Epidemiology of Boys' Club Lacrosse Injuries During the 2018 Summer Lacrosse Season
In the past 10 years, participation in boys' youth and high school lacrosse has increased by 33%. Among many club teams and tournaments, athletes may not have access to medical coverage. Additionally, these athletes face a higher volume of play than in traditional scholastic sport settings. To describe the injury characteristics of boys' nonscholastic youth and high school club lacrosse athletes over the course of a summer season. Descriptive epidemiology study. Boys' nonscholastic youth and high school lacrosse athletes, aged 8 to 18 years, who competed in tournaments. Athletic trainers at tournaments were given standardized injury report forms to document patient encounters. These reports were then entered into the Datalys Injury Surveillance Tool. Over the summer tournament season, 233 injuries were reported in 109 342 athlete-exposures (AEs) for an injury rate of 2.13 per 1000 AEs (95% confidence interval = 1.87, 2.42). The most frequently injured body parts were the head and/or face (n = 51, 22%), arm and/or elbow (n = 34, 15%), and hand and/or wrist (n = 29, 12%). The most common diagnoses were contusions (n = 63, 27%), concussions (n = 44, 19%), fractures (n = 39, 17%), and sprains (n = 35, 15%). The most often injured position was midfielder (n = 65, 41%), followed by defense (n = 48, 30%), attack (n = 36, 23%), and goalkeeper (n = 9, 6%). The concussion rate was 0.4 per 1000 AEs (95% confidence interval = 0.28, 0.52). The injury rate experienced by boys' nonscholastic club lacrosse athletes was similar to the rates of their high school counterparts as well as school-sponsored football and wrestling athletes. Because of the risk of injury, athletic training services should be available for youth and high school club lacrosse tournaments.Context
Objective
Design
Patients or Other Participants
Main Outcome Measure(s)
Results
Conclusions
Over the past 2 decades, lacrosse has been among the fastest growing sports in the United States. The number of participants in boys' youth and high school lacrosse has risen from 351 127 in 2010 to 467 135 in 2017, an increase of approximately 33%.1 Additionally, the number of high schools that sponsor lacrosse has risen by 24% from 2012 to 2017.1 Lacrosse is classified as a full-contact sport, and the injury rate for high school boys' lacrosse (1.64 per 1000 athlete-exposures [AEs]) trailed only football (3.27 per 1000 AEs) and wrestling (2.43 per 1000 AEs).2 With regard to concussion rates, boys' high school lacrosse again fell in third place with a rate of 0.4 per 1000 AEs, behind football and ice hockey.3
Injury rates for boys' high school and youth lacrosse have been reported to range from 1.642 to 2.264 per 1000 AEs. Several medical associations, including the American Medical Association,5 American Academy of Family Physicians,6 and American Medical Society for Sports Medicine,7 advocated that certified athletic trainers (ATs) be present at all high school athletic events. Although athletes in a previous study8 participated in school-sponsored seasons in which an AT was more likely to be present, many also participated in nonscholastic club lacrosse teams. Club lacrosse athletes travel with their teams to compete in regional and national club tournaments. Approximately 400 to 500 boys' club lacrosse tournaments occur annually (P. Lawrence, personal interview, September 2019). Of these 400 to 500 tournaments, 65 are sanctioned by US Lacrosse, the national governing body of lacrosse.9 The organization mandates that ATs be present at sanctioned club lacrosse tournaments,10 yet the level of medical care available at unsanctioned events has not been investigated. Youth sport organizations range from large, organized programs, such as the Amateur Athletic Union, to local community-based programs run by parents and volunteers.11 Many organizations that run club lacrosse tournaments are largely unregulated and are managed by individuals who may or may not implement best practices for the health and safety of their participants.11
Club athletes represent a unique population within the sporting community. A typical weekend for a club lacrosse athlete during the summer season includes 4 to 5 games played over 2 days. The athletes repeat this pattern for most, if not all, weekends in the summer. Additionally, the volume has increased as midweek tournaments have become popular in the past 3 to 5 years (P. Lawrence, personal interview, September 2019). Thus, these athletes may play in 10 to 15 lacrosse games in a 7-day period. The frequency and volume of game activity far exceed those of the typical high school athlete, who, on average, plays 1 to 3 games per week over 10 weeks.12–17 Whether the increased volume in the summer club lacrosse setting could lead to a greater risk of injury or a predisposition to specific types of injury (or both) is unknown.18,19 Most researchers who described the epidemiology of youth lacrosse focused on high school settings. The purpose of our study was to address the injury characteristics of boys' youth and high school lacrosse club athletes during a nonscholastic club lacrosse summer tournament season.
METHODS
Data were collected over the course of the 2018 summer club lacrosse tournament season. Details of the tournaments included in data collection are provided in Table 1. For each event, ATs were available at a rate of 1 for every 2 fields in play. The ATs were stationed in multiple labeled medical tents throughout the venues and used radios for communication with officials and field coordinators. Athletes would either approach the medical tent to ask for assistance from an AT or a field coordinator would summon an AT via radio to a particular field to evaluate a player.

Games were played and refereed according to US Lacrosse rules20 for athletes aged 14 and under and National Federation of State High Schools Associations rules21 for high school athletes. The rules vary slightly depending on age, with the major difference relating to stick and body contact. For athletes participating in 12U (12 years and younger) divisions, no body checking and only limited stick checking are allowed.20 For athletes participating in 14U (14 years and younger) divisions, body checking and stick checking are allowed, provided both hands remain on the stick.20 For athletes in high school divisions, body checking and 1-handed stick checking are both allowed.21 All games were played on a 110- × 60-yd (101- × 55-m) field with a few minor exceptions for some 10U (10 years and younger) and 9U (9 years and younger) divisions (Table 1). Games varied in length from 44 minutes to 48 minutes (Table 1). Tournament 9 games were shortened per organization policy due to extreme heat. All tournaments used a running central clock to keep time.
The ATs who worked these tournaments completed standardized injury report forms (Supplemental Figure 1) provided by the host for each injury that they encountered. At the end of each event, the medical director collected the injury reports from the ATs and entered them into the Datalys Injury Surveillance Tool (Datalys Center Inc, Indianapolis, IN). At the end of the summer season, Datalys generated a deidentified report of injury characteristics for the summer season. The university institutional review board accepted the protocol as exempt.
An AE was defined as a single athlete participating in a single game in which he was exposed to the possibility of an athletic injury. To calculate the AEs, the number of games played in a given tournament were identified and then multiplied by the number of teams participating in each game (2) and the average number of players on each team (22). For example, AEs were calculated as follows for a tournament in which 100 games were played: 100 games × 2 teams × 22 players for a total of 4400 AEs.
An injury was defined as any medical condition resulting from participation in the tournament that required evaluation from an on-site AT, regardless of whether any participation time was lost. The ATs were encouraged to record each interaction they had with an athlete, but this was subject to some variability. It was up to the individual AT to determine which injuries were documented. It is possible that some injuries not requiring treatment or activity restriction were not recorded. A time-loss injury was defined as any injury that prevented the athlete from returning to activity on the day of the injury.
RESULTS
Over the course of the summer club lacrosse seasons' 11 events, a total of 109 342 AEs occurred. Among those AEs, a total of 233 injuries were recorded, for an injury rate of 2.13 per 1000 AEs (95% confidence interval [CI] = 1.87, 2.42). The highest injury rate among the 11 events was 5.95 per 1000 AEs (95% CI = 3.83, 8.86), and the lowest was 1.60 per 1000 AEs (95% CI = 0.98, 2.48). Of the injuries, 81% (n = 189) resulted in the athlete's removal from play for at least the remainder of the day. The average age of the patients was 14.8 ± 2.12 years.
The 3 most frequently injured body parts were the head and/or face (22%, n = 51), arm and/or elbow (n = 34, 15%), and hand and/or wrist (n = 29, 12%; Table 2). Of the 51 head and/or face injuries, 44 (86%) were concussions, 5 (10%) were lacerations, and 2 (4%) were contusions. Of the 34 injuries to the elbow and/or arm, 18 (53%) were contusions and 15 (44%) were acutely assessed as fractures. Of the 29 injuries to the hand and/or wrist, 14 (50%) were acutely assessed as fractures, 7 (25%) were sprains, and 3 (10.7%) were contusions.

The most frequently reported injury diagnoses were contusions (n = 63, 27%), concussions (n = 44, 19%), fractures (n = 39, 17%), and sprains (n = 35, 15%). Of the reported contusions, 18 (29%) occurred at the arm and/or elbow; 13 (21%), the neck; and 8 (13%), the trunk. Of the reported fractures, 15 (38%) affected the arm and/or elbow; 14 (36%), the hand and/or wrist; and 4 (10%), the shoulder. Of the reported sprains, 15 (43%) involved the ankle; 7 (20%), the knee; and 7 (20%), the hand and/or wrist. Overall injury characteristics by body part and diagnosis are described in Table 2.
For a relatively large proportion of documented injuries (32%, n = 75), the position of the injured player was reported as other and/or unknown. After removing injury reports for which the player's position was not known, we found that the positions most often injured were midfield (41%), defense (30%), attack (23%), and goalkeeper (6%). The characteristics of injuries sustained by each position are described in Figures 1 and 2.



Citation: Journal of Athletic Training 55, 10; 10.4085/1062-6050-0272.19



Citation: Journal of Athletic Training 55, 10; 10.4085/1062-6050-0272.19
Midfield
Of the injuries to midfielders (n = 65), the most commonly injured body parts were the arm and/or elbow (n = 10, 15%), knee (n = 9, 14%), hand and/or wrist (n = 7, 11%), and ankle (n = 7, 11%). The most frequent diagnoses among midfielders were contusions (n = 26, 40%), sprains (n = 9, 14%), and fractures (n = 7, 11%). The most cited mechanisms of injury for midfielders were stick contact (n = 23, 35%), player contact (n = 16, 25%), and noncontact (n = 12, 18%).
Defense
Of the injuries to defensive players (n = 48), the most commonly injured body parts were the head and/or face (n = 6, 13%), the arm and/or elbow (n = 6, 13%), and the knee (n = 6, 13%). The most frequent diagnoses among defensive players were sprains (n = 12, 25%), fractures (n = 11, 23%), and contusions (n = 9, 19%). The most cited mechanisms of injury for defensive players were player contact (n = 12, 25%), noncontact (n = 11, 23%), and stick contact (n = 7, 15%).
Attack
Of the injuries to attack players (n = 36), the most commonly injured body parts were the head and/or face (n = 7, 19%), the arm and/or elbow (n = 5, 14%), and the ankle (n = 5, 14%). The most frequent diagnoses among attack players were contusions (n = 11, 31%), fractures (n = 8, 22%), and concussions (n = 6, 17%). The most cited mechanisms of injury for attack players were stick contact (n = 15, 42%), surface contact (n = 6, 17%), and player contact (n = 5, 14%).
Goalkeeper
Of the injuries to goalkeepers (n = 9), the most commonly injured body parts were the hand and/or wrist (n = 6, 67%), the head and/or face (n = 2, 22%), and the hip and/or groin (n = 1, 11%). The most frequent diagnoses among goalkeepers were fractures (n = 3, 33%) and sprains (n = 2, 22%). The most cited mechanisms of injury among goalkeepers were ball contact (n = 6, 67%), surface contact (n = 1, 11%), and stick contact (n = 1, 11%).
DISCUSSION
The overall injury rate we observed (2.13 per 1000 AEs) was similar to the 1.64 to 2.26 per 1000 AEs rates noted by previous researchers2,4,22 among high school athletes. Although the injury rate among these youth club athletes with access to an AT was similar to that in their high school counterparts, whether the access to medical care is comparable with other tournaments is unknown. In 2015, approximately 70% of public high schools in the United States had access to full-time, part-time, or per diem athletic training services.8 No data currently exist with regard to medical coverage for youth club sport athletes.
Concussion
A total of 44 concussions occurred, for a rate of 0.4 per 1000 AEs (95% CI = 0.28, 0.52). Previous authors3 demonstrated the same rate in a high school population. Lincoln et al23 found that 73% of all injuries to the head, face, or eyes of high school boys' lacrosse players were concussions, which was similar to the rate we found (77%). During the current study, head injuries were managed extremely conservatively. The ATs who managed these patients during the tournaments had no previous relationships with their patients and, therefore, made the decision to withdraw them from play at the slightest indication of cognitive dysfunction. Additionally, no follow-up evaluations were available to confirm the diagnosis of concussion.
Fractures
A total of 39 fractures were reported, which accounted for 17% of all injuries. The rate of fracture noted here, 0.36 per 1000 AEs, is slightly lower than the 0.49 per 1000 AEs measured by earlier researchers.24 Our value may be moderately inflated as well because radiographic follow-ups were rarely available to confirm the on-field diagnosis of fracture. It is possible, therefore, that a number of contusions were misdiagnosed as fractures.
Positional Differences
Midfielder was the most frequently injured position (n = 65, 41%). This is likely because midfielders, as transitional players who are often active in both offense and defense, cover the most ground during a game. The most common diagnoses for midfielders and attack players were contusions: 40% and 31%, respectively. Athletes in these 2 positions are most often in possession of the ball and are, thus, subject to stick checks from opposing players. Defensive players sustained the largest proportion of injuries from player contact (25%) and noncontact (23%) mechanisms. Defensive players often encounter offensive players in an attempt to keep them from scoring and to distance them from the net. The large proportion of noncontact injuries may reflect the fact that they face away from the net and shift in response to the movements of the attack players.
Limitations
Data were collected at each event using pen and paper. This approach may not have allowed for the depth and accuracy available via an electronic medical record system. Additionally, different ATs provided coverage from week to week; therefore, documentation may not have been consistent throughout data collection. Although we encouraged the ATs to document all encountered injuries, each individual decided which injuries to record. Some injuries that did not require treatment or activity restriction may not have been recorded at the discretion of the AT. Athletes participating in the events were largely unknown to the AT staff, and hence, a conservative approach to removal from play was generally applied. For injuries that were diagnosed as fractures, confirmation via imaging was rarely available. As a result, it is possible that some injuries were misdiagnosed as fractures. In calculating the number of AEs, we assumed that each team consisted of 22 players. We arrived at this number through consultation with club and tournament directors; complete rosters of each team were not available. It is likely that the number of athletes per team ranged from 17 to 26, with the average being approximately 22. However, we cannot confirm that each member of the team participated in each game, so the AEs could be overrepresented, thereby diluting the injury rate and making it appear lower.
Future Research
Researchers should continue to examine the risk of injury associated with youth club sport participation. This population represents a unique sample within the sporting community that plays multiple games per day for several days in a row. Future authors should quantify the volume of gameplay throughout the summer and determine if this increased volume is associated with any changes in injury risk or the occurrence of particular injuries (eg, strains, sprains, and tendinitis). Additionally, the injury risk should be examined throughout the club season to determine if increased volume has a cumulative effect on injury risk in the later weeks of the summer. Our study did not provide a discrete category for heat-related illnesses. Because exertional heat stroke is a major concern for health care professionals working summer tournaments, this area should be explored in the future. Also, the availability of on-site medical coverage for these athletes in club sport settings should be investigated.
CONCLUSIONS
The overall injury rate observed in the present study was comparable with that seen earlier in high school contact-sport athletes. The most frequently injured position on the field was midfield, followed by defense, attack, and goalkeeper. The most common injury diagnosis was contusion. Concussions comprised 19% of total injuries, which was consistent with the report of previous researchers but possibly inflated due to conservative injury management. Because of the risk of injury associated with boys' club lacrosse, we recommend that athletic training services be available at large-scale youth club lacrosse tournaments and showcases to manage patients when both minor and major injuries occur.

Injury diagnosis by position.

Injury mechanism by position.
Contributor Notes