Descriptive Report of Injuries Sustained by Secondary School Baseball Players Categorized by Community-Level Socioeconomic Status

Key Points

• Athletic health care underuses contextual factors such as community-level socioeconomic status or concentrated disadvantage to address access and resource needs within communities served.

Baseball has long been considered America’s pastime and continues to be one of the most popular sports in secondary school athletics.¹ Over the past 25 years, injury risks and rates in secondary school baseball have been well documented.^2–5 While these reports have increased the knowledge of injury trends in baseball, including sport specialization and injury risk,^4,6–8 authors of few studies have explored injuries in relation to the social determinants of health and their role in contributing to the health and well-being of populations. Social determinants of health include factors related to economic stability, health care and education access and quality, and neighborhoods and built environment characteristics. Geographic regions, such as where children are raised and go to school, constitute an important social determinant of health. The varied experiences and opportunities of athletes reared in communities of advantage or disadvantage may predispose them to different levels of injury risk over time.^9,10 For example, having more money to invest in sports and leisure may equate to greater sport specialization and higher training volume for some athletes and fewer opportunity and ability to participate for others.¹¹ Additionally, resources, such as athletic training access, proximity to advanced sports medicine practitioners, and barriers to accessing health care (eg, time, money, transportation), in secondary schools located in advantaged or disadvantaged communities may differ, which could affect injury reporting and diagnosis.^12–14 Understanding the effect of community-level socioeconomic status on injury trends may serve as a critical first step in promoting care that is equitable for all athletes.

One of the challenges with exploring community-level socioeconomic status is that it is a latent construct that is not directly observed yet is a powerful driver of many social, emotional, and physical health outcomes. Concentrated disadvantage is a widely used measure of community-level socioeconomic status that incorporates the complex and synergistic effects of socioeconomic factors such as poverty, income, education, employment, and other important communal characteristics to compare relative social vulnerability from one community or neighborhood to another.^15–17 Concentrated disadvantage is therefore a robust measure of the wealth or disadvantage in a geographic area that influences individual outcomes, neighborhood resources, and public school policies and resources. Notably, health and well-being of a community are correlated with the socioeconomic status of the community, with pronounced disparities between those living in higher socioeconomic areas compared with those in lower socioeconomic areas.^18–20 Among adolescents from communities that are more socioeconomically disadvantaged, lower well-being has been observed, which speaks to the influence these communities have on the lives of the people who live in them.^21–24

Efforts to explore socioeconomic factors in athletic health care are beginning, with authors largely examining the effect on access to athletic training services^{12,13,23,25,26} or sports specialization, or describing injury characteristics.^11,27–29 Further, a limitation with the current body of evidence is that authors exploring socioeconomic factors have largely focused on individual-specific measures of socioeconomic status, such as the percentage of students receiving free or reduced lunch, as opposed to a composite measure that includes a variety of influential community-level factors that creates a more realistic and meaningful picture of the advantage or disadvantage of communities and the lived environment. Focus on the context of communities, such as the neighborhood and built environment of each secondary school, is the essence of social ecologic theory and social determinants of health that contribute to inequities in populations.¹⁶ Additionally, authors of most studies have not analyzed the effect of community level of advantage or disadvantage at the level of a single sport. Assessments at the single sport level provide consideration of the specific nuances of a sport and may illuminate different injury trends unique to that sport. Therefore, the purpose of this study was to describe the characteristics of injuries sustained by secondary school baseball players by community-level socioeconomic status, a measure of the concentrated disadvantage of a community.

Methods

Results

The NATION-SP captured 320 baseball injuries across 140 619 AEs, for an overall IR of 2.4/1000 AEs between the 2014–2015 and 2018–2019 academic years. Of those, 166 (52.0%; IR = 2.3/1000 AEs) occurred in the 24 schools located in affluent communities, 50 (15.6%; IR = 1.4/1000 AEs) in the 12 schools located in average-wealth communities, and 104 (32.5%; IR = 3.3/1000 AEs) in the 12 schools located in disadvantaged-wealth communities. Schools located in affluent and disadvantaged-wealth communities had higher IRs during competition (affluent: n = 86, IR = 2.8/1000 AEs, IRR = 1.5, 95% CI = 1.11, 2.05; disadvantaged: n = 52, IR = 4.3/1000 AEs, IRR = 1.6, 95% CI = 1.12, 2.41) than practice (affluent: n = 80, IR = 1.9/1000 AEs; disadvantaged: n = 52, IR = 2.7/1000 AEs), whereas IRs in schools located in average-wealth communities did not exhibit differences by event type (competition: n = 20, IR = 1.9/1000 AEs; practice: n = 30, IR = 1.2/1000 AEs; IRR = 1.6, 95% CI = 0.90, 2.78).

The Table presents frequencies and rates according to the injury characteristics of injury mechanism, body part injured, diagnosis, and TL across community-level socioeconomic status. The top rate for most injury characteristics was the same across community-level socioeconomic status, with contact, sprain or strain, and NTL ranking highest in terms of injury mechanism, diagnosis, and TL, respectively (Table). For body part injured, schools located in average-wealth and disadvantaged-wealth communities saw the highest frequencies of shoulder or clavicle injuries, and ankle injuries were the most frequent in schools located in affluent communities.

Table.Injury Frequencies and Rates for Mechanism of Injury, Common Body Parts Injured, Common Diagnoses, and Time to Return to Play From Baseball Injury by Community-Level Socioeconomic Status

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Discussion

With this study, we are the first to describe injury characteristics of secondary school baseball athletes across levels of school community-level socioeconomic status, an important step in exploring the effect of social determinants of health on athletic populations and communities. Schools located in communities of wealth disadvantage had the largest overall IR (3.3/1000 AE), followed by schools in affluent (2.3/1000 AE) and average-wealth (1.4/1000 AE) communities. Further, both schools located in affluent and disadvantaged-wealth communities saw greater IRs in baseball competitions than baseball practices, while no difference was found in the rate of baseball injury in schools located in average-wealth communities by event type. While overall IRs by mechanism, body part, diagnosis, and TL were relatively low, the most common injury characteristic within most of these categories was consistent across community-level socioeconomic status groups. Exploring factors such as the built environment, including schools, neighborhoods, and levels of community disadvantage, may help identify potential contributors to injury occurrence among baseball athletes. The finding that the overall baseball IR was not the same across the school community-level socioeconomic status groupings should be further explored because something may be occurring that varies these baseball athletes’ injury risk. For example, characteristics of baseball as well as realities of wealth advantaged and disadvantaged communities warrant discussion. Examining these findings through a baseball-specific lens may provide a fuller understanding of the data, and the following discussion presents ideas aimed at sparking interest in future hypothesis-driven research.

The IR for high school baseball players observed in this study, regardless of community-level socioeconomic status, was 2.4/1000 AEs. This value falls in the middle of rates reported in other descriptive epidemiology reports (0.98–5.44 injuries/1000 AEs), and differences may partially be explained by the reporting method and the years in which the data were collected.^2,3,5 None of the communities in the current study reached a rate of injury as high as 5.44/1000 AEs, and the largest rate per community in this study was from schools in wealth-disadvantaged areas (3.3/1000 AEs). Across most injury characteristics, a consistent trend emerged regardless of community-level socioeconomic status, with the highest baseball IRs resulting from contact mechanisms, diagnosed as sprains or strains, and classified as NTL injuries. Shoulder or clavicle injuries were most frequent in average- and disadvantaged-wealth communities, and ankle injuries were most frequent in affluent communities, although the shoulder and clavicle were a close second. Collectively, these data suggest that ATs managing the health care of secondary school baseball athletes should be prepared to treat upper extremity injuries and sprains and advocate for ways to reduce the occurrence of contact injuries, particularly in controlled environments such as practice. Across schools in affluent and wealth-disadvantaged communities, the rate of baseball injuries was higher during competition than practice, but this was not observed in schools located in average-wealth communities where the rates were not different. Higher rates of injury during competition have been reported in other epidemiology research, which has been attributed to factors such as elevated play intensity, more aggressiveness and contact, and the competitive play environment.^35,36 Further, the rates of injury were highest when the injury did not result in lost playing time, a finding consistent across other descriptive epidemiology studies.^3,37 More research is needed to explore and better understand the factors associated with baseball injuries that allow continued play to determine if and how prevention strategies may reduce injury risk.

Across levels of community disadvantage, NTL baseball injuries were more frequent, accounting for at least 40% of injuries, than injuries resulting in lost playing time. Loss of 1 to 6 days of play was the second most frequent for baseball players in schools located in affluent and disadvantaged-wealth communities, although injuries resulting in 7 or more days of lost playing time was the second most frequent for baseball players in average-wealth communities. From a large study conducted across 10 male and female sports, Powell and Barber-Foss reported that baseball injuries had the highest proportion (31%) of injuries resulting in more than 7 days of missed play when compared with the other sports.³⁸ Findings from the current study suggest that at least 20% of baseball injuries reported resulted in 7 or more days of lost play, and baseball players from schools located in average-wealth communities had 32% of injuries in this category, which is closer to the report of Powell and Barber-Foss. Time to return to sport participation after injury is influenced by a variety of potentially interwoven factors, such as those related to injury location and severity, principles of tissue healing, clinician expertise and clinical decisions, return-to-play guidelines or practices, and access to health care. Exploration into the factors associated with time lost from play are needed. In the current study, all of the schools had access to an AT, although the model and availability of athletic training services likely varied.³⁹ Researchers have suggested that schools with higher socioeconomic status,^13,40 fewer students on free and reduced lunch,^25,26 and higher sports medicine budgets⁴¹ have greater access to ATs or athletic training services than schools with lower socioeconomic status, but whether this access influences return-to-play trajectories has not been studied regarding the care of baseball athletes.

The frequency of specific body parts injured may be partially explained through physiologic factors that are attributed to when an athlete begins playing baseball and particularly specializes in the sport. Regarding the shoulder, less engagement in sport has been shown to influence osseous adaptations and range of motion in the throwing shoulder and has been linked to injury in baseball athletes. Additionally, the age and position when a baseball athlete begins throwing relative to skeletal maturity is related to humeral retroversion in the throwing arm, which is hypothesized to have a protective role and allow more external rotation during the cocking phase for torque generation and performance gains.^42–44 Baseball athletes who do not engage in throwing until the time when the humeral physes begin to close, which is about age 14, are less likely to limit the physiological derotation of the humeral head and present with less humeral retroversion, ultimately creating a situation of susceptibility to instability, pain, and injury.⁴⁵ In the current study, the highest frequency of injuries in baseball athletes from schools in disadvantaged- and average-wealth communities was in the shoulder or clavicle. Whether the players from schools in these communities were affected by age or position playing baseball is unknown. Interestingly, ankle injuries were the most frequent injury in players from schools located in affluent communities, and the shoulder or clavicle was second most frequent. Authors of studies in youth baseball tend to focus on the shoulder as an area of concern for developing athletes, yet no authors have explored injury patterns across community-level socioeconomic status, and this is an area for future research.

Across levels of community socioeconomic status, about half of all injuries suffered by baseball players were due to some form of contact, with the other half split primarily between noncontact and overuse type injuries. High rates of contact injuries in baseball have been reported from high schools and emergency room data sources, and contact with baseballs, bases, bats, and player collisions are all contributing factors.^2,46–48 Recommendations for the use of protective equipment, such as facemasks,^2,49 and rule changes, such as breakaway bases,^50,51 have been made in efforts to reduce the frequency of baseball contact injuries. Overuse injuries tend to be more difficult to correctly record from a surveillance perspective, given inconsistent definitions and variability in how people classify overuse injuries, such as coding as a mechanism of injury, an injury type, or both.^2,52,53 Collins and Comstock reported that noncontact injuries, which in their study also included overuse injuries, made up 30% of injuries in high school baseball players.² Overuse injury frequencies in the current study were upward of at least 42% across levels of community disadvantage when considering the categories overuse and noncontact injuries together. However, the rates of overuse injury in the current study were lower across all communities than those previously reported by Roos et al.⁵³ Given the descriptive nature of this study, the reason for the higher frequency of contact injuries in these baseball communities is unknown and should be further explored. Efforts to reduce contact injuries should contribute to a safer baseball experience for athletes.

Across the community groups, sprains and strains accounted for at least 35% of injury diagnoses. In wealth-disadvantaged communities, a substantial percentage of contusion injuries was also found. Researchers have identified sprains or strains and contusions as the top 2 most frequent diagnoses in high school baseball, which aligns with the findings from affluent and disadvantaged-wealth communities, although fractures were the second most common injury diagnosis in average-wealth communities.² Athletic trainers working with baseball athletes should consider injury prevention programs to minimize sprain and strain injuries yet also be prepared to manage them if they happen.

A challenge with exploring the effect of community socioeconomic status on populations is that the methods used to classify communities vary. Researchers investigating socioeconomic factors and youth athletes have often used an income-based estimate compared with the geographical-based approach used in this study.^12,13,28 While income-based measures seem intuitive, they may be generated using a limited or even single source of information, such as state median household income, census poverty level, or percentage of students who quality for free or reduced lunch.^{12,13,25,26,28,29} These measurements, therefore, only capture the economic aspect of socioeconomic status and overlook other critical social determinants of health of the built environment, including the educational levels within a community and the social and community context of the neighborhood where a secondary school is located.⁵⁴ In the current study, we determined community-level disadvantage by using principal component analysis of community-based variables from the American Community Survey measured at the ZIP Code Tabulation Area of the school. This robust approach considers a variety of social determinants of health, including race, female-headed households, education attainment, and types of health insurance coverage, providing a more realistic and meaningful construct from which to classify populations or communities as affluent, average wealth, and wealth disadvantaged.^32,33 A geographical-based lens, such as with concentrated disadvantage, allowed the exploration of the effect that the social determinants of health of the built environment has on people in a community. The variation in the overall IRs across the communities suggests that built environment may play a role in influencing injury patterns in high school baseball players. Researchers should consider this robust approach when examining IRs and AT coverage in relation to socioeconomic factors because it provides an estimate that goes beyond simple differences in income and may better reflect the social determinants of health of the community being studied and described.

Limitations

Schools were included based on a sample of convenience, and only schools with ATs were included. Consequently, it is not possible to determine if IRs differ depending on access or level of access to an AT. Access may play a role in injury and return-to play patterns considering that, when an AT is not present in a school, care is often provided to cover acute injuries, such as through emergency medical services, which likely limits availability of on-site preventative medicine.¹⁴ Further, because all schools employed ATs, it is possible that the inclusion criteria biased the sample toward wealthier communities with access to athletic training services. Additionally, the employment status of each AT was unknown, and it is possible that employment status could influence reporting of injuries.³⁹ However, as reported by Kerr et al, schools with part-time athletic training employment models for care had lower IRs than schools with full-time models, suggesting underreporting of injuries.³⁹ Findings from the current study suggest that schools in disadvantaged-wealth areas had the largest overall IR of all communities. If underreporting is a concern, due to factors such as employment model, then the rates in disadvantaged-wealth communities are likely higher than reported in this study. However, while the employment status of individual ATs may be an important factor, the current research is based on the theory that the community-level socioeconomic status is also a major social determinant of injuries in high school baseball players and provides a unique perspective of community wealth that is associated with injuries. The full effect of factors surrounding the socioeconomic influence in communities warrants further study.

ConclusionS

This study is a descriptive report of baseball injuries suffered by players in schools located in affluent, average-wealth, and disadvantaged-wealth communities. While many injury patterns are consistent across socioeconomic communities, examining injuries through the lens of community levels of disadvantage provides insight into subtle differences that could help to develop information targeted prevention strategies or determine resource needs. Health care should be designed to address the unique challenges and strengths that influence athletes in a community—ultimately aiming to reduce disparities in health outcomes and access to resources.