Ergonomics
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The aim of this study was to quantify the physiological responses of Police Officers wearing chemical, biological, radiological and nuclear personal protective equipment (CBRN PPE) during firearms house entry (FE) unarmed house entry (UE) and crowd control (CC) simulations. Participants volunteered from the UK Police Force [FE (n = 6, age 33 ± 4 years, body mass 85.3 ± 7.9 kg, (·)VO₂max 53 ± 5 ml · kg⁻¹ · min⁻¹), UE and CC (n = 11, age 34 ± 5 years, body mass 88.5 ± 13.8 kg, (·)VO₂max 51 ± 5 ml · kg⁻¹ · min⁻¹)]. Heart rate reserve (HRR) during FE was greater than UE (74 ± 7 vs. 62 ± 6%HRR, p = 0.01) but lower in CC (39 ± 7%HRR, p < 0.01). Peak core body temperature was greater during FE (39.2 ± 0.3°C) than UE (38.9 ± 0.4°C, p < 0.01) and CC (37.5 ± 0.3°C, p < 0.01), with similar trends in skin temperature. There were no differences in the volume of water consumed (1.13 ± 0.44 l, p = 0.51) or change in body mass (-1.68 ± 0.65 kg, p = 0.74) between simulations. The increase in body temperature was a primary physiological limitation to performance. Cooling strategies and revised operating procedures may improve Police Officers' physical performance while wearing CBRN PPE. ⋯ In recent years, the likelihood of Police Officers having to respond to a chemical, biological, nuclear or radiological (CBRN) incident wearing personal protective equipment (PPE) has increased. Such apparel is likely to increase physiological strain and impair job performance; understanding these limitations may help improve Officer safety and operational effectiveness.
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Indian infantry soldiers carry smaller magnitudes of loads for operational requirements. The ground reaction forces (GRFs) and impulse responses of 10 healthy male Indian infantry soldiers were collected while they walked carrying operational loads between 4.2 and 17.5 kg (6.5-27.2% of mean body weight (BW)) and a control condition of no external load (NL). The GRF and impulse components were normalised for BW, and data for each load condition were compared with NL in each side applying one-way analysis of variance followed by Dunnett's post hoc test. ⋯ Result indicates that smaller magnitudes of loads produced kinetic changes proportional to system weight, similar to heavier loads with the possibility of increased injury risk. Observed smaller asymmetric changes in gait may be considered as postural adjustment due to load. Unique physical characteristics of Indian soldiers and the probable design shortcomings of the existing backpack might have caused significant changes in GRF and peak impulse during smaller load carriage.
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Two studies are reported which first observe, and then attempt to replicate, the cognitive demands of intensive care unit (ICU) activity whilst concurrently learning audible alarms. The first study, an observational study in an ICU ward, showed that the alarms are very frequent and co-occur with some activities more than others. The three most frequently observed activities observed in the ICU were drugs (calculation, preparation and administration), patient observation and talking. The cognitive demands of these activities were simulated in a second, laboratory-based experiment in which alarms were learned. The results showed that performance in the alarm task generally improved as participants were exposed to more repetitions of those alarms, but that performance decrements were observed in the secondary tasks, particularly when there were two or three of them. Some confusions between the alarms persisted to the end of the study despite prolonged exposure to the alarms, confusions which were likely caused by both acoustic and verbal labelling similarities. ⋯ The cognitive demands of working in an ICU were observed and simulated whilst alarms were learned. Alarms should generally avoid sharing similar rhythmic (and other) characteristics. The simulation task described here could be used for testing alarm learning without requiring a clinical environment.
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When selecting a respirator, it is important to understand how employees' motor, visual and cognitive abilities are impacted by the personal protective equipment. This study compares dust, powered-air-purifying and full-face, negative-pressure respirators. Thirty participants performed three varied tasks. Each participant performed each task without a respirator and while wearing the three respirator types. The tasks included a hand tool dexterity test, the Motor-Free Visual Perception Test and the Serial Sevens Test to evaluate fine motor, visual and cognitive performance, respectively. The time required for task completion and the errors made were measured. Analysis showed no significant effect due to respirator use on the task completion time. A significant increase was found in the error rate when participants performed the cognitive test wearing the full-face, negative-pressure respirator. Participants had varying respirator preferences. They indicated a potential for full-face, negative-pressure respirators to negatively affect jobs demanding high cognitive skills such as problem solving and decision-making. ⋯ while respirators are life-saving personal protective equipment (PPE), they can unintentionally reduce human performance, especially if job characteristics are not considered during PPE selection. An experiment was conducted to compare three respirators (dust respirator, powered-air-purifying respirators and full-face respirator) for varying task types. The full-face respirator was found to affect human cognitive performance negatively.