Development of role-related minimum cardiorespiratory fitness standards for firefighters and commanders

A minimum cardiorespiratory fitness standard was derived for firefighters following a metabolic demands analysis. Design and minimal acceptable performance of generic firefighting task simulations (i.e. hose running, casualty evacuation, stair climb, equipment carry, wild-land fire) were endorsed by a panel of operationally experienced experts. Sixty-two UK firefighters completed these tasks wearing a standard protective firefighting ensemble while being monitored for peak steady-state metabolic demand and cardiovascular strain. Four tasks, endorsed as valid operational simulations by ≥90% of participants (excluding wild-land fire; 84%), were deemed to be a sufficiently valid and reliable basis for a fitness standard. These tasks elicited an average peak steady-state metabolic cost of 38.1 ± 7.8 ml kg^?1 min^?1. It is estimated that healthy adults can sustain the total duration of these tasks (~16 min) at ≤90% maximum oxygen uptake and a cardiorespiratory fitness standard of ≥42.3 ml kg^?1 min^?1 would be required to sustain work.

Practitioner Summary: A cardiorespiratory fitness standard for firefighters of ≥42.3 ml kg^?1 min^?1 was derived from monitoring minimum acceptable performance of essential tasks. This study supports the implementation of a routine assessment of this fitness standard for all UK operational firefighters, to ensure safe physical preparedness for occupational performance.     

Developing physical and physiological employment standards: Translation of job analysis findings to assessments and performance standards – A systematic review

Physical employment standards (PES) are developed with the aim of ensuring that an employee's physical and physiological capacities are commensurate with the demands of their occupation. While previous commentaries and narrative reviews have provided frameworks for the development of PES, this is the first systematic review of the methods used to translate job analysis findings to PES tests and performance standards for physically demanding occupations. A search of PubMed and Google Scholar was conducted for research articles published in English up to and including March 2015. Two authors independently reviewed and extracted data.The search yielded 87 potentially eligible papers, including 60 peer reviewed journal articles and 17 technical reports. 57 papers were excluded leading to a final data set of 31 papers, representing 22 studies. Job analysis was most commonly conducted through subjective determination of job tasks followed by objective quantification and validation. Determination of criterion tasks was evenly distributed through subjective and objective methods with criterion tasks being defined most commonly as most demanding, critical and/or frequent. Generic predictive and task-related predictive tests were more commonly observed in isolation or in combination when compared to task simulation tests. Performance standards were more commonly criterion-referenced than norm-referenced with a variety of statistical methods utilised. This review provides recommendations for researchers when developing physical employment standards for a variety of occupations.     

Comparison of measured and self-reported anthropometric information among firefighters: implications and applications

This study evaluated the accuracy of self-reported body weight and height compared to measured values among firefighters and identified factors associated with reporting error. A total of 863 male and 88 female firefighters in four US regions participated in the study. The results showed that both men and women underestimated their body weight ( ? 0.4 ± 4.1, ? 1.1 ± 3.6 kg) and overestimated their height (29 ± 18 , 17 ± 16 mm). Women underestimated more than men on weight (p = 0.022) and men overestimated more than women on height (p < 0.001). Reporting errors on weight were increased with overweight status (p < 0.001) and were disproportionate among subgroups. About 27% men and 24% women had reporting errors on weight greater than ± 2.2 kg, and 59% men and 28% women had reporting errors on height greater than 25 mm.

Practitioner Summary: This study along with literature revealed that the self-reported approach is not a sustainable option for anthropometric surveys, even for gathering data from physically active professional groups, such as firefighters, who presumably are knowledgeable of their body dimensions. Self-reported anthropometric information is undependable in important population subgroups.     

The European,Japanese and US protective helmet,gloves and boots for firefighters: thermoregulatory and psychological evaluations

The purpose of this study was to investigate the physiological and subjective responses of the European, Japanese (JPN) and US firefighters' helmet, gloves and boots for international standardisation. Three experimental conditions were evaluated (clothing mass: 9.4, 8.2 and 10.1 kg for the three conditions, respectively) at the air temperature of 32°C and 60% relative humidity. The results showed that there was no significant difference among the three conditions in oxygen consumption, heart rate, total sweat rate, rectal temperature and mean skin temperature, whereas peripheral temperatures and subjective perceptions were lower in the JPN condition than in the other conditions (P < 0.05). These results indicate that a 0.5-kg reduction in helmet mass and a 1.1-kg reduction in boot mass during exercise resulted in a significant decrease in head and leg temperatures and subjective perceptions, while a 1.9-kg reduction in total clothing mass had insignificant influences on the metabolic burden and overall body temperature.     

Jerry can carriage is an effective predictor of stretcher carry performance

Carrying a casualty on a stretcher is a critical task conducted in a range of occupations. To ensure that personnel have the requisite physical capacity to conduct this task, two bilateral jerry can carries were used to predict individual performance in a four-person stretcher carry. Results demonstrated a bilateral 22-kg jerry can carry (R² = 0.59) had superior predictive ability of stretcher carry performance than a bilateral 15-kg jerry can carry (R² = 0.46). Pre- to post-carry changes in grip endurance (p > 0.05), back–leg isometric strength (p > 0.05) and leg power (p > 0.05) were not significantly different between carry tasks. There was no significant difference in heart rate (p > 0.05) and oxygen consumption (p > 0.05) between the stretcher carry and either jerry can carry. Thus, on the basis of performance correlations and physiological measures, the 22-kg jerry can carry is an appropriate predictive assessment of four-person stretcher carriage.

Practitioner Summary: This study investigated the ability of a jerry can carry to predict individual performance on a four-person stretcher carry. Performance correlations were substantiated with physiological measures to demonstrate similar physical requirements between task and test. These results can be used to set physical employment standards to assess stretcher carriage.     

The ageing Australian firefighter: an argument for age-based recruitment and fitness standards for urban fire services

Currently, there is no enforcement of physical standards within Australian fire services post-recruitment, possibly leading to inappropriate fitness and body composition. This study evaluated the impacts of ageing on physical standards of Australian firefighters. Seventy-three firefighters from three different 10-year age groups [25–34 years (n = 27), 35–44 years (n = 27), 45–54 years (n = 19)] volunteered for physical testing using dual-energy X-ray analysis and existing fitness tests used for recruitment by an Australian fire service. Older (45–54 years) participants demonstrated significantly poorer physical standards compared with younger participants including cardiovascular fitness (p < 0.05), strength (p = 0.001) and simulated operational power testing tasks (p < 0.001). Age-related body composition changes were also observed independent of body mass index. Minimum recruitment standards and fitness programs need to account for age-related declines in physical capabilities to ensure that the minimum standard is maintained regardless of age.

Practitioner Summary: Using dual-energy X-ray analysis and established fitness testing protocols, this study aimed to gain an appreciation of the current standards of body composition and fitness of Australian firefighters and the effects of ageing on their physical abilities post-recruitment. The study demonstrated a significant decline in physical standards due to age.     

Development of physical selection procedures for the British Army. Phase 2: Relationship between physical performance tests and criterion tasks

This paper is the second in a series of three to describe the development of physical selection standards for the British Army. The first paper defined criterion tasks (single lift, carry, repetitive lift and carry, and loaded march tasks) and set standards on the criterion tasks for all British Army trades. The principal objective was to determine which combination of physical performance tests could be best used to predict criterion task performance. Secondary objectives included developing so-called ‘gender-free’ and ‘gender-unbiased’ models. The objectives were met by analysing performance data on the criterion tasks and a large battery of physical performance tests collected from 379 trained soldiers (mean age 23.5 (SD 4.45) years, stature 1734 (SD 79.5) mm, body mass 71.4 (SD 10.58) kg). Objective 1 was met: the most predictive physical performance tests were identified for all criterion tasks. Both single lift tasks were successfully modelled using muscle strength and fat free mass scores. The carry model incorporated muscle endurance and body size data, but the errors of prediction were large. The repetitive lift models included measures of muscle strength and endurance, and body size, but errors of prediction were also large. The loaded march tasks were successfully modelled incorporating indices of aerobic fitness, supplemented by measures of strength, endurance or body size and composition. The secondary objectives were partially fulfilled, though limitations in the data hampered the process. Although only one model (a loaded march) was gender-free, three models were gender-related (i.e. contained ‘gender’ explicitly in the model). The remaining six were gender-specific (i.e. were appropriate for men or for women). Owing to both a lower accuracy of prediction in women's scores and a greater tendency for the women's scores to be distributed around the pass standards, a greater percentage of women than men were misclassified as passing or failing, resulting in indirect discrimination. A validation of the models in a separate sample of the user population of recruits is reported in the third paper in this series.     

Fuzzy-Bayesian network for refrigeration compressor performance prediction and test time reduction

A typical characteristic of refrigeration compressor performance tests is their long duration. A reduction in the time periods related to this activity can be achieved using unsteady-state data analysis. This paper presents an original approach to predicting compressor performance using Bayesian networks and a hybrid Fuzzy-Bayesian network. All analysis was performed using real test data.     

Performance requirements of physically strenuous occupations: validating minimum standards for muscular strength and endurance

Employment rights legislative mandates passed in the USA over the last three decades emphasize the importance of validating performance standards for physically strenuous occupations. This study validated minimally acceptable standards for the muscular strength and endurance necessary to perform fire suppression activities. Incumbent firefighters (n?=?153) selected for key demographic characteristics completed a simulated set of firefighting tasks (Fire Suppression Evolution) and then a Predictor Test Battery of physical abilities tests. Regression analysis revealed that three predictor test items (hose drag/high rise pack carry; arm lift; arm endurance) combined to significantly predict performance time of the Fire Suppression Evolution (p???0.01). Firefighters (n?=?41) rating videotaped performance times of the Fire Suppression Evolution determined that more than one-half a standard deviation slower than the mean time established by the incumbents reflected unacceptable performance. Approximately 80% of incumbent firefighters passed the minimally acceptable performance standard. Use of the 3-predictor test battery would correctly identify 89% of successful performers and 72% of unsuccessful performers. This study demonstrates that validation of minimal physical performance standards will identify a cohort of individuals with a high probability of not being able to perform critical fire suppression activities. This finding has important implications for examining the relationship between physical performance standards and medical and economic outcomes.     

A review of: “Human Factors in Signalling Systems: Specific applications to railway signaling” By M. MASHOUR. (Stockholm: Almqvist & Wiksell International,and New York: Wiley, 1974.) [Pp. 341.] Sw.kr. 120.

A free-recall memory task was used to assess the after-effects of strenuous exercise on the cognitive functioning of young adults. In a first study, 24 college-age subjects performed tests of memory immediately following a treadmill run to voluntary exhaustion. The number of words recalled following exercise did not differ from the number of words recalled by 24 subjects in a non-exercise control group. Further, there were no differences in the serial position effect between the two groups. In a second study, 12 highly fit subjects were compared with 12 subjects of average fitness. No differences were found.     

Physical employment standard for Canadian wildland firefighters: examining test–retest reliability and the impact of familiarisation and physical fitness training

Abstract

To assess the impact of repeat performances (familiarisation) plus exercise training on completion time for the Ontario Wildland Firefighter (WFF) Fitness Test circuit (WFX-FIT), normally active general population participants (n = 145) were familiarised to the protocol then randomised into (i) exercise training, (ii) circuit only weekly performances or (iii) controls. At Baseline, the WFX-FIT pass rate for all groups combined was 11% for females and 73% for males, indicating that the Ontario WFX-FIT standard had a possible adverse impact on females. Following test familiarisation, mean circuit completion times improved by 11.9% and 10.2% for females and males, respectively. There were significant improvements in completion time for females (19.8%) and males (16.9%) who trained, plus females (12.2%) and males (9.8%) who performed the circuit only, while control participants were unchanged. Post training, the pass rate of the training group was 80% for females and 100% for males.

Practitioner Summary: This paper details the impact of familiarisation plus exercise training as accommodation to mitigate potential adverse impact on initial attack wildland firefighter test performance. The results underscore the importance of test familiarisation opportunities and physical fitness training programmes that are specific to the demands of the job.     

The effects of multiple firefighting activities on information processing and work performance in a smoke‐diving room: An intervention study

Firefighters perform various tasks during firefighting operations under unknown and unpredictable conditions. The present study investigated the impact of firefighting activities and cooling tactics on information processing and work performance. Firefighters performed typical firefighting tasks in the four experimental conditions, namely i) no cooling device (NC), ii) cooling gel (CG), iii) cool vest (CV), and iv) cooling gel and cool vest (CG + CV). The measurement of information processing, Paced Auditory Serial Addition Test (PASAT) scores decreased significantly after the firefighting activities in the four conditions, relative to baseline. The results revealed no significant difference in PASAT scores among the four conditions. However, the performance time (PT) was significantly shorter for the CV and CG + CV compared to the NC and CG conditions. The findings confirmed that the firefighting activities have a detrimental effect on information processing. The CG + CV and CV were more effective than CG and NC in improving PT during firefighting. However, the cooling strategies have a negligible effect on improving information processing performance.     

面向钢轨监测的无线传感器网络网关设计与性能测试

针对我国铁路钢轨实时广域监测的重大需求,通过研究异构无线传感器网络（WSNs）通信技术,设计并实现了一种基于Zig Bee-3G通信的无线传感器网络网关.进行了通信电路设计和电磁兼容设计,并在WinCE操作系统平台上实现了Zig Bee网络与3G网络之间的互联,开发了网关远程维护管理模块.对网关设备分别进行了网络传输性能测试和电磁兼容测试,测试结果表明：此网关传输效率高、抗电磁干扰能力强,能够满足铁路轨道监测现场的应用要求.     

A homogeneity property of discrete‐time systems: Stability and convergence rates

A new definition of homogeneity for discrete‐time systems is introduced. As in the continuous‐time case, the property can be verified algebraically in the transition map of the system, and it implies that a dilation of the initial conditions leads to a scaling of the trajectory. Stability properties and convergence rates of the system's solutions can be established by considering only the homogeneity degree. The existence of homogeneous Lyapunov and Lyapunov‐like functions is proven.     

Evaluation of performance and load in simulated rescue tasks for a novel design SCBA: effect of weight,volume and weight distribution

A self-contained breathing apparatus (SCBA) with an innovative rucksack shape that provides a better distribution of its weight over the middle and lower parts of the back (device C: 6l, 13.7 kg) was compared with two conventional SCBA which differed from each other in volume and weight (A: 6l, 15 kg, B: 6.8l, 11.7 kg). Twelve fire-fighters (27-49 yr) performed three exercises while using the three SCBA in a systematically permuted sequence. The exercises consisted of simulated rescue work under natural climatic conditions in a dwelling on the second floor and several typical elements of severe fire-fighting actions. Duration, heart rate, breathing frequency, rectal temperature, and sweat loss were recorded. Perceived exertion was rated and the carrying features of the SCBA were subjectively evaluated. The exercise was executed faster with the rucksack device, heart rates were then lower and the carrying features were evaluated as better. Thus, the weight of the SCBA was shown to be less important than its distribution.     

Android手机自动化性能测试工具的研究与开发

针对手机性能测试中效率低、工作量大等问题,提出自动化性能测试的方法,并运用这一方法设计了Android平台手机性能测试的FLEX-ANDROID工具。对这一工具的组成结构和测试脚本的编写进行了详细研究,并且对如何计算和生成测试结果进行了分析说明。通过使用自行研发的FLEX-ANDROID工具进行自动化测试,并将自动化测试所花时间和手动测试时间进行对比,结果表明,自动测试速度大约为手动测试速度的3倍。这表明FLEX-ANDROID工具能够有效提升测试工作效率,大幅度缩减测试时间,减少测试工作的重复劳动。     

飞机定时机构自动测试系统的设计与实现

针对多种不同型号定时机构的测试问题,研制了通用的自动测试系统。采用PCI、GPIB和RS-232等多种总线仪器设计了具有标准化、模块化结构的硬件平台。在满足测试技术指标的前提下,能够完成对13种定时机构产品的电压、电流、时间和绝缘阻抗等性能的测试,取代了原有的13个不同的测试仪器。     

Impacts of anger on driving performance: A comparison to texting and conversation while driving

Traditionally, driver distraction has been categorized into four types: visual, biomechanical, auditory, and cognitive. However, the place of emotion in driving research is largely undefined. The present study investigates the specific influences of anger – representative emotion arisen while driving, on driving performance, compared to those of traditional distraction tasks. In total, seventy-eight participants were recruited and placed into one of four driving conditions: physical (visual-biomechanical) distraction, cognitive (cognitive-auditory) distraction, emotional (anger), and control conditions. The results demonstrated that anger degrades driving performance as much as or more than other distraction types, specifically, in a yellow traffic signal situation. The causes for these results, underlying mechanisms, and other considerations are discussed with implications for future research.     

实验室测试数据实时收发系统的设计与实现

为在实验教学中实时掌握学生的实验测试情况并进行有效的指导,利用AVR单片机和RF4432无线射频模块,设计了一个实验数据无线收发系统。针对实验中的两个主要流程,在射频模块的FIFOs模式下,提出了一套满足实验教学需求的上位机和下位机无线通信协议,并采用时分通信防止数据冲突。详细介绍通信链路的建立、主机与从机的通信协议和通信时序、可视化界面的设计思路。将此系统应用于密立根油滴实验进行了测试,结果表明该系统能高效稳定地运行,达到了实时监测学生实验进度的要求,能有效提高实验教学效率。