Henrik Koblauch1, Mette K Zebis1, Mikkel H Jacobsen2, Bjarki T Haraldsson1, Klaus P Klinge3, Tine Alkjær4,5, Jesper Bencke6, Lars L Andersen7. 1. Department of Physiotherapy, University College Copenhagen, 2200 Copenhagen N, Denmark. 2. Department of Occupational Therapy, University College Copenhagen, 2200 Copenhagen N, Denmark. 3. Danish National Police, 1780 Copenhagen V, Denmark. 4. Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark. 5. The Parker Institute, Bispebjerg and Frederiksberg Hospital, 2000 Frederiksberg, Denmark. 6. Human Movement Analysis Laboratory, Amager-Hvidovre Hospital, 2650 Hvidovre, Denmark. 7. National Research Centre for Working Environment, 2100 Copenhagen Ø, Denmark.
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.
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.