The Eagle Tactical Athlete Program Reduces Musculoskeletal Injuries in the 101st Airborne Division (Air Assault).

UNLABELLED: The Eagle Tactical Athlete Program (ETAP) was scientifically developed for the U.S. Army's 101st Airborne Division (Air Assault) to counter unintentional musculoskeletal injuries (MSIs). PURPOSE: To determine if ETAP would reduce unintentional MSIs in a group of 101st Airborne Division (Air Assault) Soldiers. METHODS: ETAP-trained noncommissioned led physical training. 1,720 Soldiers were enrolled (N = 1,136 experimental group [EXP], N = 584 control group [CON]) with injuries tracked before and after initiation of ETAP. The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes were analyzed and described the anatomic locations, anatomic sub-locations, onset, and injury types. McNemar tests compared the proportions of injured subjects within each group. RESULTS: There was a significant reduction in the proportion of Soldiers with preventable MSIs in the EXP (pre: 213/1,136 (18.8%), post: 180/1,136 (15.8%), p = 0.041) but not in the CON. In addition, there was a significant reduction in stress fractures in the EXP (pre: 14/1,136 (1.2%), post: 5/1,136 (0.4%), p = 0.022) but no significant differences in the CON. CONCLUSION: The current analysis demonstrated that ETAP reduces preventable MSIs in garrison. The capability of ETAP to reduce injuries confirms the vital role of a scientifically designed training program on force readiness and health.

Musculoskeletal, biomechanical, and physiological gender differences in the US military.

UNLABELLED: The repeal of the Direct Ground Combat Assignment Rule has renewed focus on examining performance capabilities of female military personnel and their ability to occupy previously restricted military occupational specialties. Previous research has revealed female Soldiers suffer a greater proportion of musculoskeletal injuries compared to males, including a significantly higher proportion of lower extremity, knee, and overuse injuries. Potential differences may also exist in musculoskeletal, biomechanical, and physiological characteristics between male and female Soldiers requiring implementation of gender-specific training in order to mitigate injury risk and enhance performance. PURPOSE: To examine differences in musculoskeletal, biomechanical, and physiological characteristics in male and female Soldiers. METHODS: A total of 406 101st Airborne Division (Air Assault) Soldiers (348 male; 58 female) participated. Subjects underwent testing for flexibility, isokinetic and isometric strength (percent body weight), single-leg balance, lower body biomechanics during a stop jump and drop landing, body composition, anaerobic power/capacity, and aerobic capacity. Independent t tests assessed between-group comparisons. RESULTS: Women demonstrated significantly greater flexibility (P<.01-P<.001) and better balance (P≤.001) than men. Men demonstrated significantly greater strength (P≤.001), aerobic capacity (47.5±7.6 vs 40.3±5.4 ml/kg/min, P<.001), anaerobic power (13.3±2.1 vs 9.5±1.7 W/kg, P<.001), and anaerobic capacity (7.8±1.0 vs 6.1±0.8 W/kg, P<.001) and lower body fat (20.1±7.5 vs 26.7±5.7 (%BF), P<.001). Women demonstrated significantly greater hip flexion and knee valgus at initial contact during both the stop jump and drop landing tasks and greater knee flexion at initial contact during the drop landing task (P<.05-P<.001). CONCLUSIONS: Gender differences exist in biomechanical, musculoskeletal, and physiological characteristics. Sex-specific interventions may aid in improving such characteristics to optimize physical readiness and decrease the injury risk during gender-neutral training, and decreasing between-sex variability in performance characteristics may result in enhanced overall unit readiness. Identification of sex-specific differences in injury patterns and characteristics should facilitate adjustments in training in order for both sexes to meet the gender-neutral occupational demands for physically demanding military occupational specialties.

The addition of body armor diminishes dynamic postural stability in military soldiers.

Poor postural stability has been identified as a risk factor for lower extremity musculoskeletal injury. The additional weight of body armor carried by Soldiers alters static postural stability and may predispose Soldiers to lower extremity musculoskeletal injuries. However, static postural stability tasks poorly replicate the dynamic military environment, which places considerable stress on the postural control system during tactical training and combat. Therefore, the purpose of this study was to examine the effects of body armor on dynamic postural stability during single-leg jump landings. Thirty-six 101st Airborne Division (Air Assault) Soldiers performed single-leg jump landings in the anterior direction with and without wearing body armor. The dynamic postural stability index and the individual stability indices (medial-lateral stability index, anterior-posterior stability index, and vertical stability index) were calculated for each condition. Paired sample t-tests were performed to determine differences between conditions. Significant differences existed for the medial-lateral stability index, anterior-posterior stability index, vertical stability index, and dynamic postural stability index (p < 0.05). The addition of body armor resulted in diminished dynamic postural stability, which may result in increased lower extremity injuries. Training programs should address the altered dynamic postural stability while wearing body armor in attempts to promote adaptations that will result in safer performance during dynamic tasks.

Air assault soldiers demonstrate more dangerous landing biomechanics when visual input is removed.

Soldiers are subjected to increased risk of musculoskeletal injuries in night operations because of limited visual input. The purpose of this study was to determine the effect of vision removal on lower extremity kinematics and vertical ground reaction forces during two-legged drop landings. The researchers tested 139 Air Assault Soldiers performing a landing task with and without vision. Removing visual input resulted in increased hip abduction at initial contact, decreased maximum knee flexion, and increased maximum vertical ground reaction force. Without vision, the timing of maximum ankle dorsiflexion for the left leg was earlier than the right leg. The observed biomechanical changes may be related to the increased risk of injury in night operations. Proper night landing techniques and supplemental training should be integrated into Soldiers' training to induce musculoskeletal and biomechanical adaptations to compensate for limited vision.

Less body fat improves physical and physiological performance in army soldiers.

The purpose of this study was to compare physical and physiological fitness test performance between Soldiers meeting the Department of Defense (DoD) body fat standard (< or = 18%) and those exceeding the standard (> 18%). Ninety-nine male 101st Airborne (Air Assault) Soldiers were assigned to group 1: < or = 18% body fat (BF) or group 2: > 18% BE. Groups 1 and 2 had similar amounts of fat-free mass (FFM) (66.8 +/- 8.2 vs. 64.6 +/- 8.0, p = 177). Each subject performed a Wingate cycle protocol to test anaerobic power and capacity, an incremental treadmill maximal oxygen uptake test for aerobic capacity, isokinetic tests for knee flexion/extension and shoulder internal/external rotation strength, and the Army Physical Fitness Test. Results showed group 1: < 18% BF performed significantly better on 7 of the 10 fitness tests. In Soldiers with similar amounts of FFM, Soldiers with less body fat had improved aerobic and anaerobic capacity and increased muscular strength.

Minimal additional weight of combat equipment alters air assault soldiers' landing biomechanics.

The additional weight of combat and protective equipment carried by soldiers on the battlefield and insufficient adaptations to this weight may increase the risk of musculoskeletal injury. The objective of this study was to determine the effects of the additional weight of equipment on knee kinematics and vertical ground reaction forces (VGRF) during two-legged drop landings. We tested kinematics and VGRF of 70 air assault soldiers performing drop landings with and without wearing the equipment. Maximum knee flexion angles, maximum vertical ground reaction forces, and the time from initial contact to these maximum values all increased with the additional weight of equipment. Proper landing technique, additional weight (perhaps in the form of combat and protective equipment), and eccentric strengthening of the hips and knees should be integrated into soldiers' training to induce musculoskeletal and biomechanical adaptations to reduce the risk of musculoskeletal injury during two-legged drop landing maneuvers.

Warrior Model for Human Performance and Injury Prevention: Eagle Tactical Athlete Program (ETAP) Part I.

INTRODUCTION: Physical training for United States military personnel requires a combination of injury prevention and performance optimization to counter unintentional musculoskeletal injuries and maximize warrior capabilities. Determining the most effective activities and tasks to meet these goals requires a systematic, research-based approach that is population specific based on the tasks and demands of the warrior. OBJECTIVE: We have modified the traditional approach to injury prevention to implement a comprehensive injury prevention and performance optimization research program with the 101st Airborne Division (Air Assault) at Ft. Campbell, KY. This is Part I of two papers that presents the research conducted during the first three steps of the program and includes Injury Surveillance, Task and Demand Analysis, and Predictors of Injury and Optimal Performance. METHODS: Injury surveillance based on a self-report of injuries was collected on all Soldiers participating in the study. Field-based analyses of the tasks and demands of Soldiers performing typical tasks of 101st Soldiers were performed to develop 101st-specific laboratory testing and to assist with the design of the intervention (Eagle Tactical Athlete Program (ETAP)). Laboratory testing of musculoskeletal, biomechanical, physiological, and nutritional characteristics was performed on Soldiers and benchmarked to triathletes to determine predictors of injury and optimal performance and to assist with the design of ETAP. RESULTS: Injury surveillance demonstrated that Soldiers of the 101st are at risk for a wide range of preventable unintentional musculoskeletal injuries during physical training, tactical training, and recreational/sports activities. The field-based analyses provided quantitative data and qualitative information essential to guiding 101st specific laboratory testing and intervention design. Overall the laboratory testing revealed that Soldiers of the 101st would benefit from targeted physical training to meet the specific demands of their job and that sub-groups of Soldiers would benefit from targeted injury prevention activities. CONCLUSIONS: The first three steps of the injury prevention and performance research program revealed that Soldiers of the 101st suffer preventable musculoskeletal injuries, have unique physical demands, and would benefit from targeted training to improve performance and prevent injury.

Warrior Model for Human Performance and Injury Prevention: Eagle Tactical Athlete Program (ETAP) Part II.

INTRODUCTION: Physical training for United States military personnel requires a combination of injury prevention and performance optimization to counter unintentional musculoskeletal injuries and maximize warrior capabilities. Determining the most effective activities and tasks to meet these goals requires a systematic, research-based approach that is population specific based on the tasks and demands of the Warrior. OBJECTIVE: The authors have modified the traditional approach to injury prevention to implement a comprehensive injury prevention and performance optimization research program with the 101st Airborne Division (Air Assault) at Fort Campbell, KY. This is second of two companion papers and presents the last three steps of the research model and includes Design and Validation of the Interventions, Program Integration and Implementation, and Monitor and Determine the Effectiveness of the Program. METHODS: An 8-week trial was performed to validate the Eagle Tactical Athlete Program (ETAP) to improve modifiable suboptimal characteristics identified in Part I. The experimental group participated in ETAP under the direction of a ETAP Strength and Conditioning Specialist while the control group performed the current physical training at Fort Campbell under the direction of a Physical Training Leader and as governed by FM 21-20 for the 8-week study period. RESULTS: Soldiers performing ETAP demonstrated improvements in several tests for strength, flexibility, performance, physiology, and the APFT compared to current physical training performed at Fort Campbell. CONCLUSIONS: ETAP was proven valid to improve certain suboptimal characteristics within the 8-week trial as compared to the current training performed at Fort Campbell. ETAP has long-term implications and with expected greater improvements when implemented into a Division pre-deployment cycle of 10-12 months which will result in further systemic adaptations for each variable.