Increasingly, clinicians and researchers are focusing on tactical athletes—including warfighters, firefighters, law enforcement officers, and other professionals—as a unique population with regard to lower extremity injuries.
By Hank Black
Almost 15 years ago, the US secretary of defense called for rates of accidents and injuries in the armed services to be driven down significantly to enhance readiness for battle, and save money and training time.1 Thus began a long march toward recognition of service personnel as a special type of athlete.
Tactical athletes, as they are now known, also include firefighters, law enforcement personnel, emergency medical technicians, and others whose protect-and-defend professions require high-level physical abilities—and, in turn, high-level medical care.
Experts in this field say tactical athletes, like those competing at collegiate or Olympic levels, should be given every chance to be at the top of their game.
“We need to start treating our warfighters and first responders as the athletes they are—their sport is protecting the public,” according to Kenneth Games, PhD, LAT, ATC, who directs a research center at Indiana State University in Terre Haute that focuses on firefighters and other civilian tactical athletes.
Interest in working with tactical athletes is growing. Sports medicine and athletic trainer organizations are heavily engaged in the field, the American Physical Therapy Association is launching a related special interest section, and strength and conditioning specialists have created a certification program for the area. A wave of tactical-fitness exercises has gained popularity in the commercial fitness world, supplanting “boot camp” for many who seek high-intensity workouts.
In November 2016, the National Athletic Trainer’s Association (NATA) devoted a whole issue of its journal (the Journal of Athletic Training [JAT]) to the subject of tactical athletes.2
“These are people who dedicate their lives to serving us, and who depend on functioning at their highest possible level of athleticism to carry out the many challenges they face, often under life-threatening circumstances,” said guest coeditor JoEllen M. Sefton, PhD, ATC, who directs the Warrior Research Center at Auburn University in Alabama. “As such, they deserve the best we can give in terms of research and clinical care.”
Sefton works with all levels of warfighters, from cadets to special operations forces, many of them at Fort Benning, GA, just a few miles east of Auburn.
Much of the research focused on reducing musculoskeletal injuries in tactical athletes involves the lower extremities, where the majority of noncontact injuries occur. In Army trainees, for example, chronic knee injuries account for up to 44% of all injuries.3
The potential payoff is high. In the special JAT issue, Nathaniel S. Nye, MD, and colleagues found that 12.5% of Air Force trainees who sustained at least one musculoskeletal injury were more than three times more likely to be discharged from the service than their uninjured counterparts, and the cost of such injuries totaled more than $21.8 million in medical and nonmedical expenses.4
The sports medicine model of injury prevention and management is most fully realized by embedded teams of training specialists in deployed units of the armed services, according to an editorial Nye coauthored that accompanied the study in JAT. Nye, a primary care sports medicine physician attached to the 559th Trainee Health Squadron at Joint Base San Antonio-Lackland, TX, pointed out that the usual medical care model in the armed services still resembles the model used for many civilians, including primary care referrals, 15-minute appointments, and long waits for specialty consultations.
“We have top-notch sports medicine programs for our intercollegiate athletes, but only meager facilities and services are available to the tactical athletes of our special operations training units,” Nye said. “Even a small reduction in trainee attrition would bring large cost savings.”
The first discussions about embedded sports medicine teams began in the 1990s, with the Marine Corps and Navy recognizing the need for dedicated sports medicine professionals to provide on-site rapid assessment and care.5 Teams might include athletic trainers, physical therapists, strength and conditioning specialists, sports medicine physicians, and surgeons, backed up by a full bench of researchers in biomechanics, epidemiology, and other fields.
Many trainees hide their injuries for fear that a healthcare provider will remove them from their duty status and their team, Nye said.
“Embedding healthcare providers into operational organizations, to ensure that they understand the mission and know the people, will significantly bridge this gap,” he said.
Prediction and prevention
Predicting and preventing injury in trainees is the focus of much current research. Scott D. Carow, DSc, PT, OCS, SCS, led a study6 of new cadets at the US Military Academy in West Point, NY, that showed a reduction in risk of acute knee-joint injury in a cohort whose trainers (upper-class cadets who had been through a two-week supervisory course) were supervised by professional staff, either a physical therapist or athletic trainer, compared with another group performing the same exercise program whose trainers had no supervision.
Although the findings seem to support increasing the direct involvement of medical professionals during training, Carow noted that isn’t necessarily a realistic option.
“That model of putting a PT or AT behind every platoon to make sure movement was executed correctly would be impractical,” Carow said. “There’s one PT per brigade [3500 soldiers] now, so we have to come up with better instruction of training leaders or exercises unit-level leaders can correctly supervise.”
Carow, now stationed at William Beaumont Army Medical Center in El Paso, TX, noted the Army has developed a Master Fitness Trainers Course with a goal of including one such trainer in every company secondary to their main military occupation specialty, such as truck driver.
“That may be the right way to try integrating this training at the unit level,” he said.
A complex problem
A coauthor on the West Point study, Anthony I. Beutler, MD, program director for the Military Sports Medicine Fellowship at the Uniformed Services University in Bethesda, MD, said, “Injury reduction is a very complex problem, and it is difficult to think of a single strategy that would dramatically work across the board.”
As an example, he said, the Army tasked his group with conducting a comprehensive literature review (not for publication) of running shoe styles—in particular, minimalist versus traditional cushioned running shoes—and asked if one type of shoe would be appropriate for every military trainee.
“Our recommendation was, ‘No,’” Beutler said. “We know that transitioning someone from traditional heel strike running to midfoot running is a time when injuries are very likely to happen.7 So we wouldn’t want to just have one type of shoe for basic trainees to choose from, since shoe type might force them to alter their biomechanics in unpredictable and nonbeneficial ways. The individuality of the trainee—the athlete—is really quite striking.”
Games developed the Tactical Athlete Research and Education Center at Indiana State, where he is assistant professor in the Department of Applied Medicine and Rehabilitation and director of the Neuromechanics, Interventions, and Continuing Education Research Laboratory.
He agrees with Nye that tactical athletes are typically reluctant to leave duty for treatment of nagging musculoskeletal issues—persistent knee pain, for example. Like warfighters, he said, firefighters are part of a team whose members depend on each other. But firefighters, and other first responders, also fear the possibility of losing time and pay.
“If they go to clinic and get a prescription for nine physical therapy sessions, at three a week, they may be on half-pay all that time,” Games said.
Games targets lower extremity injury prevention through a program of functional training that has firefighters carrying up to 100 lbs of personal protective equipment, as they might be required to use while on the job, which alters the parameters of neuromuscular control and muscular systems, he said.
“Fatigue makes an athlete perform more poorly on dynamic balance, for example, so we have them do a five-minute activity protocol in their equipment before putting them through balance exercises. It’s the combination of exercises and equipment restrictions that make you work harder and fatigue faster and therefore risk missing a jump and spraining an ankle, for example,” he said.
The functional training strategy—now in press but described in several presentations at the NATA annual meeting in June8-10—calls for a collaborative team to address muscular strength, balance and neuromuscular control, mobility, and cardiovascular fitness, he said.
The JAT special issue included several other studies involving the lower extremities.
- Sefton et al identified cut-off scores for events in one common fitness screen, the Army 1-1-1 Fitness Assessment. The analysis will help clinicians assess the risk of musculoskeletal injuries for various military specialty units and identify recruits most likely to successfully complete their basic training.11
- Kollock et al conducted a meta-analysis that found individuals with knee overuse symptoms—which account for up to 44% of injuries in military trainees and are also a significant concern in active-duty and reserve warfighters—have lower absolute and normalized hip muscle strength compared with asymptomatic controls, and might benefit from training to strengthen specific muscles.3
- Cameron et al systematically reviewed the literature on osteoarthritis (OA) and the tactical athlete whose occupation requires repetitive bending, squatting, kneeling, and lifting.12 In 12 retrospective cohort studies meeting their criteria, the group found a significantly higher incidence of OA—including knee OA and hip OA specifically—compared with controls who were not tactical athletes. The disparities persisted regardless of age or sex, and increased with age.
- In a cohort study involving 2479 Chinese military cadets over two years, Ma et al found the incidence of meniscal injury was 10.08 per 1000 person-years, with overweight or obese cadets (8% of the study population) at greatest risk of such injury.13 In addition, the researchers found medial meniscal injuries were twice as frequent as lateral ones. The incidence of meniscal injury was higher than in a 2012 study of active-duty US military service members, which also found a similar distribution of medial and lateral injuries.14
Although the US study on meniscal injuries did not look at body mass index (BMI), US Army researchers reported in 2016 that higher BMI was associated with increased risk of musculoskeletal injury in new soldiers followed for two years.15 Hruby et al suggested focusing recruitment on individuals with BMI of 21 to 23 kg/m2—the range associated with the lowest risk of incidence.15
Footwear has always been a concern for the armed services. Combat boots were required for training and duty prior to 1980, when, on the intuitive assumption that fewer injuries would occur, running shoes were allowed for training.16,17
Surprisingly, no reduction in injury rate was evident in a recent systematic review18 of studies in basic training that examined injury rates before and after the historic change to running shoes. However, anecdotally reported methodological issues related to how often the running shoes were actually worn during training may have affected the findings.19
The recent popularity of minimalist running shoes also doesn’t seem to have affected injury rates in military personnel. In more than 1300 male soldiers in a single brigade, Tyson Grier, MS, a kinesiologist with the Army Public Health Center (Provisional) in Aberdeen Proving Ground, MD, and colleagues found no differences in overuse injury rates for a traditional running-shoe group (motion control, stability, or cushioning shoe) and a minimalist running-shoe group (“barefoot,” minimalist, or transitional shoe).20
Wendi H. Weimar, PhD, director of Auburn University’s Sport Biomechanics Laboratory, analyzes gait and other characteristics of military basic trainees to help them attain running patterns associated with a reduced risk of lower extremity injury. She is an assistant professor in the university’s Department of Kinesiology.
“We might encourage them to take a shorter stride, and land on their midfoot rather than their heel, particularly if running on sand with or without a heavy rucksack,” Weimar said.
She teaches trainees to tie their boots with a runner’s loop to allow the foot to fit better in the heel cup and have a truer gait. More shoe design and materials options are available to match individual job requirements, including different cleat configurations and sole thicknesses.
“And orthotics, while not prescribed on a global basis, are available as needed, to promote performance and avoid injury,” Weimar said.
She also takes note of how soldiers—and other tactical athletes—fill the side pockets of their cargo pants.
“A lot of paramedics and police officers carry weight on their side pockets, which can alter the weight distribution and affect the way they swing their weight forward,” she said.
In 2010, Timothy Sell, PhD, PT, FACSM, and colleagues at the University of Pittsburgh helped develop and implement the Eagle Tactical Training Program21,22 in Fort Campbell, KY, specifically for an Army airborne unit after determining its injury profile, which was high in lower extremity injuries.
Among other aspects, the program featured a different type of workout daily (speed/agility/balance one day, muscular strength the next, then interval running, power, and endurance training). The training was associated with improvements in soldiers’ strength, flexibility, balance, anaerobic power, agility, and annual fitness scores.21,22
Last year Sell et al published a related study23 that found program graduates had significantly lower numbers of preventable musculoskeletal injuries and stress fractures compared with controls.
“It shows the importance of a scientifically designed training program tailored to a target population,” said Sell, who is now associate professor and director of the Michael W. Krzyzewski Human Performance Laboratory in the Department of Orthopedic Surgery at Duke University in Durham, NC.
Sell was one of the several researchers and clinicians interviewed who expressed their respect for and appreciation of the tactical athletes they worked with.
“While I am not in the service, it’s a great privilege to support and work with men and women who are dedicated to our safety and well-being,” he said.
Hank Black is a freelance writer in Birmingham, AL.
- Rumsfeld DH. Reducing preventable accidents. Memorandum. Offıce of the US Secretary of Defense. Published May 19, 2003.
- Sefton J, Burkhardt T, eds. J Athl Train 2016;51(11).
- Kollock RO, Andrews C, Johnston A, et al. A meta-analysis to determine if lower extremity muscle strengthening should be included in military knee overuse injury-prevention programs. J Athl Train 2016;51(11):919-926.
- Nye NS, Pawlak MT, Webber BJ, et al. Description and rate of musculoskeletal injuries in Air Force basic military trainees, 2012-2014. J Athl Train 2016;51(11):858-865.
- Nye NS, de la Motte SJ. Editorial: Rationale for embedded musculoskeletal care in Air Force training and operational units. J Athl Train 2016;51(11):846-848.
- Carow SD, Haniuk EM, Cameron KL, et al. Risk of lower extremity injury in a military cadet population after a supervised injury-prevention program. J Athl Train 2016;51(11):905-918.
- Salzler MJ, Kirwan HJ, Scarborough DM, et al. Injuries observed in a prospective transition from traditional to minimalist footwear: correlation of high impact transient forces and lower injury severity. Physician Sportsmed 2016;44(4):373-379.
- Games KE, Csiernik AJ, Winkelmann ZK, et al. Fatigue diminishes static and dynamic balance in firefighters. J Athl Train 2017;52(6):S151.
- Csiernik AJ, Winkelmann ZK, Eberman LE, et al. Personal protective equipment diminishes static and dynamic balance in firefighters. J Athl Train 2017;52(6):S38.
- Rogers SM, Winkelmann ZK, Eberman LE, Games KE. Examination of the triple hop for distance as a predictor of lower extremity performance in firefighter equipment. J Athl Train 2017;52(6):S39.
- Sefton JM, Lohse KR, McAdam JS. Prediction of injuries and injury types in Army basic training, infantry, armor, and cavalry trainees using a common fitness screen. J Athl Train 2016;51(11):849-57.
- Cameron KL, Driban JB, Svoboda SJ. Osteoarthritis and the tactical athlete: a systematic review. J Athl Train 2016;51(11):952-961.
- Ma JZ, Cui SF, Hu F, et al. Incidence and characteristics of meniscal injuries in cadets at a military school, 2013-2015. J Athl Train 2016;51(11):876-879.
- Jones JC, Burks R, Owens BD, et al. Incidence and risk factors associated with meniscal injuries among active-duty US military service members. J Athl Train 2012;47(1):67-73.
- Hruby A, Bulathsinhala L, McKinnon CCJ, et al. BMI and lower extremity injury in US Army soldiers, 2001-11. Am J Prev Med 2016;50(6):e163-e171.
- Fort Benning testing athletic shoes. Sneakers may get foothold in Army. Stars and Stripes website. http://www.stripes.com/customer-service/archives. Published May 21, 9183. Accessed February 25, 2017.
- US Department of the Army. Physical Readiness Training, Field Manual 21-20. Washington, DC: Department of the Army; October 31, 1980.
- Knapik JJ, Jones BH, Steelman RA. Physical training in boots and running shoes: a historical comparison of injury incidence in basic combat training. Mil Med 2015;180(3):321-328.
- Ingraham P. Boot blooper. Painscience.com. https://www.painscience.com/microblog/boot-blooper.html. Published December 22, 2014. Accessed July 11, 2017.
- Grier T, Canham-Chervak M, Bushman T, et al. Minimalist running shoes and injury risk among United States Army Soldiers. Am J Sports Med 2016;44(8):1439-1446.
- Sell TC, Abt JP, Crawford K, et al. Warrior model for human performance and injury prevention: Eagle Tactical Athlete Program (ETAP) Part I. J Spec Oper Med 2010;10(4):2-21.
- Abt JP, Sell TC, Crawford K, et al. Warrior model for human performance and injury prevention. Eagle Tactical Athlete Program (ETAP) Part II. J Spec Oper Med 2010;10(4):22-33.
- Sell TC, Abt JP, Nagai T, et al. The Eagle Tactical Athlete Program reduces musculoskeletal injuries in the 101st airborne division (air assault). Mil Med 2016;181(3):250-257.