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

Evaluation of the relationship between occupational-specific task performance and measures of physical fitness, cardiovascular and musculoskeletal health in firefighters

INTRODUCTION

Firefighters are required to perform physically strenuous tasks such as hose drags, victim rescues, forcible entries and stair climbs to complete their public safety mission. Occupational-specific tasks are often used to evaluate the ability of firefighters to adequately/safely perform their duties. Depending on the regions, occupational-specific tasks include six to eight individual tasks, which emphasize distinct aspects of their physical fitness, while also requiring different levels of cardiovascular (CVH) and musculoskeletal health (MSH). Therefore, the aim of this study was to evaluate the relationship between specific occupational task performance and measures of physical fitness, cardiovascular and musculoskeletal health.

METHODS

Using a cross-sectional design, 282 full-time male and female firefighters were recruited. A researcher-generated questionnaire and physical measures were used to collect data on sociodemographic characteristics, CVH, MSH and weekly physical activity habits. Physical measures were used to collect data on physical fitness and occupational-specific task performance.

RESULTS

Absolute cardiorespiratory fitness (abV̇O2max), grip strength, leg strength, push-ups, sit-ups and lean body mass (all p < 0.001) had an inverse association with completion times on all occupational-specific tasks. Age was positively related to the performance of all tasks (all p < 0.05). Higher heart rate variability (HRV) was associated with better performance on all tasks (all p < 0.05). Bodyfat percentage (BF%) and diastolic blood pressure were positively associated with the step-up task (p < 0.05). Lower back musculoskeletal injury (LoBMSI), musculoskeletal discomfort (MSD), and lower limb MSD were associated with a decreased odds of passing the step-up. Upper body MSIs (UBMSI), LoBMSIs and Lower back MSD were associated with decreased odds of passing the rescue drag.

CONCLUSION

Firefighters that were taller, leaner, stronger and fitter with a more favourable CVH profile, higher HRV and less musculoskeletal discomfort performed best on all occupational-specific tasks.

Posture Evaluation of Firefighters During Simulated Fire Suppression Tasks

BACKGROUND

Posture mechanics during fire suppression tasks are associated with musculoskeletal injuries in firefighters.

METHODS

This study uses the Ovako Working Posture Analyzing System (OWAS) ergonomics tool to describe and evaluate the postures of 48 firefighters during 3 simulated tasks: (a) hose drag, (b) hose pull, and (c) high-rise pack lift. Ergonomics intervention prioritizations based on the OWAS action classification (AC) scores were identified using Wilcoxon signed-rank tests. Chi-square analyses identified associations between firefighter characteristics and OWAS AC scores.

FINDINGS

The initial hose pick-up phase of each task was identified as a high priority for ergonomics intervention (OWAS AC = 4) in 45.8%, 54.2%, and 45.8% of cases for Tasks 1, 2, and 3, respectively. Lower BMI was associated with higher AC scores for the initial hose pick-up during Task 3 (likelihood ratio = 9.20, p value = .01).

CONCLUSION

The results inform ergonomics priorities for firefighter training based on the tasks analyzed. Application to Practice: This study evaluates the posture mechanics of three commonly performed firefighting tasks. The results help inform an ergonomics training intervention focused on posture mechanics during occupational activities for firefighters.

Association between physical fitness and musculoskeletal health in firefighters

Introduction: Firefighters are often placed in situations that require high levels of physical exertion, leading to significant strain on firefighters' musculoskeletal system, predisposing them to musculoskeletal discomfort (MSD) and/or musculoskeletal injury (MSI). Physical fitness programs are often recommended and justified, in part, to prevent injuries. The aim of this study was to determine the association between physical fitness and musculoskeletal health (MSH) in firefighters. Methods: A total of 308 full-time firefighters took part in the study conducted in Cape Town, South Africa. Physical fitness tests encompassed a non-exercise estimation for cardiorespiratory fitness, grip and leg strength for upper and lower body strength, push-ups and sit-ups for muscular endurance, and sit-and-reach for flexibility. The Nordic Musculoskeletal Questionnaire and Cornell Musculoskeletal Discomfort Questionnaire were used to determine MSIs and MSD, respectively. A p-value <0.05 indicated statistical significance. Results: Every one-unit increase in AbVO2max, push-ups, sit-ups, and sit-and-reach decreased the odds of firefighters reporting MSIs by 5% (p = 0.005), 3% (p = 0.017), 3% (p = 0.006), and 3% (p = 0.034), respectively. Every one repetition increase in push-up capacity increased the odds of firefighters reporting neck, elbow and forearm, wrist and hand, and thigh discomfort by 3% (p = 0.039), 4% (p = 0.031), 5% (p = 0.002), and 5%` (p = 0.007), respectively. Every one repetition increase in sit-up capacity increased the odds of firefighters reporting upper back discomfort and thigh discomfort by 5% (p = 0.045) and 7% (p = 0.013), respectively. Conclusion: Maintenance of physical fitness is likely beneficial in reducing MSIs, which, however, may increase the feeling of MSD in firefighters. In addition, it may be noticed that there is an ideal level of physical fitness that is conducive to the reduction of MSIs and should be studied further.

Association between Physical Fitness and Cardiovascular Health in Firefighters

Firefighters perform strenuous work in dangerous and unpredictable environments requiring optimal physical conditioning. The aim of this study was to investigate the association between physical fitness and cardiovascular health (CVH) in firefighters. This cross-sectional study systematically recruited 309 full-time male and female firefighters between the ages of 20 to 65 years in Cape Town, South Africa. Physical fitness was assessed using absolute (abV̇O2max) and relative oxygen consumption (relVO2max), grip and leg strength, push-ups and sit-ups, sit-and-reach for flexibility and lean body mass (LBM). CVH encompassed age, smoking, blood pressure (BP), blood glucose, lipid profile, body mass index, body fat percentage (BF%), and waist circumference. Linear regressions and logistic regressions were applied. Multivariable analysis indicated that relVO2max was associated with systolic BP (p < 0.001), diastolic BP (p < 0.001), non-fasting blood glucose (p < 0.001), and total cholesterol (p = 0.037). Poor CVH index was negatively associated with relV̇O2max (p < 0.001), leg strength (p = 0.019), and push-ups (p = 0.012). Furthermore, age was inversely associated with V̇O2max (p < 0.001), push-up and sit-up capacity (p < 0.001), and sit-and-reach (p < 0.001). BF% was negatively associated with abV̇O2max (p < 0.001), grip and leg strength (p < 0.001), push-ups (p = 0.008), sit-ups (p < 0.001), and LBM (p < 0.001). Cardiorespiratory fitness, muscular strength, and muscular endurance were significantly associated with a better overall CVH profile.

Longitudinal changes in cardiorespiratory fitness among firefighters based on a fixed 12.0 MET standard and an age-adjusted fitness standard

BACKGROUND

Firefighting is a physically demanding profession. Firefighters (FFs) need adequate physical fitness (PF) to perform duty tasks efficiently. While FFs' work demands are constant throughout their career, there is an expected age-related decline in PF.

OBJECTIVE

To describe longitudinal changes in cardiorespiratory fitness (CRF) based on a fixed (12.0 METs) and an age-adjusted standard and compare the prevalence of fit/unfit firefighters (FFs) over eight years.

METHODS

297 Brazilian male firefighters were randomly selected. CRF was assessed by the 12-minute Cooper test. To compare the prevalence's of fit/unfit FFs depending on the standard (12 METs vs. age-adjusted), the McNemar test was used.

RESULTS

The reduction in the prevalence of fit firefighters was 4.4-fold higher when the analysis did not consider age.

CONCLUSION

After eight years, the prevalence of fit FFs decreased by 30.5% based on the fixed standard, while this reduction was only 7% when using an age-adjusted standard.

Cardiovascular Disease Risk Factors, Musculoskeletal Health, Physical Fitness, and Occupational Performance in Firefighters: A Narrative Review

Introduction

Firefighting is a strenuous occupation that requires firefighters to be in peak physical condition. However, many firefighters have risk factors for cardiovascular disease, impaired musculoskeletal health, and are not physically fit for duty, which all negatively impact their occupational performance. Therefore, the aim of this review is to determine the relationship between cardiovascular disease risk factors, musculoskeletal health, physical fitness, and occupational performance in firefighters.

Methods

The electronic databases PubMed, SCOPUS, and Web of Science were searched online via the library portal of the University of the Western Cape. Publications and grey literature between the years 2000 to present were used. In total, 2607 articles were identified; after the removal of duplicates 1188 articles were then screened, and were excluded for not meeting initial screening criteria. The remaining 209 full-text articles were screened based on the inclusion and exclusion criteria, where 163 articles were excluded. Only studies that were quantitative were included. This left 46 articles that were then finally included in the current narrative review.

Results

The current literature indicated that significant relationships existed between cardiovascular risk factors, musculoskeletal health, physical fitness, and occupational performance. The results indicated firefighters who were aged, obese, physically inactive, cigarette smokers, and unfit were at the highest risk for cardiovascular and musculoskeletal health complications, and unsatisfactory occupational performance. Musculoskeletal health complications significantly affected occupational performance and work ability and were related to physical fitness of firefighters. Most cardiovascular risk factors were related to physical fitness, and all physical fitness parameters were related to occupational performance in firefighters.

Conclusion

The overwhelming evidence in the current review established that physical fitness is related to occupational performance. However, the relationship between cardiovascular risk factors and musculoskeletal health in relation to occupational performance is less clear and still understudied. Significant gaps remain in the literature.

Fitness Fights Fires: Exploring the Relationship between Physical Fitness and Firefighter Ability

Background: Regular exercise in firefighters may be effective in preventing or attenuating ill health (e.g., hypertension, diabetes, and obesity), as well as improving their firefighting ability. The purpose of this study was to investigate the relationship between physical fitness and firefighting ability. Methods: Male firefighter recruits' (n = 89; age = 27.1 ± 4.2 yrs) physical fitness and firefighting ability were assessed at Week 1 and Week 7 during a basic firefighting training academy. Physical fitness was assessed via 1.5 mile run time, sit-up and push-up repetitions, the Young Men's Christian Association (YMCA) bench press test, vertical jump height, and sit-and-reach flexibility, while firefighting ability was assessed via completion time on a firefighting skills test. Results: Fitness predicted significant variance in firefighting ability at Week 1 (R²= 0.46; p < 0.01) and Week 7 (R² = 0.46; p < 0.01), after accounting for age and body mass index. Cardiovascular endurance accounted for 22.4% (FΔ (1, 85) = 25.75) and 39.3% (FΔ (1, 85) = 55.53) while muscular endurance accounted for an additional 19.0% (FΔ (3, 82) = 10.34) and 6.3% (FΔ (3, 82) = 3.2) unique variance in firefighting ability at Week 1 and Week 7, respectively. Conclusions: Given the strong association between fitness and firefighting performance, municipal departments may want to focus on increasing fitness levels among firefighters.

Relationship Between Various Coronary Artery Disease Risk Factors in Firefighters

OBJECTIVE

To determine the correlation between the various coronary artery disease risk factors in firefighters.

METHODS

The study used a quantitative, cross-sectional, and correlational study design. A total of 124 full-time firefighters were conveniently recruited to participate. Research procedures were based on the ACSM guidelines.

RESULTS

Significances were found between age and body mass index (BMI) (r = 0.42, P < 0.001), age and waist circumference (WC) (r = 0.52, P < 0.001), BMI and WC (r = 0.88, P < 0.001), BMI and diastolic blood pressure (DBP) (r = 0.48, P < 0.001), between WC and DBP (r = 0.48, P < 0.001) and between gender and cigarette smoking (χ2[1] = 5.66, P = 0.017).

CONCLUSION

There were significant strong relationships between BMI, SBP, DBP, dyslipidemia, and increasing age, especially in male firefighters. Reducing key risk factors should be emphasized.

Women Firefighters' Health and Well-Being: An International Survey

OBJECTIVES

This study aimed to identify specific health and well-being issues that women firefighters may experience as part of their daily working practices. Issues identified from this under-represented population can drive future research, education, and strategy to guide safety and health practices.

METHODS

A total of 840 women firefighters from 14 separate countries (255 United Kingdom and Ireland, 320 North America, 177 Australasia, and 88 mainland Europe) completed the survey over a 4-month period. Questions related to general health and well-being and role-specific health concerns, gender-related issues, and available exercise facilities.

RESULTS

Women firefighters in North America reported a higher prevalence of lower back (49%) and lower limb (51%) injuries than all other groups. North American respondents reported more heat illnesses (45%) than respondents from other places (36%). Although many participants did not respond, of those who did, 39% thought the menstrual cycle (199/512) or menopause (55/151) affected their work, and 36% were concerned for their ability to meet future job demands. Sixteen percent felt confident they could complete the role after 60 years of age. Women firefighters identified a lack of strength and conditioning support (50%) or lack of gym access (21%). There appears to be poor availability of female-specific personal protective equipment, with availability greatest in the United Kingdom (66%) compared with the sample as a whole (42%).

CONCLUSIONS

There is a need for female-specific strength and conditioning support and facilities to decrease injury and illness risk and improve longevity. Research and education into gynecological issues, heat exposure, and their effects on women firefighters' fertility and cancer risk is required.

The effect of age on fitness among female firefighters

Background

The physical demands of firefighting require both cardiovascular and muscular fitness, which both decline with age. While much has been published on age-related changes among male firefighters (FFs), data on female FFs are lacking.

Aims

To describe cardiorespiratory fitness (CRF) and muscular fitness in a sample of female career FFs ranging in age from 25 to 60 years and determine whether ageing affects their achievement of the current recommended professional CRF standards of 12 metabolic equivalents (METs).

Methods

Data were collected on female FFs over an 11-year period. A cross-sectional analysis using one-way analysis of variance with Bonferroni post hoc comparisons was used to compare age groups.

Results

There were 96 study participants. Maximum METs was significantly higher (P < 0.01) in the 25- to 34-year age group (14.6 ± 2.1) compared with the 35-44 age group (12.9 ± 2.0 METs) and the 45-54 age group (12.2 ± 1.8 METs, P < 0.001). While the mean values of all measured age groups met or exceeded the 12-MET profession standard, as many as one-third of FFs <45 years of age and 43% of FFs >45 years of age fell below the benchmark of 12 METs. Muscular fitness as measured by maximum number of push-ups, sit-ups and back endurance was not significantly different between age groups.

Conclusions

Fire departments should recognize and take steps to ensure all female FFs maintain CRF and muscular fitness throughout their careers.

Accuracy of Tympanic Temperature Measurement in Firefighters Completing a Simulated Structural Firefighting Task

INTRODUCTION

In the course of their duties, firefighters risk heat stroke and other medical conditions due to exertion in high-temperature environments. Infrared tympanic temperature measurement (TTym) is often used by Emergency Medical Services (EMS) to assess the core body temperature of firefighters. The accuracy of TTym in this setting has been called into question. Hypothesis/Problem This study aimed to examine the accuracy of TTym for core body temperature assessment at emergency firefighting events compared with gastrointestinal temperature measurement (TGI) as measured by ingestible thermometers.

METHODS

Forty-five (42 male, three female) professional urban firefighters from an Australian fire service completed two 20-minute work periods in a 100°C (± 5°C) heat chamber while wearing personal protective clothing (PPC) and breathing apparatus (weighing approximately 22 kg). Measurements were taken immediately before entering, and on exiting, the heat chamber. Tympanic temperature was assessed by an infrared tympanic thermometer and TGI was measured by ingestible sensor and radio receiver.

RESULTS

Complete data were available for 37 participants. Participant temperatures were higher on exiting the heat chamber than at baseline (TTym: 35.9°C (SD=0.7) vs 37.5°C (SD=0.8); TGI: 37.2°C (SD=0.4) vs 38.6°C (SD=0.5)). Tympanic temperature underestimated TGI on average by 1.3°C (SD=0.5) before entering the chamber and by 1.0°C (SD=0.8) following the exercise. Using pooled data, the average underestimation was 1.2°C (SD=0.7).

CONCLUSION

Tympanic thermometers cause an unreliable measure of core body temperature for firefighters engaged in fire suppression activities. Accurate and practical measures of core body temperature are required urgently.

Chronic occupational exposures can influence the rate of PTSD and depressive disorders in first responders and military personnel

BACKGROUND

First responders and military personnel experience rates of post-traumatic stress disorder (PTSD) far in excess of the general population. Although exposure to acute traumatic events plays a role in the genesis of these disorders, in this review, we present an argument that the occupational and environmental conditions where these workers operate are also likely contributors.

PRESENTATION OF THE HYPOTHESIS

First responders and military personnel face occupational exposures that have been associated with altered immune and inflammatory activity. In turn, these physiological responses are linked to altered moods and feelings of well-being which may provide priming conditions that compromise individual resilience, and increase the risk of PTSD and depression when subsequently exposed to acute traumatic events. These exposures include heat, smoke, and sleep restriction, and physical injury often alongside heavy physical exertion. Provided the stimulus is sufficient, these exposures have been linked to inflammatory activity and modification of the hypothalamic-pituitary axis (HPA), offering a mechanism for the high rates of PTSD and depressive disorders in these occupations.

TESTING THE HYPOTHESIS

To test this hypothesis in the future, a case-control approach is suggested that compares individuals with PTSD or depressive disorders with healthy colleagues in a retrospective framework. This approach should characterise the relationships between altered immune and inflammatory activity and health outcomes. Wearable technology, surveys, and formal experimentation in the field will add useful data to these investigations.

IMPLICATIONS OF THE HYPOTHESIS

Inflammatory changes, linked with occupational exposures in first responders and military personnel, would highlight the need for a risk management approach to work places. Risk management strategies could focus on reducing exposure, ensuring recovery, and increasing resilience to these risk contributors to minimise the rates of PTSD and depressive disorders in vulnerable occupations.

Towards best practice in physical and physiological employment standards

While the scope of the term physical employment standards is wide, the principal focus of this paper is on standards related to physiological evaluation of readiness for work. Common applications of such employment standards for work are in public safety and emergency response occupations (e.g., police, firefighting, military), and there is an ever-present need to maximize the scientific quality of this research. Historically, most of these occupations are male-dominated, which leads to potential sex bias during physical demands analysis and determining performance thresholds. It is often assumed that older workers advance to positions with lower physical demand. However, this is not always true, which raises concerns about the long-term maintenance of physiological readiness. Traditionally, little attention has been paid to the inevitable margin of uncertainty that exists around cut-scores. Establishing confidence intervals around the cut-score can reduce for this uncertainty. It may also be necessary to consider the effects of practise and biological variability on test scores. Most tests of readiness for work are conducted under near perfect conditions, while many emergency responses take place under far more demanding and unpredictable conditions. The potential impact of protective clothing, respiratory protection, load carriage, environmental conditions, nutrition, fatigue, sensory deprivation, and stress should also be considered when evaluating readiness for work. In this paper, we seek to establish uniformity in terminology in this field, identify key areas of concern, provide recommendations to improve both scientific and professional practice, and identify priorities for future research.

Age, human performance, and physical employment standards

The proportion of older workers has increased substantially in recent years, with over 25% of the Canadian labour force aged ≥55 years. Along with chronological age comes age-related declines in functional capacity associated with impairments to the cardiorespiratory and muscular systems. As a result, older workers are reported to exhibit reductions in work output and in the ability to perform and/or sustain the required effort when performing work tasks. However, research has presented some conflicting views on the consequences of aging in the workforce, as physically demanding occupations can be associated with improved or maintained physical function. Furthermore, the current methods for evaluating physical function in older workers often lack specificity and relevance to the actual work tasks, leading to an underestimation of physical capacity in the older worker. Nevertheless, industry often lacks the appropriate information and/or tools to accommodate the aging workforce, particularly in the context of physical employment standards. Ultimately, if appropriate workplace strategies and work performance standards are adopted to optimize the strengths and protect against the vulnerability of the aging workers, they can perform as effectively as their younger counterparts. Our aim in this review is to evaluate the impact of different individual (including physiological decline, chronic disease, lifestyle, and physical activity) and occupational (including shift work, sleep deprivation, and cold/heat exposure) factors on the physical decline of older workers, and therefore the risk of work-related injuries or illness.

Water immersion for post incident cooling of firefighters; a review of practical fire ground cooling modalities

Rapidly cooling firefighters post emergency response is likely to increase the operational effectiveness of fire services during prolonged incidents. A variety of techniques have therefore been examined to return firefighters core body temperature to safe levels prior to fire scene re-entry or redeployment. The recommendation of forearm immersion (HFI) in cold water by the National Fire and Protection Association preceded implementation of this active cooling modality by a number of fire services in North America, South East Asia and Australia. The vascularity of the hands and forearms may expedite body heat removal, however, immersion of the torso, pelvis and/or lower body, otherwise known as multi-segment immersion (MSI), exposes a greater proportion of the body surface to water than HFI, potentially increasing the rates of cooling conferred. Therefore, this review sought to establish the efficacy of HFI and MSI to rapidly reduce firefighters core body temperature to safe working levels during rest periods. A total of 38 studies with 55 treatments (43 MSI, 12 HFI) were reviewed. The core body temperature cooling rates conferred by MSI were generally classified as ideal (n = 23) with a range of ~0.01 to 0.35 °C min(-1). In contrast, all HFI treatments resulted in unacceptably slow core body temperature cooling rates (~0.01 to 0.05 °C min(-1)). Based upon the extensive field of research supporting immersion of large body surface areas and comparable logistics of establishing HFI or MSI, it is recommended that fire and rescue management reassess their approach to fireground rehabilitation of responders. Specifically, we question the use of HFI to rapidly lower firefighter core body temperature during rest periods. By utilising MSI to restore firefighter Tc to safe working levels, fire and rescue services would adopt an evidence based approach to maintaining operational capability during arduous, sustained responses. While the optimal MSI protocol will be determined by the specifics of an individual response, maximising the body surface area immersed in circulated water of up to 26 °C for 15 min is likely to return firefighter Tc to safe working levels during rest periods. Utilising cooler water temperatures will expedite Tc cooling and minimise immersion duration.

Repeat work bouts increase thermal strain for Australian firefighters working in the heat

BACKGROUND

Firefighters regularly re-enter fire scenes during long duration emergency events with limited rest between work bouts. It is unclear whether this practice is impacting on the safety of firefighters.

OBJECTIVES

To evaluate the effects of multiple work bouts on firefighter physiology, strength, and cognitive performance when working in the heat.

METHODS

Seventy-seven urban firefighters completed two 20-minute simulated search and rescue tasks in a heat chamber (105 ± 5°C), separated by a 10-minute passive recovery. Core and skin temperature, rate of perceived exertion (RPE), thermal sensation (TS), grip strength, and cognitive changes between simulations were evaluated.

RESULTS

Significant increases in core temperature and perceptual responses along with declines in strength were observed following the second simulation. No differences for other measures were observed.

CONCLUSIONS

A significant increase in thermal strain was observed when firefighters re-entered a hot working environment. We recommend that longer recovery periods or active cooling methods be employed prior to re-entry.