Tactical athletes are individuals performing in service occupations that have significant physical fitness and performance requirements with the potential for exposure to life-threatening situations every day. The term is most commonly used to reference military service members, law enforcement, firefighters, and emergency responders (1). The physical requirements of these occupations can often involve direct physical trauma, long movements under load, and the need to suddenly sprint or bypass obstacles. Because of the unique physical requirements of tactical athletes, sports medicine providers need to ensure that clinical evaluations of this population consider their tactical and administrative requirements.
The physical requirements of individual tactical athletes can vary widely based on their specific profession and even their specific duty within that profession. For example, the United States Army has physical standards that all service members must meet. However, different occupations within the Army have individualized daily requirements. The daily physical requirements of a personnel clerk are vastly different from those of an infantryman. Similarly, within the United States Air Force, a fighter pilot and an aircraft mechanic have vastly different physical requirements and occupational exposures. In law enforcement, a special weapons and tactics officer and a traffic officer would have significantly different demands. As sports medicine professionals evaluating a tactical athlete, it is essential to identify the individual tactical athlete's occupational requirements, because there may be tactical athletes with widely different daily physical requirements even in the same unit or team.
In addition to the physical requirements of tactical athletes, many of their professions, particularly within the military, have administrative requirements to document physical and cognitive limitations. In most military services, there is a baseline assumption that all service members are healthy and capable of doing all physical tasks required for the job unless there is written medical documentation otherwise. When a tactical athlete is injured and unable to perform these tasks, they require specific documentation of their limitations to allow rehabilitation and recovery from their injuries while informing their leadership of their readiness status. In addition to the basic documentation of physical limitations, some tactical athletes may be on a special duty status that creates additional administrative requirements, such as aviation, dive, or parachuting duties. Physicians outside of military systems are generally not expected to be familiar with the details of these administrative requirements. However, it is essential that the patient's physical restrictions or limitations are communicated back to either their military command or the military medical system. Law enforcement and rescue personnel may require similar reporting regarding mental health issues that affect safe weapon handling in law enforcement or respiratory conditions that affect equipment use for fire fighters. Clear communication ensures that appropriate physical limitations are followed and prevents the patient from further injuring themselves or placing their coworkers at risk by being unable to assist in emergencies. The restrictions of the Health Insurance Portability and Accessibility Act (HIPAA) still apply to tactical athletes. However, at least in the case of military service members, if nonmilitary health care providers communicate directly with the patient's military health care team or provide written documentation to the service member that focuses exclusively on current limitations, rather than diagnosis or injury history, HIPAA compliance can be maintained.
Musculoskeletal injuries cause a significant burden for tactical athletes. Within the United States military, more than 40% of all medical encounters can be attributed to acute and chronic musculoskeletal conditions (2). In 2017, more military service members received care for musculoskeletal conditions than for any other category of diagnoses (3).
The incidence of specific injuries varies depending on the tactical athlete. Military trainees have very high injury rates, ranging from 12.5% in U.S. Air Force trainees (4) to 61% in Army initial entry trainees (5). Female trainees, in particular, have extremely high injury rates with 82% of female Army initial entry trainees having at least one injury during basic training (5). A majority of trainee injuries involve the lower extremities, and most are attributed to overuse or cumulative microtrauma, rather than acute traumatic events (5). The cost for these injuries is significant. It includes not only medical expenses but also lost training time for trainees and the cost of the training provided when service members' injuries are significant enough to require removal from military service. It is estimated that the annual direct and indirect costs of injuries in U.S. Army Initial Entry Training alone exceed US $200 million per year (5).
In other military settings, the incidence and distribution of injuries vary with the physical requirements of the setting. In army infantry brigades, 30% of the soldiers reported injuries over a 6-month period. The most common injury locations were the knee (19%), ankle (15%), back (13%), foot (8%), and shoulder (7%). The most common activities associated with injuries were running (32%), lifting heavy objects (13%), and walking or marching under load (11%) (6). Among airmen in Air Force Special Operations, a similar distribution was noted with the lower extremities being the most common injury site, followed by the lower back and the upper extremities. The most common activities associated with injuries were weight lifting, followed by tactical training (7). In Navy Sea, Air, and Land Teams, whose mission profile requires more work in water, upper-extremity injuries were more common (38%), followed by lower extremity injuries (35%) and the back (24%) (8). In military and nonmilitary helicopter pilots, on the other hand, back and neck pain predominate with 57% to 67% reporting neck pain while flying and up to 82% reporting back pain while flying (9,10). Much of this pain has been attributed to the load placed on the neck by night vision goggles and ergonomic issues related to back support while flying (10).
Less literature has been published on injury patterns in nonmilitary tactical athletes. However, as with military tactical athletes, the available evidence suggests that injury patterns reflect the common physical loads encountered. In law enforcement personnel, injury incidence has been reported to vary from 250 to 2500 injuries per 1000 police officers per annum. The most common injuries were sprains and strains (42% to 95%) with the most common causes being assaults from noncompliant offenders and operational training (11). Chronic injuries also are a concern, with 50% of respondents reporting back pain in a survey of Minnesota police officers (12). In firefighters and emergency medical services personnel, Poplin et al. (13) reported an annual injury rate of 17% with the most common injuries being sprains and strains and the most common causes being patient transport, exercise, and training.
Exertional Compartment Syndrome
Chronic exertional compartment syndrome (CECS) is not a problem unique to tactical athletes. However, the inability of most tactical athletes to adjust their level of physical exertion has direct implications for the medical management of this condition for these populations. CECS has two diagnostic components: pain in the involved compartment exacerbated by a specific exercise and relieved upon cessation of this exercise, and the elevation of the intramuscular compartment pressure (IMCP) in those compartments after exercise (14,15). Conservative treatment measures include prolonged rest, modification of physical activity, anti-inflammatory agents, orthotics, ultrasound, massage, stretching, and electrical stimulation (16) with surgical fasciotomy or fasciectomy reserved for those who do not improve with the above mentioned interventions. Tactical athletes are unique due to their inability to modify certain required physical activities beyond the demands of their occupation, which often leads to limited success of conservative treatments and a more rapid progression to surgical intervention. A recent systematic review included more than 1500 patients and demonstrated a failure rate of 94% for conservative treatment (17).
The threshold for determining elevated IMCP is a topic of some debate. The majority of research on CECS uses the diagnostic threshold established by Pedowitz et al. (18) in 1990, with diagnostic thresholds of 30 mm·Hg at 1-min postexercise or 20 mm·Hg at 5 min postexercise. This threshold has demonstrated high sensitivity (97%) but not specificity (10%). Roscoe et al. (19) proposed an alternative diagnostic criteria utilizing continuous monitoring of the IMCP. Using a diagnostic threshold of 105 mm·Hg during exercise at the point of maximum tolerable pain demonstrated a sensitivity of 63% and specificity of 95% in a small study of 40 individuals. Based on this small study, the specificity of their results would limit false positive and potentially unnecessary interventions in patients that would not have been excluded by the Pedowitz et al. criteria. Further research is required to determine more specific IMCP testing techniques and thresholds.
Despite being the gold standard for the management of CECS, surgical fasciotomy or fasciectomy fails to provide sustained relief in 10% to 40% of cases in the civilian population (17,20,21). The effectiveness of surgical interventions for a military population appears to be significantly worse. In a case series of 41 military patients who underwent fasciotomy, only 46% experienced clinical improvement, and only 22% improved enough to return to an unrestricted medically deployable status (22). These findings are in stark contrast to the civilian community, where 75% of patients report returning to their previous level of activity after fasciotomy (17). In a second case series published by McCallum et al. in 2014, 70 extremities in 46 patients were treated with surgical fasciotomy for CECS. With an average follow-up of 26 months, only 19 (41.3%) were able to return to full active military service, while 17 (37%) stayed in the military with physical and duty limitations, and 10 (21.7%) had to leave the military altogether. These case series demonstrate the poor outcomes of surgical interventions in the military compared with civilian athletes, which is likely due to military patients' inability to modify their physical activities postoperatively (15).
Given these relatively poor outcomes after surgical intervention in CECS, alternative treatment options are needed. In 2012, Diebal et al. presented a case series of 10 patients with CECS treated with a 6-wk training program consisting of 45-min sessions thrice weekly designed to eliminate the hindfoot strike, increase step rate to 180 steps per minute, and use the hamstring group to pull the foot from the ground instead of using the gastrocnemius and soleus muscles to push off. At 1 year, 8 of 10 were running at least 5 km two to three times per week with the other two being limited by unrelated acute injuries (23). A similar intervention performed on Norwegian service members was reported by Helmhout et al. (16) in 2015. These service members showed improvement in pain, distance running, self-reported function, and measured IMCP.
A newer promising intervention is an intracompartmental injection of botulinum toxin (BoNT-A). BoNT-A inhibits the release of acetylcholine at the motor endplate. The effects of a BoNT-A injection are expected to last 2 to 3 months. However, BoNT-A injections have shown effectiveness beyond this timeframe via mechanisms that are not entirely understood. It is hypothesized that some degree of muscle atrophy and loss of contractile tissue results in prolonged improvement but has not resulted in decreased athletic performance (24).
A retrospective case series assessing 42 compartments in 16 patients reported by Isner-Horobeti et al. (14) in 2013 demonstrated clinical improvement in 10 of 16 patients 1 month after BoNT-A injection guided by electrical stimulation. Post hoc evaluation 3 to 9 months later (average 4.4 months) demonstrated decreased average compartment pressures and resolution of pain in 15 of 16 patients. Within the military setting, Hutto et al. (25) reported a case in 2018, where a military service member with anterior and lateral CECS was treated with BoNT-A and demonstrated symptom resolution through 10 months of follow-up. BoNT-A is not without side effects, and both foot drop and soreness in the injected muscle groups have been reported, but some of this may be due to the fact that the ideal dose has not yet been determined.
Because of the relatively poor functional outcomes after fasciotomy in military patients with CECS, we recommend initial treatment of tactical athletes with noninvasive modalities, particularly running form modification and BoNT-A injection, prior to consideration of surgical treatment.
Heat injuries, which include heat cramps, heat exhaustion, and heat stroke, are a prominent concern in many athletic populations, but especially so among tactical athletes. In 2018, there were a total of 578 heat stroke and 2214 heat exhaustion diagnoses among active duty service members in the United States for a rate of 0.45 and 1.71 cases per 1000 person-years, respectively. The incidence rate was more than three times higher among recruit trainees when compared with other service members (26). Organizations of tactical athletes are unique in that they must juggle the need to protect tactical athletes from heat-related illness with the requirement to perform realistic training and actual operations that may occur in extreme heat conditions.
Previous reviews of heat illnesses in military trainee populations have demonstrated that BMI extremes (both high and low), and medication use (specifically NSAIDs, opioids, and stimulants) were key modifiable risk factors that increased the risk for heat illness. In addition, prior heat illness, younger age groups, female sex, black race, having never married or being divorced, and lower or missing cognitive aptitude scores and lower or missing physical fitness test scores were nonmodifiable risk factors associated with a higher risk of heat illnesses. As might be expected, the incidence of heat illnesses increased at training locations with lower altitudes and warmer climates (27,28). One proposed method to mitigate the risk of heat injury is to expose tactical athletes to graduated strenuous activity in each new geographic location. Tactical athletes, particularly military recruits, are at risk performing new activities in new locations with unique climates. Gradually exposing the tactical athletes to higher levels of exertion should help to develop heat tolerance (27).
While a full discussion of the management of heat injuries is beyond the scope of this article, the most important concept in management is the immediate treatment of the heat stroke with rapid cooling. The goal time is less than 30 min for cooling to a normalized temperature (29). Casa et al. (30,31) have previously described the relative efficacy of various cooling methods. In the ideal, resource-rich environment, ice-water or cold-water immersion is the treatment of choice. However, in more austere locations, other more portable methods may be required. In the authors' experience, the ice burrito method, which cools the patient utilizing sheets and towels that are soaked in an ice slurry in a water cooler is particularly effective in remote or more austere environments because it is portable, and the ice cooler can be strapped to the exterior of a vehicle (Fig. 1).
Because prior heat injury is a significant risk factor for developing future heat injury and future training may place tactical athletes in situations where they are again exposed to extremes of exertion and heat, a common conundrum encountered when assessing tactical athletes after heat injury involves determining when to return them to full duty. Return to activity policies can be designed to ensure the safety of a tactical athlete as they reacclimate to activity during the period of decreased heat tolerance immediately following a heat injury. While research suggests that the norm is for individuals to recover within a few weeks with appropriate treatment, some do experience long-term complications with reduced exercise capacity and heat tolerance potentially increasing the risk of subsequent heat injury (27,33). ACSM has published clinical guidelines for return to play after exertional heat stroke, that require the resolution of symptoms, normalization of laboratory values, and graded heat acclimatization to improve tolerance (Table) (34).
Laboratory-based exercise-heat tolerance testing may not be routinely available in clinical settings. However, should such testing be warranted, regional experts can be engaged to help guide further assessment.
Rehabilitation and Treatment Plan Considerations
In general, the treatment of most injuries will be the same in tactical athletes as it is in other athletes. However, there are external considerations that may alter treatment plans and must be considered.
While tactical athletes do not have traditional athletic seasons and competitions, military service members may have scheduled missions, field training exercises, or overseas deployments. The presence of an injury may not automatically disqualify a tactical athlete from participating in these events, particularly when the athlete may be a member of a smaller unit where the loss of one team member could lead to mission failure. When developing a treatment plan, it is important to work with tactical athletes to determine how a planned treatment, particularly if it may lead to prolonged downtime, would impact other occupational requirements. As with other athletes, it is common that a treatment plan may be altered or delayed to allow a tactical athlete to complete a mission or important training event. If treatment is delayed, it is extremely important, as discussed above, to relay information regarding the service member's functional status to their unit or military medical provider to ensure that physical limitations do not place the service member or their teammates at risk.
Tactical athletes may require additional rehabilitation and reconditioning compared with injured nonathletic patients. When released from care and cleared to return to work, tactical athletes may immediately find themselves in situations where their lives or the lives of those around them depend on their ability to perform arduous physical tasks. In addition, their employing organizations will generally assume that they have no physical or functional limitations unless there is explicit communication from medical professionals stating otherwise. In some cost-conscious health systems, it is common for injured patients to be released at a point where they are clinically pain-free but have not fully regained their prior endurance and agility. Ardern et al. (35) have described a model of return to sport that progresses from returning to participation through returning to sport to return to performance. This model can be adapted to tactical athletes with a progression from return to participation to return to duty, and ultimately return to tactical performance (Fig. 2) (36). Return to participation is similar to the initial model in that it describes when the tactical athlete is capable of physical activity, but not ready to return to duty. Return to duty describes when the tactical athlete has returned to performing occupational tasks, but has not reached prior levels of tactical performance. Return to tactical performance describes when the tactical athlete has returned to their prior level of physical and psychological performance within a tactical or occupational context. Because of the potential for tactical athletes to experience unpredictable life-threatening situations at almost any time, it is the authors' opinion that tactical athletes are better served with a more conservative rehabilitative course that ensures return to tactical performance, with a focus on the restoration of endurance and agility, prior to being released from treatment. In civilian occupations, such as law enforcement, firefighters, and EMS, this may take the form of a formal work-hardening program. In military occupations, this will often involve a longer reconditioning phase with a focus on specific functional or tactical tasks associated with the service member's potential duties.
Traumatic Brain Injury and Posttraumatic Stress Disorder as Comorbid Conditions
A full discussion of the management of traumatic brain injuries (TBI) and Posttraumatic stress disorder (PTSD) is outside the scope of this article as both are complex diagnoses that require multidisciplinary management. However, both conditions are important to consider when treating tactical athletes because of their prevalence and because their presence may complicate the management of other more routine diagnoses. The United States Defense and Veterans Brain Injury Center reports 383,947 TBI in the U.S. military from 2000 through the first quarter of 2018 (37). Approximately 19% of the service members from the current wars sustained at least one mild TBI (38). With more than 2 million veterans of the wars in Iraq and Afghanistan, this has resulted in substantial disease burden. In a similar manner, between 5% and 15% of U.S. service members have symptoms of PTSD (38). This is likely an underestimate as the military experiences similar issues with underreporting symptoms as athletic populations do. Previous studies have demonstrated a link between the diagnosis of TBI or PTSD and a higher prevalence of chronic pain in both military and nonmilitary tactical athletes (39,40). Thus, when evaluating tactical athletes in a sports medicine setting, particularly for chronic conditions that have not responded to initial treatment, there may be some benefit to assessing whether comorbid TBI or PTSD is present.
The paradigm for how tactical athletes train and receive initial care for their musculoskeletal concerns is undergoing a massive paradigm shift. A number of militaries and law enforcement agencies across the globe are moving away from a traditional model where physical training is entirely separate from medical care toward the development of integrated organizations focused on human performance optimization (41). Early work toward this end included developing dedicated sports medicine teams, such as the U.S. Navy SMART clinics and the embedding of athletic trainers with military training units (42). These concepts have now progressed to multiple organizations developing integrated facilities similar to college training rooms where tactical athletes have access to professional strength and conditioning coaches, sports dietitians, athletic trainers, physical therapists, and mental performance specialists working in an integrated team focused on training and rehabilitating tactical athletes for their specific mission requirements (43). Some special operations units have extended this concept even further, integrating behavioral health and spiritual support assets, such as chaplains into the team in an attempt to optimize the “whole human.”
This new model has implications for sports medicine providers. First, it may affect how tactical athletes present for care. As many of these organizations have open access for tactical athletes, the athletes may often have received significant care from their unit athletic trainers and physical therapists before ever seeing a sports medicine provider in a clinical setting. Second, it may provide an alternative source for the rehabilitation of an injured tactical athlete. In one author's experience, the integrated team capable of smoothly transitioning a patient from physical therapy to reconditioning to standard physical training leads to improved long-term outcomes for tactical athletes as they return to duty fully prepared to perform their duties.
In conclusion, tactical athletes are a unique population with significant rates of musculoskeletal injuries. Sports medicine providers need to ensure that they are considering the occupational and administrative requirements of the tactical athlete when evaluating these patients.
The authors declare no conflict of interest and do not have any financial disclosures.
The views expressed herein are those of the authors and do not reflect the official policy or position of the Defense Health Agency, Department of the Air Force, Department of the Army, Department of Defense, or the U.S. Government.
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