Relationship Between Physical Activity Participation and Recovery Outcomes in College-Aged Adults With a Concussion.

CONTEXT: Previously, the most common treatment for a concussion was prolonged physical and cognitive rest. Recently, researchers have suggested that earlier physical activity (PA) may be better at promoting recovery. Researchers have not evaluated the relationship between free-living PA (eg, walking) and symptom reporting or recovery duration. OBJECTIVE: To assess the relationship between free-living PA participation and 2 recovery outcomes in college-aged adults with a concussion. DESIGN: Prospective cohort. SETTING: National Collegiate Athletic Association Division I and III universities. PATIENTS OR OTHER PARTICIPANTS: Thirty-two college-aged adults (68.8% female, age = 19.8 ± 1.4 years) with a concussion. MAIN OUTCOME MEASURE(S): Participants completed a postconcussion symptom evaluation at visits 1 (<72 hours from concussion) and 2 (8 days later). Between visits, each participant's PA was monitored using an Actigraph GT9X Link PA monitor and expressed as total PA (counts per minute) and percentage of PA time spent in moderate-to-vigorous intensity (%MVPA). Recovery time was the number of days from injury occurrence to medical clearance. With separate hierarchical multiple regressions, we evaluated the relationship between total PA and each recovery variable (visit 2 symptom severity, recovery time). Additionally, with separate exploratory hierarchical multiple regressions, we evaluated the relationship between %MVPA and each recovery variable. Statistical significance was set a priori at P ≤ .05. RESULTS: Participants averaged 2446 ± 441 counts per minute and spent 12.1% ± 4.2% of their PA performing MVPA. Participants yielded median (interquartile) symptom severities of 28 (24) and 2 (8) for visit 1 and 2, respectively. Average recovery time was 14.7 ± 7.5 days. Total PA did not significantly contribute to the model for visit 2 symptom severity (P = .122) or recovery time (P = .301). Similarly, %MVPA had little contribution to the model for visit 2 symptom severity (P = .358) or recovery time (P = .276). CONCLUSIONS: We suggest that free-living PA may not be enough to reduce symptoms or shorten recovery. Thus, clinicians may need to provide patients with more structured PA protocols mimicking findings from previous researchers.

Vestibular/Ocular Motor Screening Assessment Outcomes After Sport-Related Concussion in High School and Collegiate Athletes.

CONTEXT: Vestibular and ocular motor assessment is an emerging clinical assessment for patients with sport-related concussion (SRC). The increased use of these assessments by clinicians calls for the examination of outcomes that may affect clinical practice. OBJECTIVE: To compare vestibular and ocular motor impairments in high school and collegiate athletes within 72 hours of SRC and examine the distribution of impairments in these populations based on pre-established clinical cutoff scores. DESIGN: Cross-sectional study. SETTING: High school and collegiate athletics. PATIENTS OR OTHER PARTICIPANTS: Data were collected from 110 athletes (high school: n = 47, age = 15.40 ± 1.35 years; college: n = 63, age = 19.46 ± 1.28 years) within 72 hours of sustaining an SRC. MAIN OUTCOME MEASURE(S): Total and change scores were calculated for the Vestibular/Ocular Motor Screening (VOMS) tool, along with average near point of convergence (NPC) distance. Separate Mann-Whitney U tests were used to compare group differences, and χ2 analyses were used to examine the proportion of athletes with scores greater than clinical cutoff scores for all VOMS outputs. The α level was set a priori at .05. RESULTS: No differences were found between high school and collegiate athletes for VOMS total and change scores and NPC distance. A larger proportion of the sample had scores greater than the cutoff for all total scores (P < .001) and change scores in horizontal vestibulo-ocular reflex (59.01%; P < .001), vertical vestibulo-ocular reflex (60.91%; P < .001), and visual motion sensitivity (60.91%; P < .001). However, a larger proportion demonstrated smooth pursuit change scores (85.45%; P < .001) and NPC distances (73.64%; P = .01) that were less than the cutoff scores. CONCLUSIONS: During the acute phase of SRC, high school and collegiate athletes presented with similar vestibular and ocular motor impairments as measured using the VOMS, but vestibular tasks appeared to cause greater symptom provocation. Lastly, VOMS change scores may offer more clinical utility compared with total scores in assessing specific impairments after SRC.

Removal From Activity After Sports- Related Concussion in Sex-Comparable Sports From the Michigan High School Athletic Association.

BACKGROUND: Research has demonstrated that female athletes are more likely to report their sports-related concussion (SRC) symptoms compared with male athletes; however, it is unknown if these reporting behaviors correspond to immediate removal from activity in sex-comparable sports. PURPOSE: To compare the incidence of high school student-athletes removed and not removed from activity after SRC in sex-comparable sports in Michigan. STUDY DESIGN: Descriptive epidemiology study. METHODS: Participants included student-athletes diagnosed with SRC participating in Michigan High School Athletic Association-sponsored athletic activities (22 sex-comparable sports) between 2016 and 2019. All SRCs were recorded in the association's Head Injury Reporting System (HIRS) by certified athletic trainers, administrators, or coaches. Removal from activity indicated that the student-athlete was removed from play at the time of an injury event. If the student-athlete reported that his or her suspected injury event occurred earlier during activity or if symptom onset was delayed, "not removed from activity" was entered into the HIRS. Incidence proportions were calculated by dividing SRCs not removed by total SRCs in each sport. Risk ratios were calculated by dividing the incidence proportions of girls not removed by boys not removed in each sport. RESULTS: A total of 4418 (2773 female, 1645 male) SRCs were reported, with the most occurring in female soccer players (n = 1023). Overall, 515 girls and 243 boys were not removed from activity, resulting in incidences of 0.19 (95% CI, 0.17-0.20) and 0.15 (95% CI, 0.13-0.17), respectively. Across all sports, girls were 1.26 (95% CI, 1.09-1.45) times as likely to not be removed from activity compared with boys. Of the sports with the most SRCs-soccer, basketball, baseball/softball, and lacrosse-girls had 1.37 (95% CI, 1.09-1.72), 1.15 (95% CI, 0.89-1.47), 1.19 (95% CI, 0.77-1.84), and 1.35 (95% CI, 0.94-1.95) times the risk of not being removed, respectively. CONCLUSION: Girls were at greater risk of not being removed from activity compared with boys in sex-comparable sports. Results from this study should be incorporated into SRC education in Michigan and potentially elsewhere to inform affiliated personnel of potential sex differences and protect female student-athletes from further harm.

Factors Associated With Concussion Nondisclosure in Collegiate Student-Athletes.

CONTEXT: Mandated concussion education has aimed to improve student-athlete knowledge; however, some collegiate student-athletes continue to not disclose concussion. Concussion knowledge may not be the only factor influencing reporting, as student-athlete sex, sport, and pressure from external stakeholders (eg, coaches, teammates, fans, parents or family) have all been documented as influencing collegiate concussion-reporting behavior. OBJECTIVE: To examine factors associated with concussion nondisclosure in collegiate student-athletes. DESIGN: Cross-sectional study. SETTING: Four National Collegiate Athletic Association Division I and two Division II universities. PATIENTS OR OTHER PARTICIPANTS: A total of 1125 collegiate student-athletes completed the survey, and 741 provided viable responses and were included for data analysis. MAIN OUTCOME MEASURE(S): We used a 10- to 15-minute electronic or paper-and-pencil survey that asked about personal and sport demographics, diagnosed concussions and nondisclosed concussion history, concussion knowledge, and level of agreement regarding pressure to play after a head impact experienced during collegiate sport participation. Significant univariable factors were entered into a multivariable logistic regression analysis. RESULTS: Sex (P = .005), sport-risk type (P < .001), diagnosed concussion history (P < .001), concussion knowledge (P = .017), and pressure from coaches (P < .001), teammates (P < .001), fans (P = .024), and parents or family (P = .003) were factors associated with concussion nondisclosure in individual univariable logistic regressions. After we conducted multivariable analyses, male sex (P = .001), high concussion-risk sport participation (P = .048), diagnosed concussion history (P < .001), increased concussion knowledge (P = .013), and experiencing pressure from coaches to continue playing after sustaining a hit to the head (P = .002) were factors associated with concussion nondisclosure in collegiate student-athletes. CONCLUSIONS: Our results suggest that concussion-education programs should go beyond the identification of signs and symptoms to include the dangers of continuing to play, long-term consequences, and transparency about concussion protocols. Comprehensive concussion-education programs should involve coaches and athletes to improve the reporting culture.

Predictors of Concussion Nondisclosure in Collegiate Student-Athletes.

CONTEXT: Mandated concussion education has aimed to improve student-athlete knowledge; however, some collegiate student-athletes continue to not disclose concussion. Concussion knowledge may not be the only factor influencing reporting, as student-athlete sex, sport, and pressure from external stakeholders (eg, coaches, teammates, fans, parents or family) have all been documented as influencing collegiate concussion-reporting behavior. OBJECTIVE: To examine predictors of concussion nondisclosure in collegiate student-athletes. DESIGN: Cross-sectional study. SETTING: Four National Collegiate Athletic Association Division I and two Division II universities. PATIENTS OR OTHER PARTICIPANTS: A total of 1125 collegiate student-athletes completed the survey, and 741 provided viable responses and were included for data analysis. MAIN OUTCOME MEASURE(S): We used a 10- to 15-minute electronic or paper-and-pencil survey that asked about personal and sport demographics, diagnosed concussions and nondisclosed concussion history, concussion knowledge, and level of agreement regarding pressure to play after a head impact experienced during collegiate sport participation. Significant univariable predictor variables were entered into a multivariable logistic regression analysis. RESULTS: Sex (P = .005), sport-risk type (P < .001), diagnosed concussion history (P < .001), concussion knowledge (P = .017), and pressure from coaches (P < .001), teammates (P < .001), fans (P = .024), and parents or family (P = .003) were predictors of concussion nondisclosure in individual univariable logistic regressions. After we conducted multivariable analyses, male sex (P = .001), high concussion-risk sport participation (P = .048), diagnosed concussion history (P < .001), increased concussion knowledge (P = .013), and experiencing pressure from coaches to continue playing after sustaining a hit to the head (P = .002) were predictors of concussion nondisclosure in collegiate student-athletes. CONCLUSIONS: Our results suggest that concussion-education programs should go beyond the identification of signs and symptoms to include the dangers of continuing to play, long-term consequences, and transparency about concussion protocols. Comprehensive concussion-education programs should involve coaches and athletes to improve the reporting culture.

Sport Concussion Assessment Tool Symptom Inventory: Healthy and Acute Postconcussion Symptom Factor Structures.

CONTEXT: Previous researchers have examined factor structures for common concussion symptom inventories. However, they failed to discriminate between the acute (<72 hours) and subacute (3 days-3 months) periods after concussion. The Sport Concussion Assessment Tool (SCAT) is an acute assessment that, when compared with other concussion symptom inventories, includes or excludes symptoms that may result in different symptom factors. OBJECTIVE: The primary purpose was to investigate the symptom factor structure of the 22-item SCAT symptom inventory in healthy, uninjured and acutely concussed high school and collegiate athletes. The secondary purpose was to document the frequency of the unique SCAT symptom inventory items. DESIGN: Case series. SETTING: High school and college. PATIENTS OR OTHER PARTICIPANTS: A total of 1334 healthy, uninjured and 200 acutely concussed high school and collegiate athletes. MAIN OUTCOME MEASURE(S): Healthy, uninjured participants completed the SCAT symptom inventory at a single assessment. Participants in the acutely concussed sample completed the SCAT symptom inventory within 72 hours after concussion. Two separate exploratory factor analyses (EFAs) using a principal component analysis and varimax extraction method were conducted. RESULTS: A 3-factor solution accounted for 48.1% of the total variance for the healthy, uninjured sample: cognitive-fatigue (eg, feeling "in a fog" and "don't feel right"), migraine (eg, neck pain and headache), and affective (eg, more emotional and sadness) symptom factors. A 3-factor solution accounted for 55.0% of the variance for the acutely concussed sample: migraine-fatigue (eg, headache and "pressure in the head"), affective (eg, sadness and more emotional), and cognitive-ocular (eg, difficulty remembering and balance problems) symptom factors. CONCLUSIONS: The inclusion of unique SCAT symptom inventory items did not alter the symptom factor structure for the healthy, uninjured sample. For the acutely concussed sample, all but 1 unique SCAT symptom inventory item (neck pain) loaded onto a factor.

Sport Concussion Assessment Tool Symptom Inventory: Healthy and Acute Postconcussion Symptom Factor Structures.

CONTEXT: Previous researchers have examined factor structures for common concussion symptom inventories. However, they failed to discriminate between the acute (<72 hours) and subacute (3 days-3 months) periods after concussion. The Sport Concussion Assessment Tool (SCAT) is an acute assessment that, when compared with other concussion symptom inventories, includes or excludes symptoms that may result in different symptom factors. OBJECTIVE: The primary purpose was to investigate the symptom factor structure of the 22-item SCAT symptom inventory in healthy, uninjured and acutely concussed high school and collegiate athletes. The secondary purpose was to document the frequency of the unique SCAT symptom inventory items. DESIGN: Case series. SETTING: High school and college. PATIENTS OR OTHER PARTICIPANTS: A total of 1334 healthy, uninjured and 200 acutely concussed high school and collegiate athletes. MAIN OUTCOME MEASURE(S): Healthy, uninjured participants completed the SCAT symptom inventory at a single assessment. Participants in the acutely concussed sample completed the SCAT symptom inventory within 72 hours after concussion. Two separate exploratory factor analyses (EFAs) using a principal component analysis and varimax extraction method were conducted. RESULTS: A 3-factor solution accounted for 48.1% of the total variance for the healthy, uninjured sample: cognitive fatigue (eg, feeling "in a fog" and "don't feel right"), migraine (eg, neck pain and headache), and affective (eg, more emotional and sadness) symptom factors. A 3-factor solution accounted for 55.0% of the variance for the acutely concussed sample: migraine fatigue (eg, headache and "pressure in the head"), affective (eg, sadness and more emotional), and cognitive ocular (eg, difficulty remembering and balance problems) symptom factors. CONCLUSIONS: The inclusion of unique SCAT symptom inventory items did not alter the symptom factor structure for the healthy, uninjured sample. For the acute concussed sample, all but 1 unique SCAT symptom inventory item (neck pain) loaded onto a factor.

The Sport Concussion Assessment Tool-5 (SCAT5): Baseline Assessments in NCAA Division I Collegiate Student-Athletes.

The purpose of this study was to report baseline values for the SCAT5 in NCAA Division I collegiate student-athletes, while also evaluating if sex, health diagnoses, or sport type influenced baseline performance. A sample of 462 collegiate student-athletes (212 females, 250 males, (19.21±1.32 years)) completed the SCAT5 prior to the 2017-18, 2018-19 or 2019-20 athletic seasons. Descriptive statistics were reported for symptom total (22 possible), symptom severity (132 possible), orientation (5 possible), immediate memory (30 possible), concentration (5 possible), delayed recall (10 possible), total SAC score (50 possible), 3 mBESS stances (10 possible), and mBESS score (30 possible). Separate Mann-Whitney U tests were conducted to identify sex, health diagnoses (concussion history, ADD/ADHD, depression/anxiety), and sport type (contact, non-contact) differences for all SCAT5 components. Alpha level was set a priori <.05. Student-athletes reported 1.96± 3.37 symptoms with a severity of 3.43±7.63, and an overall SAC score of 35.14±5.23 (orientation 4.96±0.20, immediate memory 20.18±3.40, concentration 3.60±1.14, delayed recall 6.41±1.94). Student-athletes participating in contact sports, had ADD/ADHD, or depression/anxiety reported more symptoms and at greater severity (p=<.001-.01). Those with ADD/ADHD performed worse on mBESS (p=.01-.03). No sex differences were found for any SCAT5 components (p=.08-.90). This study presents reference values for the SCAT5 by sex, health diagnoses, and sport type. Healthcare professionals may utilize these normative values when individual baseline references are unavailable.

College Athletic Trainers' Perceptions of Rest and Physical Activity When Managing Athletes With a Sport-Related Concussion.

CONTEXT: Cognitive and physical rest are commonly utilized when managing a sport-related concussion (SRC); however, emerging research now suggests that excessive rest may negatively impact recovery. Despite current research recommendations, athletic trainers (ATs) may be behind in implementing this emerging research into clinical practice. OBJECTIVE: To assess college ATs' perceptions and implementation of an emerging SRC management approach (cognitive and physical rest and activity). DESIGN: Cross-sectional study. SETTING: Survey. PARTICIPANTS: A total of 122 (11.8%) ATs (53.3% female; 10.8 [9.8] y experience; 8.7 [6.9] SRCs managed annually) responded to the survey, which was randomly distributed to 1000 members of the National Athletic Trainers' Association, as well as 31 additional ATs from varying universities. MAIN OUTCOME MEASURES: A 5-point Likert scale assessed the ATs' perceptions and clinical practices as they relate to specific athlete behaviors (ie, texting, sleeping). The ATs were asked about their willingness to incorporate physical activity into clinical practice. RESULTS: Playing video games (95.9%) and practicing (93.4%) were the activities most perceived to extend SRC recovery. However, sleeping more than usual (7.4%) and increased time in a dark environment (11.5%) were viewed as less likely to extend recovery. ATs restricted practicing (98.4%) and working out (91.8%) for athletes with SRC, while sleeping more than usual (6.6%) and increased time in a dark environment (13.1%) were less restricted. About 71% of the ATs would implement light physical activity for athletes with a symptom score of 1 to 5, 31% with scores of 6 to 10, and 15% with scores of 11 to 20. About 43%, 74%, and 97% believe that light, moderate, and vigorous physical activity, while symptomatic, will extend recovery, respectively. CONCLUSIONS: The ATs were receptive to including light physical activity into their SRC management, although only in certain situations. However, most ATs' beliefs and clinical practices did not completely align with emerging research recommendations for the management of SRCs.

Preseason to Postseason Changes on the BTrackS Force Plate in a Sample of College Athletes.

CONTEXT: Balance testing is a vital component in the evaluation and management of sport-related concussion. Few studies have examined the use of objective, low-cost, force-plate balance systems and changes in balance after a competitive season. OBJECTIVE: To examine the extent of preseason versus postseason static balance changes using the Balance Tracking System (BTrackS) force plate in college athletes. DESIGN: Pretest, posttest design. SETTING: Athletic training facility. PARTICIPANTS: A total of 47 healthy, Division-I student-athletes (33 males and 14 females; age 18.4 [0.5] y, height 71.8 [10.8] cm, weight 85.6 [21.7] kg) participated in this study. MAIN OUTCOME MEASURES: Total center of pressure path length was measured preseason and postseason using the BTrackS force plate. A Wilcoxon signed-rank test was conducted to examine preseason and postseason changes. SEM and minimal detectable change were also calculated. RESULTS: There was a significant difference in center of pressure path length differed between preseason (24.6 [6.8] cm) and postseason (22.7 [5.4] cm) intervals (P = .03), with an SEM of 3.8 cm and minimal detectable change of 10.5 cm. CONCLUSIONS: Significant improvements occurred for center of pressure path length after a competitive season, when assessed using the BTrackS in a sample of college athletes. Further research is warranted to determine the effectiveness of the BTrackS as a reliable, low-cost alternative to force-plate balance systems. In addition, clinicians may need to update baseline balance assessments more frequently to account for improvements.

Acute and protracted disruptions to inhibitory control following sports-related concussion.

Extant evidence demonstrates disruptions to inhibitory control from as little as six months to as long as several years following sports-related concussion. However, the sensitivity of tasks requiring inhibitory control for detecting disruptions to cognition during the acute, subacute, and protracted phases of recovery remains in question. Accordingly, the purpose of this study was to examine concussion-related disruptions to inhibitory control across recovery. Athletes with sports-related concussion (n = 55; 22 female) completed an inhibitory control task within 72 h of injury, after returning to play, and within one month following return to play. Matched control athletes (n = 55; 22 female) were tested at similar intervals. Behavioral indices of performance were analyzed using univariate multi-level modeling. Findings indicated that the concussion group exhibited decrements to inhibitory control immediately after injury and up to one month following return to play, with no such observable differences at the return to play period. In addition to being sensitive to detecting chronic cognitive deficits resulting from sports-related concussion, these findings suggest that inhibitory control measures have the requisite sensitivity to identify the immediate and protracted signs of neurocognitive dysfunction following sports-related concussion. Accordingly, integrating assessments of inhibitory control into baseline, post-injury, and post-season measurement of cognitive function may prove useful for tracking the acute and persistent effects of sports-related concussion across an athlete's career. Athletes exhibiting impaired inhibitory control across the phases of recovery may be at greater risk of reinjury, thereby suggesting that integrating inhibitory control assessments into existing clinical measures may be of interest for informing concussion management and return-to-play decisions.

Preliminary evidence for differential trajectories of recovery for cognitive flexibility following sports-related concussion.

OBJECTIVE: A critical barrier to the understanding of disruptions to cognitive flexibility following sports-related concussion is the use of assessments that conflate shifts of visuospatial attention and contextual rules. Because these dissociable forms of cognitive flexibility are subserved by distinct neural networks, the utility of a cognitive flexibility assessment following concussion may be reduced, depending upon the extent to which the task requires shifting visuospatial attention relative to shifting contextual rules. Accordingly, the current investigation examined the extent to which these aspects of cognitive flexibility exhibit differential trajectories of recovery following a sports-related concussion. METHOD: Twenty-two athletes with sports-related concussions were assessed on a cognitive flexibility task with 2 switch conditions (i.e., perceptual-based and contextual rule-based) within 72 hr of injury, after return to play, and within 1 month following return to play. Thirty-three healthy control athletes were tested at the same intervals. RESULTS: Findings revealed that concussed athletes demonstrated protracted disruptions in task performance on a visuospatial attention-based cognitive flexibility task relative to healthy controls, whereas disruptions in task performance on a contextual rule-based cognitive flexibility task resolved after the acute phase of injury. These findings suggest that dissociable forms of cognitive flexibility exhibit differential trajectories of recovery. CONCLUSIONS: Therefore, evaluations detecting sports-related concussion disruptions in cognitive flexibility may be reduced depending on the extent to which they rely on contextual rule-based decisions. Test batteries focusing on visuospatial attention-based demands may be useful additions to aid in the objective assessment and follow-up management of athletes following the acute phase of injury. (PsycINFO Database Record

Sports-Related Concussion Occurrence at Various Time Points During High School Athletic Events: Part 2.

BACKGROUND: Sports-related concussion (SRC) injury rates, and identifying those athletes at the highest risk, have been a primary research focus. However, no studies have evaluated at which time point during an athletic event athletes are most susceptible to SRCs. PURPOSE: To determine the clinical incidence of SRCs during the start, middle, and end of practice and competition among high school male and female athletes in the state of Michigan. STUDY DESIGN: Descriptive epidemiological study. METHODS: There were 110,774 male and 71,945 female student-athletes in grades 9 through 12 (mean time in high school, 2.32 ± 1.1 years) who participated in sponsored athletic activities (13 sports) during the 2015-2016 academic year. An SRC was diagnosed and managed by a medical professional (ie, MD, DO, PA, NP). SRC injuries were reported by certified athletic trainers, athletic administrators, and coaches using the Michigan High School Athletic Association Head Injury Reporting System. Time of SRC was defined as the beginning, middle, or end of practice/competition. Clinical incidence was calculated by dividing the number of SRCs in a time point (eg, beginning) by the total number of participants in a sport per 100 student-athletes (95% CI). Risk ratios were calculated by dividing one time point by another time point. RESULTS: There were 4314 SRCs reported, with the highest in football, women's basketball, and women's soccer. The total clinical incidence for all sports was 2.36 (95% CI, 2.29-2.43) per 100 student-athletes. The most common time for SRCs was the middle, followed by the end of all events. Athletes had a 4.90 (95% CI, 4.44-5.41) and 1.50 (95% CI, 1.40-1.60) times greater risk during the middle of all events when compared with the beginning and end, respectively. There was a 3.28 (95% CI, 2.96-3.63) times greater risk at the end of all events when compared with the beginning. CONCLUSION: Athletes were at the greatest risk for SRCs at the middle of practice and competition when compared with the beginning and end. CLINICAL RELEVANCE: The current study suggests that medical attention is particularly important during the middle of all athletic events. Intervention measures to limit SRCs may be most beneficial during the middle of athletic events.

Sex Differences in the Clinical Incidence of Concussions, Missed School Days, and Time Loss in High School Student-Athletes: Part 1.

BACKGROUND: Sports-related concussion (SRC) injury rates are well established in collegiate athletics through epidemiological studies using the National Collegiate Athletic Association Injury Surveillance System. However, few studies have examined sex differences, time loss, and missed school days in high school athletes, especially at the state level. PURPOSE: To identify sex differences in the clinical incidence of SRCs, missed school days, and time loss in high school student-athletes. STUDY DESIGN: Descriptive epidemiological study. METHODS: A total of 193,757 (116,434 male and 77,323 female) student-athletes (10th grade ± 1.1) participating in Michigan High School Athletic Association (MHSAA)-sponsored athletic activities were recorded in the Head Injury Reporting System. Certified athletic trainers, school athletic administrators, and coaches from MHSAA high schools reported SRC data and overall participation for the 2015-2016 academic year. Total concussive injuries, as well as missed school days and time loss for each concussive injury, were reported. The clinical incidence was calculated by dividing the number of SRCs in a particular category by the number of participants in that category and presented with 95% CIs. Relative risk ratios (RRs) were determined for sex-comparable sports. RESULTS: The overall clinical incidence for all sports was 1.7 per 100 player-seasons (95% CI, 1.6-1.8) and 1.9 (95% CI, 1.8-2.0) for male sports and 1.5 (95% CI, 1.4-1.6) for female sports. Female athletes were at a 1.9 (95% CI, 1.8-2.2) times greater risk for enduring SRCs than male athletes in sex-comparable sports, with a greater risk in baseball/softball (RR, 2.7 [95% CI, 1.9-3.8]), basketball (RR, 2.5 [95% CI, 2.1-2.9]), and soccer (RR, 1.6 [95% CI, 1.4-1.9]). Female student-athletes had significantly longer time loss than male student-athletes ( P < .001). The mean number of missed school days did not differ between sexes ( P = .70). CONCLUSION: High school female student-athletes have a higher risk for an SRC in all sex-comparable sports except lacrosse. This may be because of biomechanical differences of the head-neck segment, hormonal differences, and the fact that female athletes are more likely to report symptoms after a suspected SRC. CLINICAL RELEVANCE: Despite sex differences in the clinical incidence of SRCs and time loss from participation in high school sports, the numbers of missed school days are relatively similar between sexes.