Injury Proportion Ratios Research Articles

Epidemiology of National Collegiate Athletic Association Men's and Women's Cross-Country Injuries, 2009-2010 Through 2013-2014.

Recent injury-surveillance data for collegiate-level cross-country athletes are limited. To describe the epidemiology of National Collegiate Athletic Association (NCAA) men's and women's cross-country injuries during the 2009-2010 through 2013-2014 academic years. Descriptive epidemiology study. Aggregate injury and exposure data collected from 25 men's and 22 women's cross-country programs, providing 47 and 43 seasons of data, respectively. Collegiate student-athletes participating in men's and women's cross-country during the 2009-2010 through 2013-2014 academic years. Injury rates; injury rate ratios (RRs); injury proportions by body site, diagnosis, and apparatus; and injury proportion ratios were reported with 95% confidence intervals (CIs). The Injury Surveillance Program captured 216 injuries from men's cross-country and 260 injuries from women's cross-country, leading to injury rates of 4.66/1000 athlete-exposures (AEs) for men (95% CI = 4.04, 5.28) and 5.85/1000 AEs for women (95% CI = 5.14, 6.56). The injury rate in women's cross-country was 1.25 times that of men's cross-country (95% CI = 1.05, 1.50). Most injuries affected the lower extremity (men = 90.3%, women = 81.9%). The hip/groin-injury rate in women (0.65/1000 AEs) was higher than that in men (0.15/1000 AEs; RR = 4.32; 95% CI = 1.89, 9.85). The ankle-injury rate in men (0.60/1000 AEs) was higher than that in women (0.29/1000 AEs; RR = 2.07; 95% CI = 1.07, 3.99). Common diagnoses were strains (men = 19.9%, women = 20.4%) and inflammation (men = 18.1%, women = 23.8%). The majority of injuries were classified as overuse (men = 57.6%, women = 53.3%). Consistent with prior research, injury distributions varied between male and female athletes, and the injury rate among females was higher. Understanding the epidemiology of these cross-country injuries may be important for developing appropriate preventive interventions.

Epidemiology of Sports-Related Concussion in NCAA Athletes From 2009-2010 to 2013-2014

Background: The epidemiology of sports-related concussion (SRC) among student-athletes has been extensively researched. However, recent data at the collegiate level are limited. Purpose: To describe the epidemiology of SRC in 25 National Collegiate Athletic Association (NCAA) sports. Study Design: Descriptive epidemiology study. Methods: SRC data from the NCAA Injury Surveillance Program during the 2009-2010 to 2013-2014 academic years were analyzed. Concussion injury rates, rate ratios (RRs), and injury proportion ratios were reported with 95% CIs. National estimates were also calculated to examine linear trends across time. Results: During the study period, 1670 SRCs were reported, representing a national estimate of 10,560 SRCs reported annually. Among the 25 sports, the overall concussion rate was 4.47 per 10,000 athlete-exposures (AEs) (95% CI, 4.25-4.68). Overall, more SRCs occurred in competitions (53.2%). The competition rate (12.81 per 10,000 AEs) was larger than the practice rate (2.57 per 10,000 AEs) (competition vs practice, RR = 4.99; 95% CI, 4.53-5.49). Of all SRCs, 9.0% were recurrent. Most SRCs occurred from player contact (68.0%). The largest concussion rates were in men’s wrestling (10.92 per 10,000 AEs; 95% CI, 8.62-13.23), men’s ice hockey (7.91 per 10,000 AEs; 95% CI, 6.87-8.95), women’s ice hockey (7.50 per 10,000 AEs; 95% CI, 5.91-9.10), and men’s football (6.71 per 10,000 AEs; 95% CI, 6.17-7.24). However, men’s football had the largest annual estimate of reported SRCs (n = 3417), followed by women’s soccer (n = 1113) and women’s basketball (n = 998). Among all SRCs, a linear trend did not exist in national estimates across time (P = .17). However, increases were found within specific sports, such as men’s football, women’s ice hockey, and men’s lacrosse. Conclusion: The estimated number of nationally reported SRCs has increased within specific sports. However, it is unknown whether these increases are attributable to increased reporting or frequency of concussions. Many sports report more SRCs in practice than in competition, although competition rates are higher. Men’s wrestling and men’s and women’s ice hockey have the highest reported concussion rates. Men’s football had the highest annual national estimate of reported SRCs, although the annual participation count was also the highest. Future research should continue to longitudinally examine SRC incidence while considering differences by sex, division, and level of competition.

Epidemiology of Hamstring Strains in 25 NCAA Sports in the 2009-2010 to 2013-2014 Academic Years

Background: The epidemiology of hamstring strains among student-athletes has been extensively researched. However, there is a paucity of recent data describing patterns of hamstring strains. Purpose: To describe the epidemiology of hamstring strains in 25 National Collegiate Athletic Association (NCAA) championship sports. Study Design: Descriptive epidemiology study. Methods: Hamstring strains data were analyzed from the NCAA Injury Surveillance Program during the 2009-2010 to 2013-2014 academic years. Hamstring strain injury rates, rate ratios (RRs), and injury proportion ratios were reported with 95% CIs. Results: During the study period, 1142 hamstring strains were reported, leading to an injury rate of 3.05 per 10,000 athlete-exposures (AEs). Most hamstring strains occurred during practices (68.2%). However, the competition rate (5.24 per 10,000 AEs) was larger than the practice rate (2.56 per 10,000 AEs; RR = 2.05; 95% CI, 1.81-2.32). A slight majority occurred during the regular season (52.9%). However, the preseason rate (5.00 per 10,000 AEs) was larger than the regular season/postseason rate (2.34 per 10,000 AEs; RR = 2.14; 95% CI, 1.90-2.40). Men’s football, men’s soccer, and women’s soccer contributed the greatest proportion of hamstring strains (35.3%, 9.9%, and 8.3%, respectively). Most hamstring strains were due to noncontact (72.3%). Of all hamstring strains, 12.6% were recurrent, 37.7% resulted in a time loss of <24 hours, and 6.3% resulted in a time loss >3 weeks. Variations in hamstring strain patterns existed by sport. The hamstring strain rate was larger in men than in women in soccer (RR = 1.60; 95% CI, 1.22-2.11), baseball/softball (RR = 1.66; 95% CI, 1.07-2.59), and indoor track (RR = 1.88; 95% CI, 1.26-2.78). In addition, proportions of hamstring strains that were recurrent were higher among men in most sex-comparable sports, but this difference was not significant. Conclusion: Hamstring strain rates were higher in the preseason and in competition. Student-athletes should be acclimatized to the rigors of preseason participation. Meanwhile, further surveillance should investigate the effectiveness of prospective prevention programs in an effort to reduce the prevalence of initial and recurrent hamstring strain injuries.

Epidemiology of National Collegiate Athletic Association Women's Gymnastics Injuries, 2009-2010 Through 2013-2014.

Recent injury-surveillance data for collegiate-level women's gymnastics are limited. In addition, researchers have not captured non-time-loss injuries (ie, injuries resulting in restriction of participation <1 day). To describe the epidemiology of National Collegiate Athletic Association (NCAA) women's gymnastics injuries during the 2009-2010 through 2013-2014 academic years. Descriptive epidemiology study. Aggregate injury and exposure data collected from 11 women's gymnastics programs providing 28 seasons of data. Collegiate student-athletes participating in women's gymnastics during the 2009-2010 through 2013-2014 academic years. Women's gymnastics data from the NCAA Injury Surveillance Program (ISP) during the 2009-2010 through 2013-2014 academic years were analyzed. Injury rates; injury rate ratios; injury proportions by body site, diagnosis, and apparatus; and injury proportion ratios were reported with 95% confidence intervals (CIs). The ISP captured 418 women's gymnastics injuries, a rate of 9.22/1000 athlete-exposures (AEs; 95% CI = 8.33, 10.10). The competition injury rate (14.49/1000 AEs) was 1.67 times the practice injury rate (8.69/1000 AEs; 95% CI = 1.27, 2.19). When considering time-loss injuries only, the injury rate during this study period (3.62/1000 AEs) was lower than rates reported in earlier NCAA ISP surveillance data. Commonly injured body sites were the ankle (17.9%, n = 75), lower leg/Achilles tendon (13.6%, n = 57), trunk (13.4%, n = 56), and foot (12.4%, n = 52). Common diagnoses were ligament sprain (20.3%, n = 85) and muscle/tendon strain (18.7%, n = 78). Overall, 12.4% (n = 52) of injuries resulted in time loss of more than 3 weeks. Of the 291 injuries reported while a student-athlete used an apparatus (69.6%), most occurred during the floor exercise (41.9%, n = 122) and on the uneven bars (28.2%, n = 82). We observed a lower time-loss injury rate for women's gymnastics than shown in earlier NCAA ISP surveillance data. Safety initiatives in women's gymnastics, such as "sting mats," padded equipment, and a redesigned vault table, may have contributed to minimizing the frequency and severity of injury.

Impact locations and concussion outcomes in high school football player-to-player collisions.

Little research has examined concussion outcomes in terms of impact location (ie, the area on the head in which the impact occurred). This study describes the epidemiology of concussions resulting from player-to-player collision in high school football by impact location. National High School Sports-Related Injury Surveillance Study data (2008/2009-2012/2013) were analyzed to calculate rates and describe circumstances of football concussion (eg, symptomology, symptom resolution time, return to play) resulting from player-to-player collisions by impact location (ie, front-, back-, side-, and top-of-the-head). Most concussions resulting from player-to-player collisions occurred from front-of-the-head (44.7%) and side-of-the-head (22.3%) impacts. Number of symptoms reported, prevalence of reported symptoms, symptom resolution time, and length of time to return to play were not associated with impact location. However, a larger proportion of football players sustaining concussions from top-of-the-head impacts experienced loss of consciousness (8.0%) than those sustaining concussions from impacts to other areas of the head (3.5%) (injury proportion ratio 2.3; 95% confidence interval 1.2-4.2; P = .008). Players had their head down at the time of impact in a higher proportion of concussions caused by top-of-the-head impacts (86.4%) than concussions from impacts to other areas of the head (24.0%) (injury proportion ratio 3.6; 95% confidence interval 3.2-4.0; P < .001). Among high school football players who sustained concussions due to player-to-player collisions, concussion outcomes were generally independent of impact location. Recommended strategies for reducing the proportion of top-of-the-head impacts include improved education regarding tackling with proper "head-up" technique.

Epidemiology of Knee Injuries among U.S. High School Athletes, 2005/2006–2010/2011

U.S. high school athletes sustain millions of injuries annually. Detailed patterns of knee injuries, among the most costly sports injuries, remain largely unknown. We hypothesize that patterns of knee injuries in U.S. high school sports differ by sport and sex. U.S. high school sports-related injury data were collected for 20 sports using the National High School Sports-Related Injury Surveillance System, High School RIO™. Knee injury rates, rate ratios (RR), and injury proportion ratios were calculated. From 2005/2006 to 2010/2011, 5116 knee injuries occurred during 17,172,376 athlete exposures (AE) for an overall rate of 2.98 knee injuries per 10,000 AE. Knee injuries were more common in competition than in practice (rate ratio = 3.53, 95% confidence interval [CI] = 3.34-3.73). Football had the highest knee injury rate (6.29 per 10,000 AE) followed by girls' soccer (4.53) and girls' gymnastics (4.23). Girls had significantly higher knee injury rates than boys in sex-comparable sports (soccer, volleyball, basketball, baseball/softball, lacrosse, swimming and diving, and track and field; RR = 1.52, 95% CI = 1.39-1.65). The most commonly involved structure was the medial collateral ligament (reported in 36.1% of knee injuries), followed by the patella/patellar tendon (29.5%), anterior cruciate ligament (25.4%), meniscus (23.0%), lateral collateral ligament (7.9%), and posterior cruciate ligament (2.4%). Girls were significantly more likely to sustain anterior cruciate ligament injuries in sex-comparable sports (RR = 2.38, 95% CI = 1.91-2.95). Overall, 21.2% of knee injuries were treated with surgery; girls were more often treated with surgery than boys in sex-comparable sports (injury proportion ratio = 1.30, 95% CI = 1.11-1.53). Knee injury patterns differ by sport and sex. Continuing efforts to develop preventive interventions could reduce the burden of these injuries.

Epidemiology of United States High School Sports-Related Fractures, 2008-09 to 2010-11

Background: High school athletes sustain millions of injuries annually, many of which are fractures. Fractures can severely affect athletes physically, emotionally, and financially and should be targeted with focused prevention methods. Hypothesis: Patterns and primary mechanisms of fractures differ by sport and gender. Study Design: Descriptive epidemiology study. Methods: High school sports-related injury data were collected from academic years 2008-09 to 2010-11 for 18 sports and from 2009-10 to 2010-11 for 2 additional sports. We used linear regression to describe annual fracture rate trends and calculated fractures rates, rate ratios (RRs), and injury proportion ratios (IPRs). Results: From 2008-09 to 2010-11, certified athletic trainers reported a total of 21,251 injuries during 11,544,455 athlete exposures (AEs), of which 2103 (9.9%) were fractures, with an overall rate of 1.82 fractures per 10,000 AEs. Fracture rates were highest in football (4.37 per 10,000 AE), boys’ ice hockey (3.08), and boys’ lacrosse (2.59). Boys sustained 79.1% of all fractures, and the overall rates of fractures were greater in boys’ sports than in girls’ sports for competition (RR, 2.82; 95% CI, 2.45-3.24) and practice (RR, 2.43; 95% CI, 2.07-2.86). The most commonly fractured body sites were the hand/finger (32.1%), lower leg (10.1%), and wrist (9.5%). Overall, 17.2% of fractures required surgery, which was higher than for all other injuries combined (IPR, 3.14; 95% CI, 2.81-3.52). The most common mechanism of fracture involved contact with another player (45.5%). Using linear regression, we found the proportion of all injuries that were fractures was inversely correlated with the athlete’s age (P = .02) but was not correlated with the athletes’ age- and gender-adjusted body mass index. Conclusion: Fractures are a significant problem for high school athletes. Targeted preventive interventions should be implemented to reduce the burdens these injuries cause the athletes.

Epidemiology of 6.6 Million Knee Injuries Presenting to United States Emergency Departments From 1999 Through 2008

While knee injuries are treated by a wide range of clinicians, patients with knee injuries frequently present to emergency departments (EDs). The knee is the most commonly injured joint by adolescent athletes with an estimated 2.5 million sports-related injuries presenting to EDs annually. The objective was to examine the epidemiology of knee injuries presenting to EDs in the United States from 1999 through 2008. The Consumer Product Safety Commission National Electronic Injury Surveillance System database (NEISS) was used to examine causes of knee injuries treated in U.S. EDs from 1999 through 2008. An estimated 6,664,324 knee injuries presented to U.S. EDs from 1999 through 2008, for a rate of 2.29 knee injuries per 1,000 population. Those 15 to 24 years of age had the highest injury rate (3.83), while children younger than 5 years had the lowest rate (0.55). The most common diagnoses were strains and sprains (42.1%), contusions and abrasions (27.1%), and lacerations and punctures (10.5%). The most common general product categories causing injury were sports and recreation (49.3%), home structures (30.2%), and home furnishings (13.6%). Several sex and age group differences were identified. For example, males sustained a higher proportion of basketball-related injuries (11.1%) than females (3.6%; injury proportion ratio [IPR] = 3.11, 95% confidence interval [CI] = 2.79 to 3.46, p < 0.001). Additionally, individuals 65 years and older sustained a higher proportion of injury due to stairs, ramps, landings, and floors (42.0%), compared to all other ages (20.1%; IPR = 2.09, 95% CI = 1.95 to 2.23, p < 0.001). Rates and patterns of knee injuries vary by sex and age. Although knee injuries will likely continue to occur most frequently among youth and young adult athletes, anticipating and responding to trends such as an increase in the incidence of knee injuries among adult and senior patients will enable clinicians to better anticipate caseloads, allocate resources, and determine best practices for diagnosis and treatment of knee injuries in different age groups.

Epidemiology of Concussions Among United States High School Athletes in 20 Sports

Background: In the United States (US), an estimated 300,000 sports-related concussions occur annually. Among individuals 15 to 24 years of age, sports are second only to motor vehicle crashes as the leading cause of concussions. Purpose: To investigate the epidemiology of concussions in high school athletes by comparing rates and patterns of concussion among 20 sports. Study Design: Descriptive epidemiology study. Methods: Using an Internet-based data collection tool, RIO, certified athletic trainers from a large, nationally disperse sample of US high schools reported athlete exposure and injury data for 20 sports during the 2008-2010 academic years. Results: During the study period, 1936 concussions were reported during 7,780,064 athlete-exposures (AEs) for an overall injury rate of 2.5 per 10,000 AEs. The injury rate was higher in competition (6.4) than practice (1.1) (rate ratio [RR], 5.7; 95% confidence interval [CI], 5.2-6.3). The majority of concussions resulted from participation in football (47.1%, n = 912), followed by girls’ soccer (8.2%, n = 159), boys’ wrestling (5.8%, n = 112), and girls’ basketball (5.5%, n = 107). Football had the highest concussion rate (6.4), followed by boys’ ice hockey (5.4) and boys’ lacrosse (4.0). Concussions represented a greater proportion of total injuries among boys’ ice hockey (22.2%) than all other sports studied (13.0%) (injury proportion ratio [IPR], 1.7; 95% CI, 1.4-2.1; P < .01). In gender-comparable sports, girls had a higher concussion rate (1.7) than boys (1.0) (RR, 1.7; 95% CI, 1.4-2.0). The most common mechanisms of injury were player-player contact (70.3%) and player–playing surface contact (17.2%). In more than 40% of athletes in sports other than girls’ swimming and girls’ track, concussion symptoms resolved in 3 days or less. Athletes most commonly returned to play in 1 to 3 weeks (55.3%), with 22.8% returning in less than 1 week and 2.0% returning in less than 1 day. Conclusion: Although interest in sports-related concussions is usually focused on full-contact sports like football and ice hockey, concussions occur across a wide variety of high school sports. Concussion rates vary by sport, gender, and type of exposure. An understanding of concussion rates, patterns of injury, and risk factors can drive targeted preventive measures and help reduce the risk for concussion among high school athletes in all sports.

Pediatric Injuries Attributable to Falls From Windows in the United States in 1990–2008

To examine the epidemiological features of pediatric injuries related to falls from windows. By using the National Electronic Injury Surveillance System, emergency department (ED) data for pediatric injury cases associated with window falls in 1990-2008 were reviewed. An estimated 98 415 children (95% confidence interval [CI]: 82 416-114 419) were treated in US hospital EDs for window fall-related injuries during the 19-year study period (average: 5180 patients per year [95% CI: 4828-5531]). The mean age of children was 5.1 years, and boys accounted for 58.1% of cases. One-fourth (25.4%) of the patients required admission to the hospital. The annual injury rate decreased significantly during the study period because of a decrease in the annual injury rate among 0- to 4-year-old children. Children 0 to 4 years of age were more likely to sustain head injuries (injury proportion ratio [IPR]: 3.22 [95% CI: 2.65-3.91]) and to be hospitalized or to die (IPR: 1.65 [95% CI: 1.38-1.97]) compared with children 5 to 17 years of age. Children who landed on hard surfaces were more likely to sustain head injuries (IPR: 2.05 [95% CI: 1.53-2.74]) and to be hospitalized or to die (IPR: 2.23 [95% CI: 1.57-3.17]) compared with children who landed on cushioning surfaces. To our knowledge, this is the first study to investigate window fall-related injuries treated in US hospital EDs by using a nationally representative sample. These injuries are an important pediatric public health problem, and increased prevention efforts are needed, including development and evaluation of innovative prevention programs.

Epidemiology of Bowling-Related Injuries Presenting to US Emergency Departments, 1990-2008

Objective. To examine bowling-related injuries presenting to US emergency departments (EDs) from 1990 to 2008. Methods. Bowling-related injury data were analyzed from the US Consumer Product Safety Commission's National Electronic Injury Surveillance System. Results. From 1990 to 2008, 8754 bowling injuries presented to US EDs, correlating to an estimated 375 468 injuries nationwide. Common body parts injured were the finger (19.0%), trunk (15.8%), and ankle/foot/toe (14.9%). Common diagnoses were sprain/strain (42.7%) and soft-tissue injury (20.3%). Children <7 years old had a higher proportion of finger injuries (49.2%) and injuries from dropping the ball (42.8%) than individuals ≥7 years old (15.9%, injury proportion ratio [IPR] = 3.09, 95% confidence interval [CI] = 2.76-3.45, P < .001; and 15.9%, IPR = 2.69, 95% CI = 2.32-3.12, P < .001, respectively). Seniors ≥65 years old sustained a greater proportion of injuries related to falling/slipping/tripping (72.4%) than individuals <65 years old (38.3%; IPR = 1.89, 95% CI = 1.74-2.05, P < .001). Conclusions. Bowling injuries vary by age and gender. Further research on such differences is needed to drive the development of targeted, evidence-based injury prevention strategies.

Injury Patterns by Body Mass Index in US High School Athletes

There are over 7 million US high school athletes and one-third are overweight or obese. Our objective was to examine injury patterns by body mass index (BMI) in high school athletes. Certified athletic trainers (ATCs) at 100 nationally representative US high schools submitted exposure and injury information during the 2005 to 08 school years via High School RIO (Reporting Information Online). We retrospectively categorized injured athletes as underweight (≤15th percentile), normal weight (15th-85th percentile), overweight (85th-95th percentile), or obese (≥95th percentile). ATCs reported 13,881 injuries during 5,627,921 athlete-exposures (2.47 injuries per 1000 athlete-exposures). Nearly two-thirds (61.4%) of injured high school athletes were normal weight. The prevalence of overweight and obesity was highest among injured football athletes (54.4%). Compared with normal weight athletes, obese athletes sustained a larger proportion of knee injuries (Injury Proportion Ratio [IPR]=1.27, 95% CI: 1.14 to 1.42) and their injuries were more likely to have resulted from contact with another person (IPR=1.31, 95% CI: 1.26 to 1.37). Compared with normal weight athletes, underweight athletes sustained a larger proportion of fractures (IPR=1.45, 95% CI: 1.10 to 1.92) and a larger proportion of injuries resulting from illegal activity (IPR=1.59, 95% CI: 1.03 to 2.46). Injury patterns differ by BMI. BMI-targeted preventive interventions should be developed to help decrease sports injury rates.

Mountain Biking–Related Injuries Treated in Emergency Departments in the United States, 1994-2007

Background: Injury research on mountain biking has been mostly limited to examining professional riders and off-road biking. Mountain bikes represent the largest segment of bike sales in the United States. Recreational mountain bike use is popular and understudied. Purpose: To describe the scope, distribution, and trends of mountain bike–related injuries treated in US emergency departments. Study Design: Descriptive epidemiologic study. Methods: A retrospective analysis was conducted with data from the National Electronic Injury Surveillance System of the US Consumer Product Safety Commission for patients aged ≥8 years from 1994 through 2007. Sample weights provided by the system were used to calculate national estimates of mountain bike–related injuries based on 4624 cases. Bivariate comparisons between categorical variables were assessed with injury proportion ratios and 95% confidence intervals. Results: Nationwide, an estimated 217 433 patients were treated for mountain bike–related injuries in US emergency departments from 1994 to 2007, an average of 15 531 injuries per year. The annual number of injuries decreased 56%, from a high of 23 177 in 1995 to 10 267 in 2007 (P < .001). The most common injuries were upper extremity fractures (10.6%) and shoulder fractures (8.3%). Patients aged 14 to 19 years sustained a greater proportion of traumatic brain injuries (8.4%) than did patients aged 8 to 13 years and ≥20 years combined (4.3%). A greater proportion of female riders (6.1%) than male riders (4.5%) were hospitalized. Conclusion: Mountain bike–related injuries decreased from 1994 to 2007. Upper extremity fractures were the most common injury. Girls and women may be more likely than boys and men to sustain more severe injuries requiring hospitalization. Despite the decline over the past decade, more can be done to improve safety and reduce injuries in this popular recreational activity.

Commentary: The Injury Proportion Ratio: What's It All About?

We thank the Journal of Athletic Training (JAT ) and Deits et al1 for allowing us to comment on the analysis of national emergency department (ED) surveillance data on hockey injuries appearing in this issue. This commentary focuses on the use in descriptive epidemiology of the injury proportion ratio (IPR). We are prompted to comment on the IPR due to its increasing use in the sports injuryprevention literature, including JAT. Our comments are aimed at examining the IPR and highlighting the usefulness and limitations of the measure in relation to other measures in injury-prevention research, notably the injury rate ratio. Our concern is that, without understanding the assumptions underlying these measures, the IPR can be easily misinterpreted, thereby leading readers to draw false conclusions. Published research2–6 has used IPRs in the context of hospital-based surveillance data as well as a Web-based high school surveillance system.7–16 By design, hospitalbased ED injury surveillance systems, such as the National Electronic Injury Surveillance System (NEISS), collect information only on injured individuals. Such surveillance systems provide useful descriptive information about severe injury patterns, such as who was injured, what types of injuries occurred, what was happening at the time of injury, and the type of care provided for that injury. However, NEISS does not collect information about the population among whom these injuries occurred or arose: the population of hockey players, in this case. Additionally, NEISS does not collect information on hockey injuries that do not result in a visit to the ED, an issue we will ignore for the purposes of this commentary.

Patients With Ice Hockey Injuries Presenting to US Emergency Departments, 1990–2006

Although the number of US ice hockey participants doubled from 1990 to 2006, no nationally representative studies have examined US ice hockey injuries among participants of all ages during this period. To describe patients with ice hockey injuries presenting to a representative sample of US emergency departments (EDs) from 1990 through 2006. Prospective injury surveillance study. The US Consumer Product Safety Commission collects data from 100 nationally representative EDs via the National Electronic Injury Surveillance System (NEISS). Individuals injured while playing ice hockey and presenting to a NEISS-affiliated ED from 1990 through 2006. Incidence and patterns of ice hockey-related injuries. From 1990 through 2006, 8228 patients with ice hockey-related injuries presented to NEISS-affiliated EDs, representing an estimated 302 368 ice hockey-related injuries sustained nationally during this time. Injuries occurred predominantly among males (93.5%). More than half of the injured were aged 9 to 14 years (28.9%) or 15 to 18 years (30.1%), and injury incidence in these age groups increased over the study period (P = .009 and P < .001, respectively). The most commonly injured body sites were the face (19.1%), wrist/hand/finger (14.1%), shoulder/upper arm (13.8%), and lower leg/ankle/foot (11.1%). Lacerations (27.0%), contusions/abrasions (23.6%), fractures (17.3%), and sprains/strains (16.9%) were the most common injuries. Falls (16.5%), contact with boards (13.6%), and contact with stick (13.0%) were the most common injury mechanisms. Compared with those aged 9 to 18 years, those aged 2 to 8 years and those older than 18 years sustained larger proportions of face (injury proportion ratio [IPR] = 2.66; 95% confidence interval [CI] = 2.29, 3.08) and mouth (IPR = 4.34; 95% CI = 2.87, 6.56) injuries. Concussions were more common among those aged 2 to 18 years (9.0%) than in those who were older than 18 years (3.7%) (IPR = 2.47; 95% CI = 1.75, 3.49). Ice hockey injury patterns vary by age and sex. Our findings indicate that many trips to the ED might be prevented by using protective equipment appropriately.

Shoulder Injuries in US High School Baseball and Softball Athletes, 2005–2008

The objective of this study was to determine factors that are involved in shoulder injury rates among high school athletes who participate in organized baseball and softball. Baseball- and softball-related injury data were collected during the 2005-2008 academic years from approximately 74 nationally representative high schools via High School Reporting Information Online. Certified athletic trainers reported 91 baseball shoulder injuries and 40 softball shoulder injuries during 528147 and 399522 athlete exposures, respectively. The injury rate was 1.72 injuries per 10000 athlete exposures for baseball and 1.00 injuries per 10000 athlete exposures for softball. Muscle strain/incomplete tears were the most common injuries in both baseball (30.8%) and softball (35.0%). In practices, throwing, not including pitching, caused more than half of softball injuries (68.2%) as compared with competition injuries (23.5%; injury proportion ratio [IPR]: 2.90 [95% confidence interval (CI): 1.17-7.15]; P = .015), whereas pitching was the most common mechanism in causing shoulder injuries during baseball practice (41.9%) compared with competitions (25.6%; IPR: 1.64 [95% CI: 0.88-3.04]; P = .17). Eighty-one percent of the baseball shoulder injuries and 82.5% of the softball shoulder injuries were new. Ten percent of baseball athletes and 5.3% of softball athletes sustained injuries that required surgery (IPR: 1.40 [95% CI: 0.32-6.10]; P = .93). Injuries that were sustained while the athlete was on the pitcher's mound were significantly more likely to result in surgery than any other field position (IPR: 2.64 [95% CI: 1.65-4.21]; P = .0061). Injured baseball players were more than twice as likely to be pitchers. Although rates and patterns of shoulder injuries are similar between baseball and softball players, injury rates and patterns differ between field positions within each sport, as well as by injury severity and the athletes' year in school.

Epidemiology of Weight Training-Related Injuries Presenting to United States Emergency Departments, 1990 to 2007

Background As participation in weight training in the United States increases, the number of persons at injury risk increases. Purpose To examine weight training-related injuries in patients presenting to US emergency departments from 1990 to 2007. Study Design Descriptive epidemiology study. Methods Weight training-related injury data were analyzed from the US Consumer Product Safety Commission's National Electronic Injury Surveillance System. Sample weights provided by this organization calculated national estimates of weight training-related injuries from the 100-hospital sample. Results From 1990 to 2007, 25 335 weight training injuries were seen in US emergency departments, correlating to an estimated 970 801 injuries nationwide. Patients’ mean age was 27.6 years (range, 6-100 years); 82.3% were male. The upper trunk (25.3%) and lower trunk (19.7%) were the most commonly injured body parts. The most common diagnosis was sprain/strain (46.1%). The most common mechanism of injury was weights dropping on the person (65.5%). A large number of injuries occurred with free weights (90.4%). Males had a larger proportion of upper trunk injuries (26.8%; injury proportion ratio [IPR], 1.45; 95% confidence interval [CI]: 1.36-1.57; P < .001) than females (18.4%). Females had a larger proportion of foot injuries (22.9%; IPR, 2.09; 95% CI: 1.93-2.26; P < .001) than males (11.0%). Persons 12 years and younger had a larger proportion of hand (37.9%; IPR, 2.08; 95% CI: 1.76-2.46; P < .001) injuries than persons 13 years or older (18.2%). Persons 55 years and older were injured more when using machines (18.2%; IPR, 1.96; 95% CI: 1.47-2.61, P < .001) than persons 54 years and younger (9.3%). Persons using free weights sustained a greater proportion of fractures/dislocations (23.6%; IPR, 2.44; 95% CI: 1.92-3.09; P < .001) than persons using machines (9.7%). Conclusion Further research is needed to drive development of targeted, age- and gender-specific, evidence-based injury prevention strategies to decrease injury rates among weight training participants.

Patterns of Recurrent Injuries among US High School Athletes, 2005-2008

Background High school sports participants sustain millions of injuries annually; many are recurrent injuries that can be more severe than new injuries. Hypothesis Recurrent injury patterns differ from new injury patterns by sport and gender. Study Design Descriptive epidemiology study. Methods High school sports injury data for the 2005 through 2008 academic years were collected via High School Reporting Information Online (RIO) from a nationally representative sample of 100 US high schools. Results From 2005 through 2008, certified athletic trainers reported 13 755 injuries during 5 627 921 athlete exposures (24.4 injuries per 10 000 athlete exposures). Recurrent injuries accounted for 10.5% of all injuries. Football players had the highest rate of recurrent injury (4.36 per 10 000 athlete exposures). Girls had higher rates of recurrent injuries than boys in soccer (injury rate ratio = 1.39; 95% confidence interval, 1.07-1.82). Recurrent injuries most often involved the ankle (28.3%), knee (16.8%), head/ face (12.1%), and shoulder (12.0%), and were most often ligament sprains (incomplete tears) (34.9%), muscle strains (incomplete tears) (13.3%), and concussions (11.6%). A greater proportion of recurrent injuries than new injuries resulted in the student choosing to end participation (recurrent = 2.4%, new = 0.7%). Recurrent shoulder injuries were more likely to require surgery than new shoulder injuries (injury proportion ratio = 4.51; 95% confidence interval, 2.82-7.20). Conclusion Recurrent injury rates and patterns differed by sport. Because recurrent injuries can have severe consequences on an athlete's health and future sports participation, injury prevention must be a priority. Knowledge of injury patterns can drive targeted preventive efforts.

The Epidemiology of US High School Basketball Injuries, 2005–2007

Background With more than a million high school athletes playing during the 2006–2007 academic year, basketball is one of the most popular sports in the United States. Hypothesis Basketball injury rates and patterns differ by gender and type of exposure. Study Design Descriptive epidemiology study. Methods Basketball-related injury data were collected during the 2005–2006 and 2006–2007 academic years from 100 nationally representative US high schools via Reporting Information Online. Results High school basketball players sustained 1518 injuries during 780 651 athlete exposures for an injury rate of 1.94 per 1000 athlete exposures. The injury rate per 1000 athlete exposures was greater during competition (3.27) than during practice (1.40; rate ratio, 2.33; 95% confidence interval, 2.10–2.57) and was greater among girls (2.08) than among boys (1.83; rate ratio, 1.14; 95% confidence interval, 1.03–1.26). The ankle/foot (39.7%), knee (14.7%), head/face/neck (13.6%), arm/hand (9.6%), and hip/thigh/upper leg (8.4%) were most commonly injured. The most frequent injury diagnoses were ligament sprains (44.0%), muscle/tendon strains (17.7%), contusions (8.6%), fractures (8.5%), and concussions (7.0%). Female basketball players sustained a greater proportion of concussions (injury proportion ratio, 2.41; 95% confidence interval, 1.49–3.91) and knee injuries (injury proportion ratio, 1.71; 95% confidence interval, 1.27–2.30), whereas boys more frequently sustained fractures (injury proportion ratio, 1.87; 95% confidence interval, 1.27–2.77) and contusions (injury proportion ratio, 1.52; 95% confidence interval, 1.00–2.31). The most common girls’ injury requiring surgery was knee ligament sprains (47.9%). Conclusion High school basketball injury patterns vary by gender and type of exposure. This study suggests several areas of emphasis for targeted injury prevention interventions.

A comparison of pediatric freestyle and Greco‐Roman wrestling injuries sustained during a 2006 US national tournament

The purpose of this study was to compare the epidemiology of freestyle and Greco-Roman wrestling injuries sustained during a 2006 United States (US) national tournament. A prospective injury surveillance study was conducted at the US 2006 ASICS/Vaughan Cadet and Junior National Championships. There were 83 freestyle- and 55 Greco-Roman-related injuries sustained, with the rate of injury per 1000 athlete-matches higher in freestyle (7.0) compared with Greco-Roman (4.6) wrestling [Rate ratio (RR)=1.51, 95% confidence interval (CI): 1.07-2.12]. Compared with Greco-Roman wrestling, there was a greater proportion of knee injuries in freestyle wrestling [injury proportion ratio (IPR)=4.17, 95% CI: 1.30-13.41]. In GrecoRoman wrestling, there were greater proportions of elbow (IPR=9.11, 95% CI: 1.13-73.59) and head/face/neck (IPR=1.72, 95% CI: 1.10-2.67) injuries and a greater proportion of concussions (IPR=1.95, 95% CI: 0.92-4.12), although the latter was statistically insignificant. Greco-Roman wrestlers sustained a greater proportion of injuries from being driven into the mat (IPR=2.97, 95% CI: 1.72-5.14). There were no statistically significant differences in injury outcome by wrestling style. The differing injury rates and patterns of injury between freestyle and Greco-Roman wrestling are likely due to the different rules between these styles that allow lower leg attacks in freestyle wrestling and encourage the use of throws in Greco-Roman wrestling.