MULTIVARIATE ANALYSIS OF INTRINSIC INJURY RISK FACTORS IN A COHORT OF US ARMY BASIC TRAINEES

A profile of injuries suffered by female soldiers serving in the Australian Army

Introduction

Female soldiers comprise an important component of any modern army, yet little research has been performed to investigate differences in the profiles of injuries reported by qualified female and male army personnel.

Aim

The aim of this study was to compare injury rates and patterns between female and male soldiers of the Australian Regular Army (ARA).

Methods

Data pertaining to all injuries reported by ARA members over a two-year period were accessed from the SENTINEL database and analysed descriptively. Findings regarding injury patterns were reported by most common location, nature, mechanism, and activity being performed at the time of injury. Injury incidence rates (IR) were calculated based on population size, and injury incidence rate ratios (IRR) comparing female and male injury rates were determined.

Results

A total of 8750 injuries were recorded across the two-year time period (2018–2020) of the study (minor injuries: n = 1766 female, n = 6870 male; serious injuries: n = 19 female, n = 95 male). Higher incidence rates of minor injuries were reported for female soldiers (IR = 20.75 injuries/100 soldiers/year) when compared to male soldiers (IR = 13.60 injuries/100 soldiers/year), with an IRR of 1.53 [95% CI = 1.46–1.60]. More serious injuries were reported at a similar rate between female (IR = 0.22/100 soldiers/year) and male soldiers (IR = 0.21/100 soldiers/year), with an IRR of 1.05 [95% CI = 0.65–1.72]. Female soldiers tended to report more ankle injuries than male soldiers who reported more knee injuries. Physical training and combat training were the most common causes of injury for both sexes.

Discussion

There were subtle differences in body locations of minor injuries within female and male soldiers. Both minor and more serious injury profiles were otherwise similar between sexes. Therefore, strategies required to minimise injuries in female soldiers may be similar in many respects to strategies required for male soldiers but require some differences to account for the subtle differences in body locations of injury, and so to ensure effectiveness across all personnel.

Musculoskeletal injuries description of an under-recognized injury problem among military personnel

INTRODUCTION

Although injuries are recognized as a leading health problem in the military, the size of the problem is underestimated when only acute traumatic injuries are considered. Injury-related musculoskeletal conditions are common in this young, active population. Many of these involve physical damage caused by micro-trauma (overuse) in recreation, sports, training, and job performance. The purpose of this analysis was to determine the incidence of injury-related musculoskeletal conditions in the military services (2006) and describe a standardized format in which to categorize and report them.

METHODS

The subset of musculoskeletal diagnoses found to be injury-related in previous military investigations was identified. Musculoskeletal injuries among nondeployed, active duty service members in 2006 were identified from military medical surveillance data. A matrix was used to report and categorize these conditions by injury type and body region.

RESULTS

There were 743,547 injury-related musculoskeletal conditions in 2006 (outpatient and inpatient, combined), including primary and nonprimary diagnoses. In the matrix, 82% of injury-related musculoskeletal conditions were classified as inflammation/pain (overuse), followed by joint derangements (15%) and stress fractures (2%). The knee/lower leg (22%), lumbar spine (20%), and ankle/foot (13%) were leading body region categories.

CONCLUSIONS

When assessing the magnitude of the injury problem in the military services, injury-related musculoskeletal conditions should be included. When these injuries are combined with acute traumatic injuries, there are almost 1.6 million injury-related medical encounters each year. The matrix provides a standardized format to categorize these injuries, make comparisons over time, and focus prevention efforts on leading injury types and/or body regions.

Incidence of injury and physical performance adaptations during military training

OBJECTIVE

Strenuous physical activity, such as military training, is known to demand a high degree of physical performance and to cause overuse injuries. However, the exact relation between injury incidence and physical fitness level and the influence of military training on measures of functional performance, such as intermittent endurance capacity and maximal jump performance, are not fully described.

METHODS

A total of 330 military conscripts were prospectively followed during military basic training. They were divided into 4 self-assessed physical fitness level groups (well trained, trained, less trained, and untrained) and underwent physical performance tests together with registration of injury incidence.

RESULTS

Twelve weeks of military basic training was found to result in an overall injury rate of 28%, with an inverse relation between physical fitness level and incidence of overuse injury (P < 0.0001). Furthermore a fourfold higher injury rate was observed in the previously untrained soldiers compared with the well-trained soldiers. An increase in intermittent endurance capacity (20-m intermittent shuttle run test) was seen in all groups, (13 to 62%, P < 0.05), whereas only the previously untrained group of soldiers improved in aerobic capacity (8 and 16%, P < 0.05; maximal oxygen uptake and Coopers 12-minute running test). Maximal jump performance, both with and without backpack loading (15 kg), decreased (5 to 13%, P < 0.05) in 93% of the soldiers despite weight loss.

CONCLUSIONS

Military basic training has a positive effect on intermittent endurance capacity but a detrimental effect on jump performance. Furthermore, low levels of physical fitness are strongly associated with proneness toward overuse injury development in soldiers going through intense training.