The First Decade of Web-Based Sports Injury Surveillance: Descriptive Epidemiology of Injuries in US High School Boys' Basketball (2005–2006 Through 2013–2014) and National Collegiate Athletic Association Men's Basketball (2004–2005 Through 2013–2014)

This study used data collected by HS RIO and the NCAA-ISP, sports injury-surveillance programs for the high school and collegiate levels, respectively. Use of the HS RIO data was approved by the Nationwide Children's Hospital Subjects Review Board (Columbus, OH). Use of the NCAA-ISP data was approved by the Research Review Board of the NCAA.

An average of 100 high schools sponsoring boys' basketball provided data to the HS RIO random sample during the 2005–2006 through 2013–2014 academic years (2005–2006 was the first year HS RIO collected data). An average of 55 NCAA member institutions (Division I = 22, Division II = 11, Division III = 22) sponsoring men's basketball participated in the NCAA-ISP during the 2004–2005 through 2013–2014 academic years. The methods of HS RIO and the NCAA-ISP are summarized in the following sections. In-depth information on the methods and analyses for this special series of articles on Web-based sports injury surveillance can be found in the previously published methodologic article.¹⁰  In addition, previous publications have described the sampling and data collection of HS RIO^4,11  and the NCAA-ISP³  in depth.

High School RIO consists of a sample of high schools with 1 or more National Athletic Trainers' Association-affiliated ATs with valid e-mail addresses. The ATs from participating high schools reported injury incidence and AE information weekly throughout the academic year using a secure Web site. For each injury, the AT completed a detailed injury report on the injured athlete (age, height, weight, etc), the injury (site, diagnosis, severity, etc), and the injury event (activity, mechanism, etc). Throughout each academic year, participating ATs were able to view and update previously submitted reports as needed with new information (eg, time loss).

Data for HS RIO during the 2005–2006 through 2013–2014 academic years originated from a random sample of 100 schools that were recruited annually. Eligible schools were randomly selected from 8 strata (12 or 13 per stratum) based on school population (enrollment ≤1000 or >1000) and US Census geographic region.¹²  The ATs from these schools reported data for the 9 sports of interest (boys' baseball, basketball, football, soccer, and wrestling; girls' basketball, soccer, softball, and volleyball). If a school dropped out of the system, a replacement from the same stratum was selected.

In HS RIO, national injury estimates were calculated from injury counts obtained from the sample. A weighting algorithm based on the inverse probability of participant schools' selection into the study (based on geographic location and high school size) was applied to individual case counts in order to calculate the national injury estimates.

The NCAA-ISP depends on a convenience sample of teams with ATs voluntarily reporting injury and exposure data.³  Participation in the NCAA-ISP, while voluntary, is available to all NCAA institutions. For each injury event, the AT completes a detailed event report on the injury or condition (eg, site, diagnosis) and the circumstances (eg, activity, mechanism, event type [ie, competition or practice]). The ATs are able to view and update previously submitted information as needed during the course of a season. In addition, ATs also provide the number of student-athletes participating in each practice and competition. Data collection for the 2004–2005 through 2013–2014 academic years is described in the following paragraphs.

During the 2004–2005 through 2008–2009 academic years, ATs used a Web-based platform launched by the NCAA to track injury and exposure data.³  This platform integrated some of the functional components of an electronic medical record, such as athlete demographic and preseason injury information. During the 2009–2010 through 2013–2014 academic years, the Datalys Center for Sports Injury Research and Prevention, Inc (Datalys Center, Indianapolis, IN) introduced a common data element (CDE) standard to improve process flow. The CDE standard allowed data to be gathered from different electronic medical record or injury-documentation applications, including the Athletic Trainer System (Keffer Development, Grove City, PA), Injury Surveillance Tool (Datalys Center), and the Sports Injury Monitoring System (FlanTech, Iowa City, IA). The CDE export standard allowed ATs to document injuries as they normally would during their daily clinical practice, as opposed to asking them to report injuries solely for purposes of participation in an injury-surveillance program. Data were de-identified and sent to the Datalys Center, where they were examined by data quality-control staff and a verification engine.

To calculate national estimates of the number of injuries and AEs, poststratification sample weights, based on sport, division, and academic year, were applied to each reported injury and AE. Weights for all data were further adjusted to correct for underreporting, according to the findings of Kucera et al,¹³  who estimated that the ISP captured 88.3% of all time-loss medical-care injury events. Weighted counts were scaled up by a factor of (0.883⁻¹). In-depth information on the formula used to calculate national estimates can be found in the previously published methodologic article.¹⁰ 

A reportable injury in both HS RIO and the NCAA-ISP was defined as an injury that (1) occurred as a result of participation in an organized practice or competition, (2) required medical attention by a certified AT or physician, and (3) resulted in restriction of the student-athlete's participation for 1 or more days beyond the day of injury. Since the 2007–2008 academic year, HS RIO has also captured all concussions, fractures, and dental injuries, regardless of time loss. In the NCAA-ISP, multiple injuries occurring from 1 injury event could be included, whereas in HS RIO, only the principal injury was captured. Beginning in the 2009–2010 academic year, the NCAA-ISP also began to monitor all non–time-loss injuries. A non–time-loss injury was defined as any injury that was evaluated or treated (or both) by an AT or physician but did not result in restriction from participation beyond the day of injury. However, because HS RIO captures only time-loss injuries (to reduce the burden on high school ATs), for this series of publications, only time-loss injuries (with the exception of concussions, fractures, and dental injuries as noted earlier) were included.

For both surveillance systems, a reportable AE was defined as 1 student-athlete participating in 1 school-sanctioned practice or competition in which he or she was exposed to the possibility of athletic injury, regardless of the time associated with that participation. Preseason scrimmages were considered practice exposures, not competition exposures.

Data were analyzed using SAS-Enterprise Guide software (version 5.4; SAS Institute Inc, Cary, NC). Because the data collected from HS RIO and the NCAA-ISP were similar, we opted to recode data when necessary in order to increase the comparability between high school and collegiate student-athletes. We also opted to ensure that categorizations were consistent among all sport-specific articles within this special series. Because methodologic variations may lead to small differences in injury reporting among these surveillance systems, caution must be taken when interpreting these results.

We examined injury counts, national estimates, and distributions by event type (practice and competition), time in season (preseason, regular season, postseason), time loss (1 to 6 days; 7 to 21 days; more than 21 days, including injuries resulting in a premature end to the season), body part injured, diagnosis, mechanism of injury, activity during injury, and position. We also calculated injury rates per 1000 AEs and injury rate ratios (IRRs). The IRR focused on comparisons by level of play (high school and college), event type (practice and competition), school size in high school (>1000 and ≤1000 students), division in college (Divisions I, II, and III), and time in season (preseason, regular season, and postseason). All IRRs with 95% confidence intervals (CIs) not containing 1.0 were considered statistically significant.

Last, we used linear regression to analyze linear trends across time of injury rates and compute average annual changes (ie, mean differences). Because of the 2 data-collection methods for the NCAA-ISP during the 2004–2005 through 2008–2009 and 2009–2010 through 2013–2014 academic years, linear trends were examined separately for each time period. All mean differences with 95% CIs not containing 0.0 were considered statistically significant.

During the study period, ATs reported a total of 7663 injuries in boys' and men's basketball (high school n = 3056, college n = 4607; Table 1). This equated to a national estimate of 793 213 high school injuries (annual average = 88 135) and 89 003 collegiate injuries (annual average = 8900). The total injury rate for high school boys' basketball was 1.55/1000 AEs (95% CI = 1.49, 1.60) and for collegiate men's basketball was 5.30/1000 AEs (95% CI= 5.15, 5.46). The total injury rate was higher for collegiate than high school (IRR = 3.43; 95% CI = 3.28, 3.59) athletes.

The total injury rate was higher for high schools with ≤1000 students than for high schools with >1000 students (IRR = 1.32; 95% CI = 1.23, 1.42; Table 1). Among colleges, Division I had a higher total injury rate than Division II (IRR = 1.17; 95% CI = 1.08, 1.27) but not Division III (IRR = 1.04; 95% CI = 0.97, 1.11). Also, Division III had a higher total injury rate than Division II (IRR = 1.12; 95% CI = 1.03, 1.22).

Among high school players, nearly equal numbers of injuries occurred during competitions and practices, whereas the majority of injuries among collegiate players occurred during practices (65.8%; Table 1). The competition injury rate was higher than the practice injury rate at both the high school (IRR = 2.38; 95% CI = 2.22, 2.56) and collegiate (IRR = 2.02; 95% CI = 1.90, 2.14) levels.

No linear trends were seen in the annual injury rates for high school practices (annual average change of −0.03/1000 AEs; 95% CI = −0.07, 0.01) or competitions (annual average change = −0.03/1000 AEs; 95% CI = −0.08, 0.03; Figure 1). A decrease was found in the 2004–2005 through 2008–2009 academic years for practices (annual average change = −0.54/1000 AEs; 95% CI = −0.86, −0.23) but not for competitions (annual average change = −0.57/1000 AEs; 95% CI = −1.39, 0.25). However, increases were noted in the 2009–2010 through 2013–2014 academic years for practices (annual average change = 0.10/1000 AEs; 95% CI = 0.01, 0.19) and competitions (annual average change of 0.28/1000 AEs; 95% CI = 0.04, 0.52).

Among both high school and collegiate athletes, the majority of injuries occurred during the regular season (high school = 77.7%, college = 62.2%; Table 2). The collegiate preseason had a higher injury rate than the regular season (IRR = 1.70; 95% CI = 1.60, 1.80) and postseason (IRR = 2.82; 95% CI = 2.33, 3.42). In addition, the injury rate was higher during the regular season than during the postseason (IRR = 1.66; 95% CI = 1.38, 2.01). Injury rates by time in season could not be calculated for high schools as AEs were not stratified by time in season.

For both high school and collegiate players, the largest proportion of injuries resulted in time loss of less than 1 week, ranging from 45.3% of injuries in high school competitions to 62.2% of injuries in collegiate practices (Table 3).

Commonly injured body parts in practices and competitions were the ankle (practices = 35.9%, competitions = 32.6%), head/face (practices = 14.8%, competitions = 21.5%), and knee (practices = 11.2%, competitions = 12.6%; Table 4). The most frequent injury diagnosis from practices and competitions was ligament sprains (practices = 43.3%, competitions = 41.1%; Table 5). Other common injury diagnoses were muscle/tendon strains (11.9%) and fractures/avulsions (10.7%) from practices and concussions (12.6%), fractures/avulsions (12.2%), and contusions (11.4%) from competitions.

The most often injured body part in practices and competitions was the ankle (practices = 25.0%, competitions = 24.3%; Table 4). Other frequently injured body parts were the head/face (13.2%), hip/thigh/upper leg (13.0%), and knee (12.4%) in practices and the knee (18.6%) and head/face (14.3%) in competitions. The most common injury diagnosis in practices and competitions was ligament sprains (practices = 32.7%, competitions = 37.7%; Table 5). Other often reported injury diagnoses were muscle/tendon strains (16.0%) and concussions (10.3%) in practices and concussions (14.3%) in competitions.

The most common mechanisms of injury during practices and competitions were contact with another person (practices = 44.1%, competitions = 51.5%), no contact (practices = 21.2%, competitions = 16.9%), and contact with the playing surface (practices = 19.0%, competitions = 26.6%; Table 6). The most frequent activity during which injury occurred in practices and competitions was rebounding (practices = 26.3%, competitions = 29.0%; Table 7).

The most often reported mechanisms of injury during practices and competitions were contact with another person (practices = 46.0%, competitions = 53.0%), no contact (practices = 29.7%, competitions = 23.1%), and contact with the playing surface (practices = 10.2%, competitions = 16.2%; Table 6). The most common activities during which injury occurred in practices and competitions were general play (practices = 35.6%, competitions = 26.4%) and rebounding (practices = 19.8%, competitions = 22.8%; Table 7).

During both high school and collegiate competitions, the most frequent injury across all positions was ankle sprain due to contact with another person (Table 8). The second most common injury was concussion for all positions in high school and among collegiate guards and knee sprain among collegiate centers and forwards; contact with another person was the most frequent mechanism for each type of injury at both levels.

This study provides the most detailed comparison of injury epidemiology in high school boys' and collegiate men's basketball players to date. National annual estimates of approximately 88 000 injuries among boys' basketball players and approximately 8900 injuries among men's basketball players highlight the importance of injury-prevention efforts. Additionally, establishing epidemiologic trends of injuries among high school and collegiate basketball players may help guide targeted injury-prevention efforts. Broad similarities in distributions of injuries by body part, specific diagnosis, and mechanism of injury in high school and collegiate basketball players suggest that both levels may benefit from similar injury-prevention strategies, although variations in injury rates by time in season and school size and division indicate that some interventions more targeted to playing level may also be warranted.

Our reported injury rates in high school boys' basketball for the 2005–2006 through 2013–2014 academic years were slightly lower than those reported by previous authors¹⁴  using only data from the 2005–2006 through 2006–2007 academic years. Compared with our injury rate of 1.55/1000 AEs, Borowski et al¹⁴  observed an overall injury rate of 1.83/1000 AEs. Our practice and competition injury rates for men's collegiate basketball were similar to those in a report⁶  from the 1988–1989 through 2003–2004 academic years. Compared with our practice and competition injury rates of 4.39/1000 AEs and 8.85/1000 AEs, respectively, Dick et al⁶  noted practice and competition injury rates of 4.3/1000 AEs and 9.9/1000 AEs, respectively. The decreases in injury rates compared with other studies may be due to changes in rules and points of emphasis⁷  over the past decade that have resulted in less player contact. Examples include changing the definition of flagrant fouls, emphasizing the calling of flagrant fouls, and creating more space under the basket during free throws. The definition of a flagrant foul has changed, and enforcement of such fouls has been emphasized, which may have resulted in players' intentionally fouling opponents less often.⁷  Emphasizing the importance of calling fouls on activities used to illegally gain rebounding position may have resulted in fewer injuries in high school basketball players. Additionally, leaving the block closest to the basket open during free throws and moving the 3-point line back have created more space for players by the basket, potentially resulting in less player-to-player contact.⁷ 

Comparisons with previous findings should be made cautiously, however, as there may have been variations in data-collection procedures and injury definitions. Across our study period, no linear trends were seen for high school injury rates, but increases were observed in more recent years for collegiate injury rates. Thus, our results reinforce the need for the continued development of injury-prevention interventions that help to decrease the incidence and severity of basketball injuries. It is important to acknowledge that given small basketball roster sizes, the injury rates presented in this study did not result in a higher number of injuries for each basketball team. An average basketball team with 15 players would expect small numbers of time-loss injuries per season. Therefore, despite the inherent risk of injury during athletic participation, the risk may not outweigh the benefits of physical activity.

Although the number of injuries was higher in boy's high school basketball, the total injury rate was higher for men's collegiate players (IRR = 3.43; 95% CI = 3.28, 3.59). The increased injury rate may be due to a greater intensity of play in collegiate basketball. Taller and stronger players at the collegiate level may also create greater forces during play, potentially increasing the risk of injury. Previous research^15–17  supports this hypothesis, as injury rates appeared to be greater among more skilled athletes in various sports. The true relationship between skill level and injury, however, is unclear. Chomiak et al¹⁸  identified the risk of injury in football as possibly twice as large for low-skill−level groups compared with high-skill–level groups within a single competition level. However, Harmon and Dick¹⁹  did not observe a relationship between the risk of anterior cruciate ligament injury and NCAA men's basketball division level. In this study, we did not examine variations in injury rates by skill levels within each competition level. Thus, the role of skill level at each competition level warrants further examination. In addition, the athletes' developmental stages were not assessed and, therefore, we were not able to ascertain the specific relationship between development and injury.

When examining injury rates within competition levels, we found that rates were higher among small high schools compared with large high schools, which could be due to smaller schools having fewer resources, such as full-time AT coverage or more experienced coaches, and potentially being less likely to implement injury-prevention strategies. Smaller schools may also have fewer highly skilled athletes, resulting in less-skilled athletes on sports teams and potentially placing them at greater risk for injury. However, as previously discussed, the true relationship between skill level and injury risk is unclear. Additionally, injury rates were higher in Division I collegiate basketball compared with Divisions II and III. Division III had a higher injury rate than Division II. The increased injury rate among Division I men's basketball players may also reflect the higher intensity of play associated with this competition level.^15–17 

Injury rates, overall as well as by body part and specific diagnosis, were greater during competitions than practices for both high school (overall IRR = 2.38; 95% CI = 2.22, 2.56) and collegiate basketball (overall IRR = 2.02; 95% CI = 1.90, 2.14). This finding is similar to the results of previous authors^6,11,20–28  who identified increased injury rates during competitions compared with practices across various competition levels and sports. Earlier HS RIO surveillance data¹¹  showed that the competition injury rate in high school boys' basketball was twice as large as the practice injury rate (IRR = 2.05; 95% CI = 1.69, 2.49). Hootman et al²⁰  noted that the competition injury rate in collegiate athletics was approximately 3.5 times larger than the practice injury rate. These findings indicate that game-play intensity appears greater during competitions compared with practices. One explanation for this increased intensity may be that athletes are willing to place themselves at risk of injury during games. Researchers²⁹  have suggested that individuals may be more willing to take risks if they feel the potential gain is meaningful enough. The perceived gain of winning a game may be sufficiently meaningful for athletes to take greater risks compared with practices. These findings may also be influenced by changes in practices over the course of a season. Teams may reduce practice time or the amount of drills involving contact late in a season, potentially reducing the likelihood of injury during these sessions and creating a discrepancy in injury rates between event types.

The most frequently injured body parts in high school boys' basketball and collegiate men's basketball were the ankle, knee (including both the tibiofemoral joint and the patellofemoral articulation), and head/face. These findings are similar to those of previous researchers^{6,11,14,20,21}  who indicated that the ankle and knee were commonly injured in basketball. Borowski et al¹⁴  identified 43.2%, 10.6%, and 12.8% of all high school boys' basketball injuries from 2005 to 2007 as affecting the ankle/foot, knee, and head/face, respectively. Similarly, Hootman et al²⁰  cited the lower extremity as the most frequently injured body part across 15 collegiate sports. Dick et al⁶  described the most often injured body parts among collegiate basketball players from 1988−1989 through 2003−2004 as the ankle (practice IRR = 1.06/1000 AEs, competition IRR = 2.33/1000 AEs) and knee (practice IRR = 0.25/1000 AEs, competition IRR = 0.66/1000 AEs).

The most frequent injury diagnoses in high school boys' basketball and collegiate men's basketball were ligament sprains, muscle/tendon strains, and concussions. These findings are consistent with previous research^6,11,14  and highlight the importance of injury-prevention programs designed to reduce ankle and knee injuries. Additionally, the concussion injury rate identified in this study highlights the continued importance of appropriate concussion recognition and management in basketball players.

The most common injury mechanisms were similar between high school and collegiate basketball players. Despite rules and points of emphasis intended to minimize the amount of contact in the sport,⁷  contact with another person was the most frequent mechanism of injury at both levels. This finding supports previous research.^6,21  Tolbert et al²¹  identified 58% of competition injuries and 41.6% of practice injuries in collegiate athletics as resulting from contact with another player. Noncontact and contact with the playing surface were the second and third most reported injury mechanisms, respectively. These findings are similar to those of Dick et al,⁶  who showed that 20.9% and 20.8% of collegiate men's basketball injuries occurring during competition were due to contact with the playing surface and noncontact mechanisms, respectively. The distribution of injuries by mechanism highlights the need for injury-prevention strategies that target a wide range of injury mechanisms.^30–35  For example, basketball players may benefit from injury-prevention programs that simulate player contact in a safe manner, as in the Fédération Internationale de Football Association 11+ program^30,32  developed for soccer players. Programs such as the Fédération Internationale de Football Association 11+ may be especially beneficial because of their focus on neuromuscular control to prevent lower extremity injuries, particularly those affecting the knee, which, according to our findings, account for a large percentage of all basketball injuries. These results also emphasize the need to enforce rules to improve player safety. Given the large proportion of injuries affecting the head/face, enforcing player-contact rules may be especially important for reducing these types of injuries during games. At the high school level, enforcement of such rules during rebounding could be particularly effective. At both levels, stressing rule enforcement of players scrambling for loose balls may help to reduce the number of injuries occurring from contact with the playing surface. Modifying practices may also reduce the number of head/face injuries that occur in practice, mainly by decreasing the number of drills performed that involve player contact, such as rebounding drills.

Our findings may not be generalizable to other playing levels, such as youth, middle school, and professional programs, or collegiate programs at non-NCAA institutions, or high schools without ATs. Furthermore, we were unable to account for factors potentially associated with injury occurrence, such as AT coverage, injury-prevention programs, and athlete-specific characteristics (eg, previous injury, functional capabilities, developmental stage). Also, although HS RIO and the NCAA-ISP are similar injury-surveillance systems, it is important to consider the differences between these systems; most evident is the fact that HS RIO used a random sample, whereas the NCAA-ISP used a convenience sample. In addition, differences may exist between high school and collegiate levels with regard to the length of the season, as well as the preseason, regular season, and postseason; the potentially longer collegiate season may increase the injury risk. We calculated injury rates using AEs, which may not be as precise an at-risk exposure measure as minutes, hours, or total number of game plays across a season. However, collection of such exposure data is more laborious than for AE data and may be too burdensome for ATs collecting data for HS RIO and the NCAA-ISP.

Although our study is one of the few to examine injury incidence across multiple levels of play (eg, high school versus college and competition versus practice), we were unable to examine differences between starters and nonstarters during competitions. Differences may also exist among freshman, junior varsity, and varsity teams due to differences in maturation status. Playing positions may vary in physical demands and the resulting injury risk. Also, AEs were not collected by position, preventing calculation of position-specific injury rates.

Injury-surveillance data were used to describe injury rates and patterns among high school boys' and collegiate men's basketball players from 2004–2005 through 2013–2014. We identified differences in injury rates by competition level and event type. Injury rates were greater in collegiate basketball and during competitions than practices at both levels. Similarities in distributions of injuries by body part, specific diagnosis, and mechanism of injury suggest that athletes at the 2 levels may benefit from similar injury-prevention strategies. However, variations in injury rates by school size and division indicate that some interventions targeted more at the playing level may also be warranted. Although the risk of injury in basketball is low during participation, our findings should nonetheless aid in the development of future injury-prevention strategies to further protect the health, safety, and well-being of basketball athletes.

The NCAA-ISP data were provided by the Datalys Center for Sports Injury Research and Prevention. The ISP was funded by the NCAA. Funding for HS RIO was provided in part by the Centers for Disease Control and Prevention grants R49/CE000674-01 and R49/CE001172-01 and the National Center for Research Resources award KL2 RR025754). The authors also acknowledge the research funding contributions of the National Federation of State High School Associations (Indianapolis, IN), the National Operating Committee on Standards for Athletic Equipment (Overland Park, KS), DonJoy Orthotics (Vista, CA), and EyeBlack (Potomac, MD). The content of this report is solely the responsibility of the authors and does not necessarily represent the official views of the funding organizations. We thank the many ATs who have volunteered their time and efforts to submit data to HS RIO and the NCAA-ISP. Their efforts are greatly appreciated and have had a tremendously positive effect on the safety of high school and collegiate student-athletes.