Expanding the injury definition: evidence for the need to include musculoskeletal conditions.

OBJECTIVES: The objectives of the study are to quantify the proportion of cumulative microtraumatic overuse injuries in a physically active population, evaluate their impact in terms of lost work time, and link them to precipitating activities to inform prevention initiatives. STUDY DESIGN: The study design is retrospective cohort study. METHODS: For a population of U.S. Army Soldiers, diagnoses from medical records (International Classification of Diseases [ICD]-9 800-999 and selected ICD-9 710-739) were matched with self-reported injury information. Common diagnoses, limited duty days, and activities and mechanisms associated with the injuries were summarized. RESULTS: Most self-reported injuries (65%) were classified by providers with diagnoses that described cumulative microtraumatic tissue damage, and these injuries led to a higher incidence of limited duty (85%) than acute traumatic injury diagnoses. Reported mechanisms and activities often indicated repetitive physical training-related onset. CONCLUSIONS: Because many diagnoses for cumulative microtraumatic musculoskeletal tissue damage are categorized as diseases to the musculoskeletal system in the International Classification of Diseases, they are often not included in definitions of injury. However, reported injury activities and mechanisms in this population provide evidence that cumulative microtraumatic injuries often arise from identifiable and preventable events. This finding confirms that these diagnoses should be classified as injuries in epidemiologic evaluations and surveillance to accurately represent injury burden.

Occupation and other risk factors for injury among enlisted U.S. Army Soldiers.

OBJECTIVE: To investigate injury risk associated with occupation and occupational physical demand levels among U.S. Army Soldiers. STUDY DESIGN: Retrospective cohort study. METHODS: Personal characteristics, physical fitness, military occupational specialty (MOS), and injury data were obtained by survey from Soldiers in an Army light infantry brigade (n = 2101). Odds ratios (OR) and 95% confidence intervals (95% CI) from a multivariate analysis assessing injury risk were calculated. RESULTS: Injury incidence for the prior 12 months was 43%. Physical fitness and behavioral factors associated with injury risk included age 21-29 (OR [age 21-29/age ≤ 20] = 1.37, 95% CI 1.00-1.90), BMI 27.5-29.9 (high-overweight) (OR high-overweight/normal = 1.62, 95% CI 1.20-2.18); BMI >29.9 (obese) (OR obese/normal = 1.73, 95% CI 1.23-2.44), cigarette smoking (OR Smoker/Nonsmoker = 1.34, 95% CI 1.11-1.63), and poor APFT two mile run performance (OR (Q4/Q1) = 1.61, 95% CI 1.19-2.19). Higher risk of injury was associated with some MOSs (OR (Chemical, Explosives & Ammunition/Infantry) = 2.82, 95% CI 1.19-6.68; OR (Armor/Infantry) = 1.53, 95% CI 1.13-2.07). CONCLUSION: This study identified a number of potentially modifiable risk factors for injuries including: maintenance of healthy weight, improved aerobic endurance, and reduction in smoking. Results also indicate certain Army occupations may be at higher risk of injury. Further investigation into reasons for their higher risk is warranted.

Risk factors associated with self-reported training-related injury before arrival at the US army ordnance school.

OBJECTIVE: This study examined risk factors for self-reported injury incurred before arrival at Ordnance School for advanced individual training (AIT). STUDY DESIGN: During AIT in-processing, soldiers (n=27,289 men and 3856 women) completed a questionnaire that collected demographic and lifestyle information, and asked if the soldier currently had an injury that would affect their AIT performance. METHODS: Potential risk factors for self-reported injury were explored using logistic regression. RESULTS: For men, self-reported injury was associated with older age [odds ratio (OR) >or=30 years/17-19 years=1.9], race (OR Black/Caucasian=1.2), basic combat training (BCT) site (OR Fort Benning/Fort Jackson=1.7; OR Fort Leonard Wood/Fort Jackson=1.6, OR Fort Knox/Fort Jackson=1.3), smoking on 20 or more days in the 30 days prior to BCT (OR smoker/non-smoker=1.2) and current illness (OR ill/not ill=6.2). For women, increased self-reported injury was associated with older age (OR>or=30 years/17-19 years=2.0), BCT site (OR Fort Leonard Wood/Fort Jackson=1.5) and current illness (OR ill/not ill=5.8). CONCLUSIONS: Certain demographic characteristics and lifestyle behaviours may be identified as injury risk factors on arrival at Ordnance AIT.

Injuries in the military: a review and commentary focused on prevention.

BACKGROUND: In November 1996, the Armed Forces Epidemiological Board (AFEB) Injury Prevention and Control Work Group issued a report that cited injuries as the leading cause of morbidity and mortality among military service members. This article reviews the types and categories of military morbidity and mortality data examined by the AFEB work group and the companion Department of Defense (DoD) Injury Surveillance and Prevention Work Group. This article further uses the injury data reviewed to illustrate the role of surveillance and research in injury prevention. The review provides the context for discussion of the implications of the AFEB work group's findings for the prevention of injuries in the military. METHODS: The AFEB work group consisted of 11 civilian injury epidemiologists, health professionals and scientists from academia, and other non-DoD government agencies, plus six military liaison officers. Injury data from medical databases were provided to the civilian experts on the AFEB work group by the all-military DoD Injury Surveillance and Prevention Work Group. The AFEB work group assessed the value of each database to the process of prevention and made recommendations for improvement and use of each data source. RESULTS: Both work groups found that injuries were the single leading cause of deaths, disabilities, hospitalizations, outpatient visits, and manpower losses among military service members. They also identified numerous data sources useful for determining the causes and risk factors for injuries. Those data sources indicate that training injuries, sports, falls, and motor vehicle crashes are among the most important causes of morbidity for military personnel. CONCLUSIONS: While the work group recommends ways to prevent injuries, they felt the top priority for injury prevention must be the formation of a comprehensive medical surveillance system. Data from this surveillance system must be used routinely to prioritize and monitor injury and disease prevention and research programs. The success of injury prevention will depend not just on use of surveillance but also partnerships among the medical, surveillance, and safety agencies of the military services as well as the military commanders, other decision makers, and service members whose direct actions can prevent injuries and disease.

Risk factors for training-related injuries among men and women in basic combat training.

PURPOSE: Past investigations indicate that training-related injuries are associated with certain performance-oriented measures of physical fitness and certain lifestyle characteristics. This study examined associations between injuries, direct (physiological) measures of physical fitness, and lifestyle characteristics. METHODS: Subjects were 756 men and 474 women performing the standardized activities involved in U.S. Army Basic Combat Training (BCT). Before BCT, a subsample of subjects (182 men and 168 women) were administered a series of tests that included a treadmill running test (peak VO2), dual-energy x-ray absorptiometry (for body composition), several measures of muscle strength, a hamstring flexibility test, and a vertical jump. A questionnaire addressed smoking habits and prior physical activity. All subjects were administered the Army Physical Fitness test consisting of push-ups, sit-ups, and a 3.2-km run. Gender, age, stature, and body mass were obtained from physical examination records. Injuries incurred during BCT were transcribed from medical records; for each medical visit, the diagnosis, anatomical location, disposition (final outcome of visit), and days of limited duty were recorded. RESULTS: Women had over twice the injury rate of men. For men and women, fewer push-ups, slower 3.2-km run times, lower peak VO2, and cigarette smoking were risk factors for time-loss injury. Among the men only, lower levels of physical activity before BCT and both high and low levels of flexibility were also time-loss injury risk factors. Multivariate analysis revealed that lower peak VO2 and cigarette smoking were independent risk factors for time-loss injury. CONCLUSIONS: Lower aerobic capacity and cigarette smoking were independently associated with a higher likelihood of injury in both men and women during a standardized program of physical training. Further studies are needed to assess associations between injury and body composition and muscular strength.

Discharges during U.S. Army basic training: injury rates and risk factors.

This study examined injury rates and risk factors for discharge in a cohort of 756 men and 474 women in U.S. Army basic combat training (BCT) at Fort Jackson, South Carolina. Investigators systematically screened trainee medical records for injuries and collected medical recommendations to temporarily remove a trainee from BCT to allow recovery from an injury. The BCT unit provided Army Physical Fitness Test (APFT) scores and trainee demographic data. Discharges were identified by reviewing discharge packets and were confirmed through rosters from the BCT units. There were 102 men and 108 women discharged. Person-time injury incidence rates (for time-loss injuries) among discharged and nondischarged men were 1.87 and 0.45 cases/100 person-days, respectively (p < 0.01); the rates for discharged and nondischarged women were 1.95 and 1.01 cases/100 person-days, respectively (p < 0.01). Men had a higher risk of discharge if they had a time-loss injury (p < 0.01), but women did not (p = 0.28). Other discharge risk factors for both men and women included a medical recommendation for removal from training to recover from an injury, lower performance on any of the three APFT events, and lower educational level. Women with more body mass or a higher body mass index also had a marginally higher risk of discharge.

The fitness training unit in U.S. Army basic combat training: physical fitness, training outcomes, and injuries.

This study involved a retrospective examination of physical fitness, training outcomes, and injury rates among personnel in the Fitness Training Unit (FTU). Personnel were assigned to the FTU based on low performance on push-ups, sit-ups, and/or a 1-mile run (N = 44 men, 95 women) and received an augmented physical fitness program before basic combat training (BCT). They were compared with 712 men and 379 women who took the same test but were not assigned to the FTU and went directly to BCT. FTU and non-FTU personnel trained in the same battalions. Army Physical Fitness Test scores and BCT outcomes (discharged or completed BCT in 8 weeks) were obtained from unit training records. Injuries during BCT were documented from a review of the medical records. On entry to BCT, FTU women had similar 2-mile run times compared with non-FTU women (21.6 vs. 21.5 minutes, respectively; p = 0.86); FTU men were considerably slower on the 2-mile run than non-FTU men (20.3 vs. 17.3 minutes; p < 0.01). FTU women and non-FTU women had similar graduation success (60% vs. 68%, respectively; p = 0.14) and time-loss injury rates (1.3 vs. 1.4 people injured/100 person-days, respectively; p = 0.90). FTU men were less likely to graduate than non-FTU men (55% vs. 82%; p < 0.01) and more likely to suffer a time-loss injury (1.2 vs. 0.7 people injured/100 person-days; p < 0.01). Efforts should be directed toward providing a sufficient training stimulus to improve the aerobic fitness level of men (as well as women) in the FTU.

Interventions to prevent softball related injuries: a review of the literature.

OBJECTIVES: To examine the published evidence on interventions to prevent softball related injuries among adults, and to encourage more epidemiologic research as a foundation for future softball injury prevention efforts. METHODS: The authors reviewed literature identified from six electronic databases for studies on softball related injuries. The search was limited to studies written in the English language, published between 1970 and 2002, and involving adult populations. Research was excluded that evaluated baseball ("hard ball") related injuries or was aimed at injury treatment. Identified studies were categorized by study design. Intervention/prevention papers were evaluated further and described in detail. RESULTS: The search strategy identified 39 studies specifically related to softball. Most studies were case reports/case series (n=13) or descriptive studies (n=11); only four were analytic or intervention/prevention studies. Studies collected data in a variety of ways, often without denominator data to permit calculation of injury rates. Studies also did not differentiate between slow or fast pitch softball activities and most did not mention the type of softball that was used. CONCLUSIONS: Surprisingly few studies exist on interventions to reduce injuries during softball, one of the most popular recreational sports in the US. Of the existing literature, much attention has been on sliding related injuries, which comprise only a segment of softball injuries. Basic epidemiologic studies describing the nature, severity, and risk factors for softball injuries in a variety of populations are needed, followed by additional intervention evaluation studies aimed at modifiable risk factors.

Injury and fitness outcomes during implementation of physical readiness training.

This study examined injury and physical fitness outcomes in Basic Combat Training (BCT) during implementation of Physical Readiness Training (PRT). PRT is the U.S. Army's emerging physical fitness training program. An experimental group (EG, n = 1284), which implemented the PRT program, was compared to a control group (CG, n = 1296), which used a traditional BCT physical training program during the 9-week BCT cycle. Injury cases were obtained from recruit medical records and physical fitness was measured using the U.S. Army Physical Fitness Test (APFT, consisting of push-ups, sit-ups and a two-mile run). Injury rates were examined using Cox regression after controlled for initial group differences in demographics, fitness and other variables. Compared to the EG, the adjusted relative risk of a time-loss overuse injury in the CG was 1.5 (95 % confidence interval [CI] = 1.0 - 2.1, p < 0.01) for men and 1.4 (95 %CI = 1.1 - 1.8, p < 0.01) for women. There were no differences between groups for traumatic injuries. On the first administration of the final APFT, the EG had a greater proportion of recruits passing the test than the CG (men: 85 % vs. 81 %, p = 0.04; women: 80 % vs. 70 %, p < 0.01). After all APFT retakes, the EG had significantly fewer APFT failures than the CG among the women (1.6 % vs. 4.6 %, p < 0.01) but not the men (1.6 % vs. 2.8 %, p = 0.18); the gender-combined EG had a higher pass rate (1.6 % vs. 3.7 %, p < 0.01). Overall, the PRT program reduced overuse injuries and allowed a higher success rate on the APFT.