Silent Struggles: Traumatic Brain Injuries and Mental Health in Law Enforcement.

OBJECTIVE: To determine the prevalence of head injuries (HIs), posttraumatic stress disorder (PTSD), and depressive symptoms in law enforcement officers (LEOs) and (2) the association between HIs and psychological health conditions. SETTING: County-level survey administered via Research Electronic Data Capture. PARTICIPANTS: A total of 381 LEOs completed the survey (age = 43 ± 11 years; 40 [11%] females; time as LEO = 1-50 years, median = 15 years). DESIGN: Cross-sectional study. MAIN MEASURES: We examined the prevalence of HIs (the Ohio State University Traumatic Brain Injury Identification Method), PTSD (PTSD Checklist-Civilian [PCL-C]), and depressive symptoms (Patient Health Questionnaire-9 [PHQ-9]). We used Mann-Whitney U and chi-square analyses to compare PTSD and depressive symptoms between those with and without a HI history. RESULTS: There were 282 (74%) participants who reported a lifetime history of 1 or more HIs; 116 (30%) sustained 1 or more HIs on the job. PCL-C scores ranged 17 to 85 (median = 27); 33 (10%) participants met or exceeded the clinical cutoff score of 50 to indicate a positive PTSD screening. Participants with a HI history (median = 29) had higher PCL-C scores than those with no HI history (median = 24; P < .001), but the proportion of participants who met the clinical cutoff for PTSD was not different between those with (n = 28, 11%) and without (n = 5, 5%) a HI history (X2 = 2.52, P = .112, odds ratio = 2.18; 95% confidence interval, 0.82-5.83). PHQ-9 scores ranged 0 to 20 (median = 3); 124 (36%) participants reported mild or greater depressive symptoms. Participants with a HI history (median = 3) had higher depressive symptoms than those with no HI history (median = 2; P = .012). The proportion of participants with mild or greater depressive symptoms was higher among those with a HI history (n = 99, 39%) than without (n = 25, 27%; X2 = 4.34, odds ratio = 1.74; 95% confidence interval, 1.03-2.93). CONCLUSION: HIs are prevalent in LEOs, which may have consequences for their performance, well-being, and career longevity. PTSD and depressive symptoms are higher in those with a HI history, suggesting LEOs need better traumatic brain injuries and mental health resources.

Female National Collegiate Athletic Association Division-I Athlete Injury Prediction by Vertical Countermovement Jump Force-Time Metrics.

ABSTRACT: Merrigan, JJ, Stone, JD, Kraemer, WJ, Vatne, EA, Onate, J, and Hagen, JA. Female National Collegiate Athletic Association Division-I athlete injury prediction by vertical countermovement jump force-time metrics. J Strength Cond Res 38(4): 783-786, 2024-Vertical countermovement jump (CMJ) assessments on force plates have been purported to screen for musculoskeletal injury risk (MSKI) but with little scientific support. Thus, this study aimed to identify associations and noncontact lower-body injury predictability with CMJ force-time metrics in female athletes. The study entailed a retrospective analysis of routine injury and performance monitoring from 155 female National Collegiate Athletics Association Division I athletes. Noncontact lower-body injuries included in analysis were confirmed by medical staff, occurred during competition or training, resulted in time loss from training, and occurred within 3 months following CMJ testing (2 maximal effort, no arm swing, jumps on dual force plates). A total of 44 injuries occurred within 3 months following CMJ baseline testing and resulted in an average of 24.5 missed days from training. Those who sustained an injury were more likely to sustain another injury (15 of 44 injuries [33.1%]; odds ratio = 3.05 [95% CI = 1.31-6.99]). For every 1-unit increase from the mean in eccentric mean power and minimum eccentric force, there was a decrease in odds of sustaining a MSKI. Despite high overall model accuracy (85.6%), the receiving operating characteristic area under the curve (65.9%) was unacceptable and the true positive rate (recall) was 0.0%. Thus, no injuries in the testing data set were correctly classified by the logistic regression model with CMJ force-time metrics as predictors. Baseline CMJ assessment may not be useful for noncontact lower-body musculoskeletal injury screening or predictability in National Collegiate Athletics Association female athletes.

Arousal/Stress Effects of "Overwatch" eSports Game Competition in Collegiate Gamers.

ABSTRACT: Kraemer, WJ, Caldwell, LK, Post, EM, Beeler, MK, Emerson, A, Volek, JS, Maresh, CM, Fogt, JS, Fogt, N, Häkkinen, K, Newton, RU, Lopez, P, Sanchez, BN, and Onate, JA. Arousal/stress effects of "Overwatch" eSports game competition in collegiate gamers. J Strength Cond Res 36(10): 2671-2675, 2022-To date, no physical response data are available for one of the most popular eSport games, Overwatch . The purpose of this investigation was to describe the stress signaling associated with competitive Overwatch play and to understand how acute hormonal responses may affect performance. Thirty-two male college-aged gamers (age: 21.3 ± 2.7 years; estimated time played per week: 18 ± 15 hours) completed the study. Subjects were randomly assigned to a 6-player team to compete in a tournament-style match. Salivary measures of cortisol and testosterone were collected immediately before (PRE) and after (POST) the first-round game, with the heart rate recorded continuously during the match. The mean characteristics were calculated for each variable and comparisons made by the skill level. Significance was defined as p ≤ 0.05. There were no differences in measures of salivary cortisol. A differential response pattern was observed by the skill level for testosterone. The low skill group displayed a significant increase in testosterone with game play (mean ± SD , testosterone PRE: 418.3 ± 89.5 pmol·L -1 , POST: 527.6 ± 132.4 pmol·L -1 , p < 0.001), whereas no change was observed in the high skill group. There were no differences in heart rate characteristics between skill groups. Overall, the average heart rate was 107.2 ± 17.8 bpm with an average max heart rate of 133.3 ± 19.1 bpm. This study provides unique physiological evidence that a sedentary Overwatch match modulates endocrine and cardiovascular responses, with the skill level emerging as a potential modulator.

Clinical Utility and Validity of Exercise Vital Sign in Children.

ABSTRACT: We reviewed charts of 14,446 sports medicine patients, children aged 5 to 18 years, over a 3-year period to determine the discriminant validity of Exercise Vital Sign (EVS) questions. A logistic regression analyzed factors related to any moderate to vigorous physical activity (MVPA). A linear regression analyzed factors related to amount of MVPA for those who participated in any weekly MVPA. Overall, 48% of children reported meeting physical activity guidelines for 420 min·wk-1. Overall, children reported 400.36 ± 280.04 min·wk-1 of MVPA. Those with depression had significantly less MVPA than those without (95% confidence interval [CI], -96.65 to -26.31). Girls had significantly less MVPA than boys (95% CI, -59.15 to -40.31). Overweight and obese children reported less MVPA compared with normal weight children (95% CIs, -42.65 to -17.29 and -91.61 to -65.50, respectively). EVS demonstrates strong discriminant validity to detect differences between groups as a function of sex, body mass index, and depression.

Differences in brain structure and theta burst stimulation-induced plasticity implicate the corticomotor system in loss of function after musculoskeletal injury.

Traumatic musculoskeletal injury (MSI) may involve changes in corticomotor structure and function, but direct evidence is needed. To determine the corticomotor basis of MSI, we examined interactions among skeletomotor function, corticospinal excitability, corticomotor structure (cortical thickness and white matter microstructure), and intermittent theta burst stimulation (iTBS)-induced plasticity. Nine women with unilateral anterior cruciate ligament rupture (ACL) 3.2 ± 1.1 yr prior to the study and 11 matched controls (CON) completed an MRI session followed by an offline plasticity-probing protocol using a randomized, sham-controlled, double-blind, cross-over study design. iTBS was applied to the injured (ACL) or nondominant (CON) motor cortex leg representation (M1LEG) with plasticity assessed based on changes in skeletomotor function and corticospinal excitability compared with sham iTBS. The results showed persistent loss of function in the injured quadriceps, compensatory adaptations in the uninjured quadriceps and both hamstrings, and injury-specific increases in corticospinal excitability. Injury was associated with lateralized reductions in paracentral lobule thickness, greater centrality of nonleg corticomotor regions, and increased primary somatosensory cortex leg area inefficiency and eccentricity. Individual responses to iTBS were consistent with the principles of homeostatic metaplasticity; corresponded to injury-related differences in skeletomotor function, corticospinal excitability, and corticomotor structure; and suggested that corticomotor adaptations involve both hemispheres. Moreover, iTBS normalized skeletomotor function and corticospinal excitability in ACL. The results of this investigation directly confirm corticomotor involvement in chronic loss of function after traumatic MSI, emphasize the sensitivity of the corticomotor system to skeletomotor events and behaviors, and raise the possibility that brain-targeted therapies could improve recovery.NEW & NOTEWORTHY Traumatic musculoskeletal injuries may involve adaptive changes in the brain that contribute to loss of function. Our combination of neuroimaging and theta burst transcranial magnetic stimulation (iTBS) revealed distinct patterns of iTBS-induced plasticity that normalized differences in muscle and brain function evident years after unilateral knee ligament rupture. Individual responses to iTBS corresponded to injury-specific differences in brain structure and physiological activity, depended on skeletomotor deficit severity, and suggested that corticomotor adaptations involve both hemispheres.

Visual and Ocular Characteristics of eSports Participants.

SIGNIFICANCE: The popularity of competitive video game play is growing rapidly. Little is known about the ocular characteristics of esports participants. Refractive error and binocular measures in young adult gamers were similar to population norms. However, tear breakup time was lower, and accommodative lag was higher. PURPOSE: In a recent report, very young video game players were found to have greater levels of refractive error and heterophoria and reduced stereopsis. The purpose of this study was to assess the visual and ocular characteristics of a group of recreational esports athletes to determine if the findings in young children were similar to findings in a group of young adult video game players. METHODS: Vision tests were performed on 36 college students during a video game combine event. Testing included high- and low-contrast visual acuity, autorefraction at distance and at 33 cm, stereoacuity, near heterophoria, and tear breakup time. Participants also indicated their level or rank in the game Overwatch. RESULTS: Fifteen participants were myopic, and 21 did not wear vision correction. The mean local stereopsis was 31.9 seconds. The mean of the esophoric value was 3.2 prism diopters, and the mean of the exophoric value was 5.7 prism diopters. The mean lag of accommodation was 0.81 D. The mean tear breakup time was 5.8 seconds. Average hours of play did not differ between those who wore vision correction and those who did not. There were no significant relationships between the hours of play and the ocular findings. CONCLUSIONS: The prevalence of refractive error and the mean heterophoria were similar to population norms, and the mean stereoacuity was normal. However, accommodative lag was slightly higher, and the tear breakup time was lower than expected. Differences in these latter values were also noted between high- and low-level Overwatch players.

Concussion Epidemiology in Athletes Who Are Deaf or Hard-of-Hearing Compared With Athletes Who Are Hearing.

OBJECTIVE: To compare the epidemiology of concussion between athletes who are deaf or hard-of-hearing (D/HoH) and athletes who are hearing. DESIGN: Descriptive epidemiology study. SETTING: Data were collected from 2 Division III athletic programs. One institution is the world's only university designed to be barrier-free for students who are D/HoH. PARTICIPANTS: Six hundred ninety-three athletes who are D/HoH and 1284 athletes who are hearing were included in this study. Athletes participated in collegiate athletics during the 2012 to 2013 through the 2016 to 2017 academic years. INTERVENTIONS: Concussion data were provided by the athletic training staff at each institution. MAIN OUTCOME MEASURES: Concussion counts, concussion rate, and injury rate ratios (IRRs) with 95% confidence intervals (95% CIs). RESULTS: Thirty athletes who are D/HoH and 104 athletes who are hearing suffered concussions. Athletes who are hearing had an increased injury rate compared with athletes who are D/HoH for all sports combined (IRR = 1.87, 95% CI, 1.26-2.78). Football athletes who are hearing also had an increased injury rate compared with football athletes who are D/HoH (IRR = 3.30, 95% CI, 1.71-6.37). Concussion rate was higher for male athletes who are hearing than male athletes who are D/HoH (IRR = 2.84, 95% CI, 1.62-4.97). No other significant differences regarding concussion risk were identified. CONCLUSIONS: Athletes who are D/HoH in sex-comparable sports may not have a higher rate of concussion than athletes who are hearing. Rate of concussion in football may be greater among athletes who are hearing compared with athletes who are D/HoH.

The Effectiveness of Cervical Strengthening in Decreasing Neck-Injury Risk in Wrestling.

Clinical Scenario: In wrestling, athletes often support a large amount of weight on their heads or are forced into extreme ranges of motion. These suboptimal movement conditions lead to a high prevalence of neck injuries in wrestlers. A large portion of the work done by the cervical musculature in wrestling is theorized to be eccentric or isometric types of contractions. Strengthening of these cervical muscles is clinically considered to play a vital role in being competitive on the wrestling mat. The cervical stability provided by strengthening these muscles may also play a part in injury prevention among wrestlers. Focused Clinical Question: Does increased cervical strength lead to a decreased risk of injury in wrestling? Summary of Search, "Best Evidence" Appraised, and Key Findings: The literature was searched for studies of level 4 evidence or higher using the Oxford Centre for Evidence-Based Medicine level of evidence system that investigated the relationship between cervical strength and injury risk in wrestling. No studies were found comparing cervical strength to injury risk in wrestling, but 2 related studies were found and have been included in this critically appraised topic. Clinical Bottom Line: There is poor evidence to support a relationship between cervical strength and injury risk in wrestling. Strength of Recommendation: There is grade C evidence to indicate that increased cervical strength decreases the risk of injury in wrestling.

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.

Low back functional health status of patient handlers.

PURPOSE: The purpose of this study was to assess low back functional health among a group of nurses with a history of low back pain symptoms in a university hospital using a direct measure of low back functional performance and compare to traditional low back disability and pain questionnaires. METHODS: Fifty-two nurses and patient care associates volunteered for the study. The clinical lumbar motion monitor (LMM) was used to directly measure low back functional performance. The participants performed a series of standard tasks involving trunk flexion and extension at different asymmetries. The LMM measures the motion signature of the participant (range of motion, velocity and acceleration) in all three planes of the body. The clinical LMM evaluation documented objective assessment of low back function normalized for age and gender. The Oswestry Disability Index (ODI) was used to evaluate self-reported disability and the McGill Pain Questionnaire visual analog scale assessed pain symptom. RESULTS: The average functional performance probability was 0.49 with a standard deviation of 0.29, indicating that on average the functional performance was impaired. The average ODI score was 13.4 with a standard deviation of 11.6. The correlation between the functional performance probability and ODI was 0.046 (not statistically significant). CONCLUSIONS: The clinical LMM functional performance measure provides a direct measure of trunk function. The low correlation between the ODI and clinical LMM functional performance probability indicates that the direct functional performance measure adds another component to our understanding of low back health or impairment that traditional questionnaires lack.

Stride Leg Ground Reaction Forces Predict Throwing Velocity in Adult Recreational Baseball Pitchers.

Ground reaction forces produced during baseball pitching have a significant impact in the development of ball velocity. However, the measurement of only one leg and small sample sizes in these studies curb the understanding of ground reaction forces as they relate to pitching. This study aimed to further clarify the role ground reaction forces play in developing pitching velocity. Eighteen former competitive baseball players with previous high school or collegiate pitching experience threw 15 fastballs from a pitcher's mound instrumented to measure ground reaction forces under both the drive and stride legs. Peak ground reaction forces were recorded during each phase of the pitching cycle, between peak knee height and ball release, in the medial/lateral, anterior/posterior, and vertical directions, and the peak resultant ground reaction force. Stride leg ground reaction forces during the arm-cocking and arm-acceleration phases were strongly correlated with ball velocity (r2 = 0.45-0.61), whereas drive leg ground reaction forces showed no significant correlations. Stepwise linear regression analysis found that peak stride leg ground reaction force during the arm-cocking phase was the best predictor of ball velocity (r2 = 0.61) among drive and stride leg ground reaction forces. This study demonstrates the importance of ground reaction force development in pitching, with stride leg forces being strongly predictive of ball velocity. Further research is needed to further clarify the role of ground reaction forces in pitching and to develop training programs designed to improve upper extremity mechanics and pitching performance through effective force development.

Development and Psychometric Evaluation of the Vocational Fit Assessment (VFA).

OBJECTIVE: The objective of this study was to determine the psychometric properties of the Vocational Fit Assessment (VFA) by examining its factor structure and subscale reliability. METHOD: This prospective cross-sectional study used two surveys (one for worker abilities and one for job demands) to collect the data needed for the psychometric evaluation of the VFA. Latent parallel analysis and ordinal exploratory factor analysis were used to iteratively refine VFA subscales. RESULTS: Ten unidimensional subscales emerged from factor analysis of VFA items: (1) Cognitive Abilities, (2) Communication Skills, (3) Computer Skills, (4) Higher Task-Related Abilities, (5) Interpersonal Skills, (6) Lower Task-Related Abilities, (7) Physical Abilities, (8) Safety, (9) Self-Determination, and (10) Work Structure. Subscale internal consistency (ordinal α) was ≥.86 for VFA for worker abilities and ≥.77 for VFA for job demands. CONCLUSION: The unidimensional structure of VFA subscales and estimates of internal consistency lend initial evidence in support of their reliability and validity.

Knee kinematics is altered post-fatigue while performing a crossover task.

PURPOSE: To examine the effect of a sequential fatigue protocol on lower extremity biomechanics during a crossover cutting task in female soccer players. METHODS: Eighteen female collegiate soccer players alternated between a fatigue protocol and two consecutive unanticipated crossover trials until fatigue was reached. Lower extremity biomechanics were evaluated during the crossover using a 3D motion capture system and two force plates. Repeated-measures ANOVAs analysed differences between three sequential stages of fatigue (pre, 50, 100%) for each dependent variable (α = 0.05). RESULTS: Knee flexion angles at initial contact (IC) for pre (-32 ± 9°) and 50% (-29 ± 11°) were significantly higher than at 100% fatigue (-22 ± 9°) (p < 0.001 and p = 0.015, respectively). Knee adduction angles at IC for pre (9 ± 5°) and 50% (8 ± 4°) were significantly higher (p = 0.006 and p = 0.049, respectively) than at 100% fatigue (6 ± 4°). CONCLUSIONS: Fatigue altered sagittal and frontal knee kinematics after 50% fatigue whereupon participants had diminished knee control at initial contact. Interventions should attempt to reduce the negative effects of fatigue on lower extremity biomechanics by promoting appropriate frontal plane alignment and increased knee flexion during fatigue status. LEVEL OF EVIDENCE: III.

Suggestions and Considerations for Application of Movement Screens to Clinical Practice.

Pre-participation and return to activity functional assessments are commonly used in clinical practice to assess movement quality and identify athletes' limitations. While there are slight differences between each specific test battery, general guidelines suggest that the tests be completed without a warm-up. This has been suggested because dynamic stretching may improve range of motion and athletic performance. However, athletes typically warm up prior to participating in sport. Therefore, researchers should investigate the acute effects of dynamic stretching on functional tests and movement screens and evaluate other factors that may influence performance on these test batteries. Scientific evidence for standardized implementation of various movement screens is lacking, and future research should aim to identify gaps in the literature to allow clinicians to properly implement evidence-based practice functional assessments. The purpose of this commentary is to discuss various considerations for implementing movement screens and assessment tools into clinical practice. LEVEL OF EVIDENCE: 5.

Models of Video Feedback for Youth Athletes Performing an American Football Tackle.

CONTEXT: Video feedback is an expeditious method for improving athlete safety when performing activities with an inherent risk of injury. Providing appropriate and validated feedback during tackling training in American football may be a mechanism for athletes to learn safe tackling performance. OBJECTIVE: To determine the effect of video feedback in the instruction of tackling form. DESIGN: Controlled laboratory study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 32 youth football athletes (28 boys, 4 girls; age = 11.8 ± 0.8 years) participated in 1 day of training. Of those, 14 participants completed 2 additional days of training and a 48-hour retention and transfer test. INTERVENTION(S): Video feedback using self as model, expert as model, combined self and expert model, and oral feedback to promote safe tackling performance in a laboratory environment. MAIN OUTCOME MEASURE(S): Shoulder extension, cervical extension, trunk angle, pelvis height, and step length by training block and over time. RESULTS: For the 1-day training group, main effects for time were observed for shoulder extension (P < .01), cervical extension (P = .01), pelvis height (P < .01), and step length (P < .01), with better performance for pelvis height and step length after combined feedback. For the 3-day training group, main effects of time were identified in pelvis height (P < .01) and step length (P < .01), with combined feedback showing better performance than other methods in shoulder extension and pelvis height. Combined feedback resulted in better performance compared with its component parts and oral feedback alone. In the combined model, participants viewed both their performance and the expert model, enabling them to see the difference between current and required performance. CONCLUSIONS: Combined feedback may be superior to other forms of feedback in improving movement performance. This effect can be generalized across disciplines that provide instruction and feedback in movement.

Headgear use in girls' lacrosse-stakeholders not ready for change.

Purpose: Mandating headgear for field players in girls' lacrosse to reduce head injuries, including concussion, has been heavily debated. However, research regarding the need and effectiveness of mandated headgear use in girls' lacrosse is still developing. Therefore, this qualitative study aimed to identify the need for and barriers to the development of mandated headgear use policies in girls' lacrosse in Ohio. Methods: We conducted six virtual focus groups, three with concussion experts (clinicians and researchers) and three with girls' lacrosse stakeholders (high school players, parents, coaches, and officials). A focus group guide was developed to explore study participants' perceptions and opinions on concussion in girls' lacrosse, headgear use among players, and policies and policy development related to headgear use or a headgear mandate. We developed the codebook using an inductive and iterative approach based on focus group transcripts and used ATLAS.TI to code and analyze the transcript data. Results: Concussion experts and stakeholders understood the potential consequences of concussion but did not perceive concussion as a pervasive problem in girls' lacrosse. The prevention of head and facial injuries was regarded as a potential benefit of headgear use. However, stakeholders expressed that the myriad of arguments discussed opposing mandated headgear use including increased aggressive play and/or targeting, concerns over changes in the game, and cost strongly outweighed the benefits. Finally, both concussion experts and stakeholders identified multiple organizations, including USA Lacrosse, who could act as facilitators and/or barriers to developing, enacting, and implementing headgear policies. Conclusions: Concussion experts and stakeholders identified possible reasons for headgear use related to injury prevention but also identified several important barriers to the development of a headgear mandate for girls' lacrosse in Ohio.

A Framework for Concussion Management Strategies in Law Enforcement Officers.

Athletic trainers are increasingly utilized in non-traditional settings, such as in law enforcement, where they can contribute to healthcare management, including concussion management of law enforcement officers (LEOs). Despite the prevalence of concussions among LEOs, there is a notable gap in concussion management guidelines for this population. LEOs may lack the education and resources necessary for concussion recognition and proper management. Drawing on advancements in concussion management in athletes and military personnel, here we present a comprehensive framework for concussion management in LEOs encompassing concussion education, a graduated return to duty (RTD) protocol, and considerations for implementation and documentation specific to law enforcement. We also present several barriers and facilitators to implementation. Due to job requirements, it is critical for law enforcement organizations and their medical providers to adopt a concussion management strategy. Without proper concussion management, LEOs may risk subsequent injury and/or suffer from prolonged recovery and adverse long-term outcomes.

Estimating marksmanship performance during walking while maintaining weapon aim.

Marksmanship performance while moving is a critical skill among tactical athletes due to the high demands of their occupational duties. Qualifications for dynamic marksmanship performance are not standardized across tactical athlete groups, which may limit comprehensive assessment of tactical athlete performance for situational awareness and adaptability to an unpredictable environment. Although static marksmanship performance provides foundational information on skills and level of ability, research is lacking on factors that influence dynamic marksmanship performance to best prepare tactical athletes for duties. The purpose of this study was to identify whether static marksmanship performance, speed of movement, load carriage, and biomechanical factors while 'shooting on the move' influenced dynamic marksmanship performance. Twenty-four male tactical athletes (22 active-duty Army Soldiers, two civilian SWAT operators; age: 23.83 ± 5.47 years; height: 1.80 ± 0.08 m; weight: 81.04 ± 7.87 kg) participated; final analyses did not include data from the two civilian operators to maintain sample homogeneity. Tactical athletes completed static and dynamic ('shoot on the move') marksmanship tasks under three load conditions: (1) no load (NL), (2) half kit (HK) of 11.34 kg, and (3) full kit (KIT) of 22.68 kg. Dynamic marksmanship was completed under three speed conditions: (1) self-selected slow speed, (2) standard speed, and (3) self-selected fast speed. Hip, knee, and ankle kinematics were collected via wireless inertial measurement units. Spatiotemporal parameters were collected via optical detection system. Marksmanship performance (accuracy) was collected via open-air acoustic target scoring and mean radial error (MRE) was calculated for both static and dynamic marksmanship tasks. Linear mixed-effects models were fit with dynamic MRE as the outcome variable with fixed effects of static MRE, load condition, speed condition, kinematics, and spatiotemporal parameters, adjusting for body mass. Alpha level was set a priori at p ≤ 0.10. The final statistical model included fixed effects of static MRE, load condition, speed condition, and time spent in double limb support. Static MRE (p < 0.01) and time spent in double limb support (p = 0.01) were significant factors. For each 1 cm increase in static MRE there was a 0.66 cm increase in dynamic MRE. For every 1% increase in time spent in double limb support while 'shooting on the move' there was a 0.13 cm increase in dynamic MRE. Findings from this study highlight that tactical athletes who have larger static stance MRE and spend a longer time in double limb support during a gait cycle exhibit an increase in MRE during 'shoot on the move' trials. Overall, dynamic shooting accuracy is not affected by lower extremity joint angles, load carriage, or speed of movement. Although strong relationships are known between gait speed, load, and lower extremity kinematics, the differences in tactical gait compared to normal gait and multi-task paradigm that likely favors marksmanship accuracy seem to present novel movement characteristics unique to occupational gait. Further investigation is warranted to identify other potential factors that may improve or worsen dynamic marksmanship performance.

A Preliminary Investigation into the Neural Correlates of Knee Loading during a Change of Direction Task in Individuals after Anterior Cruciate Ligament Reconstruction.

Background: Central nervous system (CNS) function after ACLR, quantified by the blood oxygen level dependent (BOLD) response, is altered in regions of sensory function during knee movement after ACLR. However, it is unknown how this altered neural response may manifest in knee loading and response to sensory perturbations during sport specific movements. Purpose: To investigate the relationship among CNS function and lower extremity kinetics, under multiple visual conditions, during 180° change of direction task in individuals with a history of ACLR. Methods: Eight participants, 39.3 ± 37.1 months after primary, left ACLR performed repetitive active knee flexion and extension of their involved knee during fMRI scanning. Participants separately performed 3D motion capture analysis of a 180° change of direction task under full vision (FV) and stroboscopic vision (SV) conditions. A neural correlate analysis was performed to associate BOLD signal to knee loading of the left lower extremity. Results: Involved limb peak internal knee extension moment (pKEM) was significantly lower in the SV condition (1.89 ± 0.37 N*m/Kg) compared to the FV condition (2.0 ± 0.34 N*m/Kg) (p = .018). Involved limb pKEM during the SV condition was positively correlated with BOLD signal in the contralateral precuneus and superior parietal lobe (Voxels: 53; p = .017; z-stat max: 6.47; MNI peak: 6, -50, 66). Conclusion: There is a positive association between involved limb pKEM in the SV condition and BOLD response in areas of visual-sensory integration. Activation of contralateral precuneus and superior parietal lobe brain regions may be a strategy to maintain joint loading when vision is perturbed. Level of Evidence: Level 3.

Use of accelerometers and inertial measurement units to quantify movement of tactical athletes: A systematic review.

The dynamic work environments of tactical athletes are difficult to replicate in a laboratory. Accelerometers and inertial measurement units provide a way to characterize movement in the field. This systematic review identified how accelerometers and inertial measurement units are currently being used to quantify movement patterns of tactical athletes. Seven research and military databases were searched, producing 26,228 potential articles with 78 articles included in this review. The articles studied military personnel (73.1%), firefighters (19.2%), paramedics (3.8%), and law enforcement officers (3.8%). Accelerometers were the most used type of sensor, and physical activity was the primarily reported outcome variable. Seventy of the studies had fair or poor quality. Research on firefighters, emergency medical services, and law enforcement officers was limited. Future research should strive to make quantified movement data more accessible and user-friendly for non-research personnel, thereby prompting increased use in tactical athlete groups, especially first responder agencies.