Clinical Focus

  • Orthopaedic Sports Medicine

Academic Appointments

Administrative Appointments

  • Team Physician, Golden State Warriors (2016 - 2019)
  • Team Physician, Stanford Athletics (2016 - Present)
  • Assistant Fellowship Director, Primary Care Sports Medicine Fellowship (2016 - Present)

Boards, Advisory Committees, Professional Organizations

  • Councilor, American College of Emergency Physicians, Sports Medicine Section (2020 - Present)
  • Fellowship Committee, American Medical Society for Sports Medicine (2020 - Present)
  • Alternate Councilor, American College of Emergency Physicians, Sports Medicine Section (2018 - 2020)
  • Fellow, American College of Emergency Physicians (2017 - Present)
  • Member, American Medical Society for Sports Medicine (2016 - Present)
  • Fellow, American Academy of Emergency Medicine (2014 - Present)
  • Member, American College of Emergency Physicians (2011 - Present)
  • Member, American Academy of Emergency Medicine (2011 - Present)

Professional Education

  • Board Certification: American Board of Emergency Medicine, Sports Medicine (2015)
  • Residency: Stanford University Emergency Medicine Residency (2014) CA
  • Board Certification: American Board of Emergency Medicine, Emergency Medicine (2015)
  • Fellowship: Stanford Hospital and Clinics - Dept of Orthopaedics (2015) CA
  • MD, Case Western Reserve University School of Medicine (2011)
  • BS, Stanford University, Biological Sciences with Honors (2007)

Graduate and Fellowship Programs

  • Sports Medicine (Fellowship Program)

All Publications

  • Diagnosis of Sports-Related Concussion Using Symptom Report or Standardized Assessment of Concussion. JAMA network open Harmon, K. G., Whelan, B. M., Aukerman, D. F., Hwang, C. E., Poddar, S. K., DeLeo, A., Elkington, H. A., Garruppo, G., Holliday, M., Bruce, J. M. 2024; 7 (6): e2416223


    Importance: The Sports Concussion Assessment Tool-5 (SCAT5) has been recommended for concussion evaluation and utilizes both a subjective reported symptom grading scale and objective measures of concussion including a cognitive evaluation: the Standardized Assessment of Concussion (SAC). The SAC includes testing for orientation, immediate memory, concentration, and delayed recall; a 10-word list is used to assess immediate memory and delayed recall.Objective: To determine the diagnostic accuracy of components of the SCAT5 and to provide a framework for clinical interpretation.Design, Setting, and Participants: This prospective case-control study of National Collegiate Athletic Association Division I athletes from any sport was conducted from July 2020 to December 2022 at 4 universities. Athletes completed baseline SCAT5 testing using the 10-word list. When an athlete presented acutely with suspected concussion (sideline or within 2 days), the tests were repeated. If a concussion was diagnosed, a control athlete underwent the same tests. Controls were identified and matched on comorbid conditions, sex and gender, sport, season, and baseline scores. Data analysis was conducted from August to October 2023.Main Outcomes and Measures: The primary outcomes were area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive and negative predictive value, and test-retest reliability of the symptom score; symptom severity score; the total SAC score; and the orientation, immediate memory, concentration, and delayed memory subcomponent scores on the SCAT5 compared with clinical diagnosis of concussion.Results: Baseline and postinjury data were collected on 92 athletes with concussion and 92 matched control athletes (96 men [52%] and 88 women [48%]; 110 who played a sport other than football [59%]). Diagnostic utility was considered excellent for symptom score (AUC, 0.93; 95% CI, 0.89-0.96) and symptom severity score (AUC, 0.94; 95% CI, 0.90-0.97). An increase of 2 points on the symptom score was associated with a sensitivity of 86% (95% CI, 78%-92%), specificity of 80% (95% CI, 70%-87I%), and positive predictive value of 81% (95% CI, 72%-88%). The total SAC score had poor to fair diagnostic utility (AUC, 0.70; 95% CI, 0.63-0.77); however, 41 athletes with concussion (45%) had a total SAC score at or above their baseline score (ie, within normal limits). The diagnostic utility was poor to fair for immediate memory (AUC, 0.68, 95%CI, 0.61-0.75) and delayed recall (AUC, 0.69; 95% CI, 0.62-0.77) and not useful for orientation (AUC, 0.49; 95% CI, 0.43-0.56) and concentration (AUC, 0.52 95% CI, 0.44-0.61). Test-retest reliability was fair for total SAC and poor for immediate memory and delayed recall, orientation, and concentration.Conclusions and Relevance: In this case-control study of the diagnostic accuracy of reported symptoms and the SAC, reported symptoms were the most accurate indicator of concussion while the 10-word SAC had limited sensitivity. These findings suggest that understanding the properties of the SAC is important when making the diagnosis of concussion.

    View details for DOI 10.1001/jamanetworkopen.2024.16223

    View details for PubMedID 38861257

  • Training Background and Demographic Characteristics of Primary Care Team Physicians in Professional Sports. Orthopaedic journal of sports medicine Schultz, E. A., Durtschi, M. S., Oakes, K. G., Kussman, A., Hwang, C. E. 2024; 12 (4): 23259671241242412


    Previous studies have shown that most professional head and orthopaedic team physicians are men, and most orthopaedic team physicians are fellowship-trained. It is unknown whether this holds true for primary care team physicians.To evaluate the residency and fellowship training background as well as the demographic characteristics of primary care team physicians in professional sports.Cross-sectional study.Publicly available information was used to determine the lead and supporting primary care team physicians for every US-based team in Major League Baseball, Major League Soccer, National Basketball Association, National Football League, National Hockey League, National Women's Soccer League, and Women's National Basketball Association. Data regarding training background and sex were obtained using internet-based sources.We identified 310 primary care team physicians from all 165 US-based teams in the 7 leagues included in the study. Female physicians comprised 11.5% (19/165) of the lead primary care team physicians and 14.2% (44/310) of all primary care team physicians. Overall, 66.7% (110/165) of lead primary care team physicians and 75.5% (234/310) of all primary care team physicians were sports medicine fellowship-trained. There was a higher proportion of female (37.5%) and fellowship-trained (93.8%) physicians in women's professional sports leagues. Most primary care team physicians (244/310 [78.7%]) were trained in family medicine or internal medicine.Women constituted a small minority of primary care team physicians in professional sports. Most primary care team physicians were residency trained in family medicine or internal medicine and were sports medicine fellowship-trained. The proportion of female and fellowship-trained primary care team physicians was highest in the National Women's Soccer League and the Women's National Basketball Association.

    View details for DOI 10.1177/23259671241242412

    View details for PubMedID 38680217

    View details for PubMedCentralID PMC11047226

  • Emergency Facial Injuries in Athletics. Clinics in sports medicine Tsao, J., Hwang, C. E. 2023; 42 (3): 463-471


    Dental and oral injuries are a common occurrence in sport. Initial evaluation should always begin with an assessment of the patient's airway, breathing, circulation, as well as identification of associated injuries. Tooth avulsions are the only true dental emergency. Oral lacerations frequently do not require repair; however, special attention should be paid to lip lacerations involving the vermillion border. Most tooth and oral lacerations can be treated on the field with urgent referral to a dentist.

    View details for DOI 10.1016/j.csm.2023.02.009

    View details for PubMedID 37208059

  • American Medical Society of Sports Medicine Position Statement: Mononucleosis and Athletic Participation. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine Putukian, M., McGrew, C. A., Benjamin, H. J., Hammell, M. K., Hwang, C. E., Ray, J. W., Statuta, S. M., Sylvester, J., Wilson, K. 2023


    Infectious mononucleosis (IM) is a common illness in children and young adults caused primarily by the Epstein-Barr Virus (EBV). Transmission occurs primarily through sharing oral secretions, thus IM is known as the "kissing disease." Common clinical manifestations include fever, pharyngitis, posterior cervical lymphadenopathy, and splenomegaly. Atypical lymphocytosis and transaminase elevations are common, and the diagnosis of IM is confirmed with laboratory findings of a positive heterophile antibody ("Monospot"), polymerase chain reaction, or antibodies specific to EBV. Individuals with acute IM may be quite symptomatic and not feel well enough to participate in sports. Splenic enlargement is common, with rupture a relatively rare occurrence, typically occurring within a month of symptom onset, but this risk complicates sports participation, and is often the reason for restricting activity. The management of IM is primarily supportive, with no role for antivirals or corticosteroids. The variability of clinical presentation and the risk of splenic rupture in patients with IM present clinicians with challenging return to play/return to sport (RTS) decisions. This position statement updates the Evidence-Based Subject Review on Mononucleosis by the American Medical Society for Sports Medicine published in 2008 and reviews the epidemiology, clinical manifestations, laboratory assessment, and management including RTS for the athlete with IM. This statement also addresses complications, imaging, special considerations, diversity and equity considerations, and areas for future clinical research. Understanding the evidence regarding IM and sport is essential when communicating with athletes and their families and incorporating shared decision-making in the RTS decision.

    View details for DOI 10.1097/JSM.0000000000001161

    View details for PubMedID 37186809

  • Premature ventricular contractions (PVCs) in young athletes. Progress in cardiovascular diseases Gomez, S. E., Hwang, C. E., Kim, D. S., Froelicher, V. F., Wheeler, M. T., Perez, M. V. 2022


    There is a growing body of literature focusing on the morphology, management, and outcomes of PVCs in athletes. This review summarizes this literature and establishes recommendations on management, treatment, and indications for specialist referral in this patient population. The sports medicine physician's responses and recommendation should be made in conjunction with the athletes wishes. Medications or ablations are not always necessary in all athletes if they are followed with regular evaluations.

    View details for DOI 10.1016/j.pcad.2022.10.011

    View details for PubMedID 36309100

  • Prevalence of Positive Rapid Antigen Tests After 7-Day Isolation Following SARS-CoV-2 Infection in College Athletes During Omicron Variant Predominance. JAMA network open Tsao, J., Kussman, A., Segovia, N. A., Abrams, G. D., Boehm, A. B., Hwang, C. E. 2022; 5 (10): e2237149


    Importance: The US Centers for Disease Control and Prevention shortened the recommended isolation period for SARS-CoV-2 infection from 10 days to 5 days in December 2021. It is unknown whether an individual with the infection may still have a positive result to a rapid antigen test and potentially be contagious at the end of this shortened isolation period.Objective: To estimate the proportion of individuals with SARS-CoV-2 infection whose rapid antigen test is still positive starting 7 days postdiagnosis.Design, Setting, and Participants: This case series analyzed student athletes at a National Collegiate Athletic Association Division I university campus who tested positive for SARS-CoV-2 between January 3 and May 6, 2022. Individuals underwent rapid antigen testing starting 7 days postdiagnosis to determine whether they could end their isolation period.Exposures: Rapid antigen testing 7 days after testing positive for SARS-CoV-2.Main Outcomes and Measures: Rapid antigen test results, symptom status, and SARS-CoV-2 variant identification via campus wastewater analysis.Results: A total of 264 student athletes (140 [53%] female; mean [SD] age, 20.1 [1.2] years; range, 18-25 years) representing 268 infections (177 [66%] symptomatic, 91 [34%] asymptomatic) were included in the study. Of the 248 infections in individuals who did a day 7 test, 67 (27%; 95% CI, 21%-33%) tests were still positive. Patients with symptomatic infections were significantly more likely to test positive on day 7 vs those who were asymptomatic (35%; 95% CI, 28%-43% vs 11%; 95% CI, 5%-18%; P<.001). Patients with the BA.2 variant were also significantly more likely to test positive on day 7 compared with those with the BA.1 variant (40%; 95% CI, 29%-51% vs 21%; 95% CI, 15%-27%; P=.007).Conclusions and Relevance: In this case series, rapid antigen tests remained positive in 27% of the individuals after 7 days of isolation, suggesting that the Centers for Disease Control and Prevention-recommended 5-day isolation period may be insufficient in preventing ongoing spread of disease. Further studies are needed to determine whether these findings are present in a more heterogeneous population and in subsequent variants.

    View details for DOI 10.1001/jamanetworkopen.2022.37149

    View details for PubMedID 36255722

  • Use of Monospot Testing in the Diagnosis of Infectious Mononucleosis in the Collegiate Student-Athlete Population. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine Wang, E. X., Kussman, A., Hwang, C. E. 2022; 32 (5): 467-470


    OBJECTIVE: To determine the utility of monospot testing in the diagnosis of mononucleosis in the collegiate student-athlete clinical setting.DESIGN: Retrospective cohort study.SETTING: National Collegiate Athletic Association Division I sports medicine clinic.PATIENTS: All varsity student athletes who had a monospot test and Epstein-Barr virus (EBV) titers obtained from January 1, 2016, through March 31, 2020, (n = 199) were included.INDEPENDENT VARIABLES: Monospot, EBV antibody titers, and liver transaminase results.MAIN OUTCOME MEASURES: Using EBV titers indicating acute or recent infection as the gold standard for diagnosing infectious mononucleosis (IM), the reliability of a positive monospot test and elevated liver transaminases for the diagnosis of IM were examined.RESULTS: The monospot test had a sensitivity and specificity of 80.0% and 90.6%, respectively, with a positive predictive value of 36.4% and a negative predictive value of 98.5% in this cohort. All athletes diagnosed with IM also had elevated liver transaminases.CONCLUSIONS: The specificity of the monospot test is lower than previously reported in the literature, and a positive test is not sufficient to diagnose mononucleosis in this clinical setting. Positive monospot results should be confirmed with EBV antibody testing. Elevated transaminase levels are highly correlated with acute IM and could play a supporting role in the diagnosis.

    View details for DOI 10.1097/JSM.0000000000000996

    View details for PubMedID 36083325

  • Increased Risk of ACL Injury for Female but Not Male Soccer Players on Artificial Turf Versus Natural Grass: A Systematic Review and Meta-Analysis. Orthopaedic journal of sports medicine Xiao, M., Lemos, J. L., Hwang, C. E., Sherman, S. L., Safran, M. R., Abrams, G. D. 2022; 10 (8): 23259671221114353


    Background: Both natural grass (NG) and artificial turf (AT) are popular playing surfaces for soccer. Biomechanical studies have found increased frictional forces on AT that may lead to anterior cruciate ligament (ACL) injury. The increased risk of ACL injury during soccer in female participants may amplify this effect.Purpose: To systematically review the literature for studies comparing ACL injury risk in soccer players on AT versus NG and to specifically determine whether there were differences in injury risk in male versus female players when considering the playing surface.Study Design: Systematic review; Level of evidence, 3.Methods: A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Three databases were searched for studies with evidence level 1 to 3 that compared the incidence of ACL injuries on AT versus NG in soccer players. Data recorded included study characteristics, sex, competition level, exposure setting (games or practices), turf type, and ACL injury information. Study methodological quality was analyzed using the methodological index for non-randomized studies (MINORS) score, and incidence rate ratios (IRRs) were calculated.Results: Included were 7 articles (3 studying professional soccer, 3 collegiate soccer, 1 youth-level soccer; 4 male cohorts, 2 female cohorts, and 1 male and female cohort; mean MINORS score, 20 ± 0.8). Pooled ACL injury IRRs demonstrated no significant differences in overall ACL injury risk when playing soccer on AT compared with NG (IRR = 0.57 [95% CI, 0.21-1.53]; P = .31). A significantly increased risk of ACL injury in games played on AT compared with NG was detected for female (IRR = 1.18 [95% CI, 1.05-1.31]; P = .004) but not for male players (IRR = 1.18 [95% CI, 0.97-1.42]; P = .09). Subgroup analyses showed no significant differences in injury risk for games (IRR = 1.07 [95% CI, 0.97-1.18]; P = .20) or practices (IRR = 0.21 [95% CI, 0.04-1.23]; P = .09).Conclusion: Findings indicated that female soccer players had a significantly higher risk of ACL injury when playing games on AT versus NG, whereas no significant difference was seen in male players. No differences were found for the combined male/female cohort or for soccer games or training sessions played on AT compared with NG.

    View details for DOI 10.1177/23259671221114353

    View details for PubMedID 35990873

  • Wastewater-Based Detection of Two Influenza Outbreaks ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS Wolfe, M. K., Duong, D., Bakker, K. M., Ammerman, M., Mortenson, L., Hughes, B., Arts, P., Lauring, A. S., Fitzsimmons, W. J., Bendall, E., Hwang, C. E., Martin, E. T., White, B. J., Boehm, A. B., Wigginton, K. R. 2022
  • Accuracy of Rapid Antigen vs Reverse Transcriptase-Polymerase Chain Reaction Testing for SARS-CoV-2 Infection in College Athletes During Prevalence of the Omicron Variant. JAMA network open Tsao, J., Kussman, A. L., Costales, C., Pinsky, B. A., Abrams, G. D., Hwang, C. E. 2022; 5 (6): e2217234

    View details for DOI 10.1001/jamanetworkopen.2022.17234

    View details for PubMedID 35704320

  • Comparison of SARS-CoV-2 Test Positivity in NCAA Division I Student Athletes vs Nonathletes at 12 Institutions. JAMA network open Schultz, E. A., Kussman, A., Jerome, A., Abrams, G. D., Hwang, C. E. 2022; 5 (2): e2147805


    Importance: The COVID-19 pandemic initially led to the abrupt shutdown of collegiate athletics until guidelines were established for a safe return to play for student athletes. Currently, no literature exists that examines the difference in SARS-CoV-2 test positivity between student athletes and nonathletes at universities across the country.Objective: To identify the difference in risk of COVID-19 infection between student athlete and nonathlete student populations and evaluate the hypothesis that student athletes may display increased SARS-CoV-2 test positivity associated with increased travel, competition, and testing compared with nonathletes at their respective universities.Design, Setting, and Participants: In this cross-sectional analysis, a search of publicly available official university COVID-19 dashboards and press releases was performed for all 65 Power 5 National Collegiate Athletic Association (NCAA) Division I institutions during the 2020 to 2021 academic year. Data were analyzed at the conclusion of the academic year. Schools that released at least 4 months of testing data, including the fall 2020 football season, for student athletes and nonathlete students were included in the analysis. Power 5 NCAA Division I student athletes and their nonathlete student counterparts were included in the analysis.Exposure: Designation as a varsity student athlete.Main Outcomes and Measures: The main outcome was SARS-CoV-2 test positivity for student athletes and nonathlete students at the included institutions for the 2020 to 2021 academic year, measured as a relative risk for student athletes.Results: Among 12 schools with sufficient data available included in the final analysis, 555 372 student athlete tests and 3 482 845 nonathlete student tests were performed. There were 9 schools with decreased test positivity in student athletes compared with nonathlete students (University of Arkansas: 0.01% vs 3.52%; University of Minnesota: 0.63% vs 5.96%; Penn State University: 0.74% vs 6.58%; Clemson University: 0.40% vs 1.88%; University of Louisville: 0.75% vs 3.05%; Purdue University: 0.79% vs 2.97%; University of Michigan: 0.40% vs 1.12%; University of Illinois: 0.17% vs 0.40%; University of Virginia: 0.64% vs 1.04%) (P<.001 for each). The median (range) test positivity in these 9 schools was 0.46% (0.01%-0.79%) for student athletes and 1.04% (0.40%-6.58%) for nonathlete students. In 1 school, test positivity was increased in the student athlete group (Stanford University: 0.20% vs 0.05%; P<.001). Overall, there were 2425 positive tests (0.44%) among student athletes and 30 567 positive tests (0.88%) among nonathlete students, for a relative risk of 0.50 (95% CI, 0.48-0.52; P<.001). There was no statistically significant difference in student athlete test positivity between included schools; however, test positivity among nonathlete students varied considerably between institutions, ranging from 133 of 271 862 tests (0.05%) at Stanford University to 2129 of 32 336 tests (6.58%) at Penn State University.Conclusions and Relevance: This study found that in the setting of SARS-CoV-2 transmission mitigation protocols implemented by the NCAA, participation in intercollegiate athletics was not associated with increased SARS-CoV-2 test positivity. This finding suggests that collegiate athletics may be held without an associated increased risk of infection among student athletes.

    View details for DOI 10.1001/jamanetworkopen.2021.47805

    View details for PubMedID 35138397

  • Patients Who Return to Sport After Primary Anterior Cruciate Ligament Reconstruction Have Significantly Higher Psychological Readiness: A Systematic Review and Meta-analysis of 3744 Patients Am J Sports Med Xiao, M., van Niekerk, M., Trivedi, N., Hwang, C., Sherman, S., Safran, M., Abrams, G. 2022
  • Factors Associated With a Prolonged Time to Return to Play After a Concussion. The American journal of sports medicine Wang, E. X., Hwang, C. E., Nguyen, J. N., Segovia, N. A., Abrams, G. D., Kussman, A. 2022: 3635465221083646


    Prognosticating recovery times for individual athletes with a concussion remains a challenge for health care providers. Several preinjury and postinjury factors have been proposed to be predictive of prolonged return-to-play (RTP) times, but the data in this area are still sparse.This study aimed to identify risk factors associated with prolonged recovery times and determine which are most predictive of prolonged recovery times in a head-to-head comparison.Case-control study; Level of evidence, 3.All concussions occurring between September 2017 and August 2020 at a single National Collegiate Athletic Association Division I institution were reviewed and included in this study. Preinjury modifiers including age, sex, sport, concussion history, and past medical problems were collected from the electronic medical records. Postinjury modifiers analyzed included initial and follow-up Sport Concussion Assessment Tool 5th Edition scores, vestibular evaluation findings, and eye tracking results.A total of 159 athletes and 187 concussion cases were included. Preinjury factors that were correlated with prolonged RTP times included a history of concussions (P = .015), a history of migraines (P = .013), and whether an athlete participated in an individual sport (P = .009). Postinjury factors correlated with prolonged RTP times included the total number (P = .020) and severity (P = .023) of symptoms as well as abnormal Vestibular Ocular Motor Screening findings (P = .002). Overall, 6 different symptoms (balance problems, difficulty concentrating, light sensitivity, drowsiness, fatigue/low energy, and difficulty remembering) were significantly correlated with prolonged RTP times. The study also found that the number and severity of symptoms were additive in a dose-dependent fashion. On multivariable analysis of all these factors, a history of concussions was found to be the most predictive of prolonged RTP times, while participation in an individual sport had the largest effect on recovery times.Several preinjury and postinjury risk factors were identified as being correlated with prolonged recovery times. Many of these risk factors were also found to be additive in nature. This information provides clinicians with a valuable tool in prognosticating and estimating recovery times for athletes. The study also revealed that athletes participating in individual sports had longer RTP times compared with athletes in team sports, which is a novel finding that requires further research.

    View details for DOI 10.1177/03635465221083646

    View details for PubMedID 35316113

  • Use of Platelet-Poor Plasma in Acute Quadriceps Muscle Strain in a Division I Football Placekicker: A Case Report. Current sports medicine reports Kasitinon, D., Dragoo, J. L., Hwang, C. E. 2021; 20 (11): 572-574

    View details for DOI 10.1249/JSR.0000000000000901

    View details for PubMedID 34752428

  • Splenomegaly from Recurrent Infectious Mononucleosis in an NCAA Division I Athlete. Current sports medicine reports Bakal, D. R., Kasitinon, D., Kussman, A. L., Hwang, C. E. 2021; 20 (10): 511-513

    View details for DOI 10.1249/JSR.0000000000000887

    View details for PubMedID 34622813

  • Splenomegaly from Recurrent Infectious Mononucleosis in an NCAA Division I Athlete CURRENT SPORTS MEDICINE REPORTS Bakal, D. R., Kasitinon, D., Kussman, A. L., Hwang, C. E. 2021; 20 (10): 511-513
  • Findings From Cardiovascular Evaluation of National Collegiate Athletic Association Division I Collegiate Student-Athletes After Asymptomatic or Mildly Symptomatic SARS-CoV-2 Infection. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine Hwang, C. E., Kussman, A., Christle, J. W., Froelicher, V., Wheeler, M. T., Moneghetti, K. J. 2021


    OBJECTIVE: The risk of myocardial damage after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been controversial. The purpose of this study is to report the incidence of abnormal cardiovascular findings in National Collegiate Athletic Association (NCAA) Division I student-athletes with a history of SARS-CoV-2 infection.DESIGN: This is a case series of student-athletes with SARS-CoV-2 infection and their subsequent cardiac work-up, including troponin level, electrocardiogram, and echocardiogram. Additional testing was ordered as clinically indicated.SETTING: This study was conducted at a single NCAA Division I institution.PARTICIPANTS: Student-athletes were included if they tested positive for SARS-CoV-2 by PCR or antibody testing [immunoglobulin G (IgG)] from April 15, 2020 to October 31, 2020.INTERVENTION: Cardiac testing was conducted as part of postinfection screening.MAIN OUTCOME MEASURES: This study was designed to quantify abnormal cardiovascular screening results and cardiac diagnoses after SARS-CoV-2 infection in Division I collegiate athletes.RESULTS: Fifty-five student-athletes tested positive for SARS-CoV-2. Of these, 14 (26%) had a positive IgG and 41 (74%) had a positive PCR test. Eight abnormal cardiovascular screening evaluations necessitated further testing including cardiac magnetic resonance imaging (cMRI). Two athletes received new cardiac diagnoses, one probable early cardiomyopathy and one pericarditis, whereas the remaining 6 had normal cMRIs.CONCLUSIONS: These data support recent publications which recommend the de-escalation of cardiovascular testing such as cardiac MRI or echocardiogram for athletes who have recovered from asymptomatic or mildly symptomatic SARS-CoV-2 infection. Continued follow-up of these athletes for sequelae of SARS-CoV-2 is critical.

    View details for DOI 10.1097/JSM.0000000000000954

    View details for PubMedID 34173780

  • High Specialization among Female Youth Soccer Players Is Associated with an Increased Likelihood of Serious Injury. Medicine and science in sports and exercise Xiao, M., Lemos, J. L., Hwang, C. E., Sherman, S. L., Safran, M. R., Abrams, G. D. 2021


    PURPOSE: To assess the associations between serious injury (> 3-month time loss) and level of specialization among high-level female soccer players and to compare the specialization and college commitment ages of female youth soccer players to Division I college and professional soccer athletes.METHODS: Youth, college, and professional female soccer players in the United States playing in the top league at each level were recruited to complete an anonymous online survey. The survey collected information about player demographics, soccer specialization and training patterns, history of serious injuries from soccer, and perceptions surrounding soccer specialization. Comparisons between groups were performed using 2-sample t-tests, chi-squared analyses, and multiple logistic regression models controlling for differences in age. A p-value of less than 0.05 was set as significant.RESULTS: A total of 1,018 (767 youth, 251 college/professional) athletes completed the survey. Serious injuries affected 23.6% of youth and 51.4% of college/professional athletes. Anterior cruciate ligament (ACL) tears were more prevalent in college/professional players compared to youth athletes (18.3% vs 4.0%; p < 0.001). Highly specialized youth athletes (66.5%) were more likely to have sustained a serious injury from soccer compared to athletes with low specialization (Odds Ratio (OR) = 2.28 [1.38-3.92]; p=0.008) but not moderate specialization (OR = 1.37 [0.83-2.27]; p=0.43). A higher proportion of youth athletes specialized at a young age (< 10 years) compared to college/professional players (44.2% vs 25.9%; p < 0.001).CONCLUSION: High specialization in female youth soccer players is associated with an increased likelihood of sustaining a serious injury. Current youth soccer players are specializing earlier and committing to play college soccer at a younger age compared to when current college and professional players did.

    View details for DOI 10.1249/MSS.0000000000002693

    View details for PubMedID 33927169

  • Adenovirus Infection and Rhabdomyolysis as a Cause of Acute Liver Failure in a Healthy Collegiate Football Athlete: A Case Report and Proposed Return to Play Protocol for Rhabdomyolysis. Cureus Hwang, C. E., Matheson, G., Baine, J. 2021; 13 (4): e14510


    Adenovirus is a common cause of upper respiratory and gastrointestinal tract infections. Though cases of significant organ failure and death have been reported in young children and immunocompromised individuals, adenovirus infections in healthy individuals are typically self-limiting without significant morbidity or mortality. Exertional rhabdomyolysis is a pathologic condition resulting from repetitive, excessive, or prolonged exercise, often in a hot environment, leading to acute muscle injury, renal injury and, rarely, death. We report a case of adenovirus infection leading to acute liver failure complicated by rhabdomyolysis in a collegiate football player presenting with nausea, vomiting, and diarrhea. We propose a protocol to safely guide the return to play progression for patients with complicated exertional rhabdomyolysis.

    View details for DOI 10.7759/cureus.14510

    View details for PubMedID 34079658

    View details for PubMedCentralID PMC8159334

  • Adenovirus Infection and Rhabdomyolysis as a Cause of Acute Liver Failure in a Healthy Collegiate Football Athlete: A Case Report and Proposed Return to Play Protocol for Rhabdomyolysis CUREUS Hwang, C. E., Matheson, G., Baine, J. 2021; 13 (4)
  • Recommended Musculoskeletal and Sports Medicine Model Curriculum for Emergency Medicine Residency Training. Current sports medicine reports Chow, Y. C., Waterbrook, A. L., Suffoletto, H. N., Dolbec, K. n., Myers, R. A., Denq, W. n., Hwang, C. E., Kiel, J. M., Monseau, A. J., Balcik, B. J., Santelli, J. A., Oshlag, B. L., Hudson, K. B., Delasobera, B. E., Feden, J. P., Davenport, M. n., Childress, J. M., Desai, N. N., Gould, S. J., Holschen, J. C. 2021; 20 (1): 31–46


    Musculoskeletal and sports medicine conditions are common in the emergency department (ED). Emergency physicians may not be receiving adequate education to achieve clinical competency in musculoskeletal medicine during residency training. This article aims to provide a standardized musculoskeletal and sports medicine curriculum for emergency medicine training. Broad curriculum goals include proficiency in evaluating and managing patients presenting to the ED with acute and chronic musculoskeletal complaints and other medical conditions related to or affected by physical exertion, sports participation, or environmental exposure. Specific objectives focus on knowledge of these disorders, physical examination skills, procedural skills including musculoskeletal ultrasound, appropriate consultation and referral, and patient education for these conditions. Educational methods will consist of didactics; online self-directed learning modules; simulation; and supervised clinical experiences in the ED, primary care sports medicine clinics, and orthopedic clinics if available. Curriculum implementation is expected to vary across programs due to differences in residency program structure and resources.

    View details for DOI 10.1249/JSR.0000000000000800

    View details for PubMedID 33395129

  • Increased Lower Extremity Injury Risk Associated With Player Load and Distance in Collegiate Women's Soccer. Orthopaedic journal of sports medicine Xiao, M., Nguyen, J. N., Hwang, C. E., Abrams, G. D. 2021; 9 (10): 23259671211048248


    There is limited research regarding the impact of workload on injury risk specific to women's soccer. Wearable global positioning system (GPS) units can track workload metrics such as total distance traveled and player load during games and training sessions. These metrics can be useful in predicting injury risk.To examine the relationship between injury risk and player workload as collected from wearable GPS units in National Collegiate Athletic Association (NCAA) Division I women's soccer players.Case-control study; Level of evidence, 3.Lower extremity injury incidence and GPS workload data (player load, total distance, and high-speed distance) for 65 NCAA Division I women's soccer players were collected over 3 seasons. Accumulated 1-, 2-, 3-, and 4-week loads and acute-to-chronic workload ratios (ACWR) were classified into discrete ranges by z-scores. ACWR was calculated using rolling averages and exponentially weighted moving averages (EWMA) models. Binary logistic regression models were used to compare the 7:28 rolling average and EWMA ACWRs between injured and noninjured players for all GPS/accelerometer variables. The prior 1-, 2-, 3-, and 4-week accumulated loads for all GPS/accelerometer variables were compared between the injured and uninjured cohorts using 2-sample t tests.There were a total of 53 lower extremity injuries that resulted in lost time recorded (5.76/1000 hours "on-legs" exposure time; 34 noncontact and 19 contact injuries). The prior 2-week (7242 vs 6613 m/s2; P = .02), 3-week (10,533 vs 9718 m/s2; P = .02), and 4-week (13,819 vs 12,892 m/s2; P = .04) accumulated player loads and 2-week (62.40 vs 57.25 km; P = .04), 3-week (90.97 vs 84.10 km; P = .03), and 4-week (119.31 vs 111.38 km; P = .05) accumulated total distances were significantly higher for injured players compared with noninjured players during the same time frames. There were no significant differences in player load, total distance, or high-speed distance ACWR between injured and noninjured players for both the rolling averages and EWMA calculations.Higher accumulated player load and total distance, but not ACWR, were associated with injury in women's soccer players.

    View details for DOI 10.1177/23259671211048248

    View details for PubMedID 34722786

    View details for PubMedCentralID PMC8552401

  • Calculated decisions: Ottawa ankle rule. Emergency medicine practice Hwang, C. 2020; 22 (Suppl 8): CD9–CD10


    The Ottawa ankle rule shows the areas of tenderness to be evaluated in ankle trauma patients to determine the need for imaging.

    View details for PubMedID 32805101

  • Calculated decisions: Ottawa Knee Rule. Emergency medicine practice Hwang, C. 2020; 22 (Suppl 8): CD11–CD12


    The Ottawa knee rule describes criteria for knee trauma patients who are at low risk for clinically significant fracture and do not warrant knee imaging.

    View details for PubMedID 32805102

  • Comparison of Cardiovascular Screening in College Athletes by History and Physical Examination with and without an Electrocardiogram: Efficacy and Cost. Heart rhythm Harmon, K. G., Suchsland, M. Z., Prutkin, J. M., Owens, D. S., Aukerman, D. F., Hwang, C. E., Lancaster, S. C., Petron, D. J., Poddar, S. K., Porter, D. E., Petek, B. J., Malik, A. n., Drezner, J. A. 2020


    Preparticipation screening for conditions associated with sudden cardiac death (SCD) is required in college athletes. Prior cost analyses use theoretical models based on variable assumptions; but no study uses real-life outcomes.To compare disease prevalence, positive findings and costs of two different screening strategies: history and physical examination alone or with an electrocardiogram.De-identified preparticipation data (2009-2017) from Pacific-12 Conference institutions were abstracted for cardiovascular history questions, cardiovascular physical examination, and ECG result. Secondary testing, cardiac diagnoses, return to play outcomes, and complications from testing were recorded. The costs of screening and secondary testing were based on the Centers for Medicare and Medicaid Services Physician Fee Schedule.8602 records (4955 H&P, 3647 H&P+ECG) were included. 11 conditions associated with SCD were detected; (2 H&P only, 9 H&P+ECG). The prevalence of cardiovascular conditions associated with SCD discovered with H&P alone was 0.04% (1 in 2,454) compared to 0.24% (1 in 410) when ECG was added (p=0.01), odds ratio 5.17(95% CI: 1.28, 20.85; p=0.02). Cost of screening and secondary testing with H&P alone was $130/athlete and in the ECG-added group was $152/athlete. The cost per diagnosis was $312,407 in the H&P group and $61,712 in the ECG-added group. There were no adverse outcomes from secondary testing or treatment.H&P with the addition of ECG is 6 times more likely to detect a cardiovascular condition associated with SCD than without. The addition of ECG improves the cost efficiency per diagnosis by 5-fold and should be considered at college institutions with appropriate resources.

    View details for DOI 10.1016/j.hrthm.2020.04.032

    View details for PubMedID 32380289

  • Calculated Decisions: Kocher criteria for septic arthritis Pediatric emergency medicine practice Hwang, C. 2019; 16 (12): CD1–CD2


    The Kocher criteria for septic arthritis are used to distinguish between septic arthritis and transient synovitis in a child with an in amed hip.

    View details for PubMedID 31790173

  • Calculated Decisions: HAS-BLED Score for Major Bleeding Risk Emergency medicine practice Hwang, C. 2019; 21 (8): CD3–CD4


    The HAS-BLED score estimates the risk of major bleeding for patients on anticoagulation, in order to assess risks and benefits in the care of patients with atrial fibrillation.

    View details for PubMedID 31386321

  • Calculated Decisions: Ottawa Knee Rule Pediatric emergency medicine practice Hwang, C. 2018; 14 (Suppl 9): 3–5


    The Ottawa Knee Rule describes criteria for knee trauma patients who are at low risk for clinically significant fracture and do not warrant knee imaging.

    View details for PubMedID 30183241

  • Calculated Decisions: Ottawa Ankle Rule Pediatric emergency medicine practice Hwang, C. 2018; 14 (Suppl 9): 1–3


    The Ottawa Ankle Rule shows the areas of tenderness to be evaluated in ankle trauma patients to determine the need for imaging.

    View details for PubMedID 30183240

  • Current Concepts in Concussion: A Review. Journal of the California Dental Association Ray, J. W., Hwang, C., Baine, J., Fredericson, M., Keane, G. P. 2017; 45 (6): 285-89

    View details for PubMedID 29016093

  • Calculated decisions: LRINEC Score for necrotizing soft-tissue infection Emergency medicine practice Hwang, C. n. 2017: 5–6

    View details for PubMedID 29068632

  • Improved insulin sensitivity after exercise training is linked to reduced plasma C14:0 ceramide in obesity and type 2 diabetes OBESITY Kasumov, T., Solomon, T. P., Hwang, C., Huang, H., Haus, J. M., Zhang, R., Kirwan, J. P. 2015; 23 (7): 1414-1421


    To assess the effect of exercise training on insulin sensitivity and plasma ceramides in obesity and type 2 diabetes (T2D).Twenty-four adults with obesity and normal glucose tolerance (NGT, n = 14) or diabetes (n = 10) were studied before and after a 12-week supervised exercise-training program (5 days/week, 1 h/day, 80-85% of maximum heart rate). Changes in body composition were assessed using hydrostatic weighing and computed tomography. Peripheral tissue insulin sensitivity was assessed by a 40 mU/m(2) /min hyperinsulinemic euglycemic clamp. Plasma ceramides (C14:0, C16:0, C18:0, C18:1, C20:0, C24:0, and C24:1) were quantified using electrospray ionization tandem mass spectrometry after separation with HPLC.Plasma ceramides were similar for the subjects with obesity and NGT and the subjects with diabetes, despite differences in glucose tolerance. Exercise significantly reduced body weight and adiposity and increased peripheral insulin sensitivity in both groups (P < 0.05). In addition, plasma C14:0, C16:0, C18:1, and C24:0 ceramide levels were reduced in all subjects following the intervention (P < 0.05). Decreases in total (r = -0.51, P = 0.02) and C14:0 (r = -0.56, P = 0.009) ceramide were negatively correlated with the increase in insulin sensitivity.Ceramides are linked to exercise training-induced improvements in insulin sensitivity, and plasma C14:0 ceramide may provide a specific target for investigating lipid-related insulin resistance in obesity and T2D.

    View details for DOI 10.1002/oby.21117

    View details for Web of Science ID 000356893400014

    View details for PubMedID 25966363

    View details for PubMedCentralID PMC4482773

  • Effect of an emergency department fast track on press-ganey patient satisfaction scores. The western journal of emergency medicine Hwang, C. E., Lipman, G. S., Kane, M. 2015; 16 (1): 34-38


    Mandated patient surveys have become an integral part of Medicare remuneration, putting hundreds of millions of dollars in funding at risk. The Centers for Medicare & Medicaid Services (CMS) recently announced a patient experience survey for the emergency department (ED). Development of an ED Fast Track, where lower acuity patients are rapidly seen, has been shown to improve many of the metrics that CMS examines. This is the first study examining if ED Fast Track implementation affects Press-Ganey scores of patient satisfaction.We analyzed returned Press-Ganey questionnaires from all ESI 4 and 5 patients seen 11AM - 1PM, August-December 2011 (pre-fast track), and during the identical hours of fast track, August-December 2012. Raw ordinal scores were converted to continuous scores for paired student t-test analysis. We calculated an odds ratio with 100% satisfaction considered a positive response.An academic ED with 52,000 annual visits had 140 pre-fast track and 85 fast track respondents. Implementation of a fast track significantly increased patient satisfaction with the following: wait times (68% satisfaction to 88%, OR 4.13, 95% CI [2.32-7.33]), doctor courtesy (90% to 95%, OR 1.97, 95% CI [1.04-3.73]), nurse courtesy (87% to 95%, OR 2.75, 95% CI [1.46-5.15]), pain control (79% to 87%, OR 2.13, 95% CI [1.16-3.92]), likelihood to recommend (81% to 90%, OR 2.62, 95% CI [1.42-4.83]), staff caring (82% to 91%, OR 2.82, 95% CI [1.54-5.19]), and staying informed about delays (66% to 83%, OR 3.00, 95% CI [1.65-5.44]).Implementation of an ED Fast Track more than doubled the odds of significant improvements in Press-Ganey patient satisfaction metrics and may play an important role in improving ED performance on CMS benchmarks.

    View details for DOI 10.5811/westjem.2014.11.21768

    View details for PubMedID 25671005

  • ECG diagnosis: ST-elevation myocardial infarction. The Permanente journal Hwang, C., Levis, J. T. 2014; 18 (2)

    View details for DOI 10.7812/TPP/13-127

    View details for PubMedID 24867559

    View details for PubMedCentralID PMC4022571

  • Hippocampal-dependent learning requires a functional circadian system PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Ruby, N. F., Hwang, C. E., Wessells, C., Fernandez, F., Zhang, P., Sapolsky, R., Heller, H. C. 2008; 105 (40): 15593-15598


    Decades of studies have shown that eliminating circadian rhythms of mammals does not compromise their health or longevity in the laboratory in any obvious way. These observations have raised questions about the functional significance of the mammalian circadian system, but have been difficult to address for lack of an appropriate animal model. Surgical ablation of the suprachiasmatic nucleus (SCN) and clock gene knockouts eliminate rhythms, but also damage adjacent brain regions or cause developmental effects that may impair cognitive or other physiological functions. We developed a method that avoids these problems and eliminates rhythms by noninvasive means in Siberian hamsters (Phodopus sungorus). The present study evaluated cognitive function in arrhythmic animals by using a hippocampal-dependent learning task. Control hamsters exhibited normal circadian modulation of performance in a delayed novel-object recognition task. By contrast, arrhythmic animals could not discriminate a novel object from a familiar one only 20 or 60 min after training. Memory performance was not related to prior sleep history as sleep manipulations had no effect on performance. The GABA antagonist pentylenetetrazol restored learning without restoring circadian rhythms. We conclude that the circadian system is involved in memory function in a manner that is independent of sleep. Circadian influence on learning may be exerted via cyclic GABA output from the SCN to target sites involved in learning. Arrhythmic hamsters may have failed to perform this task because of chronic inhibitory signaling from the SCN that interfered with the plastic mechanisms that encode learning in the hippocampus.

    View details for DOI 10.1073/pnas.0808259105

    View details for Web of Science ID 000260360500068

    View details for PubMedID 18832172

    View details for PubMedCentralID PMC2563080

  • blue cheese mutations define a novel, conserved gene involved in progressive neural degeneration JOURNAL OF NEUROSCIENCE Finley, K. D., Edeen, P. T., Cumming, R. C., Mardahl-Dumesnil, M. D., Taylor, B. J., RODRIGUEZ, M. H., Hwang, C. E., Benedetti, M., McKeown, M. 2003; 23 (4): 1254-1264


    A common feature of many human neurodegenerative diseases is the accumulation of insoluble ubiquitin-containing protein aggregates in the CNS. Although Drosophila has been helpful in understanding several human neurodegenerative disorders, a loss-of-function mutation has not been identified that leads to insoluble CNS protein aggregates. The study of Drosophila mutations may identify unique components that are associated with human degenerative diseases. The Drosophila blue cheese (bchs) gene defines such a novel degenerative pathway. bchs mutants have a reduced adult life span with the age-dependent formation of protein aggregates throughout the neuropil of the CNS. These inclusions contain insoluble ubiquitinated proteins and amyloid precursor-like protein. Progressive loss of CNS size and morphology along with extensive neuronal apoptosis occurs in aged bchs mutants. BCHS protein is widely expressed in the cytoplasm of CNS neurons and is present over the entire length of axonal projections. BCHS is nearly 3500 amino acids in size, with the last 1000 amino acids consisting of three functional protein motifs implicated in vesicle transport and protein processing. This region along with previously unidentified proteins encoded in the human, mouse, and nematode genomes shows striking homology along the full length of the BCHS protein. The high degree of conservation between Drosophila and human bchs suggests that study of the functional pathway of BCHS and associated mutant phenotype may provide useful insights into human neurodegenerative disorders.

    View details for Web of Science ID 000181094300020

    View details for PubMedID 12598614

    View details for PubMedCentralID PMC1975817