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Applied Ergonomics 110 (2023) 104001
Available online 11 March 2023
0003-6870/© 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license ( comparison of physical performance during one- and two-person
simulated casualty drags
C.A.J. Vine *, C. Rue, F. Walker, S.D. Blacker, S.D. Myers, J. Doherty
Occupational Performance Research Group, Institute of Sport, Nursing and Allied Health, University of Chichester, College Lane, Chichester, West Sussex, PO19 6PE, UK
Physically demanding
Physical employment standards
The ability to drag a casualty to safety is critical for numerous physically demanding occupations. This study
aimed to establish whether the pulling forces during a one-person 55 kg simulated casualty drag is representative
of a two-person 110 kg drag. Twenty men completed up to 12 × 20m simulated casualty drags using a drag bag
(55/110 kg) on a grassed sports pitch, with completion times and forces exerted measured. Completion time for
the one-person 55 and 110 kg drags were 9.56 ± 1.18s and 27.08 ± 7.71s. Completion time for the 110 kg two-
person drags for forwards and backwards iterations were 8.36 ± 1.23s and 11.04 ± 1.11s. The average indi-
vidual force exerted during the one-person 55 kg drag was equivalent to the average individual contribution
during the two-person 110 kg drag (t(16) = 3.3780, p < 0.001); suggesting a one-person 55 kg simulated casualty
drag is representative of the individual contribution to a two-person 110 kg simulated casualty drag. Individual
contributions can however vary during two-person simulated casualty drags.
1. Introduction
The ability to drag a casualty to a place of safety is a role critical task
for personnel in physically demanding occupations, such as the military
and emergency services (Hauschild et al., 2017; Lockie et al., 2019,
2020). Ensuring individuals have the physical competencies to complete
such a role-specific criterion task (defined as the most critical, frequently
completed, and physically demanding tasks for a given job-role), is not
only essential in achieving mission objectives, but also minimises undue
risk to individuals and teams (Silk and Billing, 2013). As such, physical
employment standards (PES), are frequently implemented to ensure
personnel can meet the minimum acceptable standard for a given cri-
terion task. Consequently, PES are essential for the recruitment,
training, and maintenance of role-related fitness within physically
demanding occupations (Blacker et al., 2016). An important step in
developing bona fide PES, is the comprehensive profiling of criterion
task demands (Silk and Billing, 2013). This sequentially allows for the
development, and administration of physical performance assessments
as either role related task simulations (i.e., representative tasks) or
gym-based fitness tests (i.e., predictor tests) (Reilly and Olinek, 2013).
Within the UK Armed Forces, personnel have rated casualty drag
tasks as ‘critical to their job role, with the physical demands being ‘very
hard (Flood et al., 2017). As such, a 20 m simulated casualty drag using
a 110 kg custom made bag, in 35 s was introduced as part of the new PES
for frontline roles only within the British Army (British Army, 2020). It is
important to understand that this protocol provides a standardised
approach to objectively assess casualty drag performance, given the
variability in distance, terrain and casualty mass experienced during
military training and operations. For example, in any given population
the mass of a casualty is dependent upon the dress ensemble worn (e.g.,
external load such as a backpack or breathing apparatus would add
additional mass).
Despite the importance of casualty drag tasks, a paucity of infor-
mation exists pertaining to casualty drag performance; with studies
largely focusing on the relationship between simulated casualty drags
performance and strength (Lockie et al., 2019) or anthropometric
measures (Lockie et al., 2020; Redmond et al., 2020). However, no data
are available on the comparison between one- and two-person casualty
drags, which is critical given that casualty drag tasks can be performed
alone or in pairs. The importance of this information is further high-
lighted by a key premise of PES being the ability to objectively assess an
individuals performance in a task that may be conducted as part of a
team. For example, non-frontline roles within the British Army would
‘typically conduct casualty drags in pairs, thus a representative PES,
that tests an individuals contribution to completing a two-person drag,
is required. Whilst a theoretical model (Fig. 1) may be utilised to
* Corresponding author. Institute of Sport, Nursing and Allied Health, University of Chichester, Chichester, PO19 6PE, England, UK.
E-mail address: (C.A.J. Vine).
Contents lists available at ScienceDirect
Applied Ergonomics
journal homepage:
Received 20 October 2022; Received in revised form 8 February 2023; Accepted 23 February 2023
Applied Ergonomics 110 (2023) 104001
2calculate the independent force requirements of a two-person drag,
external factors such as environmental conditions, dragging techniques,
specialist clothing/equipment worn and extraneous variables (e.g.,
motivation) will likely influence task completion, and thus necessitate
the need for ‘real-world trials. Therefore, the principal aims of the study
were to: 1) quantify and summarise the pulling forces exerted, during a
one- and two-person simulated casualty drags in physically active
civilian men; and 2) establish whether a one-person 55 kg simulated
casualty drag is representative of a two-person 110 kg simulated casu-
alty drag.
2. Methods
2.1. Participants
Twenty recreationally active men (mean ± SD: age: 27 ± 9 years;
stature: 1.80 ± 0.05 m; body mass: 87.0 ± 13.7 kg) volunteered to
participate in this study. Participants were of similar age, stature and
body mass to those previously reported for UK Military Soldiers
(Coakley et al., 2019; Vine et al., 2022). The 110 kg individual simulated
casualty drag performance was chosen to replicate the current British
Army PES requirements (British Army, 2020). The study was conducted
in accordance with the Declaration of Helsinki, with ethical approval
obtained from the Institutions Research Ethics Committee. Participants
received a comprehensive written and verbal explanation of the pro-
cedures, before providing informed written consent. To minimise
musculoskeletal injury risk, ethical approval required participants to
have a body mass greater than 60 kg.
2.2. Experimental design
Participants attended a single experimental session, wearing sports
clothing and trainers. In preparation for the session, participants were
required to abstain from strenuous exercise and alcohol 24 h prior, and
caffeine 2 h prior. Upon arrival, participants stature (213 stadiometer,
Seca Ltd, UK), and body mass (837 digital scales, Seca Ltd, UK) was
recorded to the nearest 0.01 m and 0.1 kg, respectively.
For the purposes of this study a one-person simulated casualty drag
refers to an individual participant dragging a single drag bag and a two-
person simulated casualty drag refers to two participants working
together to drag a single drag bag. During the one-person simulated
casualty drag, participants held the looped handles of the drag bag in
each hand, with their back facing the direction of travel (i.e., backwards
facing). For the two-person simulated casualty drags, participants held
one of the drag handles and faced the direction stipulated by the
experimenter for the given trial (either forwards facing; FWD [direction
of travel] or backwards facing; BWD [towards the drag bag]). All drags
were completed using an in-service British Army drag bag (61100-4
casualty drag bag, Indigo Fitness, Nuneaton, UK) with an s-beam load
cell (RS 250 kg, Tedea Huntleigh, Cardiff, UK) positioned in line with
each drag bag handle (Fig. 1) to measure force data. Data were recorded
at 1000 Hz, connected to a mobile data logger (DataLOG MWX8, Bio-
metrics Ltd, Newport, UK). For all trials, completion time was recorded
to the nearest 0.01 s using a stopwatch.
2.2.1. Experimental session
Initially, participants completed a ~5 min self-selected warm-up
followed by a self-selected number of familiarisation 55 kg drags (that
were not included within subsequent analysis). These drags afforded
participants an opportunity to practice technique and ensure they were
adequately warmed up prior to the main trials. Previously, research by
Foulis et al. (2017) has demonstrated no improvement in simulated
casualty drag performance across trials so no further familiarisation was
incorporated into the study design.
After the warm-up, participants completed up to 12 × 20 m simu-
lated casualty drags to an individual best effort, in the following order: 3
x one-person 55 kg; 1 x one-person 110 kg; 8 x two-person 110 kg drags
(4 x FWD, 4 x BWD). The three, one-person 55 kg drags were selected
given the anecdotal higher variability associated with the lower mass,
whilst the one-person 110 kg drag was collected as these data have not
previously been reported. All drags were separated by a minimum of 3
min rest and conducted using a drag bag on a grassed sports pitch. Trials
were performed on a dry, short-cut, grassed area where a 20 m drag lane
was measured out. The lane was visually inspected periodically to
ensure conditions remained consistent for all trials. In the event of the
condition of the lane deteriorating, an adjacent new drag lane was used.
Participants completed their trials within a sub-group of five partici-
pants and therefore completed each two-person drag iteration (FWD and
BWD) with each member of the sub-group. Drag pairings and iteration
order were randomly assigned.
Prior to the start of each drag, the front of the drag bag was posi-
tioned on the start line of the lane and load cells were zeroed whilst lying
on the ground. Once completed the participant(s) were instructed to
pick up and hold the handle(s) in the required manner for the given trial
condition. On the experimenters command ready, participants were
required to remove the slack from the drag bag webbing straps and
maintain a constant, but minimal force on the handles. After approxi-
mately 3 s, the command go was given, and participants were required
to complete the 20 m course as quickly as possible (Fig. 2). The
completion time was taken when the whole drag bag crossed the finish
line. To further minimise musculoskeletal injury risk to participants,
trials were stopped if the drag time exceeded 60 s.
2.3. Data analysis
Data recordings were subsequently downloaded and analysed using a
Fig. 1. Theoretical model for calculating drag performance.
Fig. 2. S-beam load cell and drag bag handle set-up during a 110 kg drag.
C.A.J. Vine et al.