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Sideline and Event Management: Section Articles

On-Site Management of Medical Encounters During Obstacle Adventure Course Participation

Lund, Adam Bsc, MEd, MD; Turris, Sheila A. PhD; McDonald, Riley BKin; Lewis, Kerrie LPN

Author Information
Current Sports Medicine Reports: May/June 2015 - Volume 14 - Issue 3 - p 182-190
doi: 10.1249/JSR.0000000000000161
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Introduction and Background

Obstacle adventure courses (OAC) have become a popular trend in recreational, athlete-oriented, mass participation events (21,29). OAC includes a variety of military style obstacles interspersed with lengths of trail running or other cardiovascular activities, often on rough and muddy terrain. An estimated 1.5 million people registered for this type of event in 2014 (16,32). Although several categories of OAC exist within the world of extreme sport these events are not currently well defined or described.

Event types include the following:

  • Adventure races (e.g., Canadian Death Race and Tough Bloke Challenge)
    •  ○ Endurance events that range from several hours to several days and require participants to take part in several different disciplines of wilderness activities including (but not limited to) kayaking, biking, orienteering, and technical climbing (39).
  • Obstacle courses (e.g., Concrete Hero, Electroshock Therapy, Tough Mudder™ (TM), and Foam Fest)
    •  ○ A running track designed with sections requiring any of the following: jumping, running, climbing, swimming, and balancing; all of these sections are combined for the purpose of testing and training participants (29).
  • Obstacle course races (e.g., The Beast, Civilian Military Combine, Down and Dirty, Extreme Rampage, Rugged Maniac, and Spartan Race)
    • ○ A competitive mass participation event where participants race through an obstacle course for the best finishing time (20).
  • Mud runs (e.g., Mudderella, Hard Charge, Kiss Me Dirty, Mayhem in the Mud, Mud Hero, Mud Stash, Mud, Sweat, and Tears, and Muddy Buddy)
    • ○ A competitive or non-competitive foot race consisting of large sections of mud without elevated or constructed obstacles (7).
  • OAC
    •  ○ An inclusive term this article will use to cover competitive and non-competitive obstacle course events.

In the most general terms, OAC events are athletic events in which participants (either as individuals or in teams) undertake a series of obstacles involving activities such as jumping, climbing, swinging, crawling, and swimming. OAC involves rugged terrain covering several kilometers (distances are variable) under adverse conditions (e.g., running through wires that give electrical shocks and water being sprayed through a hose while participants try to cross a body of cold water without falling). These events can be run “for fun” or competitively as a timed race.


Following media reports of a death at an OAC in 2013 when a male participant drowned on an obstacle known as “Walk the Plank” (28), concerns have been raised about a number of issues related to athlete safety (2,19,21,32,37). For example, the climate, the terrain, and the unique features of the obstacles may put participants at risk for a variety of illnesses and injuries including hypothermia, heat-related illness, electric shock, cardiac events, and near drowning. Infectious disease also has been identified as an issue for mud-based OAC (31,37,44), as was the case when norovirus was reported by more than 200 participants and spectators following an OAC in 2013. Finally, OAC may put strain on local health care infrastructure (2) as was the case when a hospital was forced to turn away patients from an OAC due to the volume of participants who sustained injuries after competing. However, scant academic literature documents morbidity and mortality associated with this category of events (16,39).

Athletes present to local emergency departments (ED) with traumatic injuries and illnesses. Sports medicine and emergency physicians working on-event or in local ED will benefit from the knowledge regarding expected illness and injury patterns. Teams planning on-event first aid and emergency response coverage will benefit from the knowledge of how other teams have provided on-site health services at similar events.

The current manuscript presents an analysis of a case series of two events, over 2 years each, that took place in North America between 2011 and 2013, and describes the event details, emergency response deployment considerations, transportation considerations, and injury- and illness-related presentations arising from this unique type of mass participation event.

Approach to Case Reporting

We examined deidentified patient data, contained within the Mass Gathering Medicine (MGM) Event and Patient Registry, hereafter referred to as “the Registry” (26). All patient presentations from two OAC events were reviewed, including the following: 1) Warrior Dash© (WD) (2011 and 2012) and 2) TM (2012 and 2013). Ethics approval for the Registry was obtained from the University of British Columbia’s Behavioral Research Ethics Board.

Event data are collected through the Registry to capture descriptive details of the event, the weather, risk factors, details of the medical team, equipment and capacity, as well as overall attendance numbers. A research coordinator (K. L.) collected and entered all event data into the Registry.

The Registry is a secure web-based database developed for the specific purpose of collecting data that are pertinent to the study of mass gathering and mass participation events (23). Research assistants and trained data entry volunteers prospectively entered all patient data into the Registry. Data were prospectively collected over 3 years. Patient data were extracted from Patient Encounter Forms and Minor Treatment Logs used by on-site medical teams (27).

Patient presentation rates (PPR) per 1,000 participants were calculated, as were the ambulance transfer rates (ATR) and the percentage of patients seen transported by the ambulance (PPTA). Data with regard to case mix were collected (i.e., presenting concern).

Event Injuries and Unique Challenges

The course

—The WD involves 12 obstacles and covers a distance of 3 to 4 miles (41). Participants have an average finishing time of between 50 and 75 min. In contrast, the TM is an OAC of 10 to 12 miles (average finishing time of ∼3 h and 15 min) that can include up to 25 individual obstacles, each designed by the British Special Forces (38). Each obstacle presented particular challenges with regard to risk, potential injuries, and participant rescue in the event of injury (Table 1).

Table 1
Table 1:
Obstacle breakdown and risk features

Each event took place in the summer season in a Western Canadian province (Table 2) (15). All events were held in ski resorts at the base of mountains, permitting the slope of the landscape to be an intrinsic added element.

Table 2
Table 2:
Injury, transport, and event data

On-site medical deployment

—Two groups of medical providers were involved in on-site care for injured participants at each event. A locally contracted medical services company using a mix of paid and volunteer providers (9,11,33) did the primary planning and on-site care, and the Special Operations branch of the provincial ambulance service liaised with the company to coordinate on-site responses for course extraction of supine patients and transport to the local ED (9). First aiders were the majority of the staff and were deployed in teams of two people, one team for each obstacle.

Higher level of care (HLC) staff credentialed as paramedics, physiotherapists, nurses, and physicians were assigned to roving response vehicles and/or the main medical tent located near the finish line. For all four events, health care providers on the medical teams were capable of advanced life support and resuscitation. Coverage was similar across all events. Of note, the equipment to suture wounds on-site was only available for TM 2013.

One unique feature of some OAC events is the operational challenge associated with water obstacles, particularly those involving water deep enough to require swimming. In addition to the standard obstacle medical teams (i.e., two people with first-aid training), the water obstacle teams included lifeguards and two scuba divers, with at least one prepared to be deployed immediately (i.e., dry suit, tank, and fins on) at all times.

Panic for inexperienced swimmers, injuries related to overcrowded obstacle conditions, leg cramps due to the water temperature, and dislocated shoulders from high jumps into deep water were some of the challenges for participants. Lifeguards at deep-water obstacles monitored facial expressions and lack of forward progress, intervening (depending on the level of distress present) by talking the participant to safety, throwing a rope-connected soft buoyant aid for use by the participant, and/or performing an in-water rescue with tow assist or carry.

Intervention by lifeguards was common. For example, for TM 2013 for Walk the Plank (a 12-ft jump into a deep, muddy water pit and then a swim to the other side), there were more than 80 talk rescues, as well as 115 throw rescues and 35 in-water rescues (personal communication, Michael Miller, LIT Aquatics, June 23rd, 2013).

Lifeguards identified many concerns related to visibility (i.e., too many people in the water at one time, mud in the water reducing visibility) and fatigue. With regard to fatigue, lifeguards reported that toward the end of the day, they were pulling people out more quickly when in trouble as the staff were getting fatigued and worried that they might fail to spot a participant in trouble.

A second unique feature of OAC is the operational challenge presented by backcountry, off-road scene extraction (Figure 1). Because the distances between the obstacles and main medical were long and the terrain was too rough for traditional street vehicles, all-terrain vehicles, a jeep, gators used as small-scale ambulances, and utility task vehicles were indispensible links for both medical team and equipment deployment and patient extrication and transport. Transportation of patients unable to weight bear, those requiring supine transport, and those who may require active resuscitation during extraction from the backcountry trails required specific preplanning.

Figure 1
Figure 1:
Terrain challenges.

Patient presentations

—The PPR for both the WD and the TM were similar (Table 2). Note that participant numbers are not equal between day 1 and day 2 of the TM events, with ∼85% of the participants completing the course on day 1 and the balance on day 2, a lighter, shorter day. However, the course size and number of obstacles remain constant, so the medical coverage plan could not be significantly downsized on the second day.

The absolute number of ambulance transfers was low (range, 0 to 5 per day), primarily for patients with complex lacerations or musculoskeletal (MSK) injuries with inability to weight bear. A total of 49 people were referred to local ED (mostly by private vehicles of family or friends) for assessment, imaging, and/or other diagnostics. Of note, the highest number of referrals occurred for the 2012 TM on the first day. That number dropped the following year as the medical team had the ability to suture on-site, obviating the need for some ED referrals.

Acute patient presentations were rare (Table 3). MSK injuries were the most common presentation with injuries to lower limbs predominant. At TM in 2012 and 2013, there were seven and eight shoulder dislocations, respectively. All but one of the dislocations in 2012 were reduced on the scene by a physician, and ambulance transport was avoided. No shoulder dislocations were reported at the WD for either year. Of note, there were individuals with significant injuries (e.g., shoulder dislocation) who declined referral and/or transport for imaging and chose instead to return to the event and attempt to complete the course.

Table 3
Table 3:
Cases referred for immediate follow-up in the ED


Obstacle courses have been used to train and assess the physical fitness of military recruits for many years (12,40). The expansion of OAC events to the general public presents an opportunity to better understand the hazards and predictable risks associated. OAC draws inspiration from strenuous military training programs, and accordingly, there is a level of risk associated with participating in these events (13,44).

With the exception of popular media reports detailing deaths and serious injuries, little information exists on the mortality and morbidity associated with OAC participation. Media reports with regard to injuries and fatalities resulting from OAC participation provide scant detail; however, within the United States, there have been deaths, incidents of paralysis, and numerous reports of heat-related complications, dating back to 2011 (3,5,6,14,17,18,28,30,34,36,42). In the present case series, there were no reported deaths or life-threatening patient presentations.

Townes (39) identified several major challenges in providing care during adventure races, including 1) liability, licensing and insurance issues for medical teams; 2) communication between members of the team over terrain with spotty or no cellular reception; 3) the logistics of moving supplies and people along a race course; and 4) the possibility of athlete and medical professional disagreement about decisions to return to the race after injury. All of these factors were issues during the events described above. For both the WD and TM, experienced medical directors were contracted and so each of these challenges was addressed in advance of the event rollout.

Prediction of the medical need, provision of an appropriate level of baseline medical care, and emergency management planning are top priorities during mass gathering and mass participation events. This is particularly important in the context of OAC. First, there is a potential for high acuity injuries and MSK injuries. Second, there are logistical challenges associated with providing services for large geographic areas with challenging terrain and obstacles.

As many of these events are hosted in rural locations, the nearest medical facility may be more than an hour away, requiring medical services to span the continuum between event medicine and wilderness event medicine (9). Appropriate on-site services may decrease the ripple effect (e.g., the indirect disruptive impact of events such as increases in traffic congestion and accidents as tired attendees drive home, an increase in ED visits, etc.) and the vortex effect of consuming baseline ambulances and ED services in the host community (24).

In the academic literature, three studies provide some additional insights for researchers and clinicians. Greenberg et al. (2013) (3) documented patient encounters (n = 38) in the local ED during a 2-d TM OAC. They reported a hospital transfer rate of 1.72/1,000 participants (16). In a similar study, Luke (22) reported a much lower hospital transfer rate of 0.13/1,000. Both events were TM with approximately 22,000 participants. Luke attributed the lower transfer rate to the presence of an HLC on-site medical team. Finally, Agar et al. (1) reported casualty rates for Tough Guy, a UK OAC. They described an illness/injury rate of 1% to 2% of the total number of participants.

We note that in the article of Greenberg et al., because the focus was on ED visits, no information was provided regarding the level of care available on-site. This may have affected hospital transport rates as we note that their study has a transfer rate five times the rate reported in the present case series. Since arrival modality was not reported in Greenburg’s article, the numbers are not directly compatible, as they represent ED utilization rates, not necessarily ambulance transport rates.

Given the increasing popularity of OAC, this body of literature will grow over time, providing important information about the demographics of participants, as well as the incidence of serious illnesses and injuries. As Greenberg et al. (16) argued, further study is required to establish clear, accurate injury patterns related to OAC.

Recommendations for medical directors

In order to grow the science of event medicine, it will be important to prospectively collect data from both the on-site medical team and acute care in order to accurately describe the on-site PPR, the ambulance transport rate, the rate of transport by non-ambulance vehicles, and the overall ED utilization rate based on any arrival modality. This comprehensive approach would more completely explain the impact that special events such as OAC have on host community health services.

Based on the data reported in this manuscript and the existing literature, we make the following recommendations for emergency clinicians involved in providing care for those participating in OAC events:

  1. Integrate an on-site medical team capable of treating common MSK injuries including joint reductions, heat/cold-related conditions, drowning and near drowning, as well as cardiac arrest/syncopal presentations (35).
  2. Provide due consideration for “on-event transport,” deploying responders first to injured patients on trails and remote obstacles and extracting them to a main medical area. This may require off-road vehicles suitable for transferring patients with MSK injuries and supine patients in full c-spine precautions.
  3. Ensure that a hazard/risk analysis is undertaken and consider the need for specialized equipment and personnel, such as professional lifeguards, steep angle and rope-rescue specialists, and search and rescue.
  4. Coordinate between the on-site medical team and the local health infrastructure (e.g., local ED and ambulance services) (8).
  5. Do a formal audit postevent to support planning for subsequent years. Publish the results of the audit so that minimum standards can be created to promote safer OAC events.


As is sometimes reported in the mass gathering literature (4,25,43), during peak times, some charts were incomplete. Rare, life-threatening events are unlikely to be captured given the sample size for this case series (n = 4 events).


The unique hazards and risks associated with OAC participation influence staffing for on-site medical teams, shape deployment patterns, dictate rescue equipment requirements, and impact hospital transfer rates when diagnostic imaging and definitive treatment are required. At this time health care professionals are almost entirely dependent on media reports for information about illness and injury patterns arising from participation in OAC. Rigorous documentation and dissemination of on-site and postevent health impacts are required. Without this knowledge, emergency and sports medicine physicians and other lead clinicians will have minimal evidence upon which to make recommendations regarding policies and standards for similar events.


The authors acknowledge the clinicians who provided care for athletes and those who collected data for this study including Jordan Myers, Alain Denis, Canadian Emergency Medical Services (previously, Vancouver Ambulance Service), Rockdoc Consulting, Inc., and British Columbia Emergency Health Services: Special Operations. Also, we thank Michael Miller of LIT Aquatics and Jessica McCallum for their specific input on the water hazards.


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