title: BMI and Lower Extremity Injury in U.S. Army Soldiers, 2001-2011.
abstract: Little data exist regarding the long-term impact of excess weight on lower extremity musculoskeletal injury/disorder (MID) in U.S. Army Soldiers. This prospective analysis examines the association between BMI of Soldiers at accession and risk of MID.
  
  
  
  A total of 736,608 Soldiers were followed from accession into the Army, 2001-2011. Data were analyzed January through March 2015. MID was categorized as any first incident lower extremity musculoskeletal injury/disorder, and secondarily, as first incident injury/disorder at a specific site (i.e., hips, upper legs/thighs, knees, lower legs/ankles, feet/toes). Multivariable-adjusted proportional hazards models estimated associations between BMI category at accession and MID risk.
  
  
  
  During 15,678,743 person-months of follow-up, 411,413 cases of any first MID were documented (70,578 hip, 77,050 upper leg, 162,041 knee, 338,080 lower leg, and 100,935 foot injuries in secondary analyses). The overall MID rate was 2.62 per 100 person-months. Relative to Soldiers with normal BMI (18.5 to <25 kg/m(2)) at accession, those who were underweight (<18.5); overweight (25 to <30); or obese (≥30) had 7%, 11%, and 33% higher risk of MID, respectively, after adjustment. Risks were highest in Soldiers who were obese at accession, and lowest in those with a BMI of 21-23 kg/m(2).
  
  
  
  Soldier BMI at accession has important implications for MID. A BMI of 21-23 kg/m(2) in newly accessing Soldiers was associated with the lowest risk of incident MID, suggesting that accession be limited to people within this range to reduce overall incidence of MID among service personnel.
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts; Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts.
authors.forename: Adela
authors.initials: A
authors.lastname: Hruby
authors.affiliation: Environmental Medicine Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts; Center for the Intrepid, Fort Sam, Houston, Texas.
authors.forename: Lakmini
authors.initials: L
authors.lastname: Bulathsinhala
authors.affiliation: Environmental Medicine Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts.
authors.forename: Craig J
authors.initials: CJ
authors.lastname: McKinnon
authors.affiliation: Environmental Medicine Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts; Center for the Intrepid, Fort Sam, Houston, Texas.
authors.forename: Owen T
authors.initials: OT
authors.lastname: Hill
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Montain
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Young
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts. Electronic address: tracey.smith10.civ@mail.mil.
authors.forename: Tracey J
authors.initials: TJ
authors.lastname: Smith
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D006801:Humans; D015994:Incidence; D035002:Lower Extremity / Q000293:injuries*; D008297:Male; D008889:Military Personnel; D009765:Obesity / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology