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

Abstract 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

The impact of fire suppression tasks on firefighter hydration: A critical review with consideration of the utility of reported hydration measures

BACKGROUND: Firefighting is a highly stressful occupation with unique physical challenges, apparel and environments that increase the potential for dehydration. Dehydration leaves the firefighter at risk of harm to their health, safety and performance. The purpose of this review was to critically analyse the current literature investigating the impact of fighting ‘live’ fires on firefighter hydration. METHODS: A systematic search was performed of four electronic databases for relevant published studies investigating the impact of live fire suppression on firefighter hydration. Study eligibility was assessed using strict inclusion and exclusion criteria. The included studies were critically appraised using the Downs and Black protocol and graded according to the Kennelly grading system. RESULTS: Ten studies met the eligibility criteria for this review. The average score for methodological quality was 55 %, ranging from 50 % (‘fair’ quality) to 61 % (‘good’ quality) with a ‘substantial agreement’ between raters (k = .772). Wildfire suppression was considered in five studies and structural fire suppression in five studies. Results varied across the studies, reflecting variations in outcome measures, hydration protocols and interventions. Three studies reported significant indicators of dehydration resulting from structural fire suppression, while two studies found mixed results, with some measures indicating dehydration and other measures an unchanged hydration status. Three studies found non-significant changes in hydration resulting from wildfire firefighting and two studies found significant improvements in markers of hydration. Ad libitum fluid intake was a common factor across the studies finding no, or less severe, dehydration. CONCLUSIONS: The evidence confirms that structural and wildfire firefighting can cause dehydration. Ad libitum drinking may be sufficient to maintain hydration in many wildfire environments but possibly not during intense, longer duration, hot structural fire operations. Future high quality research better quantifying the effects of these influences on the degree of dehydration is required to inform policies and procedures that ensure firefighter health and safety

A functional movement screen profile of an Australian state police force: A retrospective cohort study

BACKGROUND: Police officers are required to perform dynamic movements in unpredictable environments, the results of which can lead to injury. Early identification of poor movement patterns of a police population, and potential sub groups within this population, may provide opportunities to treat and minimise injury risks. The aim of this study was to profile the functional movement capabilities of an Australian state police force and potential sub groups through a retrospective cohort study. METHODS: Retrospective data from an Australian State Police Force were provided for analysis (♂ n = 1155, mean (±SD) age = 31.34 ± 8.41 years: ♀ n = 357, mean age = 27.99 ± 8.02 years). Data consisted of Functional Movement Screen (FMS) assessment results of male and female trainees and qualified police officers with all assessments conducted by a qualified Police Physical Training Instructor. RESULTS: Significantly higher (U = 253863, p < .001) FMS total scores were found for recruits (mean 15.23 ± SD 2.01 points) when compared to attested officers (14.57 ± 2.96 points) and differences in FMS total scores also approached significance for females (15.24 ± 2.35 points) when compared to males (14.84 ± 2.55 points, U = 186926, p = .007), with age found to be a key, significant factor in explaining these observed differences (F (1,1507) = 23.519, p < .001). The FMS components demonstrating poorest movement performance across all groups were the hurdle step and rotary stability. CONCLUSIONS: Generally, police personnel (both attested officers and recruits of both genders) of greater age have a lower functional movement capability when compared to younger personnel, with greater percentages scoring 14 or below on the FMS. Specific conditioning programs to improve strength, range of motion and stability during identified key movement types in those demonstrating poorer movement performance may serve to reduce injuries in police personnel

Associations between anthropometric characteristics and physical performance in male law enforcement officers: A retrospective cohort study

BACKGROUND: Police officers are often required to undertake physically demanding tasks, like lifting, dragging and pursuing a suspect. Therefore, physical performance is a key requirement. METHODS: Retrospective data for 76 male police officers (mean age = 39.42 ± 8.41 years; mean weight = 84.21 ± 12.91 kg) was obtained. Data included anthropometric (skinfolds, estimated percentage body fat, lean body mass and fat mass) and physical performance (1 Repetition Maximum Bench Press, 1–min sit-ups, 1-min push-ups, vertical jump, 300 m run, 1.5 mile run) measures and correlations between anthropometric measurement and fitness score were obtained. RESULTS: Estimated percentage body fat was significantly (p ≤ .001) and negatively correlated with all performance measures, except sit-ups and 300 m and 1.5 mile run performance. Estimated lean body mass was significantly and positively (p ≤ .001) correlated with push-ups, bench press and vertical jump measures, while increasing estimated fat mass was significantly (p ≤ .001) associated with reduced performance on sit-up, vertical jump, 1.5 mile run and estimated maximal voluntary oxygen uptake. CONCLUSIONS: A targeted approach, going beyond just decreasing percentage body fat to also selectively increasing lean mass, should be applied for optimal improvement in physical fitness performance

Selecting the Best of the Best: Associations between Anthropometric and Fitness Assessment Results and Success in Police Specialist Selection

International Journal of Exercise Science 11(4): 785-796, 2018. To successfully complete specialist police selection, officers must be physically fit. The aim of this study was to investigate the relationship between performance on selected anthropometric and fitness tests and successful selection into a specialist police unit. Thirty-two male police officers (mean age = 29.48±4.99 years) participated in a Barrier Fitness Assessment (BFA), followed by a Specialist Selection Course (SSC). The BFA spanned two consecutive days of testing (pull-ups, push-ups, seven-stage sit-ups, a timed loaded pack march, a Multi-Stage Fitness Test, an agility run, a lift and carry task and a 300m swim assessment). The SSC occurred 4 weeks later and consisted of 8 days of intense police training. Officers who successfully completed the SSC were graded based on their performance and this determined their ultimate selection. Data were categorized into four participant groups: Group 1 - Did not complete the BFA; Group 2 - Completed the BFA but not the SSC; Group 3 - Completed the SSC and were not selected; and Group 4 - Completed the SSC and were selected. A Spearman’s rank order correlation analysis was conducted to assess the strengths of the relationships between selection stage achieved and scores on each of the predictor variables, with significance set at 0.05. Height (p=0.011), body weight (p=0.011), pull-ups (p=0.021) and push-ups (p=0.016), seven-stage sit-up scores (p=0.042) and lift and carry speed (p=0.010) were significantly and positively correlated with level of selection success. Results suggest that candidates wishing to attempt selection into specialist police units would benefit from being tall and training to optimize musculoskeletal strength and muscular endurance

Relationships between Absolute and Relative Lower-Body Power and Foot Pursuit Ability in Law Enforcement Recruits

International Journal of Exercise Science 14(3): 1078-1089, 2021. An essential job task for law enforcement officers is a foot pursuit. Lower-body power should aid foot pursuit ability; however, there has been minimal investigation of this relationship. This study investigated relationships between absolute and relative lower-body power measured by the vertical jump (VJ) with the 75-yard pursuit run (75PR), which is a change-of-direction (COD) speed test that simulates a foot pursuit in law enforcement recruits. Data from 487 male and 95 female recruits who completed the VJ and 75PR prior to academy training was analyzed. VJ variables included VJ height, relative VJ, and peak power and power-to-body mass ratio calculated from VJ height. The 75PR was timed and involved five sprints about a square grid with four direction changes across the grid. Independent samples t-tests confirmed between-sex differences in the VJ and 75PR. Pearson’s correlations and stepwise regression calculated relationships between VJ height, body mass, and 75PR for males and females separately. Male recruits outperformed female recruits in the absolute and relative VJ and 75PR (p ≤ 0.002). There were significant relationships between all VJ variables with the 75PR for both sexes (r = -0.304 to -0.463). VJ height and body mass predicted the 75PR for male recruits (r2 = 0.208); VJ height predicted the 75PR for female recruits (r2 = 0.214). Greater absolute and relative power derived from the VJ could contribute to faster 75PR performance in recruits. In addition to foot pursuit ability, absolute power could benefit other policing tasks such as load carriage and obstacle clearance

The Bigger They Are: Relationships between Body Height and Mass with the Body Drag Task in Law Enforcement Recruits

International Journal of Exercise Science 15(4): 570-584, 2022. California law enforcement recruits must perform a body drag before they graduate academy. While this task may be challenging for smaller recruits, no research has analyzed height and body mass relationships with the body drag. Data from 643 recruits (542 males, 101 females) who completed the drag in the final weeks of academy were analyzed. The recruits lifted a 74.84-kg, 1.73-m tall dummy and dragged it 9.75 m as quickly as possible. Independent samples t-tests compared the sexes; partial correlations controlling for sex detailed relationships between height and body mass with drag time. Recruits were split into quartile groups (based on sample size) for height and body mass (Group 1: shortest, lightest; Group 4: tallest, heaviest). A one-way MANOVA, with sex as a covariate, and Bonferroni post hoc, compared the groups. Male recruits were taller, heavier, and completed the drag faster than females (p \u3c 0.001). There were small relationships between height (r = -0.255) and body mass (r = -0.211) with drag time. When split into height groups, the shortest recruits (Group 1) completed the drag 23-37% slower than all groups (p ≤ 0.031). When split into body mass groups, the lightest recruits (Group 1) were 23-35% slower than all groups (p ≤ 0.007). Most females (94-96%) were placed in Groups 1 or 2. Height and body mass could influence drag performance. Taller recruits may be able to lift the dummy off the ground, reducing friction, while heavier recruits may produce more force. Female and smaller male recruits should complete strength and power training to mitigate body size limitations

KINEMATICS OF THE BMX SX GATE START ACTION

The purpose of this study was to identify the sagittal range of motion across five joints and two body segments during the first three cranks of the BMX SX gate start, and to identify difference between females and males across these seven variables. This was achieved with markerless motion capture of 10 athletes, analysing three maximum effort gate starts using a motion capture and data analysis method previously validated in literature. It was found that the average range of motion for the trunk segment was 39 ± 6°, head segment was 38 ± 35°, shoulder joint was 87 ± 7°, elbow joint was 47 ± 15°, hip joint was 62 ± 11°, knee joint was 93 ± 12° and ankle joint was 58 ± 14°. Further analysis showed a statistically significant difference between males and females. This information can be further used to advise strength and conditioning prescription and to assess movement maturatio

Firefighter Trainee Fitness, Reasons for Academy Release, and Predictive Capabilities of Fitness Tests

Firefighter trainees need a level of fitness to be admitted to and complete a training academy. Fitness could indicate a trainee’s likelihood of graduation. PURPOSE: Determine fitness differences between trainees who graduated (GRAD) or were released due to a) injury (RELI), b) skills test performance failures (RELP), or c) resignation (RELR); and whether fitness predicted graduation or academy release. METHODS: Data from an occupational physical ability test (OPAT) for 686 trainees were analyzed, including: Illinois agility test; push-ups; pull-ups; leg tucks; estimated maximal aerobic capacity (V̇O2max) from the multistage fitness test; backwards overhead 4.54-kg medicine ball throw (BOMBT); 10-repetition maximum deadlift; and a 91.44-m farmer’s carry with 18-kg kettlebells. Data were recorded in raw and scaled scores (based on internal department scoring). Trainees were split into GRAD (n=576), RELI (n=33), RELP (n=66), and RELR (n=11) groups. A one-way ANOVA with Bonferroni post hoc calculated between-group differences. Stepwise linear regression determined whether raw and/or scaled fitness scores predicted group inclusion. Receiver operating curves (and area under the curve; AUC) derived test accuracy for predicting academy release. RESULTS: The GRAD group were superior (p≤0.04) to the: RELI group in all tests except push-ups, pull-ups, and the raw farmer’s carry score; RELP group in all tests except the farmer’s carry; RELR group in V̇O2max, scaled deadlift, and total OPAT score. The strongest predictive regression (r2=0.15) for the GRAD group included scaled scores for total OPAT, deadlift, BOMBT, and V̇O2max. For the RELI group, it was scaled V̇O2max., BOMBT, pull-up, and leg tuck scores (r2=0.06), and scaled total OPAT and BOMBT scores for the RELP group (r2=0.06). Scaled deadlift score was the strongest predictor for the RELR group (r2=0.05). Raw V̇O2max (AUC=0.71) and total OPAT (AUC=0.74) score had acceptable accuracy for predicting trainee release. Trainees who graduated were predicted to have a V̇O2max of ≥43.05 ml/kg/min and a total OPAT ≥394.5 points (out of 800). CONCLUSION: Fitness influenced academy graduation and reasons for release. Scaled scores could predict group inclusion in this department, with V̇O2max and total OPAT score providing the most accurate predictors for release