Because the military primarily recruits from a population that is accruing its peak bone mass, the BCNH subcommittee recommends that research efforts should contribute to identifying those factors, such as diet, lifestyle, and ethnicity, that may contribute to achieving peak bone mass, as well as components of military programs that may interfere with this process. The Report on Injuries in the Military: The Hidden Epidemic (AFEB, 1996) similarly recommends the identification and surveillance of those risk factors contributing to stress fracture injuries.
Efforts should be made to investigate more fully the now-preliminary linkages between low skeletal muscle mass, particularly in women, and stress fracture risk. Investigators should attempt to determine if this injury risk is a result of low skeletal muscle mass per se or a manifestation of inappropriately designed or enforced training programs.
Most of the evidence reviewed by the BCNH subcommittee indicated no detrimental effects on bone health from the use of oral contraceptives. However, the subcommittee recommends that future research is needed on the effects of implant or injectable contraceptives, such as Depo-Provera, on BMD and bone strength. Chemical formulation, dosage, and route of administration require further investigation.
Research is needed to assess the effect of military women's dietary energy status on the secretion of hormones that affect bone health, particularly in situations of high metabolic stress. Little is known about predisposing factors that alter the menstrual cycle.
The military should continue to gather dietary intake data and evidence concerning calcium intakes throughout a soldier's career as training programs, food choices, and food supply change over time.
Based on preliminary data from athletes, loss of calcium in sweat due to physical exertion during training as a potential pathophysiological factor on the development of stress fracture needs to be investigated. These preliminary data raise a broader question about the impact of high levels of activity on calcium requirement.
More research is needed that evaluates existing technologies of assessing risk of stress fracture, including ultrasound, central and peripheral DXA and central and peripheral QCT. Ultimately the cost-benefit analysis of all techniques will have to be assessed for specific uses and populations within the military.
The DoD should support the development of mechanical models that link skeletal muscle mass, force/torque, and bone stress in humans. As part of this process, efforts should be made to improve existing in vivo methods of quantifying components of these models, including mechanical loads and skeletal muscle mass.