the governing body for international games, prohibits the use of such equipment in all international play. At all levels of play, the goalkeeper is required to wear a hard protective helmet that incorporates fixed full-face protection and covering for the entire head.10,18 Interestingly, in this study, the traumatic injuries known to be suffered by goalkeepers were both concussions. This illustrates that even a maximal level of protection such as a helmet cannot completely prevent injuries.
Mouth Injuries Since the 1960s and 1970s, mouthguards have been mandated by US and Canadian sporting associations for field hockey; however, in international games, its use is still only ‘‘recommended.’’10 The initial premise was to decrease the incidence and severity of both dental injuries as well as concussions.2 A recent meta-analysis found that the overall risk of an orofacial injury is 1.6 to 1.9 times higher if a mouthguard is not worn during a sport with a risk of facial injuries.13 However, a protective effect for concussions has never been clearly established.2 Despite the long-standing rule that players wear a mouthguard at all times during play, there was a weighted occurrence of 100.2 injuries classified to the mouth during the observed time period, including 20.2 jaw contusions and 17.4 jaw fractures, which may or may not be preventable with mouthguard use. Again, the majority of these injuries, 82.5%, were caused by contact with an elevated ball or stick. This again suggests that stricter rule enforcement may help to decrease the incidence of these injuries. It also highlights the fact that while new protective equipment is being developed, traditional equipment such as mouthguards should continue to be optimized to offer the best possible protection to the athlete. For example, most literature agrees that custom-fitted mouthguards offer better protection than the stock ‘‘over-thecounter’’ or ‘‘boil and bite’’ models that most collegiate athletes use.6 Current US and international rules do not specify the type of mouthguard worn, thus potentially missing an opportunity to enhance player protection.
Nose Injuries This study reported an incidence of nose injuries to be 0.10 per 1000 AEs overall (95% CI, 0.05-0.15). The incidence of fractures, 0.05 per 1000 AEs (95% CI, 0.01-0.08) in our study, was significantly lower than the 0.29 per 1000 AEs reported by Dick et al.5 As with injuries to other parts of
the head and face, the most common mechanism of injury was contact with an elevated ball. While potentially disfiguring, generally, injuries to the nose are less severe than other HFE injuries. This is supported by the fact that only 6.3% of nose injuries in our group were season ending. As mentioned above, plastic face masks, which provide some protection to the nose, are now allowed in American high school and college field hockey. Use of these masks internationally is limited to medical necessity and on shortcorner plays. Current field hockey goggles, as regulated by the American Society for Testing and Materials (ASTM), do not provide protection to the soft tissues or bones of the nose.
Eye Injuries Nationally, 40,000 to 100,000 sport- or recreation-related eye injuries occur annually in the US.20 The most common age-related causes of North American sport-related eye injuries are baseball (leading cause of eye injuries in 5to 14-year-old athletes), basketball (leading cause of injuries in 15- to 24-year-old athletes), and racquet sports (leading cause in 25- to 65-year-old athletes).1 Although fortunately rare, the incidence of eye injuries in field hockey remains a concern. In our population, these injuries included eyelid lacerations, a corneal abrasion, an orbital fracture, and a soft tissue contusion. Of the traumatic eye injuries in this study, 39.5% were season ending for the athlete, attesting to their severity. The other athletes were able to return to play within 4 days of the incident. Similar to other injuries, the most common mechanism of injury was contact with an elevated ball, accounting for 89.7% of the injuries. Once again, this suggests that rule enforcement could help to decrease their occurrence. Proponents of HFE protection in field hockey have cited the evolution of equipment worn traditionally by ice hockey players and more recently by women’s lacrosse players. Helmets were first mandated in ice hockey in 1963 in Swedish amateur players. By the late 1960s, both the American and Canadian Amateur Hockey Associations had followed suit, requiring all players to wear protection. However, a disturbing number of eye and facial injuries still occurred. This led to the introduction of face masks, both partial and full, attached to the helmet. Finally, there was a decrease in soft tissue injuries around the face and mouth, from 38% of players per year to 9% from 1975 to 1988.23 In 2003, US Lacrosse voted to ‘‘highly recommend’’ the use of protective eyewear for all women’s lacrosse players. It became required on January 1, 2005. The delay was aimed to allow the development of appropriate equipment. This mandate came after a detailed analysis of the risk of catastrophic eye injuries as well as less severe head and face injuries. As well, the US Lacrosse Sports Science and Safety Committee worked to develop eyewear designed specifically for women’s lacrosse to offer maximal benefit while still respecting the traditions of the game. Webster et al25 published a prospective analysis of the incidence of head and face injuries in New York scholastic women’s lacrosse during a transition from sparse to almost complete eyewear use. In all play, that is, both practice and game situations, the incidence of head and eye injuries was
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Head Injuries in Field Hockey 2033
16% less in goggle wearers. However, in games alone where more aggressive play predominates, the rate associated with eyewear use was 51% less, which reached statistical significance. There were no injuries to the eye (orbit) reported in the 77,947 AEs. Cheek and scalp injury rates tended to be higher in goggle wearers, although not significantly. In another comparative study, Lincoln et al15 found no change in the rate ratio of total injuries involving all body parts, but they did find a statistically increased rate of concussions (incidence rate ratio, 1.6; 95% CI, 1.1-2.3). There is some concern that players wearing enhanced protective equipment may consider themselves to be safer and thus will play more aggressively or recklessly to assume the preprotection level of risk.26 This emphasizes the importance of the careful consideration of and monitoring for unintended consequences of injury prevention protocols. Recently, the debate over eyewear in women’s lacrosse has segued into a similar discussion regarding the use of helmets.21,24 To this point, the sport’s governing body and its supporters have argued against the use of hard helmets,24 concerned about maintaining the ‘‘integrity’’ of the game as well as preventing a false sense of protection from injuries. They do, however, continue to allow the use of soft headgear. Current NCAA field hockey rules allow the use of either full face masks or goggles if desired by individual players.18 In international games, the use of eye protection for field players (nongoalies) is allowed only with written medical permission.10 Additionally, as discussed above, defensive players at all levels of play are allowed to wear plastic face shields while defending short corners, although these must be removed once the immediate play has ended.10 While a small group has advocated for the use of soft helmets,22 there have been no significant discussions about the use of hard helmets in the game of field hockey. While they may have the ability to prevent injuries due to direct impact of the stick and ball, more research on the mechanism of injury and product development is needed to recommend their use because of the potential effect on the game. As mentioned in the introduction, US high school field hockey players must now wear protective eyewear that conforms to the standards of the ASTM.19 This mandate followed on not only the implementation of goggles in women’s lacrosse but also the 2003 joint advice of the American Academy of Ophthalmology (AAO) and American Academy of Pediatrics (AAP), who issued a statement recommending eyewear protection for participants in all sports in which there is a risk of eye injuries. They stated that properly fitting appropriate eye protectors reduce the risk of eye injuries by 90%.1
found that the NCAA ISS captured 88.2% of all time-loss injuries in men’s and women’s soccer, attesting to the reliability of the instrument. A further limitation is that all injury data are reported by athletic trainers and are not otherwise verifiable. Certainly, there is room for error in data reporting, although the conversion to a computerized reporting system has likely helped to minimize this. Additionally, as noted above, there were no NCAA Division II program participants in the NCAA ISS during this period. While this may limit the extrapolation of these data to this division, there is no known reason to suspect that these players have a different injury profile or risk than their Division I or III counterparts. Finally, the NCAA ISS only captures those injuries that necessitate time loss from play. In a study very similar to ours, Hendrickson et al8 found that 65% of HFE injuries in their field hockey population resulted in less than 1day time loss and, as such, would be missed by the NCAA ISS. This could lead to significant underreporting of all injuries. It should be noted that the NCAA mandates reporting of all dental injuries, regardless of time loss. As such, the incidence of dental injuries is less subject to the underreporting that has been found elsewhere within the ISS. However, this does limit the ability to compare the rate of dental injuries with that of other injuries.
CONCLUSION Every sport, in fact, every activity, carries some inherent risk of an injury. This study, as well as the others presented here, suggests that while the incidence of catastrophic eye injuries in field hockey is very low, the incidence of other injuries to the head and face is substantially higher. In this study, a concussion was the most common overall injury, which is concerning. Contact with an elevated ball is the most common mechanism of injury, with contact with a stick also a significant cause of morbidity. This information may now be used to help guide a multifaceted approach to injury prevention within the sport of field hockey. Involving diligent research and collaboration between medical professionals, sport leaders, and equipment manufacturers to develop effective interventions, the ultimate goal is maximal protection of the athlete balanced with a respect for the traditions of the game.
ACKNOWLEDGMENT Limitations There are several limitations inherent in the use of injury surveillance databases such as the NCAA ISS. The primary limitation of this study is that it is only a convenience sample of all injuries incurred throughout the average 250 schools sponsoring women’s collegiate field hockey. Certainly, this introduces the possibility for either overestimation or underestimation of the incidence of injuries when extrapolating to the entire population. A validation study from Kucera et al14
The author acknowledges and appreciates the support of Dr Tej Singh and the statistical assistance of Daniel Bohl, BA. Additionally, the author thanks the staff at the Datalys Center for Sports Injury Research and Prevention for their assistance. Thanks also to the many athletic trainers who have volunteered their time and effort to submit data to the NCAA ISS. Their efforts are greatly appreciated and have a tremendously positive effect on the safety of collegiate athletes.
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