Heart rate variability profile changes associated with specialist police selection activities: A case study.

BACKGROUND: Police Tactical Groups (PTGs) are specialist police units tasked with rigorous physical and psychosocial duties. Consequently, selection courses (SCs) for service in these units must also be rigorous. Given the intensity of SCs, holistic monitoring for potential overstress may be beneficial. Heart Rate Variability (HRV) is one holistic stress measure that can be obtained in austere environments. OBJECTIVE: The purpose of this study was to profile HRV during a PTG SC. Six (n = 6) qualified male police officers attempted a 36-hour PTG selection course held at an Australian state facility. METHODS: HRV was obtained from Equivitaltrademark EQ02 + LifeMonitor bioharnesses. The selection course consisted of physically demanding events with minimal sleep (approx. 45 mins). Only one candidate completed the full selection course; whose results are reported here. RESULTS: A visual time-series of 384 consecutive 5 min HRV analyses was generated. Contextual analysis was applied to appreciate HRV changes between SC serials. HRV decline occurred during the planning of a navigation exercise and a pack march. Increases in HRV were observed throughout the pack march exercise and rest period. CONCLUSION: This case study demonstrates the potential utility for selection personnel to obtain additional insight into candidate responses to various occupational challenges throughout an SC. Information provided by HRV monitoring may support leadership decisions when evaluating personnel holistically. For example, the ability to continue occupational task execution even while experiencing potential overstress (as measured by HRV) and after food and sleep deprivation is desirable. HRV may potentially inform stakeholders regarding overstress in PTG candidates.

Heart Rate Variability Assessment of Land Navigation and Load Carriage Activities in Specialist Police Selection.

Police tactical group (PTG) personnel are exposed to physical, mental, and emotional stressors. Consequently, PTG selection courses (SCs) impart similar challenges, often resulting in candidate attrition. Holistic assessment may provide additional support to stakeholders given these risks. Heart Rate Variability (HRV) is an objective holistic stress measure that may be applicable in PTG SCs but has not been thoroughly researched. Therefore, this study aimed to report HRV data in an end-user accessible format and determine the relationship between HRV and attrition. A total of 18 qualified Australian State law enforcement officers completed a 1-day physical readiness assessment. Of those, six males progressed to an additional two-day course, on which this study is focused. This two-day selection consisted of additional physical challenges and occupational assessments. HRV was obtained from 2-lead ECGs and defined as the percentage of R-R intervals that varied by ≥50 ms (pRR50). Data were summarized in a heat map of consecutive short-term analyses. Three candidates withdrew. A logistic regression based on heat map data found high HRV was significant for predicting attrition, χ2 (6) = 8.318, p = 0.004. HRV may provide insight for PTG stakeholders monitoring attrition. While the sample size was limited and replication is needed, this study tentatively establishes value for HRV monitoring in PTG SCs.

The effects of equipment carriage on functional movement quality among law enforcement officers.

Law enforcement officers (LEOs) use protective equipment to ensure safety. However, equipment carriage has been shown to impair movement quality and may increase the risk of musculoskeletal injury. Therefore, the objective of this study was to investigate the influence of equipment load carriage on functional movement as measured by the Functional Movement Screen (FMS). It was hypothesised that FMS scores would be negatively impacted by equipment carriage. A counterbalanced cross-over study was utilised and a convenience sample of 31 males and one female active-duty LEOs were included. Participants completed the FMS under two conditions: with and without equipment. Significant median decreases in the equipment condition were observed for hurdle step, shoulder mobility, and rotary stability (p < .01), and deep squat and dominant limb active straight leg raise (ASLR) (p < .05). The non-dominant limb ASLR and trunk stability push-up were similar between conditions (p > .05). Load carriage appears to impair functional movement among LEOs.Practitioner summary: Equipment carriage interferes with functional movement and neither of the two load carriage systems tested were superior to the other. When choosing between duty belt verses duty belt and outer carrier vest carriage, LEO preference, body type, and acclimation to a given carriage type should be considered.

Relationships Between Heart Rate Variability, Occupational Performance, and Fitness for Tactical Personnel: A Systematic Review.

Objectives: Heart Rate Variability has gained substantial interest in both clinical and athletic settings as a measurement tool for quantifying autonomic nervous system activity and psychophysiological stress. However, its uses in tactical work settings, such as military, police, and firefighting environments, remain controversial. Given the physical, mental, and emotional stress public safety personnel face both operationally and in training, heart rate variability measurement may be key in promoting their health, safety and operational effectiveness. Methods: This study identified, critically appraised, and summarized primary studies investigating relationships between heart rate variability and outcomes of interest to tactical personnel. Key literature databases were searched, and quality assessment checklists were applied to analyze retained literature. The results of the screening and assessment processes, along with key data extracted from each study were summarized and tabulated. Research gaps were also identified to facilitate improvements to how tactical personnel and health or performance providers may best utilize heart rate variability to monitor or promote personnel health and performance, and thereby facilitate public safety. Results: Twenty studies were included and were all of generally high quality. Cohort size, length of follow-up, measurement objectives, data acquisition, and data analysis all varied considerably across studies, precluding meta-analysis. However, study results correlating heart rate variability and relevant outcomes indicated that overall, heart rate variability is an effective indicator of key fitness and performance elements in the tactical work setting. Conclusions: Heart rate variability can be an effective health and performance tool in tactical work environments. However, measurement methods must be carefully selected and applied. Further research is required to understand causal relationships. Specifically, larger cohort inclusion and the isolation and study of specific variables unique to public safety work and training may improve the effectiveness of heart rate variability measurement to provide meaningful information to end users and providers.

What is the impact of fitness on injury risk during police academy training? A retrospective cohort study.

BACKGROUND: In the conduct of their daily duties, law enforcement officers (LEO) are often required to perform dynamic, physically demanding tasks with little or no notice, sometimes at maximal levels of exertion. Given these requirements, training for prospective LEOs must be rigorous enough to ensure that when trainees graduate, they are competent in their response to crisis and resilient enough to maintain this for the span of their career. Therefore, based on previously reported effectiveness of fitness testing in predicting injury risk in predominantly military settings, the aim of this study was to investigate relationships between a physical ability test (PAT) and risk of injury during police recruit training. METHODS: Retrospective PAT results and trainee injury records were obtained from a national police department and Mann-Whitney U tests were performed to investigate fitness differences between trainees who were, or were not, injured. Significant results were tested for effect size using Cliff's delta (CD). RESULTS: Significant differences in mean performance between groups existed for the following PAT components: pushups (injured mean 32.94 ± 8.66 reps, uninjured mean 35.67 ± 9.04 reps, p = 0.01 CD + 0.11) and right-hand grip strength (injured mean 49.61 ± 12.51 kg, uninjured mean 52.12 ± 11.17 kg, p = 0.042 CD + 0.22) for all injuries; vertical jump height (injured mean 51.75 ± 7.54 cm, uninjured mean 55.06 ± 8.19 cm, p = 0.032 CD + 0.41) for lower limb injuries, and all measures of grip strength for trunk injury. CONCLUSIONS: The results of this study suggest that a significant relationship between some PAT fitness components and injury risk exists during police recruit training.

Ability of fitness testing to predict injury risk during initial tactical training: a systematic review and meta-analysis.

OBJECTIVE: Tactical personnel (Military, Law Enforcement, Emergency Responders) require physical fitness levels sufficient for training and occupational duty. Physical conditioning aimed at increasing fitness levels during training presents an injury risk, but unfit trainees may struggle to meet occupational performance standards, further increasing injury risk to themselvesor others. Therefore, the aim of this review was to determine if fitness, asquantified by tactical fitness tests, effectively predicts injury risk during training. METHODS: Literature databases were search and relevant articles extracted. 27 Publications were included for qualitative review and seven studies reporting a timed run were included in meta-analysis. RESULTS: The combined risk ratio was 2.34 (95% CI 2.02 to2.70). Muscular endurance tests were less conclusive in their predictive abilities. Functional strength or power tests were effective predictors, but few studies reported on strength or power, indicating a need for further study inthis area. CONCLUSIONS: The meta-analysis results are supported by the occupational relevance of run tests; tactical trainees are required to perform frequent bouts of distance weight bearing activity. However, given the diverse physical requirements of tactical personnel, measures of strength and power should alsobe evaluated, especially given their effectiveness in the studies that included these measures.

Effects of Personal Body Armor on Functional Movement Capability.

The Functional Movement Screen (FMS) is a tool used to assess fundamental movement patterns and has been utilized to determine movement readiness of tactical athletes. However, tactical athletes rarely perform tasks without load carriage, and limited research evaluating loaded tactical personnel via the FMS has been conducted. Therefore, the primary aim of this study was to determine if ballistic vest wear results in movement deficits as evaluated by the FMS. A convenience sample of college students (n = 31) completed test sessions in loaded and unloaded conditions. Subjects completed each FMS movement and indicated perceived effort on a Visual Analog Scale (VAS). The Sign test was used to determine difference between FMS composite and component scores collected under each condition. The level of significance was set at p < 0.05. A significant (p < 0.001) difference in FMS composite scores was identified between loading conditions. Significant FMS score changes between load conditions were identified in the dominant side in-line lunge (p < 0.01), non-dominant side in-line lunge (p < 0.01), dominant shoulder mobility (p < 0.01), non-dominant shoulder mobility (p < 0.01), and non-dominant rotary stability (p = 0.01). Our data indicate ballistic vest wear reduces overall functional movement capacity, as well as mobility related to certain individual FMS components in the population examined. Additionally, results suggest subjects may better tolerate additional load carriage when completing tasks on their dominant side. These results raise important questions regarding design, fit, and task completion for tactical athletes utilizing a ballistic vest.

The impact of body armor on physical performance of law enforcement personnel: a systematic review.

BACKGROUND: The law enforcement officer profession requires performance of arduous occupational tasks while carrying an external load, consisting of, at minimum, a chest rig, a communication system, weaponry, handcuffs, personal protective equipment and a torch. The aim of this systematic review of the literature was to identify and critically appraise the methodological quality of published studies that have investigated the impacts of body armour on task performance and to synthesize and report key findings from these studies to inform law enforcement organizations. METHODS: Several literature databases (Medline, CINAHL, SPORTDiscus, EMBAS) were searched using key search words and terms to identify appropriate studies. Studies meeting the inclusion criteria were critically evaluated using the Downs and Black protocol with inter-rater agreement determined by Cohen's Kappa. RESULTS: Sixteen articles were retained for evaluation with a mean Downs and Black score of 73.2 ± 6.8% (k = 0.841). Based on the research quality and findings across the included studies, this review determined that while effects of body armour on marksmanship and physiological responses have not yet been adequately ascertained, body armour does have significant physical performance and biomechanical impacts on the wearer, including: a) increased ratings of perceived exertion and increased time to complete functional tasks, b) decreased work capability (indicated by deterioration in fitness test scores), c) decreased balance and stability, and d) increased ground reaction forces. CONCLUSIONS: Given the physical performance and biomechanical impacts on the wearer, body armour should be carefully selected, with consideration of the physical fitness of the wearers and the degree to which the armour systems can be ergonomically optimized for the specific population in question.