Influence of Wearing Ballistic Vests on Physical Performance of Danish Police Officers: A Cross-Over Study.

Henrik Koblauch,Mikkel H Jacobsen,Lars L Andersen,Tine Alkjær,Mette K Zebis,Jesper Bencke,Klaus P Klinge,Bjarki T Haraldsson

doi:10.3390/s21051795

Abstract

Purpose: We aimed to investigate the influence of wearing a ballistic vest on physical performance in police officers. Methods: We performed a cross-over study to investigate the influence of wearing a ballistic vest on reaction and response time, lumbar muscle endurance and police vehicle entry and exit times. Reaction and response time was based on a perturbation setup where the officers’ pelvises were fixed and EMG of lumbar and abdominal muscles was recorded. We used a modified Biering–Sørensen test to assess the lumbar muscle endurance and measured duration of entry and exit maneuvers in a variety of standard-issue police cars. Results: There was a significant difference of 24% in the lumbar muscle endurance test (no vest: 151 s vs. vest: 117 s), and the police officers experienced higher physical fatigue after the test when wearing a vest. Furthermore, officers took longer to both enter and exit police cars when wearing a vest (range: 0.24–0.56 s) depending on the model of the vehicle. There were no significant differences in reaction and response times between the test conditions (with/without vest). Discussion and Conclusion: Wearing of a ballistic vest significantly influenced the speed of movement in entry and exit of police cars and lumbar muscle endurance, although it does not seem to affect reaction or response times. The ballistic vest seems to impair performance of tasks that require maximal effort, which calls for better designs of such vests.

Highlights

IntroductionUse of ballistic vests is increasingly common among Danish police, military and security personnel on regular duty, due to an increased threat level
Use of ballistic vests is increasingly common among Danish police, military and security personnel on regular duty, due to an increased threat level.Following a terror strike in Copenhagen, Denmark in 2015, it has become mandatory to wear ballistic vests for Danish police officers when they are on active patrol in metropolitan areas
We found that there were statistically significant differences between the conditions in both entry and exit of the VW Passat and the VW Touran, indicating that, when wearing the vest, the time duration of both entering and exiting the two car types was longer than when the tasks were performed with no vest

Summary

Introduction

Use of ballistic vests is increasingly common among Danish police, military and security personnel on regular duty, due to an increased threat level. Following a terror strike in Copenhagen, Denmark in 2015, it has become mandatory to wear ballistic vests for Danish police officers when they are on active patrol in metropolitan areas. The vest is bulky, stiff and secured tightly to the trunk with a system of Velcrostraps, and as such could plausibly impact the biomechanics of the upper body negatively. The added weight has been reported to result in limited mobility and can cause significant discomfort [1,2,3,4,5,6]. The mass of the ballistic vest worn by the Danish police officers ranges 3.5–8.5 kg depending on the units the officers are assigned to. A Swedish study [7]

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