Physical activity measured by accelerometry (PA-accelerometry) is used as an indicator of physical capacity in chronic diseases. Currently, only fragmented age ranges of reference percentile curves are available for European children and adolescents. This study aimed to provide age- and sex-specific percentiles for physical activity measured by hip-worn accelerometry derived throughout the full age range of European children and adolescents. Individual-level population-based PA data measured by accelerometry from HELENA and IDEFICS/I.Family studies were pooled and harmonized. Together these studies involved children and adolescents aged 2–18 years from 12 European countries. Primary outcomes included averaged counts per minute (CPM), sedentary time (SED), light PA (LPA) and moderate-to-vigorous PA (MVPA). Generalized Additive Models for Location, Scale and Shape were used to derive age- and sex-specific reference percentile curves for these outcomes. The combined cohort consisted of 11,645 children and adolescents aged 2 to 18 years who contributed 14,610 valid accelerometry recordings, with a median accelerometer wear time of 6 days. This dataset allowed for the construction of age- and sex-specific reference percentile curves for CPM, SED, LPA, and MVPA. The curves demonstrated varying trends and variability across age groups. Conclusions: This study provides age- and sex-specific percentile curves for PA-accelerometry in European children and adolescents, addressing a current gap in the availability of full-age range reference data. These curves based on healthy children and adolescents can be used by clinicians, researchers, and policymakers to interpret PA-accelerometry measurements, track physical activity trends, and evaluate treatment responses and health interventions.

Advances in assistive exoskeleton technology, and a boom in related scientific literature, prompted a need to review the potential use of exoskeletons in defence and security. A systematic review examined the evidence for successful augmentation of human performance in activities deemed most relevant to military tasks. Categories of activities were determined a priori through literature scoping and Human Factors workshops with military stakeholders. Workshops identified promising opportunities and risks for integration of exoskeletons into military use cases. The review revealed promising evidence for exoskeletons’ capacity to assist with load carriage, manual lifting, and working with tools. However, the review also revealed significant gaps in exoskeleton capabilities and likely performance levels required in the use case scenarios. Consequently, it was recommended that a future roadmap for introducing exoskeletons to military environments requires development of performance criteria for exoskeletons that can be used to implement a human-centred approach to research and development. We assessed the state-of-the-art for the use of wearable assistive exoskeletons in UK defence and security use cases. A full systematic review of the literature was undertaken, informed by use cases developed in military stakeholder workshops. Clear gaps in exoskeleton capability and use case requirements were identified, leading to recommendations for future work.

PURPOSE: During operations, military personnel must overcome a multitude of competing physiological and cognitive stressors whilst maintaining high levels of performance. Quantifying the physical and cognitive demands of a tactical military field exercise that closely simulates operational environments may provide a better understanding of stressors placed on personnel during combat. METHODS: Four 8-soldier patrols, completing a dismounted 48-hr military tactical scenario-based field exercise, participated in the study. Physical activity was recorded continuously using a wrist-worn tri-axial accelerometer, and cognitive function was measured (Go-/No-Go, N-back, Psychomotor Vigilance Task [PVT]) pre-, mid- and post-exercise. Physical activity was described using Euclidian Norm Minus One (mg), with Moderate Vigorous Physical Activity (MVPA) and Sedentary Light Physical Activity (SLPA) as ≥ or < 113 mg, respectively. Changes in cognitive function outcome variables (overall mean reaction time [RT], accuracy-speed trade-off and number of correct and missed responses) were calculated for each test from pre-, to mid- and post-exercise. RESULTS: Participants spent a higher proportion of time completing SLPA vs MVPA (1932 ± 234 vs 1074 ± 194 min; p < 0.001). Go-/No-Go mean RT slowed over the duration of the patrol (pre- 293.3, mid- 307.0, post- 308.0 milliseconds; p = 0.03) and PVT missed responses increased significantly when assessed at mid- and post- compared to pre- (5.2 and 5.3, respectively vs. 1.4; p < 0.05). While not statistically significant, a decline in cognitive function was observed across all measures over time. CONCLUSION: The study successfully quantified the physical activity, and subsequent impact on cognitive function, in soldiers completing a 48-hr military tactical scenario-based exercise. Further research is needed to better understand how physiological stressors interact with cognitive function during military operations. FUNDING: This research project was funded by Defence Science Technology Laboratory (Dstl) and managed by the Human Social Science Research Capability (HSSRC)

Soldiers require high levels of fitness to perform physically demanding role-related tasks, such as load carriage and moving equipment. Developing cardiorespiratory endurance and muscular strength through progressive physical training programmes during Basic Training (BT) will support soldiers to perform their duties and reduce musculoskeletal injury risk. PURPOSE: To (1) quantify physical performance changes in recruits undertaking three British Army BT courses; Standard Entry (SE), Junior Entry Short (JE-Short) and Long (JE-Long) and (2) explore differences between courses, men and women, and entry fitness level. METHODS: Performance of 2 km run, medicine ball throw (MBT) and mid-thigh pull (MTP) were assessed at entry and completion of BT (14 [SE]), 23 [JE-Short] or 49 [JE-Long] weeks in duration) for 2350 (272 women) British Army recruits. Performance change was analysed with entry performance as a covariate (ANCOVA), before an additional interaction term allowing different slopes for course and gender. RESULTS: There was high heterogeneity, although BT courses saw average improvements in surrogate tests for cardiovascular endurance (2 km run: SE: -6.8% [-0.62 min], JE-Short: -4.6% [-0.43 min], JE-Long: -7.7% [-0.70 min]; all p < 0.001) and muscular strength and power (MBT: 1.0-8.8% [0.04-0.34 m]; all p < 0.05; MTP: 4.5-26.9% [6.5-28.8 kg]; all p < 0.001). Regression models indicated a form of regression to the mean whereby performance change was negatively associated with entry fitness (those with low baseline fitness exhibit larger improvements), particularly for women. However, when matched for entry fitness, men displayed considerable improvements in all tests, relative to women. CONCLUSIONS: British Army BT courses were effective in developing physical fitness and entry fitness was negatively associated with change over time. Other factors not measured including age and physical maturity could also be contributors to the training response. Individualising physical training may enhance physical fitness development and role-related job-task performance. Funded by the UK Ministry of Defence (Army).

Aim: To develop evidence-based role-specific physical employment standards and tests for National Ambulance Resilience Unit (NARU) specialist paramedics. Methods: Sixty-two (53 men, 9 women) paramedics performed an array of (1) realistic reconstructions of critical job-tasks (criterion job performance); (2) simplified, easily-replicable simulations of those reconstructions and; (3) fitness tests that are portable and/or practicable to administer with limited resources or specialist equipment. Pearson's correlations and ordinary least products regression were used to assess relationships between tasks and tests. Performance on reconstructions, subject-matter expert and participant ratings were combined to derive minimum acceptable job performance levels, which were used to determine cut-scores on appropriate correlated simulations and tests. Results: The majority of performance times were highly correlated with their respective simulations (range of r: 0.73-0.90), with the exception of those replicating water rescue (r range: 0.28-0.47). Regression compatibility intervals provided three cut-scores for each job-task on an appropriate simulation and fitness test. Conclusion: This study provides a varied and easily-implementable physical capability assessment for NARU personnel, empirically linked to job performance, with flexible options depending on organisational requirements.

BACKGROUND:The National Ambulance Resilience Unit (NARU) works on behalf of each National Health Service (NHS) Ambulance Trust in England to strengthen national resilience and improve patient outcome in challenging pre-hospital scenarios.OBJECTIVE:To conduct a Job Task Analysis and describe the physical demands of NARU roles.METHODS:A focus group was conducted to describe the physically demanding tasks performed by NARU personnel. Subsequently, the physical demands of the identified tasks were measured in 34 NARU personnel (29 male and 5 female).RESULTS:Eleven criterion tasks were identified; Swift Water Rescue (SWR), Re-board Inflatable Boat (RBIB), Set up Decontamination Tent (SDT), Clinical Decontamination (CD), Movement in Gas Tight Suits (MGTS), Marauding Terrorist Fire Arms (MTFA), Over Ground Rescue (OGR), Unload Incidence Response Unit Vehicle (UIRUV), Above Ground Rescue (AGR), Over Rubble Rescue (ORR) and Subterranean Rescue (SR). The greatest cardiovascular strain was measured during SWR, MGTS, and MTFA. The most thermally challenging tasks were the MTFA, CD, SR and OGR. The greatest muscular strength requirements were during MTFA and OGR.CONCLUSIONS:All five components of fitness (aerobic endurance, anaerobic endurance, muscular strength, muscular endurance and mobility) were required for successful completion of the physically demanding tasks performed by NARU personnel.

PURPOSE: The metabolic cost of load carriage (LC) is frequently predicted using the Pandolf et al. (1977) equation. Recent laboratory investigations have identified that the Pandolf equation under-predicts the metabolic cost of LC in untrained personnel during treadmill walking (Drain et al., 2017). However, the relationship between the actual and Pandolf predicted metabolic cost of outdoor LC in UK Armed Forces personnel has not been established. METHODS: Twenty-two UK Armed Forces personnel (Royal Marine Commandos and Parachute Regiment, mean ± SD: age 23 ± 3 years; stature 180.9 ± 4.9 cm; body mass 83.1 ± 6.6 kg; predicted V[Combining Dot Above]O2max 54.0 ± 3.1 ml·kg-1·min-1) completed 15, 20 minute stages of outdoor LC, with external load masses ranging from 25 to 70 kg. The stages were completed at a patrol, forced, and insertion marching speed (2.5, 4.8, and 5.5 km·h-1, respectively). During the final 2-4 minutes of each LC stage, oxygen uptake (V[Combining Dot Above]O ) was measured using the Douglas bag technique. Predicted V[Combining Dot Above]O2 for each speed-load mass combination was calculated using the Pandolf equation and compared to the measured V[Combining Dot Above]O2 using paired t-tests and 95 % Limits of Agreement (LoA). RESULTS: The Pandolf equation systematically under-predicted the metabolic cost of LC for all speeds and load masses combined [mean difference 3.2 ± 2.9 ml·kg-1·min-1 2 p<0.001), 95% LoA -2.5-8.9 ml·kg-1·min-1] resulting in a V predictive error of 17.5 %. Mean difference and 95% LoA at the different speeds were: (a) 2.5 km·h-1 [4.8 ± 1.9 ml·kg-1·min-1, (p<0.001), 95% LoA 1.0-8.6 ml·kg-1·min-1], (b) 4.8 km·h-1 [1.5 ± 2.7 ml·kg-1·min-1 (p<0.001), 95% LoA -3.9-6.9 ml·kg-1·min-1], and (c) 5.5 km·h-1 [4.2 ± 3.3 ml·kg-1·min-1 (p<0.001), 95% LoA -2.1-10.7 ml·kg-1·min-1], with prediction errors of 30 %, 6 % and 14 %, respectively. CONCLUSIONS: The current study demonstrates a systematic under-prediction of V[Combining Dot Above]O2 for British Army personnel during outdoor LC when applying the Pandolf equation, supporting the findings of previous laboratory studies. Furthermore, the error appears to be of greater magnitude when LC speeds are lower, i.e. at a representative patrolling pace. This in part could be attributed to the load mass distribution of the modern solider, which differs from the back mounted load carried data used to develop and refine the Pandolf equation.

PURPOSE: The National Ambulance Resilience Unit (NARU) works on behalf of each National Health Service (NHS) Ambulance Trust in England to strengthen national resilience and improve patient outcome in challenging pre-hospital scenarios. NARU personnel are trained to deal with hazardous or difficult situations and mass casualty incidents. The aim of this study was to quantify the physically demanding tasks undertaken by NARU personnel. METHODS: The study was completed in two phases. In Phase 1, 10 subject matter experts from a range of NHS Ambulance Trusts participated in a two-day researcher led workshop to define the most physically demanding tasks performed by NARU personnel. In Phase 2, 34 participants (29 men and 5 women, stature 1.77 ± 0.08 m, body mass 84 ± 14 kg, estimated VO2max 39 ± 7 mL·kg-1·min-1) performed scenarios of the tasks defined in Phase 1, with measurements of heart rate, speed of movement, load carried, and weights and forces of objects moved. Data are expressed as mean ± standard deviation. RESULTS: Eleven criterion tasks were defined in Phase 1: Swift Water Rescue, Re-board Boat, Unload Vehicle and Set-up Decontamination Unit, Clinical Decontamination (CD), Movement in Gas Tight Suits, Marauding Terrorist Firearms Attack (MTFA) , Over Ground Rescue, Unload Incidence Response Unit Vehicle, Above Ground Rescue, Over Rubble Rescue, and Subterranean Rescue. The shortest tasks were the Swift Water Rescue and Re-board Boat at ~1 min, with resultant heart rates of 76 ± 10 and 61 ± 14 %HRmax, respectively. The longest tasks were the CD and MTFA (~120 min) resulting in heart rates of 65 ± 11 and 73 ± 11 %HRmax, respectively. The greatest forces exerted were during equipment lifting and carrying (e.g. 167 kg by 6 people) and dragging of casualties (e.g. single person 88 kg casualty and stretcher drag). CONCLUSION: All five components of fitness (aerobic endurance, anaerobic endurance, muscular strength, muscular endurance and mobility) are required to successfully perform the criterion tasks undertaken by NARU personnel. These data can be used to inform interventions to enhance physical performance and develop physical employment standards for specialist ambulance responders. ACKNOWLEDGEMENT - This work was conducted in collaboration with the National Ambulance Resilience Unit in the United Kingdom.

The National Ambulance Resilience Unit (NARU) works on behalf of each National Health Service Ambulance Trust in England to strengthen national resilience and improve patient outcome in challenging pre-hospital scenarios. Specialist ambulance responders are trained to deal with hazardous or difficult situations, particularly incidents such as situations involving firearms and mass casualties. PURPOSE: To measure the physiological strain of paramedics during a scenario to treat multiple casualties in a simulated firearms incident. METHODS: Six participants (5 male / 1 female; age 27 ± 3 y; body mass 80.4 ± 11.8 kg; VO2max 46.5 ± 1.6 ml·kg·min-1) wearing ballistic personal protective equipment (19.1 ± 1.0 kg) undertook a 120 min scenario, which included a 400 m approach walk, casualty drags, sprints, and stretcher drags. Participants’ urine osmolality was measured before the scenario. Sweat losses during the scenario were estimated by changes in body mass with ad libitum fluid intake measured. Participants wore a heart rate monitor, rectal thermistor and skin thermistors (neck, hand, scapular and shin). The day before the simulation participants completed an incremental shuttle run test to measure predicted VO2max and maximum heart rate (HRmax). Data are presented as the mean ± SD; and analysed with paired sample t-tests with significance set at P<0.05. RESULTS: Urine osmolality at the start of the simulation was 450 ± 160 mOsm.kg-1. Total estimated net sweat losses during the scenario were 2.23 ± 0.34 L which was not different to fluid intake of 2.43 ± 0.42 L (P>0.05). Mean heart rate during the scenario was 73 ± 11 %HRmax. During the simulation both rectal (start to end: 37.54 ± 0.29 to 38.34 ± 0.51 °C, P=0.24) and mean skin temperatures (32.04 ± 1.08 to 30.85 ± 0.68 °C, P=0.78) did not change significantly. The range of peak rectal temperatures was 37.10-39.15 °C. CONCLUSION: Participants started the scenario in a hydrated state and sweat losses were matched by fluid intake. Although cardiovascular strain during the simulation was ‘moderate’ to ‘hard’, body temperature did not rise significantly and all participants successfully completed the two-hour scenario. These data can be used to inform interventions to enhance physical performance and develop physical employment standards for specialist ambulance responders.

The National Ambulance Resilience Unit (NARU) works on behalf of each National Health Service Ambulance Trust in England to strengthen national resilience and improve patient outcome in challenging pre-hospital scenarios. Specialist ambulance responders (HART) are trained to deal with mass casualty incidents, during which they may need to wear Breathing Apparatus (BA) inside fully encapsulated Gas Tight Suits (GTS) to treat casualties in a hazardous area. PURPOSE: To measure the physiological strain of paramedics during a simulated task to treat casualties exposed to hazardous materials. METHODS: Six participants (5 male / 1 female; age 39 ± 8 y; body mass 80.1 ± 7.9 kg; VO2max 38.05 ± 4.31 ml·kg·min-1) wearing BA and GTS (36.7 ± 1.3 kg) undertook a 30 min simulated task, which included walking 200 m to an incident, moving casualties and administering CPR for approximately 14 min. Participants’ urine osmolality was measured before the task. Sweat losses during the task were estimated by changes in body mass, with participants unable to drink due to the BA. Participants wore a heart rate monitor, rectal thermistor, and skin thermistors (neck, hand, scapular and shin). The day before the simulation, participants completed an incremental shuttle run test to measure VO2max and maximum heart rate (HRmax). Data are presented as the mean ± SD; differences were compared using paired sample t-tests with significance set at p<0.05. RESULTS: Mean urine osmolality at the start of the task was 380 ± 150 mOsm.kg-1. Total estimated sweat losses during the simulation were 0.47 ± 0.39 L. Mean heart rate during the simulation was 75 ± 15 %HRmax. During the simulation both rectal (start and end; 37.45 ± 0.03 to 38.13 ± 0.19 °C, p<0.05) and mean skin temperature (31.57 ± 0.02 to 34.04 ± 0.06 °C, p<0.05) increased. The range of peak rectal temperatures were 37.8 - 38.3 °C. CONCLUSION: Participants started the simulated task in a hydrated state and sweat losses were unable to be matched by fluid intake. Although cardiovascular strain during the task was ‘moderate’ to ‘very hard’ and body temperature increased, all participants successfully completed the 30 min simulation. These data can be used to inform interventions to enhance physical performance and to develop physical competency assessments for specialist ambulance responders.

The first stage to develop role-related, gender-free Physical Employment Standards (PES) is to identify and describe the physically demanding tasks undertaken in a role. PURPOSE: To identify the essential physically demanding tasks undertaken by Royal Marines (RM). METHODS: 158 male RM volunteered and data were collected in two parts. Part 1: A facilitated two-day focus group where subject matter experts (SMEs; from ranks of Private to Major) generated a list of essential physically demanding tasks undertaken in the RM role. Part 2: 149 participants (5 % of each rank in the incumbent RM force) were presented the SME tasks list and identified if they had completed the task, the task importance (1-6 scale, not applicable – critical) and physical demands (1-6 scale, very light – maximum). RESULTS: The focus group participants identified 23 tasks and the task completion rate, importance and physical demands were rated in the survey (Table 1).Table 1: RM tasks with survey data [data presented as mode (range)]CONCLUSION: The essential physically demanding tasks identified in this study can be used to select those most critical to the RM role, and underpin the development of future relevant role-related PES.

Introduction: A job task analysis (JTA) involves collecting objective and subjective data to quantify the physical demands of criterion tasks, a fundamental step in developing physical employment standards (PES). Load carriage (LC) is defined as walking or running with an external load; the physical demands of which are dependent on load, speed, terrain and duration. The aim of this study was to conduct a JTA to quantify the physical demands of LC tasks performed by the 10 Ground Close Combat (GCC) roles in the UK Armed Forces.

Introduction: Conducting a job task analysis (JTA) is fundamental to determine the specific tasks that employees are required to perform in their job role. Casualty Evacuation (CASEVAC) tasks by stretcher are a criterion military task and require muscle endurance, muscle strength, and aerobic endurance for successful performance; the aim of this study was to conduct a JTA for CASEVAC by stretcher tasks performed by personnel serving in Ground Close Combat (GCC) roles in the UK Armed Forces.

Purpose: A job task analysis (JTA) involves collecting subjective and objective data to quantify the physical demands of criterion tasks performed in a job role and is fundamental in developing physical employment standards (PES). The aim of this study was to conduct a JTA to quantify the requirements and physical demands of digging activity for personnel serving in Ground Close Combat (GCC) roles in the UK Armed Forces.

Purpose: Conducting boarding operations (boarding a vessel from either a small craft or from a helicopter) was identified as an important, physically demanding and unique role related task undertaken by Royal Marines (RM). Data are required to quantify the physical demands of boarding operations to inform the development of a Physical Employment Standard (PES) for Ground Close Combat (GCC) roles in the UK Armed Forces.

Purpose: A job task analysis (JTA) involves collecting subjective and objective data to quantify the physical demands of criterion tasks, a fundamental step in developing physical employment standards (PES). Casualty drags are a criterion task completed within Ground Close Combat (GCC) roles in the UK Armed Forces. The task involves dragging an injured solider wearing body armour, webbing and a weapon to a place of relative safety. However, data describing the typical parameters of a casualty drags are scarce. The aim of this study was to conduct a JTA to define the task parameters of casualty drags performed by personnel serving in GCC roles.

Purpose: Conducting a job task analysis (JTA) is fundamental to determine the specific work tasks that employees are required to perform in their job role and informing the development of job related Physical Employment Standards (PES). Movement from a parachute drop zone (DZ) to a Company rendezvous (RV) and a patrol were identified as physically demanding, criterion tasks for parachute trained forces in the British Army. The aim of this study was to conduct a JTA for parachute trained personnel serving in a British Army Parachute Regiment.

The National Ambulance Resilience Unit (NARU) works on behalf of each National Health Service Ambulance Trust in England to strengthen national resilience and improve patient outcome in challenging pre-hospital scenarios. Specialist ambulance responders are trained to wear Powered Respirator Protective Suits (PRPS) to move, treat and decontaminate casualties exposed to hazardous materials. PURPOSE: To measure the physiological strain of paramedics during a scenario to move and decontaminate multiple casualties exposed to hazardous materials. METHODS: Eight participants (7 male / 1 female; age 38 ± 10 y; body mass 90.4 ± 16.2 kg; VO2max 34.5 ± 5.6 ml·kg·min-1) undertook a 193 min scenario involving erecting a decontamination tent, then donning PRPS (11.9 ± 0.4 kg) to work for ~120 min to move and decontaminate multiple casualties. Urine osmolality was measured before the scenario. Sweat losses during the scenario were estimated from changes in body mass, with ad libitum fluid intake recorded. Participants wore a heart rate monitor, rectal thermistor, skin thermistors (neck, hand, scapular and shin). The day before the scenario participants completed an incremental shuttle run test to measure VO2max and maximum heart rate (HRmax). Data are presented as the mean ± SD; differences were compared using paired sample t-tests with significance set at p<0.05. RESULTS: Urine osmolality at the start of the scenario was 350 ± 170 mOsm.kg-1. Estimated sweat losses during the scenario were 1.40 ± 0.36 L which were less than fluid intake 2.54 ± 0.96 L (p<0.05). Mean heart rate during the scenario was 64 ± 11 %HRmax. During the scenario rectal temperature increased (start to end: 37.51 ± 0.32 to 37.88 ± 0.19 °C, p<0.05) and mean skin temperature was unchanged (31.16 ± 0.10 to 31.67 ± 1.23 °C, p>0.05). The range of peak rectal temperatures was 37.95-38.60 °C. CONCLUSIONS: Participants started the scenario in a hydrated state and sweat losses were lower than fluid intake. Cardiovascular strain during the scenario was ‘moderate’ and body temperature increased slightly. One participant was withdrawn during the scenario by the investigators due to becoming excessively fatigued. These data can be used to inform interventions to enhance physical performance and develop physical employment standards for specialist ambulance responders.

This study assessed soldier's physical demands and energy balance during the Section Commanders' Battles Course (SCBC). Forty male soldiers were monitored during the 8-week tactics phase of the SCBC. Energy expenditure was measured using the doubly labeled water method. Cardiovascular strain (heart rate) and physical activity (using triaxial accelerometer) were also monitored. Average sized portions of meals were weighed, with all recipes and meals entered into a dietary analysis program to calculate the calorie content. Energy expenditure averaged 19.6 ± 1.8 MJ · d(-1) in weeks 2 to 3 and 21.3 ± 2.0 MJ · d(-1) in weeks 6 to 7. Soldiers lost 5.1 ± 2.6 kg body mass and body fat percent decreased from 23 ± 4% to 19 ± 5%. This average weight loss equates to an estimated energy deficit of 2.69 MJ · d(-1). The Army provided an estimated 14.0 ± 2.2 MJ · d(-1) in weeks 2 to 3 and 15.7 ± 2.2 MJ · d(-1) in weeks 6 to 7. Although this provision adheres to the minimum requirement of 13.8 MJ · d(-1) set by Army regulations, soldiers were in a theoretical 5.6 MJ · d(-1) energy deficit. The physical demands of SCBC were high, and soldiers were in energy deficit resulting in loss in body mass; primarily attributed to a loss in fat mass.