Daniel R. Clifton

Physical Exam Risk Factors for Lower Extremity Injury in High School Athletes: A Systematic Review.

Objective:A stated goal of the preparticipation physical evaluation (PPE) is to reduce musculoskeletal injury, yet the musculoskeletal portion of the PPE is reportedly of questionable use in assessing lower extremity injury risk in high school-aged athletes. The objectives of this study are: (1) identify clinical assessment tools demonstrated to effectively determine lower extremity injury risk in a prospective setting, and (2) critically assess the methodological quality of prospective lower extremity risk assessment studies that use these tools. Data Sources:A systematic search was performed in PubMed, CINAHL, UptoDate, Google Scholar, Cochrane Reviews, and SportDiscus. Inclusion criteria were prospective injury risk assessment studies involving athletes primarily ages 13 to 19 that used screening methods that did not require highly specialized equipment. Methodological quality was evaluated with a modified physiotherapy evidence database (PEDro) scale. Main Results:Nine studies were included. The mean modified PEDro score was 6.0/10 (SD, 1.5). Multidirectional balance (odds ratio [OR], 3.0; CI, 1.5-6.1; P < 0.05) and physical maturation status (P < 0.05) were predictive of overall injury risk, knee hyperextension was predictive of anterior cruciate ligament injury (OR, 5.0; CI, 1.2-18.4; P < 0.05), hip external:internal rotator strength ratio of patellofemoral pain syndrome (P = 0.02), and foot posture index of ankle sprain (r = −0.339, P = 0.008). Conclusions:Minimal prospective evidence supports or refutes the use of the functional musculoskeletal exam portion of the current PPE to assess lower extremity injury risk in high school athletes. Limited evidence does support inclusion of multidirectional balance assessment and physical maturation status in a musculoskeletal exam as both are generalizable risk factors for lower extremity injury.

Relationship between functional assessments and exercise-related changes during static balance.

Abstract Clifton, DR, Harrison, BC, Hertel, J, and Hart, JM. Relationship between functional assessments and exercise-related changes during static balance. J Strength Cond Res 27(4): 966–972, 2013—The Functional Movement Screen (FMS) is currently used for injury risk prediction, although researchers have not studied its relationships to injury risk factors. The purpose of this study was to compare FMS scores at rest to changes in static balance after exercise. Second, we examined FMS scores pre and post exercise. Twenty-five participants performed center of pressure (COP) measures and FMS testing. An acclimatization session for the FMS occurred on day 1, whereas day 2 involved COP measures for static balance and FMS testing before and after a 36-minute exercise protocol. Center of pressure standard deviations in the frontal (COPML-SD) and sagittal (COPAP-SD) planes, center of pressure velocity (COP-Velocity), center of pressure area (COP-Area), and FMS scores were recorded. No significant correlations occurred between preexercise FMS scores and change in COP measures. Preexercise hurdle step scores related to preexercise COPML-SD (p = −0.46), COPAP-SD (p = −0.43), and COP-Area (p = −0.50). Preexercise in-line lunge scores related to postexercise COPAP-SD (p = −0.44) and COP-Velocity (p = −0.39), whereas preexercise active straight leg raise (ASLR) scores related to postexercise COPML-SD (p = −0.46). Functional Movement Screen scores were not related to changes in static balance after exercise and may therefore not be useful to predict who will experience greater static balance deficits after exercise. Additionally, FMS scores did not differ before and after exercise. Clinicians aiming to identify injury risk from a general static balance standpoint may find the hurdle step, in-line lunge, and ASLR useful. Clinicians aiming to identify injury risk from a change in static balance standpoint may need to explore other screening tools.

Epidemiological Patterns of Ankle Sprains in Youth, High School, and College Football:

Background: Variations in ankle injury rates and distributions among competition levels are unclear, but such data may help inform strategies to prevent ankle sprains during American football. Purpose: To describe the epidemiological patterns of ankle sprains in youth, high school (HS), and collegiate American football. Study Design: Descriptive epidemiological study. Methods: Data regarding youth, HS, and college football athletes were collected from 3 injury surveillance programs: (1) the Youth Football Safety Study (YFSS), (2) the National Athletic Treatment, Injury and Outcomes Network (NATION), and (3) the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP). During the 2012-2014 seasons, the YFSS, NATION, and NCAA ISP included 310, 184, and 71 football team-seasons, respectively. Athletic trainers (ATs) attended each practice and game and reported injuries and athlete-exposures (AEs) via their preferred injury documentation application. Ankle sprain rates for each type of ankle sprain were calculated overall, by event type (ie, practices and games), and specifically for severe injuries (ie, participation restriction time >21 days) and recurrent injuries (as defined by ATs). Rate ratios (RRs) were used to compare ankle sprain rates by competition level and event type. Injury proportion ratios (IPRs) were used to compare differences in severity, surgical needs, recurrence, injury mechanism, and injury activity by competition level. RRs and IPRs with 95% confidence intervals excluding 1.00 were considered statistically significant. Results: A total of 124, 897, and 643 ankle sprains were reported in youth, HS, and college football, respectively. This led to respective rates of 0.59, 0.73, and 1.19 sprains per 1000 AEs. The ankle sprain rate in college football was higher than the rates in HS (RR = 1.64; 95% CI, 1.48-1.82) and youth (RR = 2.01; 95% CI, 1.65-2.43) football. The proportion of ankle sprains that were recurrent in youth football was higher than the proportions in HS (IPR = 2.73; 95% CI, 1.68-4.50) and college (IPR = 2.19; 95% CI, 1.33-3.61) football. Conclusion: Ankle sprain rates were highest in college athletes. However, level-specific variations in ankle sprain severity and recurrence may highlight the need to develop level-specific policies and prevention strategies to reduce injury incidence.

Epidemiology of Knee Sprains in Youth, High School, and Collegiate American Football Players

CONTEXT   Variations in knee-sprain incidence among competition levels are unclear but may help inform prevention strategies in American football players. OBJECTIVE   To describe the epidemiology of knee sprains in youth, high school, and collegiate football players. DESIGN   Descriptive epidemiology study. SETTING   Injury and athlete-exposure (AE) data were collected from 3 injury-surveillance programs at the youth, high school, and collegiate competition levels. PATIENTS OR OTHER PARTICIPANTS   Data from 310 youth, 184 high school, and 71 collegiate football team-seasons were collected during the 2012 through 2014 seasons. MAIN OUTCOME MEASURE(S)   Knee-sprain rates and risks were calculated for each competition level. Injury rate ratios (IRRs) and risk ratios (RRs) compared knee-sprain rates by competition level. Injury proportion ratios (IPRs) compared differences in surgery needs, recurrence, injury mechanism, and injury activity by competition level. RESULTS   Knee-sprain rates in youth, high school, and collegiate football were 0.16/1000 AEs, 0.25/1000 AEs, and 0.69/1000 AEs, respectively. Knee-sprain rates increased as the competition level increased (high school versus youth: IRR = 1.60; 95% confidence interval [CI] = 1.12, 2.30; collegiate versus high school: IRR = 2.73; 95% CI = 2.38, 3.96). Knee-sprain risk was highest in collegiate (4.3%), followed by high school (2.0%) and youth (0.5%) athletes. Knee-sprain risk increased as the competition level increased (high school versus youth: RR = 3.73; 95% CI = 2.60, 5.34; collegiate versus high school: RR = 2.14; 95% CI = 1.83, 2.51). Collegiate football had the lowest proportion of knee sprains that were noncontact injuries (collegiate versus youth: IPR = 0.54; 95% CI = 0.31, 0.95; collegiate versus high school: IPR = 0.59; 95% CI = 0.44, 0.79) and the lowest proportion that occurred while being tackled (collegiate versus youth: IPR = 0.44; 95% CI = 0.26, 0.76; collegiate versus high school: IPR = 0.71; 95% CI = 0.51, 0.98). CONCLUSIONS   Knee-sprain incidence was highest in collegiate football. However, level-specific variations in the distributions of knee sprains by injury activity may highlight the need to develop level-specific policies and prevention strategies that ensure safe sports play.

Predicting injury: challenges in prospective injury risk factor identification

CONTEXT Musculoskeletal injury-prediction methods vary and may have limitations that affect the accuracy of results and clinical meaningfulness. BACKGROUND Research examining injury risk factors is meaningful, but attempting to extrapolate injury risk from studies that do not prospectively assess injury occurrence may limit clinical applications. Injury incidence is a vital outcome measure, which allows for the appropriate interpretation of injury-prediction analyses; a lack of injury-incidence data may decrease the accuracy and increase the uncertainty of injury-risk estimates. Extrapolating results that predict an injury risk factor to predicting actual injuries may lead to inappropriate clinical decision-making models. CONCLUSIONS Improved understanding of the limitations of injury-prediction methods, specifically those that do not prospectively assess injuries, will allow clinicians to better assess the clinical meaningfulness of the results.

Epidemiology of Injuries Requiring Emergency Transport Among Collegiate and High School Student-Athletes

CONTEXT: Data regarding the epidemiology of emergency-transport incidents (ETIs) of patients with sport-related injuries are lacking. Understanding the use of emergency services by athletic trainers can help improve emergency preparedness and prehospital care for injured student-athletes. OBJECTIVE: To determine the frequencies and types of ETIs resulting from athletic participation. DESIGN: Descriptive epidemiology study. SETTING: Participating colleges and high schools during 2009-2010 to 2014-2015 and 2011-2012 to 2013-2014, respectively. PATIENTS OR OTHER PARTICIPANTS:  Student-athletes in 23 high school and 25 intercollegiate sports. MAIN OUTCOME MEASURE(S):  Data on injuries requiring emergency transport were collected by each teams athletic trainer via their respective online injury-tracking software. Athletic trainers also collected data on athlete-exposures (AEs). Emergency-transport incident frequencies and injury rates per 10 000 AEs with 95% confidence intervals (CIs) were reported. For each ETI, the sport, body part, injury mechanism, and final diagnosis were recorded. RESULTS: A total of 339 and 146 ETIs were reported in collegiate and high school players, respectively. Collegiate womens ice hockey had the highest ETI rate (1.28/10 000 AEs; 95% CI = 0.71, 1.86). In high school, football had the highest rate at 0.80 per 10 000 AEs (95% CI = 0.64, 0.97). Athletes with head or face injuries required the most transports in college (n = 71, 20.9%) and high school (n = 33, 22.6%) across all sports. Strains (n = 50, 14.7%) and fractures (n = 35, 24.0%) were the leading diagnoses for patients undergoing transport in college and high school, respectively. CONCLUSIONS: Athletic trainers should maintain a high level of emergency preparedness when working with sports that have high rates and numbers of ETIs. Athletes with injuries to the head/face required the most frequent transport across competition levels. Athletic trainers should have the appropriate equipment and protocols in place to handle these patients. Future researchers should examine the differences between field and hospital diagnoses to help improve prehospital care and decrease the likelihood of unnecessary emergency transports.

Normative Functional Performance Values in High School Athletes: The Functional Pre-Participation Evaluation Project

CONTEXT   The fourth edition of the Preparticipation Physical Evaluation recommends functional testing for the musculoskeletal portion of the examination; however, normative data across sex and grade level are limited. Establishing normative data can provide clinicians reference points with which to compare their patients, potentially aiding in the development of future injury-risk assessments and injury-mitigation programs. OBJECTIVE   To establish normative functional performance and limb-symmetry data for high school-aged male and female athletes in the United States. DESIGN   Cross-sectional study. SETTING   Athletic training facilities and gymnasiums across the United States. PATIENTS OR OTHER PARTICIPANTS   A total of 3951 male and female athletes who participated on high school-sponsored basketball, football, lacrosse, or soccer teams enrolled in this nationwide study. MAIN OUTCOME MEASURE(S)   Functional performance testing consisted of 3 evaluations. Ankle-joint range of motion, balance, and lower extremity muscular power and landing control were assessed via the weight-bearing ankle-dorsiflexion-lunge, single-legged anterior-reach, and anterior single-legged hop-for-distance (SLHOP) tests, respectively. We used 2-way analyses of variance and χ2 analyses to examine the effects of sex and grade level on ankle-dorsiflexion-lunge, single-legged anterior-reach, and SLHOP test performance and symmetry. RESULTS   The SLHOP performance differed between sexes (males = 187.8% ± 33.1% of limb length, females = 157.5% ± 27.8% of limb length; t = 30.3, P < .001). A Cohen d value of 0.97 indicated a large effect of sex on SLHOP performance. We observed differences for SLHOP and ankle-dorsiflexion-lunge performance among grade levels, but these differences were not clinically meaningful. CONCLUSIONS   We demonstrated differences in normative data for lower extremity functional performance during preparticipation physical evaluations across sex and grade levels. The results of this study will allow clinicians to compare sex- and grade-specific functional performances and implement approaches for preventing musculoskeletal injuries in high school-aged athletes.