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Context: Plyometric training has been shown to be beneficial in adolescent overhead athletes. However, existing research on the effects of plyometrics on sport performance has been limited. Objective: To systematically review the current literature to investigate whether plyometric training intervention improves upper- and lower-body sport performance. Data Sources: Two electronic databases (MEDLINE and Web of Science) were searched using specific Medical Subject Headings (MeSH) terms up to February 2019, and hand-searching was performed by looking to relevant studies that were cited in other studies. Study Selection: A total of 932 items were identified and were further assessed for the eligibility in the systematic review. For a study to be eligible, each of the following inclusion criteria had to be met: (1) participants were aged 13 to 18 years and selected from a sports or athletic population and the study (2) involved the evaluation of a plyometric training intervention with an aim to improve sports performance; (3) must have included a control intervention and/or control group; (4) included a quantitative objective measure of sport performance variables concerning throwing, jumping, running, and sprinting; and (5) was published in English. Study Design: Systematic review. Level of Evidence: Level 3. Data Extraction: A first screening was conducted based on title and abstract of the articles. In the second screening, the full text of the remaining articles was evaluated for the fulfillment of the inclusion criteria. Results: A total of 14 studies were included in this review. The methodological quality of the included studies ranged from low to moderate. There is moderate evidence that plyometric training intervention improves throwing and jumping performances. There is also preliminary evidence that plyometric training intervention improves sprint performance. Conclusion: The current evidence suggests that sport performance consisting of throwing capacity, jumping ability, and sprint performance significantly improved due to plyometric training interventions in adolescent overhead athletes.

Background: Current research on concussion incidence in youth athletes (age Hypothesis: Concussion injuries commonly occur in high school sports programs. The likelihood of concussion among student-athletes (aged 13-18 years) depends on the sport they are participating in as well as the sex of the athlete. Study Design: Descriptive epidemiology study. Level of Evidence: Level 4. Methods: A retrospective analysis of all Hawaii high school athletes aged 13 to 18 years participating in 14 sports from 2011 through 2017 was performed as part of a statewide standardized concussion assessment and management program. Results: A total of 5993 concussions were identified among 92,966 athletes. The overall concussion rate was 0.96 (95% CI, 0.94-0.99). Girls’ judo had the highest concussion rate (1.92; 95% CI, 1.68-2.17) followed by football (1.60; 95% CI, 1.53-1.66). The concussion rate for boys (1.0; 95% CI, 0.97-1.03) was higher than that for girls (0.91; 95% CI, 0.87-0.95); however, in 4 of the 5 sports in which both girls and boys participated, girls had a higher rate of concussion injury. Conclusion: The likelihood of concussion among student-athletes aged 13 to 18 years may be higher than previously thought and varies depending on sport and sex. Clinical Relevance: Epidemiologic data on concussion injury in children and adolescents are useful in accurately determining the relative risks of high school sports participation and may be valuable in determining the appropriate allocation of health care and scholastic resources for student-athletes, as well as the impact of rule and training modifications designed to improve participant safety.

Background: Functional bracing is often used as an adjunct to nonoperative treatment of anterior shoulder instability, but no study has evaluated the effectiveness of in-season bracing. The purpose of this study was to examine successful return to play in a nonoperative cohort of adolescent athletes with in-season shoulder instability and compare those athletes treated with bracing to those who were not. Hypothesis: The use of functional bracing will improve success rates in a cohort of athletes treated nonoperatively for in-season shoulder instability. Study Design: Cohort study. Level of Evidence: Level 3. Methods: A total of 97 athletes with anterior shoulder instability were followed for a minimum of 1 year. The mean age was 15.8 ± 1.4 years (range, 12.0-18.0 years). All athletes were treated with initial nonoperative management. Twenty athletes (21%) were also treated with bracing while 77 (79%) were not. The athlete completing the current season and 1 subsequent season without surgery or time lost from shoulder injury was defined as a successful outcome. Results: There was no statistical difference in nonoperative success rates between the braced and nonbraced athletes ( P = 0.33). Braced athletes (n = 20) returned to play 80% of the time, while nonbraced athletes (n = 77) returned at a rate of 88%. Of the braced athletes, 85% were football players (n = 17). A football-only comparison demonstrated no difference between braced failures (26%) and nonbraced failures (16%) ( P = 0.47). Conclusion: This is the first study to evaluate the utility of functional bracing in returning an athlete to sport and completing a full subsequent season without surgery or time loss due to injury of the shoulder. In adolescent athletes with shoulder instability treated nonoperatively, functional bracing did not result in increased success rates when compared with no bracing. Clinical Relevance: The data from this study indicate that functional bracing may not improve success rates for athletes with shoulder instability.

Background: The long-term effect of sport-related concussion on mood in adolescent athletes is largely unknown. Hypothesis: Longitudinal measures of depression will worsen acutely after sport-related concussion and improve with concussion symptom resolution. Study Design: Prospective cohort study. Level of Evidence: Level 3. Methods: A population-based sample of 2160 high school athletes from 31 urban, suburban, and rural high schools completed preseason baseline concussion symptom evaluation and Patient Health Questionnaire–9 (PHQ-9) assessments over 2 years. Athletic trainers recorded onset of sport-related concussion, and concussed athletes completed the PHQ-9 assessment within 24 to 72 hours, 7 days, date of return to sport, 3 months, 6 months, and 12 months after sport-related concussion. Scores at each time point were compared to baseline with mixed-effects models and repeated-measures analysis of variance. Sex-based differences were assessed using mixed-effect models. Results: Of the 2160 athletes enrolled in the study, 125 (5.8%; 80 males, 45 females) sustained a sport-related concussion. PHQ-9 scores worsened from baseline at 24 to 72 hours (+1.05; 95% CI, 0.26-1.84; P = 0.003) and 7 days (+0.91; 95% CI, 0.23-1.60; P = 0.006). However, PHQ-9 scores improved from baseline to date of return to sport (−1.38; 95% CI, −2.20 to −0.55; P < 0.001), 3 months (−1.08; 95% CI, −1.88 to −0.28; P = 0.003), 6 months (−1.19; 95% CI, −2.04 to −0.34; P = 0.001), and 12 months after sport-related concussion (−0.76; 95% CI, −1.43 to −0.08; P = 0.028). Female athletes reported more severe concussion symptoms 24 to 72 hours after sport-related concussion compared with male athletes (female, 20.5 [interquartile range (IQR), 10.0-36.2]; male, 9.0 [IQR, 4.0-19.5]; P = 0.003). Neither PHQ-9 scores nor change in PHQ-9 scores differed between male and female athletes at any time point. Conclusion: Sport-related concussion did not worsen longitudinal measures of depressed mood in this cohort of high school athletes. Clinical Relevance: Emotional symptoms are common after sport-related concussion, but typically resolve by return to sport.