Shane V. Caswell

Trends in Concussion Incidence in High School Sports A Prospective 11-Year Study

Background: Understanding the risk and trends of sports-related concussion among 12 scholastic sports may contribute to concussion detection, treatment, and prevention. Purpose: To examine the incidence and relative risk of concussion in 12 high school boys’ and girls’ sports between academic years 1997-1998 and 2007-2008. Study Design: Descriptive epidemiology study. Methods: Data were prospectively gathered for 25 schools in a large public high school system. All schools used an electronic medical record-keeping program. A certified athletic trainer was on-site for games and practices and electronically recorded all injuries daily. Results: In sum, 2651 concussions were observed in 10 926 892 athlete-exposures, with an incidence rate of 0.24 per 1000. Boys’ sports accounted for 53% of athlete-exposures and 75% of all concussions. Football accounted for more than half of all concussions, and it had the highest incidence rate (0.60). Girls’ soccer had the most concussions among the girls’ sports and the second-highest incidence rate of all 12 sports (0.35). Concussion rate increased 4.2-fold (95% confidence interval, 3.4-5.2) over the 11 years (15.5% annual increase). In similar boys’ and girls’ sports (baseball/softball, basketball, and soccer), girls had roughly twice the concussion risk of boys. Concussion rate increased over time in all 12 sports. Conclusion: Although the collision sports of football and boys’ lacrosse had the highest number of concussions and football the highest concussion rate, concussion occurred in all other sports and was observed in girls’ sports at rates similar to or higher than those of boys’ sports. The increase over time in all sports may reflect actual increased occurrence or greater coding sensitivity with widely disseminated guidance on concussion detection and treatment. The high-participation collision sports of football and boys’ lacrosse warrant continued vigilance, but the findings suggest that focus on concussion detection, treatment, and prevention should not be limited to those sports traditionally associated with concussion risk.

Sex Differences in Head Acceleration During Heading While Wearing Soccer Headgear

CONTEXT Researchers have indicated that female soccer players may be at greater risk of concussion compared with their male counterparts. Soccer headgear is marketed for reducing head acceleration and risk of concussion. OBJECTIVE To determine the effect of sex and soccer headgear on head impact kinematics and dynamic stabilization during soccer heading. DESIGN Cross-sectional design. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS Forty-four college-aged soccer players (29 women, 15 men). INTERVENTION(S) Using a head impact model, participants performed 4 soccer headers under 3 headgear conditions (control, Head Blast Soccer Band, and Full90 Select Performance Headguard). MAIN OUTCOME MEASURE(S) Dependent variables assessed before soccer heading were head-neck anthropometrics and isometric neck muscle strength, and those assessed during soccer headers were resultant linear head acceleration, Head Injury Criteria (HIC(36)), and superficial neck muscle electromyography. Statistical analyses included multivariate and univariate analyses of variance with repeated measures, independent-samples t tests, appropriate follow-up analyses of variance and post hoc t tests, and Pearson product moment correlations (alpha = .05). RESULTS Head acceleration in women was 32% and 44% greater than in men when wearing the Head Blast (21.5 g versus 16.3 g) and Full90 Select (21.8 g versus 15.2 g), respectively (P < .05). Compared with men, women exhibited 10% greater head accelerations (20.2 g versus 18.2 g) during the control condition (P = .164). CONCLUSIONS Female soccer players exhibited greater head accelerations than their male counterparts when wearing headgear. Our results are important clinically because they indicate that soccer headgear may not be an appropriate head injury prevention tool for all athletes.

Video Incident Analysis of Concussions in Boys’ High School Lacrosse

Background: Boys’ lacrosse has one of the highest rates of concussion among boys’ high school sports. A thorough understanding of injury mechanisms and game situations associated with concussions in boys’ high school lacrosse is necessary to target injury prevention efforts. Purpose: To characterize common game-play scenarios and mechanisms of injury associated with concussions in boys’ high school lacrosse using game video. Study Design: Descriptive epidemiological study. Methods: In 25 public high schools of a single school system, 518 boys’ lacrosse games were videotaped by trained videographers during the 2008 and 2009 seasons. Video of concussion incidents was examined to identify game characteristics and injury mechanisms using a lacrosse-specific coding instrument. Results: A total of 34 concussions were captured on video. All concussions resulted from player-to-player bodily contact. Players were most often injured when contact was unanticipated or players were defenseless (n = 19; 56%), attempting to pick up a loose ball (n = 16; 47%), and/or ball handling (n = 14; 41%). Most frequently, the striking player’s head (n = 27; 79%) was involved in the collision, and the struck player’s head was the initial point of impact in 20 incidents (59%). In 68% (n = 23) of cases, a subsequent impact with the playing surface occurred immediately after the initial impact. A penalty was called in 26% (n = 9) of collisions. Conclusion: Player-to-player contact was the mechanism for all concussions. Most commonly, injured players were unaware of the pending contact, and the striking player used his head to initiate contact. Further investigation of preventive measures such as education of coaches and officials and enforcement of rules designed to prevent intentional head-to-head contact is warranted to reduce the incidence of concussions in boys’ lacrosse.

Video Incident Analysis of Head Injuries in High School Girls’ Lacrosse:

Background: Knowledge of injury mechanisms and game situations associated with head injuries in girls’ high school lacrosse is necessary to target prevention efforts. Purpose: To use video analysis and injury data to provide an objective and comprehensive visual record to identify mechanisms of injury, game characteristics, and penalties associated with head injury in girls’ high school lacrosse. Study Design: Descriptive epidemiology study. Methods: In the 25 public high schools of 1 school system, 529 varsity and junior varsity girls’ lacrosse games were videotaped by trained videographers during the 2008 and 2009 seasons. Video of head injury incidents was examined to identify associated mechanisms and game characteristics using a lacrosse-specific coding instrument. Results: Of the 25 head injuries (21 concussions and 4 contusions) recorded as game-related incidents by athletic trainers during the 2 seasons, 20 head injuries were captured on video, and 14 incidents had sufficient image quality for analysis. All 14 incidents of head injury (11 concussions, 3 contusions) involved varsity-level athletes. Most head injuries resulted from stick-to-head contact (n = 8), followed by body-to-head contact (n = 4). The most frequent player activities were defending a shot (n = 4) and competing for a loose ball (n = 4). Ten of the 14 head injuries occurred inside the 12-m arc and in front of the goal, and no penalty was called in 12 injury incidents. All injuries involved 2 players, and most resulted from unintentional actions. Turf versus grass did not appear to influence number of head injuries. Conclusion: Comprehensive video analysis suggests that play near the goal at the varsity high school level is associated with head injuries. Absence of penalty calls on most of these plays suggests an area for exploration, such as the extent to which current rules are enforced and the effectiveness of existing rules for the prevention of head injury.

Effectiveness of the Women’s Lacrosse Protective Eyewear Mandate in the Reduction of Eye Injuries

Background: In an effort to minimize the risk of catastrophic eye injury, US Lacrosse initiated mandatory use of protective eyewear in women’s lacrosse in the 2004-2005 season. Purpose: The authors compared eye injury rates in girls’ scholastic lacrosse before and after implementation of protective eyewear. They also compared head/face injury rates, concussion rates, and overall injury rates before and after the rule change to assess possible unintended consequences of the change. Study Design: Cohort study; Level of evidence, 3. Methods: The study group included female scholastic lacrosse players in the 25 public high schools in Fairfax County, Virginia, during the 2004-2009 spring seasons. Injury rates were compared with those from the same data source for the 2000-2003 seasons. Premandate versus postmandate injury rates were adjusted for athlete exposures, or total opportunities for injury throughout the season. Results: The rate of eye injuries was reduced from 0.10 injuries per 1000 athlete exposures (AEs) in 2000 through 2003 before the use of protective eyewear to 0.016 injuries per 1000 AEs in 2004 through 2009 (incident rate ratio [IRR], 0.16; 95% confidence interval [CI], 0.06-0.42). The rate ratio of head/face injuries excluding concussion also decreased (IRR, 0.44; 95% CI, 0.26-0.76). There was no change in the rate ratio of total injuries involving all body parts (IRR, 0.93; 95% CI, 0.82-1.1) after introduction of protective eyewear. However, the rate ratio of concussion increased (IRR, 1.6; 95% CI, 1.1-2.3). Conclusion: The use of protective eyewear in women’s lacrosse was associated with a reduction in the number of eye injuries. The number of head/face injuries decreased in this study group after introduction of protective eyewear, and there was no change in overall injury rates. The reason for the increase in concussion rate cannot be determined conclusively based on this study, but the authors speculate that this increase resulted largely from increased recognition and diagnosis because overall injury rates do not indicate rougher play with introduction of protective equipment.

State-Specific Differences in School Sports Preparticipation Physical Evaluation Policies

OBJECTIVE: This study evaluated the current preparticipation physical evaluation (PPE) administrative policies and cardiovascular screening content of all 50 states and Washington, DC. METHODS: PPE policies, documents, and forms from all 50 states and Washington, DC, were compared with the preparticipation physical evaluation–fourth edition (PPE-4) consensus recommendations. All electronic documents were publicly available and obtained from state interscholastic athletic associations. RESULTS: Fifty (98%) states required a PPE before participation. Most states (53%, n = 27) required a specific PPE form, whereas 24% (n = 12) of states recommended a specific form. Twenty-three states (45%) required or recommended use of the PPE-4 form or a modified version of it, and 27 states (53%) required or recommended use of outdated or unidentifiable forms. Ten states (20%) had not revised their PPE forms in >5 years. States permitted 9 different health care providers to administer PPEs. Only 22 states (43%) addressed all 12 of the PPE-4 personal and family history cardiovascular screening items, and 2 states (4%) addressed between 8 and 11 items. For the remaining 26 states, most (29%) addressed ≤3 screening items. CONCLUSIONS: Our results show that inconsistencies in PPE policies exist nationwide. Most states have been slow to adopt PPE-4 recommendations and do not adequately address the personal and family cardiovascular history questions. Findings suggest a need for PPE standardization nationwide and adoption of an electronic PPE process. This approach would enable creation of a national database and benefit the public by facilitating a more evidenced PPE.

Balance comparisons between female dancers and active nondancers.

Purpose: Female dancers have lower anterior cruciate ligament (ACL) injury rates compared with physically active women. Enhanced balance can decrease musculoskeletal injury risk. Dancers are proposed to have superior balance compared with physically active nondancers, and this may reduce their risk for ACL injury. However, whether female dancers actually have better balance than active nondancers is unclear. Method: Thirty-three women (15 dancers, 18 nondancers) performed the Balance Error Scoring System (BESS; error scores), the Star Excursion Balance Test (SEBT; percent leg length), and the Modified Bass Test of Dynamic Balance (BASS; maximum score = 100). Results: Dancers had fewer errors on the BESS than did nondancers (p < .001, 12.0 ± 6.9 vs. 25.3 ± 9.1). Dancers also had greater SEBT reach distances in the medial (right, p = .03, 90.4 ± 4.2% vs. 86.5 ± 5.5%; left, p = .04, 90.7 ± 4.5% vs. 86.7 ± 5.9%) and posteromedial directions (right, p = .01, 92.6 ± 5.6% vs. 87.0 ± 6.4%; left, p = .01, 93.9 ± 6.3% vs. 87.9 ± 6.3%), but not in the anteromedial direction (right, p = .23, 84.5 ± 4.4% vs. 86.2 ± 3.5%; left, p = .51, 86.4 ± 3.5% vs. 85.5 ± 4.0%). BASS scores were similar between groups (p = .58, 90.6 ± 5.5 vs. 91.7 ± 56). Conclusions: The novel findings of the study are that dancers had greater balance than did nondancers in some but not all tests. Although dancing may improve balance as compared with not dancing, it is not better than physical activity in improving balance. Thus, balance comparisons between dancers and nondancers may not fully explain why female dancers exhibit low ACL injury rates compared with physically active women. Other factors (e.g., anticipated/unanticipated movement demands) should be examined to understand the ACL injury disparity between dancers and physically active women.

An in-vivo model of functional head impact testing in non-helmeted athletes

Development of a functional in-vivo head impact testing model would enhance the ability to elucidate mechanisms underlying individual responses to head impact in sports where a helmet is not worn. The objective of this paper is to describe a novel in-vivo method of assessing human head linear impact acceleration during the functional activity of soccer heading, using a repeated-measures design in a university research laboratory. 17 college-aged soccer players (age, 20.93 years (standard deviation (SD), 1.17 years); height, 170.39cm (SD, 10.15cm); mass, 71.50kg (SD, 9.89kg); head—neck mass, 5.90kg (SD, 0.83kg)) participated in this study. All participants read and signed a university Institutional-Review-Board-approved informed consent before participating. The resultant linear head acceleration (in units of g) was measured for each participant during soccer heading. The head impact model consisted of controlled soccer headers and a triaxial accelerometer affixed to a custom-fitted mouthpiece. A force-sensitive resistor on the forehead assessed impact quality. Standard soccer balls were projected from a JUGS soccer machine travelling at 11.10m/s (25mile/h) and covering a distance of 11m (35ft). The subjects performed standing or simulated headers while aiming at a target positioned 5m in front of them. The intra-class correlation coefficient (ICC2,1) was 0.845 for resultant accelerations. In this paper, the development and testing of a novel in-vivo functional human head impact testing model are described. Results suggest that this methodology has potential for assessing resultant peak linear head impact accelerations during the functional activity of soccer heading and in other non-helmet-wearing sports.

Video Analysis Verification of Head Impact Events Measured by Wearable Sensors

Background: Wearable sensors are increasingly used to quantify the frequency and magnitude of head impact events in multiple sports. There is a paucity of evidence that verifies head impact events recorded by wearable sensors. Purpose: To utilize video analysis to verify head impact events recorded by wearable sensors and describe the respective frequency and magnitude. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Thirty male (mean age, 16.6 ± 1.2 years; mean height, 1.77 ± 0.06 m; mean weight, 73.4 ± 12.2 kg) and 35 female (mean age, 16.2 ± 1.3 years; mean height, 1.66 ± 0.05 m; mean weight, 61.2 ± 6.4 kg) players volunteered to participate in this study during the 2014 and 2015 lacrosse seasons. Participants were instrumented with GForceTracker (GFT; boys) and X-Patch sensors (girls). Simultaneous game video was recorded by a trained videographer using a single camera located at the highest midfield location. One-third of the field was framed and panned to follow the ball during games. Videographic and accelerometer data were time synchronized. Head impact counts were compared with video recordings and were deemed valid if (1) the linear acceleration was ≥20g, (2) the player was identified on the field, (3) the player was in camera view, and (4) the head impact mechanism could be clearly identified. Descriptive statistics of peak linear acceleration (PLA) and peak rotational velocity (PRV) for all verified head impacts ≥20g were calculated. Results: For the boys, a total recorded 1063 impacts (2014: n = 545; 2015: n = 518) were logged by the GFT between game start and end times (mean PLA, 46 ± 31g; mean PRV, 1093 ± 661 deg/s) during 368 player-games. Of these impacts, 690 were verified via video analysis (65%; mean PLA, 48 ± 34g; mean PRV, 1242 ± 617 deg/s). The X-Patch sensors, worn by the girls, recorded a total 180 impacts during the course of the games, and 58 (2014: n = 33; 2015: n = 25) were verified via video analysis (32%; mean PLA, 39 ± 21g; mean PRV, 1664 ± 619 rad/s). Conclusion: The current data indicate that existing wearable sensor technologies may substantially overestimate head impact events. Further, while the wearable sensors always estimated a head impact location, only 48% of the impacts were a result of direct contact to the head as characterized on video. Using wearable sensors and video to verify head impacts may decrease the inclusion of false-positive impacts during game activity in the analysis.

National Athletic Trainers' Association Position Statement: Preventing and Managing Sport-Related Dental and Oral Injuries.

OBJECTIVE To provide athletic trainers, health care professionals, and all those responsible for the care of athletes with clinical recommendations for preventing and managing sport-related dental and oral injuries. BACKGROUND Participation in competitive sports continues to grow at both the interscholastic and intercollegiate levels. Therefore, exposure to, and the incidence of athletic-related injury, including orofacial injury, will also likely increase. At the time of this writing, the leading governing agencies for interscholastic (National Federation of State High School Associations) and intercollegiate (National Collegiate Athletic Association) sports require only protective orofacial equipment (eg, mouthguards) for 5 and 4, respectively, of their sanctioned sports. Although orofacial injuries represent a small percentage of all sport-related injuries, the financial burden associated with these injuries (eg, tooth avulsion) can exceed