Lower Extremity Stress Fractures in the Military Jeremy M. Jacobs, MD a , Kenneth L. Cameron, PhD, MPH, ATC b , John A. Bojescul, MD a, * INTRODUCTION Stress fractures are common injuries in athletes, dancers, and military populations. 1–6 These fractures can be partial or complete fractures of bone that result from repetitive microtrauma. Bone remodeling normally occurs as a balance of osteoclastic resorp- tion and osteoblastic production in response to physiologic stress and mechanical loads. As osteoblastic activation lags behind resorption, there is a period of time when fracture risk increases because of weakened bone. 7–9 Many individuals who sustain stress fractures can identify a sudden increase in workout intensity or duration as a precipitating factor for injury, and it is thought that gradual progressions in both exercise intensity and duration may reduce the risk of fracture. 3 As the nation has become more sedentary and overweight in recent years, the overall fitness level of mil- itary recruits has declined. 10 As a result, the rigorous physical requirements during basic combat training place the new soldier at an increased risk for sustaining several lower extremity overuse injuries; however, one of the most significant injuries a Dwight David Eisenhower Army Medical Center, 300 E Hospital Road, Ft Gordon, GA 30905, USA; b Keller Army Community Hospital, 900 Washington Road, West Point, New York 10996, USA * Corresponding author. E-mail address: John.a.bojescul2.mil@mail.mil KEYWORDS  Stress fracture  Military  Recruit  Femoral neck KEY POINTS  Stress fractures of the lower extremities are common among the military population and athletes.  Modifiable risk factors include poor nutritional status, low entry-level fitness, and rapid progression of intensity and duration of exercise.  Nonmodifiable risk factors include female sex, advanced age, and those individuals who have already sustained a stress fracture.  Prevention is aimed at manipulating the modifiable risk factors, such as altering overall training volume and limiting distance running.  In the soldier or athlete who presents with activity-related pain, stress fractures should be given significant consideration during the clinical evaluation. Clin Sports Med 33 (2014) 591–613 http://dx.doi.org/10.1016/j.csm.2014.06.002 sportsmed.theclinics.com 0278-5919/14/$ – see front matter Published by Elsevier Inc.