Assessing gait changes in firefighters due to fatigue and protective clothing

Each year, roughly 11,000 firefighters are injured as a result of slips, trips and falls, which account for over 25% of all fireground injuries. Wearing personal protective equipment (PPE) can increase risk of fall-related injuries due to its weight, restrictiveness, and increased heat stress. Modification of PPE may serve to mitigate firefighter injuries related to loss of balance and falls. We examined the effects of choosing ‘enhanced’ protective clothing (lightweight, breathable, and less restrictive compared to typical firefighting PPE) and simulated firefighting tasks (18-min bout over four activities) on subsequent gait performance. To assess the effect of wearing protective clothing and firefighting activity, seven gait parameters and three movement errors were assessed during level and obstacle-crossing walking tasks. Forty-four firefighters wore one of two types of PPE (‘Standard’, ‘Enhanced’) during three testing conditions (baseline in station uniform, pre-firefighting activity in PPE, and post-firefighting activity in PPE). The effect of donning any PPE was found to significantly impair gait performance. Fatigue may impact effective mobility since more movement errors were observed during post-activity than pre-activity assessments. Although the Enhanced PPE did not lead to any significant differences in gait parameters compared to Standard PPE, participants in Enhanced PPE made twice as many movement errors, potentially attributed to lack of familiarity with the gear. These results suggest that wearing firefighting PPE and heat-stress induced fatigue are associated with reduced gait performance and increased risk for tripping over obstacles.     

防护服对消防员工效性能影响的定量研究*

为开发高性能防护服以提升救援效率,基于人体试验,测量受试者穿戴灭火防护服、半封闭防化服、全封闭防化服以及基础服装（对照组）时静态条件下左右手握力值、疲劳度（RPE）和活动受限程度,通过方差分析、接受者操作特征（ROC）曲线图、相关性分析进行定量研究。研究结果表明:灭火防护服对消防员工效性能影响大于防化服,灭火防护服较对照组握力减小32%、RPE增大54%、活动受限程度增大35倍,且RPE和活动受限程度均与握力呈显著负相关（p<0.001）。研究结果可为消防员个体防护服装设计、测试、性能提升等提供理论支撑,也可为消防员生命安全保障研究提供基础数据。     

Self-Rated Physical Loads of Work Tasks Among Firefighters

Objectives. The present study sought to identify firefighters’ rated physical demands for the most frequently occurring work tasks and to determine if the ratings differed between full-time and part-time firefighters to help create a basis for the development of physical employment tests for firefighters. Methods. An extensive questionnaire was completed by 125 and 68 firefighters in 2000 and 2010, respectively. The data were analysed with the Mann-Whitney U test and binominal test and ranked on the basis of the responses in each category. Results. Significant differences were seen between the full- and part-time firefighters. The work tasks rated as the most physically strenuous in terms of aerobic fitness, muscle strength, work posture and body control by most respondents were smoke diving upstairs (carrying a hose), victim rescue in different ways, carrying a stretcher over terrain and pulling a hose. Conclusions. Physically strenuous work tasks should be included in the end-point performance variables used to select physical performance tests for firefighters. The part-time firefighters with no experience in several of the work tasks suggests that work-related exercises are important if both groups of firefighters are expected to do similar work.     

The Impact of Occupational Load Carriage on Carrier Mobility: A Critical Review of the Literature

Military personnel and firefighters are required to carry occupational loads and complete tasks in hostile and unpredictable environments where a lack of mobility may risk lives. This review critically examines the literature investigating the impacts of load carriage on the mobility of these specialist personnel. Several literature databases, reference lists, and subject matter experts were employed to identify relevant studies. Studies meeting the inclusion criteria were critiqued using the Downs and Black protocol. Inter-rater agreement was determined by Cohen’s κ Twelve original research studies, which included male and female participants from military and firefighting occupations, were critiqued (κ = .81). A review of these papers found that as the carried load weight increased, carrier mobility during aerobic tasks (like road marching) and anaerobic tasks (like obstacle course negotiation) decreased. As such, it can be concluded that the load carried by some specialist personnel may increase their occupational risk by reducing their mobility.     

中美消防员殉职原因的对比研究

根据中美两国2000-2014年消防员伤亡数据,从伤亡数量、事故类型、殉职原因等方面进行对比分析。结果表明:从接警次数与牺牲人数比、每10万起火灾死亡人数比来看,中国高于美国;两国由于火场作业造成的消防员牺牲人数最多,发生事故数量最多;中国消防人员殉职主要原因是建筑物坍塌、爆炸、交通事故,故在灭火救援作业中,防止建筑物倒塌事故、提高消防员的应急避险能力及培养消防员安全意识是中国消防员急需加强的能力。研究成果对进一步强化消防队伍能力建设、减少消防人员伤亡有一定指导意义。     

The effect of artificial smoke compound on physiological responses,cognitive functions and work performance during firefighting activities in a smoke-diving room: an intervention study

This study investigated the combined effect of firefighting operations and exposure to smoke on physiological responses, cognitive functions and physical performance among firefighters. Each firefighter was engaged in two experimental conditions: (a) without artificial smoke, control (NS); (b) with artificial smoke (WS). The results of data analysis revealed that heart rate and body temperature increased significantly after the firefighting activities in the two conditions relative to baseline. In addition, reaction time (RT) and correct response (CR) decreased after the activity relative to baseline and there was a significant difference in RT and CR between the NS and WS conditions. There was also a significant difference in performance time between the NS and WS conditions. These findings demonstrated that a smoke compound has an insignificant effect on physiological responses during firefighting activity. On the contrary, the smoke compound has a detrimental influence on cognitive and physical performance.     

Association between resiliency and posttraumatic growth in firefighters: the role of stress appraisal

The purpose of this study was to establish the relation between resiliency and the level of positive changes, comprising posttraumatic growth in a group of firefighters experiencing job-related traumatic events and the mediating role of stress appraisal in this relation. The study was performed on a group of 100 firefighters from firefighting and rescue brigades, out of which 75 admitted to experiencing a traumatic event. Firefighters covered by the study were on average 31.51 years old (SD?=?6.34). A Polish version of Posttraumatic Growth Inventory, the Resiliency Assessment Scale and Stress Appraisal Questionnaire were used in the study. The results have shown that 22.7% of firefighters displayed low, 58.6% average and 18.7% high intensity of positive changes resulting from a traumatic event. Resiliency poorly correlates with posttraumatic growth expressed in changes in self-perception, and strongly correlates with stress appraisal, negatively correlates with threat and harm/loss and positively correlates with challenge. Appraisal of stress as a threat and challenge appeared to be mediators of the relationship between resiliency and posttraumatic growth.     

Comparison of Canadian firefighters and healthy controls based on submaximal fitness testing and strength considering age and gender

Introduction. Few studies have addressed whether firefighters are fitter than the general population and possess sufficient levels of aerobic capacity and muscle strength to perform on-duty tasks in a safe and efficient manner, considering age and gender. We aimed to evaluate the fitness levels of Hamilton firefighters, and to determine the effects of age and gender. Methods. In total, 89 participants were recruited. The modified Canadian aerobic fitness test was used to determine participants’ estimated maximal oxygen consumption (V_O2max) levels. For upper and lower body strength levels, a calibrated J-Tech hand-held dynamometer and a National Institute for Occupational Safety and Health (NIOSH) lifting device was used respectively. Results. Firefighters’ mean (SD) V_O2max level was 40.30?±?6.25?ml·kg^?1·min^?1. Age proved to have a statistically significant impact on V_O2max (p?<?0.001). Gender displayed statistically significant effects on strength levels. Firefighters’ age was the only statistically significant independent variable, and accounted for 61.00% of the variance in firefighters’ aerobic capacity levels. Conclusions. Firefighters possessed somewhat similar aerobic capacities but much higher levels of body strength when compared with the general population. With age, firefighters’ aerobic capacities decreased; however, their upper and lower body strength levels remained the same.     

Performance on a Work-Simulating Firefighter Test Versus Approved Laboratory Tests for Firefighters and Applicants

Aim. Firefighters must meet minimum physical demands. The Norwegian Labour Inspection Authority (NLIA) has approved a standardised treadmill walking test and 3 simple strength tests for smoke divers. The results of the Trondheim test were compared with those of the NLIA tests taking into account possible effects of age, experience level and gender. Methods. Four groups of participants took part in the tests: 19 young experienced firefighters, 24 senior male firefighters and inexperienced applicants, 12 male and 8 female. Results. Oxygen uptake (V_O2) at exhaustion rose linearly by the duration of the treadmill test. Time spent on the Trondheim test was closely related to performance time and peak V_O2 on the treadmill test. Senior experienced firefighters did not perform better than equally fit young applicants. However, female applicants performed poorer on the Trondheim test than on the treadmill test. Performance on the Trondheim test was not closely related to muscle strength beyond a minimum. Conclusion. Firefighters completing the Trondheim test in under 19 min fit the requirements of the NLIA treadmill test. The Trondheim test can be used as an alternative to the NLIA tests for testing aerobic fitness but not for muscular strength. Women’s result of the Trondheim test were poorer than the results of the NLIA treadmill test, probably because of their lower body mass.     

扑救液化石油气储罐爆炸火灾安全距离的确定

液化石油气储罐爆炸火灾是一类比较难于扑救的特殊火灾，如何根据现场的情况快速评估事故危害，并确定灭火指挥和人员疏散的安全距离，是消防指挥员指挥决策的重要问题，也是难点问题。本文研究了液化石油气储罐发生BLEVE时的热辐射和冲击波计算方法，并导出了安全距离的确定方法。对于消防指挥员快速决策具有十分重要的意义。     

一种改进的模拟水灭火过程对抗式交互模型

针对虚拟火灾和燃气真火模拟训练系统中的灭火过程交互模型,研究了改进型对抗式系统动力学特性模型,并完成符号求解。讨论并提出了消防员行为、火场外部特征等要素变化条件下的模型架构,给出了连续时间区间的模拟灭火交互模型序列构成形式。分析了交互过程控制参数特性、功能和物理意义,对灭火过程的简化模拟方法进行了完整描述。运用模型编制了消防水灭火典型过程的参数化交互控制时序规律,给出了灭火过程交互模型实际应用的基本方法和步骤。     

建筑物火灾时人员的认知水平对疏散心理和行为影响研究

在建筑物火灾中,个体行为因人员的个体特征、认知水平、社会特质、面临不同危险局面等因素的不同会呈现出极大的差异性。因此,在建筑物火灾中,人员应急疏散策略和方案在充分考虑紧急情况下外界环境因素的同时,还必须综合考虑处于火灾等紧急情况下的人员心理和行为特征。本研究是在大量调查问卷获得的数据和资料的基础上,基于一定的数学模型,利用相应的统计分析方法,主要讨论体现人员认知水平的文化程度、消防知识与经验二个因素对疏散心理和行为的影响特点。研究结果将充实我国人员疏散心理和行为反应数据库,为建筑防火性能化设计和人员消防培训提供基础数据和指导。     

Effectiveness of a physical activity program on weight,physical fitness,occupational stress,job satisfaction and quality of life of overweight employees in high-tech industries: a randomized controlled study

Introduction. This study aimed to examine the effectiveness of a physical activity (PA) program on weight control, physical fitness, occupational stress, job satisfaction and quality of life of overweight and sedentary employees in high-tech industries. Methods. Participants in the intervention group (n?=?37) were instructed to carry out a PA program at moderate intensity for 60?min/session, 3 sessions/week for 12 weeks. Those in the control group (n?=?38) received no PA program and were asked to continue their routine lifestyle. Evaluations were performed at baseline and at the end of the intervention. Results of structured questionnaires and blood biochemistry tests and evaluations of physical fitness were analyzed. Results. The PA program effectively reduced the number of risk factors for metabolic syndrome and body fat percentage, and improved physical fitness such as flexibility, muscular strength and endurance and cardiorespiratory endurance. The intervention also significantly decreased levels of serum triglyceride, total cholesterol and low-density lipoprotein cholesterol. Significant positive effects on work control, interpersonal relationships at work, global job satisfaction and quality of life were also demonstrated. Conclusion. This study showed that a PA program can be helpful in improving physical, physiological and psychological outcomes for overweight and sedentary employees in high-tech industries.     

不同区域古村镇消防行车时间统计特征研究

消防队介入时间是减少火灾损失、提高灭火成功概率的关键,作为消防队介入时间的重要部分,行车时间受到路况、天气等因素的影响,具有很大的不确定性.以位于远郊区和城市中心区域的两个典型古建筑群灭火救援的消防行车时间为研究对象,采用基于电子地图模拟导航的方法实时获取不同时刻消防站到古建筑群的行车时间,结合数据统计对比分析结果表明...     

消防员运动性疲劳监测量表的评价

为了预防战训损伤,利用消防员运动性疲劳监测量表,研究评价消防员训练疲劳。通过基层消防救援队伍量表数据的统计分析,探讨量表的题目编制,包括题目区分度分析和辨别力分析,检验量表的信效度,进而构建量表的参考常模,评价消防员疲劳等级及类型。研究结果表明:量表题目及结构符合标准,根据量表得分确定消防员是否疲劳,并将消防员疲劳划分为轻度疲劳、过度疲劳2个等级,以及应激过度主导和恢复不足主导2个类别,从而有效监测消防员战训情况,提高消防救援队伍战斗力。     

高层建筑新型灭火装置的设计

高层建筑外围火灾灭火工作开展困难,为增强灭火效果,本文按照自上而下的灭火思路,探讨在高层建筑顶部设计一种新型灭火装置。该装置可迅速转向火灾一侧,升降到准确的高度,从外向内灭火。克服了现有云梯消防车存在的举高有限、供水器材的耐压强度不够等问题。该装置的设计可在紧急情况下弥补现有灭火设施的不足,为高层建筑外围灭火解决方案的完善提供了新的参考。     

Development of a 3D risk analysis technique for fire disaster and its application on accident simulation of a public site

In this research, we constructed a three-dimensional fire risk analysis technique (3D-FRAT) for common building fires. To demonstrate its effect, the 3D-FRAT employed a self-developed 3D risk-calculating module in combination with the Fire Dynamics Simulator (FDS) software to simulate the Welcome Restaurant accident that happened on February 15, 1995 in Taichung City, Taiwan. This study only focuses on thermal radiation and provide a preliminary method to quantify a fire risk. Different firefighting equipment that comply with the related building and fire-preventive regulations have been used in the simulations to test their mitigating effectiveness on the accident. The results were shown by animation, 3D pictures, and sliced pictures to facilitate the researchers’ understanding of human hazards caused by thermal radiation or smoke in a specific fire accident. The minimal personnel escaping times for different hazardous factors were estimated; various firefighting designs that can reduce loss of human life and property were also perused. According to the simulation results, the individual risk values in Welcome Restaurant were between 3.108 × 10⁻⁹ to 2.719 × 10⁻⁵ (deaths/year). It is foreseeable that the 3D-FRAT can become a useful tool for related organizations to choose better fire-resistant buildings or fire-fighting equipment in the future.     

Assessment of urinary protein composition in response to consecutive days of wildland firefighting

The purpose of this study was to examine the pattern of urinary protein excretion induced by 3 consecutive days of wildland firefighting. Eighteen male active-duty military personnel served as the participants. All testing on the 3 consecutive days was conducted at a Northwestern USA fire camp. All participants consumed military-based foods containing 2620–2864?kcal/day. The work activity was evaluated with an accelerometer in association with body weight and hydration markers over the experimental period. Urinary samples were collected pre and post workshift on days 1 and 3 to assess glomerular and tubular protein excretion (total protein, albumin, β₂-microglobulin, N-acetyl-β-d-glucosaminidase and creatinine). The urinary levels of glomerular and tubular protein were not significantly different. The main findings of the present study indicate that similar alterations of urinary protein composition can be observed over consecutive days of wildland firefighting, which appears to be dependent on intensity rather than total work output.