The Functional Movement Screen and Self-reported Injury in Senior Military College Cadets.

INTRODUCTION: Secular trend of increasing musculoskeletal injuries (MSKIs) across all branches of the U.S. Military is a critical limiting factor in the effective and efficient process of preparing military personnel for combat. The need to evaluate functional capacity beyond current physical fitness test (PFT) standards is the key in understanding an individual's risk of noncombat-related injury. The purpose of this study is to evaluate the relationship between Functional Movement ScreenTM (FMS) scores, incidence of musculoskeletal injuries, and standardized PFT scores among freshman Cadets during their first 10 weeks of enrollment at a senior military college. MATERIALS AND METHODS: Eighty-two participants (72 male and 10 female participants; mage: 18.2 years) completed the FMS, an institution-specific PFT (2-min maximum pushups, 2-min maximum abdominal crunches, and 1.5 mile timed run), and an Incidence of Injury and Incidence of Pain Questionnaire. Independent t-tests, Spearman's rank correlation coefficients logistic regression analysis, and Receiver Operator Curves were performed to evaluate relationships between the study variables. RESULTS: FMS composite and PFT sex-normed total scores were higher in females (16.4, 236.1) than in males (15.0, 204.9). Ninety percent of all females reported injury or pain during the 10-week survey period compared to 48% of males. CONCLUSIONS: No significant difference between FMS scores and injury and pain was found within both sex groups. Therefore, use of the composite FMS score as an indicator for risk of injury or to predetermine PFT performance is not recommended for this study's population. The rate of incidence of injury or pain in Cadets during a 10-week enrolment period is high. Females outperformed males in the FMS and PFT and reported higher rates of injury and pain. The utility of the FMS may be limited when substantially scaled for implementation across entire military populations. Future research should evaluate performance associations of the FMS with Army Combat Fitness Test components in a population of equally distributed sex and race.

Potential relevance of a motor skill "proficiency barrier" on health-related fitness in youth.

This study investigated the potential impact of a motor skill proficiency barrier on measures of cardiorespiratory (CRF) and musculoskeletal (MSF) fitness in youth. A sample of 241 youth (114 girls) aged 10 - 18 years, completed the Motor Competence Assessment battery with composite scores indexed according to age- and gender-adjusted percentile scores. Motor competence (MC) levels were categorized as low (≤ 25%tile - proficiency barrier), moderate (≥ 26%tile to < 75%tile), and high (≥ 75%tile). CRF levels (Health Risk, Needs Improvement, and Healthy) were assessed using the Fitnessgram® 20 m PACER test. Low (≤ 20%tile), moderate (≥ 21%tile to ≤ 80%tile), and high (≥ 80%tile) MSF levels were assessed using grip strength normative data. Two 3 × 3 chi-square tests were conducted to determine the probability of MC level predicting CRF and MSF levels. Results demonstrated statistically significant models for performance on both the PACER (χ2[4, N = 241] = 22.65, p < .001) and grip strength (χ2[4, N = 241] = 23.95, p < .001). Strong evidence of a proficiency barrier impacting CRF was noted, as no low skilled youth met the "Healthy" fitness zone standards for PACER performance. Evidence supporting a barrier with grip strength was not as strong, as 20.8% of youth exhibiting low MC displayed high grip strength. However, all individuals with high levels of MC demonstrated at least moderate grip strength. Results emphasize the importance of developing MC during childhood as it may provide a protective effect against unhealthy CRF and MSF across youth.HighlightsThese data support the notion of Seefeldt's (1980) proficiency barrier as it relates to CRF, as no youth demonstrating low MC met the healthy fitness zone criteria for PACER performance. The development of MC may both directly and indirectly provide a protective effect against unhealthy CRF levels across childhood and adolescence.Evidence supporting a proficiency barrier with MSF as measured by grip strength was not as strong; however, all individuals with high levels of MC demonstrated at least moderate grip strength. Thus, the development of MC may be a protective factor to mitigate low levels of MSF via enhanced neuromuscular function.Promoting the development of MC in a variety of developmentally appropriate activities and settings (e.g. MC skills practice, structured and unstructured play, and performance contexts) is important to promote positive trajectories of CRF and MSF across childhood and adolescence.

Reinvest to Assess: Advancing Approaches to Motor Competence Measurement Across the Lifespan.

Measurement of motor competence is a vital process to advancing knowledge in the field of motor development. As motor competence is being more widely linked to research in other academic domains (e.g., public health, neuroscience, behavioral health), it is imperative that measurement methodology and protocols are reproducible with high degrees of validity and reliability. When addressing the plethora of available assessments, mostly developed for youth populations, there are potential questions and concerns that need to be addressed and/or clarified. One of the most prominent issues is the lack of a lifespan measure of motor competence, which is at odds with the premise of the field of motor development-studying changes in motor behavior across the lifespan. We address six areas of concern in lifespan assessment which include: (1) lack of assessment feasibility for conducting research with large samples, (2) lack of accountability for cultural significance of skills assessed, (3) limited sensitivity and discriminatory capabilities of assessments, (4) developmental and ecological validity limitations, (5) a problematic definition of 'success' in skill performance, and (6) task complexity and adaptability limitations. It is important to critically analyze current assessment methodologies as it will help us to envision the development and application of potential new assessments through a more comprehensive lens. Ultimately, we propose that reinvesting in how we think about assessment will be highly beneficial for integrating motor development from a holistic perspective, impact scientific advancements in other developmental domains, and increase global and lifespan surveillance of motor competence.

A state-by-state and regional analysis of the direct medical costs of treating musculoskeletal injuries among US Army trainees.

INTRODUCTION: Low physical activity (PA) and physical fitness (PF) are well-known factors for chronic diseases generally and cardiovascular diseases specifically. The economic burden from these chronic diseases is also well documented, as is their disproportionate prevalence among states in the Southern region of the U.S. Low PA and PF have also become recognized factors impacting military readiness and national security. Specifically, low PA and PF are highly correlated with musculoskeletal injures (MSKIs), now considered the greatest medical impediment to military readiness. Prior research shows low PF and MSKI incidence are greater among Army recruits from Southern states, however no previous research has investigated the economic impact of MSKIs at the state- and regional-level. The aim of this study was to determine the economic impact of MSKIs among U.S. Army initial military trainees on a state- and regional-basis. METHODS: Rosters for recruits entering U.S. Army Initial Military Training (IMT) for fiscal year 2017 were obtained (n = 103,487). Roster data included the unique personal identifier, demographics with postal zip code, training start/end dates, and height and weight and were subsequently linked to medical encounters and cost data from the Military Health System Data Repository. Trainees with one or more MSKIs were considered injury cases (n = 33,509) and were stratified by gender. The percent of trainee MSKI cases was calculated as number of injury cases divided by total number of trainees. For each injury case, the direct medical cost for MSKIs was calculated. The percent of trainees and direct medical costs for MSKIs were aggregated to home-state and regional-levels for the four U.S. Census tract regions. A test for equality of proportions was performed at state- and regional-levels to investigate differences in percent of trainees with MSKIs by state/region. A one-way ANOVA was used to investigate possible differences in medical cost/trainee by region. RESULTS: 34% (n = 33,509) of all trainees sustained at least one MSKI. State-specific MSKI percentages showed ten states having the greatest percentage of trainees with at least one MSKI, eight of which were from the South region (AL, FL, GA, LA, MS, NC, SC, TN). The South was the only region to have a statistically significantly higher percentage of trainees with MSKIs at 34% (p < 0.001), as compared to all other regions. The total direct medical cost of treating MSKIs among all trainees was $14,891,563. The South was the costliest region ($7,168,997), accounted for nearly 50 % of the total national cost, and had the highest mean MSKI cost/trainee. DISCUSSION: This study was the first in demonstrating the disproportionate economic burden Southern states pose to the U.S. Department of Defense resulting from its significantly higher MSKI cost. PA and PF are known to ameliorate chronic disease and MSKI burden among general and military populations. Therefore, increasing PA and PF among all young Americans, and specifically those living in Southern states, is imperative for improving public health and reducing the economic and practical burden of MSKIs on military readiness and national security.

Association between Functional Movement Screen Scores and Athletic Performance in Adolescents: A Systematic Review.

This study systematically reviews the literature examining the relationship between Fundamental Movement Screen (FMS©) scores and athletic performance in youth. We searched English-language papers on PubMed/MEDLINE, SportsDiscus, CINAHL, and EBSCO for the following inclusion criteria: Participants aged between 11 and 17 years, studies had to include the Functional Movement Screen© (FMS©) and at least one of the following performance outcomes, highlighted by athletic development models (i.e., long-term athletic development (LTAD), youth physical development (YPD)): agility, speed, power, strength, endurance, and balance (YPD), fitness (LTAD), or sport-specific skill (LTAD and YPD). A total of 3146 titles were identified, with 13 relevant studies satisfying the inclusion criteria after full-text screening. The results of this systematic review suggest that children and youth who score highly on the FMS© also tend to have better scores for agility, running speed, strength, and cardiovascular endurance. The strength of associations was weak to moderate in nature. Only one study was considered or controlled for biological maturation in their analysis. These results provide evidence that, while there is a relationship between FMS© scores and tests of athletic performance in youth, they are not the same thing and should be considered conceptually different constructs.

Convergent validity and sex invariant factor structure of the Movement Imagery Questionnaire-3 - Second version (MIQ-3S): Healthy, young adult reference data.

Aligned with the approach that established the factor structure of the Movement Imagery Questionnaire-3 (MIQ-3), this study extended the two-factor structure of the Movement Imagery Questionnaire - Revised Second version (MIQ-RS). The extension involves assessment of both internal and external visual imagery abilities along with kinesthetic imagery ability. Participants (N = 396) completed the new Movement Imagery Questionnaire - 3 Second Version (MIQ-3S) along with the Vividness of Movement Imagery Questionnaire-2 (VMIQ-2) which measure the same three imagery abilities. Alpha coefficients and between scale Spearman correlations for internal, external, and kinesthetic abilities indicated items were internally consistent (α > 0.87) and established convergent validity (r > 0.69), respectively. MIQ-3S scale means ranged from 5.56 (SD = 1.10) to 5.98 (SD = 0.84), with no differences by sex. The three scales were not multicolinear as intra-scale correlations ranged from 0.47 to 0.61, supporting the three abilities were related, but separate constructs. A multi-trait multimethod confirmatory factor analysis (MTMM CFA), with sex invariance, was conducted to confirm the 3-factor structure of the MIQ-3S. Results from 396 healthy male (n = 200) and female (n = 196) adult college-aged students (M = 21.91, SD = 2.37) indicated a correlated-traits correlated-uniqueness model provided the best fit to the data (CFI = 0.99; SRMR = 0.05; RMSEA = 0.03), while displaying sex invariance. These findings provide baseline data on college-aged, healthy adult participants providing reference data to those investigating imagery abilities among injured populations and practitioners interested in tracking individuals in rehabilitation.

The Relationship Between Functional Motor Competence and Performance on the Army Combat Fitness Test in Army Reserve Officer Training Corps Cadets.

INTRODUCTION: The development of functional motor competence (FMC; i.e., neuromuscular coordination and control required to meet a wide range of movement goals) is critical to long-term development of health- and performance-related physical capacities (e.g., muscular strength and power, muscular endurance, and aerobic endurance). Secular decline in FMC among U.S. children and adolescents presents current and future challenges for recruiting prospective military personnel to successfully perform the physical demands of military duty. The purpose of the current study was to examine the relationship between FMC and physical military readiness (PMR) in a group of Cadets enrolled in an Army Reserve Officer Training Corps program. MATERIALS AND METHODS: Ninety Army Reserve Officer Training Corps Cadets from a southeastern university and a military college in the southeast (females = 22; Mage = 19.5 ± 2.5) volunteered for participation in the study. Cadets performed a battery of eight FMC assessments consisting of locomotor, object projection, and functional coordination tasks. To assess PMR, Cadets performed the Army Combat Fitness Test (ACFT).Values from all FMC assessments were standardized based on the sample and summed to create a composite FMC score. ACFT scores were assigned to Cadets based upon ACFT scoring standards. We used Pearson correlations to assess the relationships between individual FMC assessment raw scores, FMC composite scores, and total ACFT points. We also evaluated the potential impact of FMC on ACFT in the entire sample and within each gender subgroup using hierarchical linear regression. Finally, we implemented a 3 × 2 chi-squared analysis to evaluate the predictive utility of FMC level on pass/fail results on the ACFT by categorizing Cadets' composite FMC score into high (≥75th percentile) moderate (≥25th percentile and <75th percentile), and low (<25th percentile) based on the percentile ranks within the sample. ACFT pass/fail results were determined using ACFT standards, requiring a minimum of 60 points on each the ACFT subtests. RESULTS: FMC composite scores correlated strongly with total ACFT performance (r = 0.762) with individual FMC tests demonstrating weak-to-strong relationships ACFT performance (r = 0.200-0.769). FMC uniquely accounted for 15% (95% CI: -0.07 to 0.36) of the variance in ACFT scores in females (R2 = 0.516, F2,19 = 10.11, P < 0.001) and 26% (95% CI: 0.09-0.43) in males (R2 = 0.385, F2,65 = 20.37, P < 0.001), respectively, above and beyond the impact of age. The 3 × 2 chi-squared analysis demonstrated 74% of those with low, 28% with moderate, and 17% with high FMC failed the ACFT (χ2 [1, N = 90] = 27.717, V = 0.555, P < 0.001). CONCLUSION: FMC composite scores are strongly correlated with ACFT scores, and low levels of FMC were a strong predictor of ACFT failure. These data support the hypothesis that the development of sufficient FMC in childhood and adolescence may be a critical antecedent for PMR. Efforts to improve FMC in children and adolescents may increase PMR of future military recruits.

Fit to Play? Health-Related Fitness Levels of Youth Athletes: A Pilot Study.

ABSTRACT: Pfeifer, CE, Sacko, RS, Ortaglia, A, Monsma, EV, Beattie, PF, Goins, J, and Stodden, DF. Fit to play? Health-related fitness levels of youth athletes: A pilot study. J Strength Cond Res 36(1): 245-251, 2022-A recent National Strength and Conditioning Association position statement suggests that many youth are not prepared for the physical demands of sport. The purpose of this study was to compare health-related fitness (HRF) of youth athletes with normative findings from the general population. We recruited 136 athletes (63 male and 73 female athletes) aged 11-19 (16.01 ± 1.35) years and collected HRF (body composition, cardiorespiratory endurance, musculoskeletal strength and endurance). Results were categorized based on FITNESSGRAM® standards and compared with Canadian youth general population normative data. Most male athletes were classified as "needs improvement" for cardiorespiratory and muscular endurance, and body mass index (BMI). Conversely, most female athletes were at or above the "healthy fitness zone" for all measures. Male athletes at both age groups (11-14, 15-19; p < 0.001) and female athletes aged 11-14 (p < 0.05) demonstrated lower cardiorespiratory endurance compared with Canadian general population. Female athletes (both age groups) demonstrated greater muscular strength, and male athletes (age, 15-19 years) demonstrated lower BMI than the Canadian general population. The results are concerning as male athletes demonstrated poorer HRF compared with the general population. Although most female athletes were within healthy ranges, a portion of them were still at risk. Considering the demands sport places on the body, evaluating HRF is paramount for performance and injury prevention but more importantly for overall health. Youth sport and strength coaches should evaluate and aim to enhance HRF, as participation in sport does not guarantee adequate HRF. Promoting long-term athletic development and life-long health should be a priority in youth.

The Potential Role of Functional Motor Competence to Promote Physical Military Readiness: A Developmental Perspective.

Decreased physical fitness in military recruiting populations is problematic for the development of physical military readiness (PMR) and presents a threat to national security. The demonstration of low levels of fitness may be an indicator of a more foundational problem in the physical development of military recruits. We propose the development of functional motor competence (FMC) across childhood and adolescence as a necessary antecedent to advanced PMR training and military-specific tasks (i.e., rucking and obstacle course navigation) and as an integral part of sustained PMR. The development of FMC supports increases in cardiovascular and muscular endurance through repeated efforts performed during practice and in sport, as well as muscular power as many FMC movements mimic plyometrics in a strength in conditioning sense. We posit that an inadequate foundation in FMC will serve as a barrier to achieving sufficient PMR and combat success of the fighting force. We propose three possible solutions to ensure sufficient PMR levels through the implementation of developmentally appropriate FMC-based training. First would be promoting FMC-based training in junior reserve officer training corp and ROTC programs. Second would be a more global approach, on the scale of the National Defense Education Act, specifically focusing on promoting quality daily physical education that could reach millions of children. Third, individual branches could begin promoting the tenets of foundational FMC training concepts in their physical training manuals, which ideally would address FMC before and throughout basic training, as well as subsequent active duty training.

THE ASSOCIATION BETWEEN THE FUNCTIONAL MOVEMENT SCREENTM, Y-BALANCE TEST, AND PHYSICAL PERFORMANCE TESTS IN MALE AND FEMALE HIGH SCHOOL ATHLETES.

BACKGROUND: Poor balance, lack of neuromuscular control, and movement ability are predictors of performance and injury risk in sports and physical activity participation. The Functional Movement Screen™ (FMS™) and lower quarter Y-Balance Test (YBT) have been used by clinicians to evaluate balance, functional symmetry, and static and dynamic movement patterns, yet little information exists regarding the relationship between the FMS™, YBT, and physical performance tests (e.g. vertical jump) within the high school population. PURPOSE: The purpose of this study was to investigate the relationship between the FMSTM, dynamic balance as measured by the YBT and physical performance tests (standing long jump, vertical jump, Pro Agility Test) in male and female high school athletes. STUDY DESIGN: Cohort study. METHODS: Fifty-six high school athletes (28 females, 28 males; mean age 16.4 ± 0.1) who participated in organized team sports were tested. Participants performed the FMS™, YBT, and three physical performance tests (standing long jump, vertical jump, Pro Agility Test). RESULTS: Females outperformed males on the FMS™ and YBT, while males outperformed females on the performance tests. In both sexes, the composite FMSTM score was positively correlated with the left and composite YBT scores. Agility was negatively correlated with composite FMSTM in males (p < 0.05) and the left and composite YBT in females (p < 0.05). CONCLUSIONS: The FMSTM and YBT may evaluate similar underlying constructs in high school athletes, such as dynamic balance and lower extremity power. The results of this study demonstrate the utility of the FMS and YBT to relate multiple constructs of muscular power to an individual's ability to balance. Furthermore, establishing the need for the utilization and application of multiple field-based tests by sports medicine professionals and strength and conditioning coaches when evaluating an athlete's movement and physical performance capabilities. Utilization of multiple field-based tests may provide the first step for the development of injury prevention strategies and long-term athlete development programs. LEVEL OF EVIDENCE: 2b.

FUNCTIONAL MOVEMENT SCREEN™ in YOUTH SPORT PARTICIPANTS: EVALUATING the PROFICIENCY BARRIER for INJURY.

BACKGROUND & PURPOSE: The number of youth participating in sport increases yearly; however, the evaluation of youths' movement ability and preparedness for sport remains inadequate or neglected. The Functional Movement Screen (FMS™) is an assessment of an individual's movement quality that has been utilized to evaluate risk of injury in collegiate and professional sport; however, there is minimal support regarding the predictive value of the screen in youth sport. The purpose of this study was to evaluate the mean and distribution of FMS™ performance in sport participants age 11-18, and to evaluate the existence of a composite FMS™ score proficiency barrier to predict injury risk. STUDY DESIGN: Prospective cohort study. METHODS: One hundred, thirty-six participants (63 male, 73 female) age 11 to 18 years (16.01 + 1.35) were recruited from local schools and sport organizations. The FMS™ was administered prior to each participant's competitive season and scored by researchers who demonstrated reliability in assessments derived from the screen (κw = 0.70 to 1). Injury data were collected by the participants' Athletic Trainer over one season. An injury was defined as any physical insult or harm resulting from sports participation that required an evaluation from a health professional with time modified or time lost from sport participation. RESULTS: Females scored significantly higher than males for mean FMS™ composite score (t = 14.40; m = 12.62; p < 0.001), and on individual measures including: the hurdle step (t = 1.91; m = 1.65; p < 0.001), shoulder mobility (t = 2.68; m = 2.02; p < 0.001), active straight leg raise (t = 2.32; m = 1.87; p < 0.001), and the rotary stability components (t = 1.91; m = 1.65; p < 0.05). Two FMS™ composite scores (score < 14 and <15) significantly increased the odds of injury (OR = 2.955). When adjusting for sport, there was no score relating to increased odds of injury. CONCLUSION: Dysfunctional movement as identified by the FMS™ may be related to increased odds of injury during the competitive season in youth athletes. Consideration of an individual's movement within the context of their sport is necessary, as each sport and individual have unique characteristics. Addressing movement dysfunction may aid in injury reduction and potentially improve sport performance. LEVEL OF EVIDENCE: 1b.

Motor competence and health-related fitness in children: A cross-cultural comparison between Portugal and the United States.

BACKGROUND: Motor competence and health-related fitness are important components for the development and maintenance of a healthy lifestyle in children. This study examined cross-cultural performances on motor competence and health-related fitness between Portuguese and U.S. children. METHODS: Portuguese (n = 508; 10.14 ± 2.13 years , mean ± SD) and U.S. (n = 710; 9.48 ± 1.62 years) children performed tests of cardiorespiratory fitness (Progressive Aerobic Cardiovascular Endurance Run), upper body strength (handgrip), locomotor skill performance (standing long jump), and object projection skill performance (throwing and kicking). Portuguese and U.S. children were divided into 2 age groups (6-9 and 10-13 years) for data analysis purposes. A two-factor one-way analysis of covariance (ANOVA) was conducted with the Progressive Aerobic Cardiovascular Endurance Run, handgrip, standing long jump scores, kicking, and throwing speed (km/h) as dependent variables. RESULTS: Results indicated that Portuguese children, irrespective of sex, presented better performances in locomotor and cardiorespiratory performance (standing long jump and Progressive Aerobic Cardiovascular Endurance Run) than U.S. children in both age bands. U.S. children outperformed Portuguese children during throwing and handgrip tests. Kicking tests presented gender differences: Portuguese boys and U.S. girls outperformed their internationally matched counterparts. CONCLUSION: Cultural differences in physical education curricula and sports participation may impact differences in motor competence and fitness development in these countries.

Children's metabolic expenditure during object projection skill performance: New insight for activity intensity relativity.

Objective: To examine children's energy expenditure (EE) during object projection skill performance at three intensity intervals. Methods: Children's (42, Mage = 8.1) average metabolic equivalents of task (METs) were calculated using a COSMED K4b2 while they repeatedly performed blocks of kicking, throwing (overhand), and striking (two-handed) during 6, 12, and 30-s interval conditions. A repeated-measures analysis of covariance examined differences in METs while controlling for skill level. Results: Data indicated a main effect for interval condition (df = 2, 123, F = 94.36, p <.001, η2 = .605). Post hoc t-tests demonstrated decreasing performance interval times yielded progressively higher METs (p <.001) across the three conditions (30s = 4.5±0.8 METs, 12s = 6.3±1.3, 6s = 8.3±1.6). There also was a main effect for sex (df = 1,120, F = 52.28, p <.001 η2 = .305). Boys demonstrated higher METs at each performance interval (p <.001). Conclusion: Skill practice with a maximum of one trial every 30s resulted in the equivalent of at least moderate physical activity (>4.0 METs) and intervals of 6s demonstrated vigorous physical activity (>7.0 METs). Practicing/performing object projection skills, even at intervals that allow for adequate instruction and feedback (i.e., 1 trial/30s), promotes MVPA in children.

RISK FACTORS ASSOCIATED WITH NON-CONTACT ANTERIOR CRUCIATE LIGAMENT INJURY: A SYSTEMATIC REVIEW.

BACKGROUND: With the increasing number of individuals participating in sports every year, injury - specifically anterior cruciate ligament (ACL) injury - remains an inherent risk factor for participants. The majority of ACL injuries occur from a non-contact mechanism, and there is a high physical and financial burden associated with injury. Understanding the risk factors for ACL injury may aid in the development of prevention efforts. PURPOSE: The purpose of this review was to synthesize and appraise existing literature for risk factors associated with non-contact anterior cruciate ligament (ACL) injury in both sexes. STUDY DESIGN: Systematic review. METHODS: An electronic literature search was conducted utilizing the MEDLINE database and The Cochrane library for articles available through February 2016. All titles and abstracts were reviewed and full text articles meeting eligibility criteria were assessed in detail to determine inclusion or exclusion. Articles reviewed in full text were reviewed for scientific evidence of risk factors for ACL injury. Results from studies were extracted and initially classified as either intrinsic or extrinsic risk factors, and then further categorized based upon the evidence presented in the studies meeting inclusion criteria. Data extracted from eligible studies included general study characteristics (study design, sample characteristics), methodology, and results for risk factors included. RESULTS: Principal findings of this systematic review identified the following risk factors for ACL injury in both sexes: degrading weather conditions, decreased intercondylar notch index or width, increased lateral or posterior tibial plateau slope, decreased core and hip strength, and potential genetic influence. CONCLUSIONS: Neuromuscular and biomechanical risk factors may be addressed through neuromuscular preventative training programs. Though some extrinsic and other inherent physiological factors tend to be non-modifiable, attempts to improve upon those modifiable factors may lead to a decreased incidence of ACL injury. LEVEL OF EVIDENCE: 2a.

New insight for activity intensity relativity, metabolic expenditure during object projection skill performance.

This study examined the metabolic cost (METs) of performing object projection skills at three practice trial intervals (6, 12, and 30 seconds). Forty adults (female n = 20) aged 18-30 (M = 23.7 ± 2.9 years) completed three, nine-minute sessions of skill trials performed at 6, 12, and 30 second intervals. Participants performed kicking, throwing and striking trials in a blocked schedule with maximal effort. Average METs during each session were measured using a COSMED K4b2. A three (interval condition) X two (sex) ANOVA was conducted to examine differences in METs across interval conditions and by sex. Results indicated a main effect for interval condition (F(5,114) = 187.02, p < .001, η2 = 0.76) with decreased interval times yielding significantly higher METs [30 sec = 3.45, 12 sec = 5.68, 6 sec = 8.21]. A main effect for sex (F(5, 114) = 35.39, p < .001, η2 = 0.24) also was found with men demonstrating higher METs across all intervals. At a rate of only two trials/min, participants elicited moderate physical activity, with 12 and 6-second intervals exhibiting vigorous PA. Demonstrating MVPA during the performance of object projection skill performance has potential implications for PA interventions.