title: Musculoskeletal, biomechanical, and physiological gender differences in the US military.
abstract: 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.
  
  
  OBJECTIVE
  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.
authors.affiliation: Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Katelyn F
authors.initials: KF
authors.lastname: Allison
authors.forename: Karen A
authors.initials: KA
authors.lastname: Keenan
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Sell
authors.forename: John P
authors.initials: JP
authors.lastname: Abt
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
authors.forename: Jennifer
authors.initials: J
authors.lastname: Deluzio
authors.forename: Mark
authors.initials: M
authors.lastname: McGrail
authors.forename: Scott M
authors.initials: SM
authors.lastname: Lephart
mesh_terms: D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D008889:Military Personnel / Q000706:statistics & numerical data; D010101:Oxygen Consumption; D016059:Range of Motion, Articular; D013647:Task Performance and Analysis; D014481:United States; D034941:Upper Extremity / Q000502:physiology
keywords: aerobic and anaerobic fitness; female; flexibility; kinematics; male; strength