The effects of body armour on the power development and agility of police officers

Load carriage does not reduce absolute mechanical power output but reduces agility in elite military police officers

Objectives. The main objective of this study was to evaluate mean propulsive velocity (MPV), mean propulsive force (MPF) and mean propulsive power (MPP) in elite police officers under LOADED and UNLOADED conditions. The study also investigated the association of body composition and strength levels under the same load conditions. Methods. Twenty-one men from an elite unit in Brazil participated in the study, performing Smith machine half squats and an agility test. Dual energy X-ray absorptiometry measured body composition; a linear encoder measured MPV, MPF and MPP during the half squats; and a manual chronometer registered agility test performance. Results. The results showed that wearing and carrying occupational loads did not alter the squat exercise's MPP, MPV and MPF but reduced the performance of relative MPP and agility (p < 0.05). The results also showed that MPP had a higher association with force (i.e., MPF and one-repetition maximum [1RM]) than velocity (i.e., MPV and agility) under the LOADED condition (p < 0.05). Among the body composition variables, only lean body mass was associated with MPP under the LOADED condition (p < 0.05). Conclusion. These findings suggest that load carriage does not reduce absolute mechanical power output, but reduces the relative MPP and agility in military police officers.

The comfort and functional performance of personal protective equipment for police officers: a systematic scoping review

This scoping review aimed to identify and summarise evidence on the comfort and functional performance of police officer personal protective equipment (PPE). The Arksey and O'Malley (2005) five-stage framework for scoping reviews was followed. PubMed, CINAHL, Scopus, and Web of Science were searched, and 35 articles were included in the review. The findings show that increased police PPE mass increases heart rate, metabolic energy expenditure, and perceived exertion in response to exercise. Unisex armour designs cause increased discomfort for females with larger bra sizes. PPE reduces joint-specific range of motion, with the design and location impairing movement more than mass. Jumping and sprinting performance is decreased with heavy PPE but unaffected by lighter protection, while agility is compromised with most forms of protection. Future research is needed on the fit and function of PPE for specialist police units, such as mounted police, along with further investigations on how fit can affect functional performance.

Association of anthropometric characteristics of law enforcement officers with perceived ratings of fit, comfort, and pain in the use of body armor

Knowledge gaps exist on association between law enforcement officer (LEO) anthropometric characteristics and perceived body armour fit, armour discomfort, and armour-caused pain. This study assessed the correlation and identified influential torso dimensions for armour sizing and design applications. Nine-hundreds and seventy-four LEOs across the U.S. participated in a national study on LEO armour use and body dimensions. Perceived ratings of armour fit, armour discomfort, and body pain were found moderately correlated with each other. In addition, armour fit ratings were associated with certain torso anthropometric characteristics, such as chest circumference, chest breadth, chest depth, waist circumference, waist breadth (sitting), waist front length (sitting), body weight, and body mass index. LEOs who reported armour poor fit, armour discomfort, and armour-caused pain had a larger mean of body dimensions than the "armor good fit" group. More women than men had poor fit, discomfort, and body pain in the use of body armour.Practitioner summary: The identified influential body measurements can be used as the "drivers" for multivariate analyses to develop an improved armour sizing system to further LEO protection. The study also suggests consideration of gender specific armour sizing systems to accommodate differences in torso configurations between male and female officers and to resolve the concern that more female officers had poor armour fit than male officers.

Effects of 12-week full body resistance exercise on vertical jumping with and without military equipment in Slovenian Armed Forces

INTRODUCTION

Jumping ability is one of the most important physical qualities in military personnel. Previous training intervention studies have shown equivocal effects on jumping ability. In this study, we assessed the effect of a 12-week resistance exercise programme on countermovement jump (CMJ) performance with and without military equipment.

METHODS

Ninety-six members of the Slovenian Armed Forces (age range 20-47 years) were allocated to the intervention (n=65) and the control (n=32) group. The intervention group performed 2 sessions of full body resistance exercise per week for 12 weeks, while the control group continued with their regular training routine. Before and after the intervention, CMJ assessment using force plates was conducted with and without military equipment.

RESULTS

CMJ testing with and without equipment both exhibited high to excellent relative and absolute reliability. The intervention elicited statistically significant (p=0.011-0.026; η2=0.05-0.06), but small improvements in CMJ height when performed without equipment (from 28.2±3.8 cm to 29.5±3.3 cm) and with equipment (from 25.3±3.7 cm to 27.1±6.1). Other variables showed even smaller or trivial changes.

CONCLUSIONS

This study suggests that CMJ with equipment could be a reliable tool to assess jumping performance specific to requirements of military work, which would increase the ecological validity of the testing. The present structured full-body training intervention showed modest improvements in jumping ability in both testing conditions.

TRIAL REGISTRATION NUMBER

NCT0341546.

Tactical vests worn by law enforcement: is this improving stability for optimal job performance?

Objectives. The purpose of this study was to determine whether equipped tactical vests would improve postural stability of law enforcement officers (LEOs) versus a duty belt or without either condition. Methods. Volunteers were police officers (n = 25, 22 males, three females; age 42.4 ± 3.2 years; weight 101.65 ± 19.4 kg; height 178.92 ± 8.2 cm). The Institutional Review Board approved the investigation. A Bertec posturography plate (Bertec Inc., USA) determined four center of pressure (CoP) scores - eyes open stable surface (EOSS), eyes closed stable surface (ECSS), eyes open perturbed surface (EOPS), eyes closed perturbed surface (ECPS) - and four limit of stability (LoS) scores - frontal plane (LoSF), posterior plane (LoSP), left sagittal plane (LoSL), right sagittal plane (LoSR). Results. A repeated-measures multivariate analysis of variance (MANOVA) demonstrated no statistical difference within subject group CoP scores EOSS (p = 0.723), ECSS (p = 0.252), EOPS (p = 0.079) and ECPS (p = 0.137). Comparing between groups, the tactical vest demonstrated significance over the other CoP group conditions with ECPS (p = 0.001). The duty belt group showed significance with ECSS (p = 0.001). LoS variables indicated no significant results between groups. Conclusion. Tactical vests demonstrated improvements in ECPS scores (p = 0.001) compared to either group.

Effects of Occupational Load on the Acceleration, Change of Direction Speed, and Anaerobic Power of Police Officers

ABSTRACT

Kukić, F, Janković, R, Dawes, JJ, Orr, R, and Koropanovski, N. Effects of occupational load on the acceleration, change of direction speed, and anaerobic power of police officers. J Strength Cond Res XX(X): 000-000, 2022-Police officers engage in movements such as foot pursuits, sudden directional changes, or prolonged sprinting while wearing occupational loads (including body armor, baton, radio, handcuffs, and sidearm). This study investigated the effects of incrementally heavier loads carried by police students on their physical performance. Police students (n = 63; male n = 39 male and 24 female students) performed an acceleration over a 10-m distance (Acc10m), Illinois agility test (IAT), and 300-yard shuttle run test (ShR300y) without load, with a 5-kg load (handgun, spare empty magazine, baton, and handcuffs), and with a 10-kg load (loaded vest). The effects of different load conditions were investigated for both sexes using a repeated-measure analysis of variance and Cohen's effect size. Female students carried relatively heavier loads and were slower than male students in Acc10m, IAT, and ShR300y. Load significantly (p < 0.001) impaired the performance in Acc10m, IAT, and ShR300y in both sexes, but the effects were greater (p < 0.001) among female police students. A load as little as 5 kg was sufficient to reduce Acc10m, IAT, and ShR300y among police students. Increasing the load to 10 kg (i.e., wearing the body armor) did not significantly affect Acc10m and IAT among male students, but it did affect Acc10m and IAT among female students. Sprint endurance (i.e., ShR300y) was strongly affected by both loads regardless of sex. Strength and conditioning programs should focus on strength, power, and anaerobic endurance to improve performance while carrying occupational loads. Occasional training with loads similar to those at work may further ensure that officers are fit for purpose.

A combined training program's effect on anthropometry, body composition, physical fitness and blood pressure in elite police

BACKGROUND

Combined training (CT) simultaneously associates aerobic and strength exercises. Worldwide, studies on CT´s on Police officers' physical fitness are scarce. This study aims to measure a 4-month CT program's impact in the Close Protection Unit of the Portuguese Elite Police.

METHODS

A pre-and post-test study included 32 participants (mean age 30.1±2.7 years old). Anthropometry, body composition, physical fitness, and blood pressure assessments were collected. Statistical analysis was performed using IBM Statistical Package for Social Sciences (SPSS, 26.0) with a significance level at p≤0.05.

RESULTS

The main results showed an improvement in anthropometrics; aerobic capacity, strength, muscular endurance, and systolic blood pressure. However, a lean mass decrease, a fat mass increase, and worse results in other bioimpedance measures were observed.

CONCLUSIONS

In this study, the poor body composition results may imply a closer look for health concerns, although physical fitness has improved. Thus, it might be suggested that a CT program is helpful to increase physical fitness in elite police officers. Yet, improvements for its future application can be suggested, namely to include and address hydration level, nutrition, and rest/sleep moments. Moreover, because a high physical fitness level is needed in these population throughout their lifespan, ministerial policies should develop specific training programs, that can reduce morbidity and premature mortality, and have a major cos-teffectiveness impact on public health.

Do Barrier Test Results Predict Survival in Specialist Police Tactical Selection Courses?

Entry to specialist police tactical teams is governed by performance on a physically intense and psychologically demanding selection course. The aim of this study was to determine the attributes associated with completion of a specialist police selection course. Data pertaining to 18 candidates was obtained including 1 min push-ups, loaded pull-ups, loaded 30 m crawl, agility run, 1.2 km run and multi-stage fitness assessment. Comparisons from those who did and did not complete the selection week were performed and a hierarchical multiple regression performed. Eleven candidates finished, with significant difference found in those who completed the course in push-ups (+9.1 reps), loaded pull-ups (+2.9 reps), 1.2 km run (−16 s), loaded crawl (−6.3 s), agility (−0.67 s) and VO_2max (+4.8 mL/kg/min). In combination, the fitness assessments pull-ups, 30 m loaded crawl and agility time were found to predict 70% of the variability in course completion (adjusted R² = 0.70, F (3,14) = 14.373, p = 0.001). When assessed independently, push-ups, 1.2 km run and VO_2max results only predicted a non-significant 0.02%, 0.29% and 0.12%, respectively, of course completion. Completion was influenced by aerobic fitness, upper limb strength and endurance and agility. These variables appear to be predictive of course success.

Associations between Fitness Measures and Change of Direction Speeds with and without Occupational Loads in Female Police Officers

Female police officers may be required to pursue offenders on foot while wearing occupational loads. The aim of this study was to determine relationships between fitness measures and change of direction speed (CODS) in female police officers and the influence of their occupational loads. Retrospective data were provided for 27 female police officers (age = 32.19 ± 5.09 y, height = 162.78 ± 5.01 cm, and mass = 71.31 ± 13.42 kg) and included fitness measures of: lower-body power (standing long jump (SLJ)), upper-body and trunk muscle endurance (push-up (PU) and sit-up (SU)), aerobic power (estimated VO2max), and CODS (Illinois agility test). The CODS test was performed without and with occupational load (10 kg). Paired sample t-tests (between-load conditions) and Pearson's correlations (relationships between measures) were performed with linear regression analysis used to account for the contribution of measures to unloaded and loaded CODS performance. CODS was significantly slower when loaded (unloaded = ~23.17 s, loaded = ~24.14 s, p < 0.001) with a strong, significant relationship between load conditions (r = 0.956, p < 0.001). Moderate to strong, significant relationships were found between all fitness measures ranging from estimated VO2max (r = -0.448) to SU (r = -0.673) in the unloaded condition, with the strength of these relationships increasing in the loaded condition accounting for 61% to 67% of the variance, respectively. While unloaded agility test performance was strongly associated with loaded performance, female police officer CODS was significantly reduced when carrying occupational loads. A variety of fitness measures that influence officer CODS performances become increasingly important when occupational loads are carried.