Positional Analysis of Body Composition Using Dual-Energy X-Ray Absorptiometry in National Collegiate Athletic Association Division I Football and Men's Lacrosse.

ABSTRACT: Zabriskie, HA, Dobrosielski, DA, Leppert, KM, Droege, AJ, Knuth, ND, and Lisman, PJ. Positional analysis of body composition using dual-energy X-ray absorptiometry in National Collegiate Athletic Association Division I football and men's lacrosse. J Strength Cond Res 36(6): 1699-1707, 2022-Despite the widespread use of dual-energy X-ray absorptiometry (DXA), few studies have examined differences in body composition between positions within sports and none have reported DXA-derived body composition reference values for men's lacrosse. The purpose of this study was to examine differences in measures of total and regional body composition and bone mineral density (BMD) using DXA across sport positions in a large cohort of National Collegiate Athletic Association Division I male lacrosse and football players. A total of 294 male athletes (football, n = 196; lacrosse, n = 98) underwent DXA. One-way analysis of variance or Kruskal-Wallis tests were used to examine whether body composition variables differed by sports position. In football, position was a significant determinant for every compositional variable in football athletes (all, p < 0.05; effect size range = 0.24-0.79). Offensive linemen had the highest total body fat percentage (30.1 ± 2.9%), followed by fullbacks (26.7 ± 3.3%) and defensive linemen (24.6 ± 5.7%); wide receivers had the lowest (14.5 ± 2.1%). For total body BMD, defensive linemen had the highest (1.70 ± 0.09 g·cm-3), followed by linebackers (1.67 ± 0.09 g·cm-3) and offensive linemen (1.65 ± 0.09 g·cm-3); kickers had the lowest (1.45 ± 0.11 g·cm-3) BMD. In lacrosse, no differences were found between positions for any total or regional body composition and BMD measure (all, p > 0.05). Our data confirm that total and regional measures of body composition and BMD vary across positions in football but not in men's lacrosse. Unlike football, similarities in body composition among lacrosse players may indicate that the uniformity of training demands or preferred player attributes in team selection outweigh the unique positional demands in gameplay.

Association of Functional Movement Screen and Y-Balance Test Scores With Injury in High School Athletes.

ABSTRACT: Lisman, P, Hildebrand, E, Nadelen, M, and Leppert, K. Association of functional movement screen and Y-Balance Test scores with injury in high school athletes. J Strength Cond Res 35(7): 1930-1938, 2021-The purpose of this study was to determine the association between functional movement screen (FMS) and Y-Balance Test (YBT) performance and lower extremity injury in a sample of male high school athletes. A total of 124 high school football (n = 89), lacrosse (n = 25), and baseball (n = 10) players underwent FMS and YBT before the start of their competitive seasons. Time loss lower extremity injury incidence data were tracked by each team's certified athletic trainer and used for analysis. Receiver operating characteristic (ROC) curves were calculated to determine the optimal cutpoints for FMS composite score (CS) and YBT measures, including CS and reach distance asymmetry for anterior, posteromedial, and posterolateral directions, for predicting injury. No cutpoints on the ROC curves maximized sensitivity and specificity; therefore, FMS CS and YBT measures (CS and asymmetry) were analyzed as continuous variables. Logistic regression models adjusted for age and sport revealed no significant associations between FMS CS and lower extremity injury (odds ratio [OR] = 0.99; 95% confidence interval [CI] = 0.83-1.20). Similar findings were found for YBT asymmetry in all directions (ORs ranged from 0.98 to 1.08) and CS (OR = 0.99; 95% CI = 0.95-1.04). There were also no significant associations between the presence of asymmetry and low score (score of 1) on any individual FMS test and injury. Overall, FMS and YBT were not associated with increased risk of lower extremity injury in this sample of high school athletes. These findings do not support the use of FMS and YBT as stand-alone injury risk assessments in high school athletes.

Body Composition Values of NCAA Division 1 Female Athletes Derived From Dual-Energy X-Ray Absorptiometry.

ABSTRACT: Dobrosielski, DA, Leppert, KM, Knuth, ND, Wilder, JN, Kovacs, L, and Lisman, PJ. Body composition values of NCAA Division 1 female athletes derived from dual-energy x-ray absorptiometry. J Strength Cond Res 35(10): 2886-2893, 2021-This study generated descriptive data for regional and total body composition and bone mineral density (BMD) measures using dual-energy x-ray absorptiometry (DXA) across 12 NCAA Division 1 female competitive sports. Two hundred seventy-eight female collegiate athletes underwent DXA: basketball (BB; n = 28), cross country (CC = 11), field hockey (FH; n = 35), gymnastics (GYM; n = 23), lacrosse (LAX; n = 48), soccer (SOC; CC = 27), softball (SB; n = 24), swimming and diving (SW; n = 35), tennis (TN; n = 11), track and field ([TR-throw; n = 10]; [TR-run; n = 10]), and volleyball (VB; n = 16). Descriptive statistics for all body composition and BMD measures were calculated. Group mean differences in all regional and total body composition (all, p < 0.001; η2 range = 0.177-0.365) and BMD (all, p < 0.001; η2 range = 0.317-0.383) measures were observed between teams. The total BF% for gymnasts (23.5%) was lower than TN, FH, LAX, SB, and TR-throw (mean difference range: -4.6 to -12.9%, all p < 0.01); TR-throw had the highest total BF% (36.4%). Cross country had lower total BMD (1.17 g·cm-2) than FH, TR-throw, LAX, GYM, SOC, SB, VB, and BB (mean difference range: -0.12 to -0.26 g·cm-2, all p < 0.01); BB and TR-throw had the highest total BMD (1.40 and 1.43 g·cm-2, respectively). Our data confirm that regional and total body composition and BMD measures varied across female collegiate sports. These findings may assist sports medicine and strength and conditioning practitioners with identifying sport-specific goal values for BF% and BMD to optimize program design.

Examination of Sleep and Injury Among College Football Athletes.

Burke, TM, Lisman, PJ, Maguire, K, Skeiky, L, Choynowski, JJ, CapaldiII, VF, Wilder, JN, Brager, AJ, and Dobrosielski, DA. Examination of sleep and injury among college football athletes. J Strength Cond Res 34(3): 609-616, 2020-The purpose of this study was to characterize subjective sleep metrics in collegiate football players at the start of the season, determine the relationship between preseason subjective sleep measures and in-season objective sleep characteristics, and examine the association between subjective and objective sleep metrics and incidence of time-loss injury during the competitive season. Ninety-four Division I football players completed 5 validated sleep-related questionnaires to assess sleep quality, insomnia severity, daytime sleepiness, sleep apnea risk, and circadian preference before the start of the season. Clinical thresholds for sleep questionnaires were used to determine risk of sleep disorders. Continuous wrist actigraphy was collected throughout the season to generalize sleep behaviors. Time-loss injury incidence data were recorded and used for analysis. Results indicated that 67.4% (60 of 89) of athletes scored above clinical threshold in at least 1 questionnaire to indicate sleep disorder risk. At the start of the season, players subjectively reported an average sleep duration of 7:16 ± 1:18 hours:minutes, which was in contrast to the 6:04 ± 0:41 hours:minutes measured through actigraphy during the season. Logistic regression models adjusted for age and body mass index revealed no significant associations between injury and subjective (odds ratio [OR] = 1.00; 95% confidence interval [CI] = 0.99-1.01) and objective (OR = 1.01; 95% CI = 0.99-1.02) sleep duration or measures attained from sleep questionnaires (ORs ranged from 1.01 to 2.87). Sleep metrics (quantity and quality) were not associated with increased risk of injury in this cohort of collegiate football players.

Systematic Review of the Association Between Physical Fitness and Musculoskeletal Injury Risk: Part 3-Flexibility, Power, Speed, Balance, and Agility.

de la Motte, SJ, Lisman, P, Gribbin, TC, Murphy, K, and Deuster, PA. Systematic review of the association between physical fitness and musculoskeletal injury risk: part 3-flexibility, power, speed, balance, and agility. J Strength Cond Res 33(6): 1723-1735, 2019-We performed a systematic review and evaluation of the existing scientific literature on the association between flexibility, power, speed, balance, and agility, and musculoskeletal injury (MSK-I) risk in military and civilian populations. MEDLINE, EBSCO, EMBASE, and the Defense Technical Information Center were searched for original studies published from 1970 to 2015 that examined associations between these physical fitness measures (flexibility, power, speed, balance, and agility) and MSK-I. Methodological quality and strength of the evidence were determined after criteria adapted from previously published systematic reviews. Twenty-seven of 4,229 citations met our inclusion criteria. Primary findings indicate that there is (a) moderate evidence that hamstring flexibility, as measured by performance on a sit-and-reach test or active straight leg raise test assessed with goniometry, and ankle flexibility, assessed with goniometry, are associated with MSK-I risk; (b) moderate evidence that lower body power, as measured by performance on a standing broad jump or vertical jump with no countermovement, is associated with MSK-I risk; (c) moderate evidence that slow sprint speed is associated with MSK-I risk; (d) moderate evidence that poor performance on a single-leg balance test is associated with increased risk for ankle sprain; and (e) insufficient evidence that agility is associated with MSK-I risk. Several measures of flexibility, power, speed, and balance are risk factors for training-related MSK-I in military and civilian athletic populations. Importantly, these findings can be useful for military, first responder, and athletic communities who are seeking evidence-based metrics for assessing or stratifying populations for risk of MSK-I.

Functional movement screen and Y-Balance test scores across levels of American football players.

Few studies have investigated differences in functional movement assessment performance across scholastic levels of competition. This study examined Functional Movement Screen (FMS) performance in middle school (MS), high school (HS) and collegiate (COL) American football players and Y-Balance test (YBT) scores in MS and HS players. Functional movement measurements were collected for MS (N = 29; age = 12.8 ± 0.7 years), HS (N =52; age = 15.7 ± 1.2 years), and COL (N =77; age = 19.9 ± 1.4 years) football players prior to each group's competitive season. Differences in composite FMS and YBT measurements were examined using Welch's ANOVA and Mann-Whitney U-tests, respectively. Chi-square analyses examined normality of score distributions for individual FMS tests. The MS group displayed a lower composite FMS (12.9 ± 1.9) than both HS (14.0 ± 1.7) and COL (14.1 ± 2.1) groups (p = 0.019). COL players scored significantly lower on the Shoulder Mobility (SM) but higher on the Deep Squat (DS), In-line Lunge (ILL), Active Straight-Leg Raise (ASLR) and Push-Up (PU) than both HS and MS groups. No differences were found between MS and HS groups for any YBT normalized reach distances and side-to-side reach distance differences. FMS performance varied with football competition level whereas YBT performance did not. The results suggest that football competition levels normative data and injury-risk thresholds should be established when using FMS scores to guide performance and injury prevention programming.

A Systematic Review of the Association Between Physical Fitness and Musculoskeletal Injury Risk: Part 1-Cardiorespiratory Endurance.

Musculoskeletal injuries (MSK-Is) are a significant health problem for both military and athletic populations. Research indicates that MSK-I is associated with physical fitness; however, the association between specific components of physical fitness and MSK-I in military and athletic populations has not been systematically examined. Our goal was to systematically review the literature to provide a best evidence synthesis on the relationship between components of physical fitness and MSK-I risk in military and civilian athletic populations. This first of 3 manuscripts focuses on cardiorespiratory endurance (CRE). MEDLINE, EBSCO, EMBASE, and the Defense Technical Information Center were searched for original studies published from 1970 through 2015 that examined associations between physical fitness and MSK-I. Forty-nine of 4,229 citations met our inclusion criteria. Primary findings indicate that there is (a) strong evidence that poor performance on a set distance run for time is a predictor for MSK-I risk in both genders; (b) strong evidence that poor performance on timed shuttle runs is a predictor for MSK-I risk in males; (c) moderate evidence in males and limited evidence in females that poor performance on a timed step test is a predictor of MSK-I risk; and (d) limited or insufficient evidence that poor performance on the Cooper run test, maximal and submaximal aerobic graded exercise tests, and the Conconi test are predictors of MSK-I risk in males or females or both. Several measures of CRE are risk factors for training-related MSK-I in military and civilian athletic populations, indicating that CRE may be an important measure for MSK-I risk stratification.

Systematic Review of the Association Between Physical Fitness and Musculoskeletal Injury Risk: Part 2-Muscular Endurance and Muscular Strength.

de la Motte, SJ, Gribbin, TC, Lisman, P, Murphy, K, and Deuster, PA. A systematic review of the association between physical fitness and musculoskeletal injury risk: part 2-muscular endurance and muscular strength. J Strength Cond Res 31(11): 3218-3234, 2017-This is a systematic review and evaluation of the current evidence on the association between both muscular endurance (ME) and muscular strength (MS) and musculoskeletal injury (MSK-I) risk in military and civilian populations. MEDLINE, EBSCO, EMBASE, and the Defense Technical Information Center were searched for original studies published from 1970 through 2015 which examined associations between physical fitness (ME and MS) and MSK-I in military or civilian populations. Methodological quality and strength of the evidence were determined following criteria adapted from previously published systematic reviews. Forty-five of 4,229 citations met our inclusion criteria. Although results for some tests did vary by sex, taken together, our primary findings indicate there is (a) a strong evidence that poor performance in a push-up test is associated with MSK-I risk; (b) moderate evidence that poor performance in sit-up test is associated with MSK-I risk; (c) moderate evidence that isokinetic ankle and knee flexion strength, and isometric strength assessments at the back, elbow, or knee are associated with MSK-I risk; and (d) limited evidence that poor performance in a pull-up test and isotonic assessments of muscular strength are associated with MSK-I. Several measures of ME/MS are moderately or strongly associated with risk of MSK-I, but additional research is needed to identify and recommend specific assessments of ME/MS that predict MSK-I in both men and women. Future studies should also consider measures of ME and MS as a function of upper body, lower body, and core strength, and their potential association with specific, rather than general, MSK-I.

The Relationship Between Functional Movement, Balance Deficits, and Previous Injury History in Deploying Marine Warfighters.

Screening for primary musculoskeletal injury (MSK-I) is costly and time-consuming. Both the Functional Movement Screen (FMS) and the Y-Balance Test (YBT) have been shown to predict future MSK-I. With a goal of optimizing the efficiency of primary MSK-I screening, we studied associations between performance on the FMS and YBT and whether history of MSK-I influenced FMS and YBT scores. In total, 365 deploying Marines performed the FMS and YBT as prescribed. Composite and individual scores were each categorized as high risk or low risk using published injury thresholds: High-risk FMS included composite scores ≤14 and right-to-left (R/L) asymmetry for Shoulder Mobility, In-Line Lunge, Straight Leg Raise, Hurdle Step, or Rotary Stability. High-risk YBT consisted of anterior, posteromedial, and/or posterolateral R/L differences >4 cm and/or composite differences ≥12 cm. Pearson's χ tests evaluated associations between: (a) all FMS and YBT risk groups and (b) previous MSK-I and all FMS and YBT risk groups. Marines with high-risk FMS were twice as likely to have high-risk YBT posteromedial scores (χ = 10.2, p = 0.001; odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.3-3.2). History of any MSK-I was not associated with high-risk FMS or high-risk YBT. However, previous lower extremity MSK-I was associated with In-Line Lunge asymmetries (χ = 9.8, p = 0.002, OR = 2.2, 95% CI = 1.3-3.6). Overall, we found limited overlap in FMS and YBT risk. Because both methods seem to assess different risk factors for injury, we recommend FMS and YBT continue to be used together in combination with a thorough injury history until their predictive capacities are further established.

Factor structure of the functional movement screen in marine officer candidates.

Functional movement screening (FMS) is a musculoskeletal assessment that is intended to fill a gap between preparticipation examinations and performance tests. Functional movement screening consists of 7 standardized movements involving multiple muscle groups that are rated 0-3 during performance; scores are combined into a final score, which is intended to predict injury risk. This use of a sum-score in this manner assumes that the items are unidimensional and scores are internally consistent, which are measures of internal reliability. Despite research into the FMS' predictive value and interrater reliability, research has not assessed its psychometric properties. The present study is a standard psychometric analysis of the FMS and is the first to assess the internal consistency and factor structure of the FMS, using Cronbach's alpha and exploratory factor analysis (EFA). Using a cohort of 877 male and 57 female Marine officer candidates who performed the FMS, EFA of polychoric correlations with varimax rotation was conducted to explore the structure of the FMS. Tests were repeated on the original scores, which integrated feelings of pain during movement (0-3), and then on scores discounting the pain instruction and based only on the performance (1-3), to determine whether pain ratings affected the factor structure. The average FMS score was 16.7 ± 1.8. Cronbach's alpha was 0.39. Exploratory factor analysis availed 2 components accounting for 21 and 17% and consisting of separate individual movements (shoulder mobility and deep squat, respectively). Analysis on scores discounting pain showed similar results. The factor structures were not interpretable, and the low Cronbach's alpha suggests a lack of internal consistency in FMS sum scores. Results do not offer support for validity of the FMS sum score as a unidimensional construct. In the absence of additional psychometric research, caution is warranted when using the FMS sum score.

Consortium for health and military performance and American College of Sports Medicine Summit: utility of functional movement assessment in identifying musculoskeletal injury risk.

Prevention of musculoskeletal injuries (MSKI) is critical in both civilian and military populations to enhance physical performance, optimize health, and minimize health care expenses. Developing a more unified approach through addressing identified movement impairments could result in improved dynamic balance, trunk stability, and functional movement quality while potentially minimizing the risk of incurring such injuries. Although the evidence supporting the utility of injury prediction and return-to-activity readiness screening tools is encouraging, considerable additional research is needed regarding improving sensitivity, specificity, and outcomes, and especially the implementation challenges and barriers in a military setting. If selected current functional movement assessments can be administered in an efficient and cost-effective manner, utilization of the existing tools may be a beneficial first step in decreasing the burden of MSKI, with a subsequent focus on secondary and tertiary prevention via further assessments on those with prior injury history.

Exertional heat illness: the role of heat tolerance testing.

Exertional heat stroke (EHS) is a common clinical problem for both athletes and warriors; however, evidence-based guidance for return-to-play/duty (RTP/RTD) decisions is limited. Heat tolerance testing (HTT) has been proposed as a potential tool that, when combined with appropriate clinical information, may assist in RTP/RTD decisions. However, currently, no standard of care is available for performing HTT. The Israeli Defense Forces (IDF) HTT protocol, which was developed over decades of careful research, has proven useful for IDF warriors and is utilized by other militaries to assist in RTD decisions. The present case studies are used to discuss the efficacy of the IDF HTT in determining RTD for two warriors who experienced EHS. Strengths and limitations of the IDF HTT, along with current and potential roles in clinical decision-making and in future thermoregulation research, are discussed.

Examination of overhead and single-leg squat kinematics and lower extremity injury in female collegiate athletes.

BACKGROUND: Overhead squat (OHS) and single-leg squat (SLS) tests have been used as screening tools to identify injury risk in athletic populations. Yet, no study has examined the association between specific trunk and lower extremity (LE) kinematic measures acquired during OHS and SLS performance and LE injury incidence in female collegiate athletes. The purpose of this study was to examine the association between LE and trunk kinematics captured during OHS and SLS performance and LE injury in female collegiate athletes. METHODS: This was a prospective cohort study. One hundred eight Division I female collegiate athletes underwent OHS and SLS testing before the start of their competitive season. A Microsoft Kinect sensor using Athletic Movement Assessment software (PhysiMax®) was used to capture kinematic variables: hip flexion, knee flexion, knee frontal plane projection angle (FPPA), and trunk flexion. Participants were tracked during one competitive season for incidence of LE injury. Logistic regression models were used to examine the association between OHS and SLS measures and injury. RESULTS: Twenty-three (21.3%) participants suffered a LE injury. No significant associations were found between any OHS (odds ratio [OR] range: 0.91-1.08) or SLS (OR range: 0.81-1.22) kinematic measure and incidence of LE injury. CONCLUSIONS: Sagittal plane LE and trunk kinematics and knee FPPA during OHS and SLS performance were not associated with LE injury in this cohort of athletes. Our findings do not support the use of these select kinematic measures captured during OHS and SLS testing as stand-alone injury risk assessments in female collegiate athletes.

The Association Between Sleep and Musculoskeletal Injuries in Military Personnel: A Systematic Review.

INTRODUCTION: Musculoskeletal injuries (MSKIs) are a significant health problem in the military. Accordingly, identifying risk factors associated with MSKI to develop targeted strategies that attenuate injury risk remains a top priority within the military. Insufficient sleep has garnered increased attention as a potential risk factor for MSKI in both civilians and military personnel. Yet, there are no systematic evaluations of the potential association between sleep and MSKI in the military. The purpose of this review is to examine the relationship between sleep and injury in military personnel. MATERIALS AND METHODS: Literature searches were performed in multiple electronic databases using keywords relevant to sleep quantity and quality, MSKI, and military populations. Two investigators independently assessed the methodological quality of each study using the Newcastle-Ottawa Scale for cohort studies or an adapted form of this scale for cross-sectional studies. RESULTS: The search yielded 2402 total citations, with 8 studies (3 cohort and 5 cross-sectional) fitting the inclusion criteria. Overall, the systematic review found 5 of the 8 reviewed studies supporting an association between sleep (quality and duration) and MSKI in military personnel. Specifically, poor sleep was associated with increased injury incidence in 2 cohort and 3 cross-sectional studies. CONCLUSION: This is the first systematic review to evaluate the published literature on the association between sleep and MSKI risk in military populations. Although there is currently limited research on this topic, findings suggest that sleep is associated with MSKI and should be considered when designing strategies aimed at reducing MSKI risk in military personnel.

The Association Between Poor Sleep and the Incidence of Sport and Physical Training-Related Injuries in Adult Athletic Populations: A Systematic Review.

BACKGROUND: The importance of achieving an adequate amount of sleep to optimize health and athletic performance is well recognized. Yet, a systematic evidence compilation of the risk for sport-related injury in adult athletic populations due to poor sleep does not exist. OBJECTIVE: To examine the association between poor sleep and sport and physical training-related injuries in adult athletic populations. DATA SOURCES: Electronic databases were searched using keywords relevant to sleep quantity and quality, and musculoskeletal injury and sport-related concussion (SRC). ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies were included in this systematic review if they were comprised of adult athletic populations, reported measures of sleep quantity or quality, followed participants prospectively for injury, and reported an association between sleep and incidence of sport or physical training-related injury. STUDY APPRAISAL: The methodological quality of each study was assessed using the Newcastle-Ottawa Scale for Cohort Studies. RESULTS: From our review of 12 prospective cohort studies, we found limited evidence supporting an association between poor sleep and injury in adult athletic populations. Specifically, there is (a) insufficient evidence supporting the associations between poor sleep and increased risk of injury in specific groups of athletic adults, including professional or elite athletes, collegiate athletes, elite or collegiate dancers, and endurance sport athletes; and (b) limited evidence of an association between poor sleep and increased risk of SRC in collegiate athletes. CONCLUSIONS: The current evidence does not support poor sleep as an independent risk factor for increased risk of sport or physical training-related injuries in adult athletic populations. Given the methodological heterogeneity and limitations across previous studies, more prospective studies are required to determine the association between sleep and injury in this population.

The Relationship between Landing Error Scoring System Performance and Injury in Female Collegiate Athletes.

BACKGROUND: The Landing Error Scoring System (LESS) is a standardized tool used to identify aberrant biomechanical movement patterns during a jump-landing task. Prior authors have examined the value of the LESS in identifying ACL injury risk in athletic populations. Yet, no study has evaluated the association between LESS performance and incidence of any type of lower extremity injury in female collegiate athletes across multiple sports. PURPOSE: The purpose of this study was to examine the association between LESS performance as measured with a markerless motion-capture system and lower extremity injury in female collegiate athletes. STUDY DESIGN: Prospective cohort study. METHODS: One hundred and ten DI female collegiate athletes (basketball, n=12; field hockey, n=17; gymnastics, n=14; lacrosse, n=27; softball, n=23; volleyball, n=17) completed a jump-landing test prior to the start of their sport seasons. The LESS was automatically scored using a Microsoft Kinect sensor and Athletic Movement Assessment software (PhysiMax®). Participants were tracked throughout one competitive season for incidence of time-loss lower extremity injury. A Receiver Operating Characteristic curve determined the optimal cutpoint for the total LESS score for predicting injury. Pearson's Chi squared statistics examined the association between injury and LESS total scores >5. The Fisher exact test evaluated group differences for the frequency of receiving an error on individual LESS test items. RESULTS: Female collegiate athletes with LESS scores >5 were not more likely to be injured than those with scores ≤5 (χ2=2.53, p=0.111). The relative risk of injury to this group was 1.78 (95% CI=0.86, 3.68) while the odds ratio was 2.10 (95% CI=0.83, 5.27). The uninjured group was more likely to receive an error on lateral trunk flexion at initial contact than the injured group (p=0.023). CONCLUSION: The LESS total score was not associated with an increased odds of lower extremity injury in this cohort of female collegiate athletes. Future studies to examine the association between individual LESS item scores and injury are warranted. LEVEL OF EVIDENCE: 1b.

Sex differences in lower extremity kinematics during overhead and single leg squat tests.

The Overhead Squat (OHS) and Single-Leg Squat (SLS) are two clinical tests used by practitioners to identify high-risk biomechanical movement patterns. Several published studies have reported sex differences in SLS performance; however, few have investigated variations during the OHS and none has measured kinematics with a marker-less motion capture system. Therefore, this study aimed to compare biomechanical movement patterns between male and female collegiate athletes during OHS and SLS testing. Seventy-five females and 58 male athletes completed OHS and SLS . A Microsoft Kinect sensor using Athletic Movement Assessment software (PhysiMax®) was used to measure kinematics. For the OHS, males displayed greater peak knee frontal plane projection angles (FPPA) (M:26°±10°, F:20°±8°; P < 0.05), peak hip flexion (M:-94°±14°, F:-87°±15°; P < 0.05), and peak trunk flexion angles (M:11°±11°, F:6°±9°; P < 0.05). For the SLS (dominant-limb), males displayed greater peak trunk flexion (M:32°±6°, F:27°±7°; P < 0.05). For the non-dominant limb, females displayed greater peak knee FPPA (F:-12°±9°, M:-8°±9°; P < 0.05) whereas males displayed greater peak trunk flexion angles (M:32°±5°, F:27°±7°; P < 0.05). These findings suggest the need for practitioners to develop sex-specific corrective exercise programmes in effort to improve lower extremity kinematics in athletes.

Weight management program for first responders: Feasibility study and lessons learned.

BACKGROUND: Overweight and obesity are significant concerns for first responders (firefighters and emergency medical service providers). OBJECTIVE: This pilot study examines the feasibility of a weight loss program for career first responders. METHODS: Participants were career first responders with BMI≥30 and interest in losing weight. Baseline height, weight, and body composition using dual x-ray absorptiometry, Pittsburgh Sleep Quality Index (PSQI), and a Functional Movement Screen (FMS) with follow-up weight and body composition were assessed. A 10-week weight loss program used evidence-based lifestyle goals (encouraged increasing activity levels, using tailored calorie goals, following the DASH diet, tracking with a phone app) and weekly in-person sessions with a student coach-in-training who reviewed weight and tracking information. RESULTS: Participants (N = 10) were 39.0±9.9 years old with a BMI of 35.6±4.7 kg/m2. There were significant reductions in weight -4.8±2.3 kg and percent body fat -3.9±1.7%. All participants had a PSQI score >5 indicating poor quality of sleep. Nine participants had FMS scores ≤14 indicating increased risk of injury. CONCLUSION: The use of commercially available apps with support from a student coach-in-training and evidence-based weight loss recommendations is a feasible approach to support career firefighters in their weight loss efforts.

Fabricating a better mouthguard. Part II: the effect of color on adaptation and fit.

The thermoforming process involves the heating of plastic sheets to a critical temperature followed by the shaping of the heated material into a three-dimensional structure. Given that custom-fabricated mouthguards are produced using the thermoforming process, the adaptation of plastic sheets to a stone model of the dentition is likely to be affected by the ability of the mouthguard material to be heated. The purpose of this study was to establish if material color affected the adaptation and fit of custom-made mouthguards. Twelve stone models were used in this investigation. Five mouthguards were produced using each model. These mouthguards were made using clear-, white-, black-, blue- and green-colored ethyl vinyl acetate. The force required to remove the various colored mouthguards from the corresponding stone models was determined using a strain gauge housed within a specially designed apparatus. Each of the mouthguards were tested three times at two different angles of pull -45 degrees and 90 degrees . Statistical tests performed using the average amount of force required for mouthguard removal revealed an angle by color interaction. Post hoc analyses revealed that the mean force required to remove the clear-colored mouthguards from their respective stone models was significantly less than the force required to pull away blue-, black- and green-colored mouthguards. This difference between clear- and dark-colored mouthguards was observed at both angles tested with the exception of the black mouthguard which differed from the clear-colored mouthguard only when removed at an angle of 90 degrees . The results of the present study indicate that by using dark-colored mouthguard material, one can achieve superior adaptation and thus produce a more firmly fitting mouthguard.

The Interrelationship of Common Clinical Movement Screens: Establishing Population-Specific Norms in a Large Cohort of Military Applicants.

CONTEXT: Musculoskeletal injuries (MSK-Is) are a leading cause of missed duty time and morbidity in the military. Modifiable risk factors for MSK-Is, such as inadequate core stability, poor movement patterns, and dynamic balance deficits, have not been identified in military applicants on entering service. OBJECTIVE: To establish normative functional movement data using a series of screens in military applicants entering basic training and explore relationships among several movement tests. DESIGN: Cross-sectional study. SETTING: Military Entrance Processing Station. PATIENTS OR OTHER PARTICIPANTS: A total of 1714 (1434 male, 280 female) military applicants entering the US Army (n = 546), Navy (n = 414), Air Force (n = 229), or Marine Corps (n = 525). INTERVENTION(S): We conducted the Functional Movement Screen (FMS), Y-Balance Test (YBT), overhead squat (OHS), and Landing Error Scoring System (LESS). Movements were assessed using the scoring convention for each screen. MAIN OUTCOME MEASURE(S): The FMS, YBT, OHS, and LESS scores and associations among the movement screens as well as clinical meaningfulness. RESULTS: A total of 1037 of the 1714 enrolled applicants were screened on the day they left for basic training. Normative means for this population were established: FMS = 14.7 ± 1.8, YBT anterior-reach difference = 3.1 ± 3.0 cm, mean YBT composite differences = 8.0 ± 6.8 cm, mean YBT composite percentage = 90.9% ± 8.3%, OHS errors = 5.0 ± 2.8, and LESS score = 5.7 ± 2.1. Backward regression results revealed that the YBT composite percentage was related to the FMS and OHS scores in males and to the FMS and LESS results in females. However, clinically meaningful relationships between the tests varied for both males and females. CONCLUSIONS: Sex-normative values for the FMS, YBT, OHS, and LESS screens were established for US military applicants, and some of the assessments overlapped. Overall, males performed better on the OHS and LESS and achieved a greater YBT composite percentage than females. The regression results revealed movement screen performance relationships that varied by sex and clinical meaningfulness. In future studies, we will determine if performance on any of the screens is associated with MSK-Is in basic trainees.