LAUSR

This article reviews the physiological, biomechanical, and health impacts of load carriage on the female soldier and includes issues impacting on the female athlete and hence female soldier. Physiological factors (e.g., mass, strength, and aerobic endurance) and biomechanical factors (e.g., forward trunk lean and step length) have the potential to increase the energy cost of load carriage and injury risk. Optimal load carriage conditioning guidelines are presented while considering issues specific to the female soldier, including the female athlete triad and pelvic floor muscle dysfunction, which can likewise reduce performance and increase injury risk. LOAD CARRIAGE AND THE FEMALE SOLDIER W ith the removal of sex restrictions from military combat trades (65), the numbers of women serving in defense forces are growing (19), and there has been an increase in female soldiers engaged in combat (9), receiving awards for combat actions (94) and becoming combat fatalities (94). While on combat operations, soldiers, regardless of sex, are required to carry heavy loads, loads that history would indicate are increasing (47,70). These carried loads include vital stores, ammunition, and equipment and can exceed 45 kg on combat operations (20,75). Considering these loads, women are, on average, about 13 kg lighter than men and have approximately 35% less muscle mass (36). As such, a set combat load (e.g., 45 kg) carried by a female soldier could equate to a much higher load relative to body or muscle mass when compared with their male counterpart. Earlier research by Orr et al. (75), before the removal of sex restrictions from combat roles, found that female soldiers carried similar relative loads (% of body mass) when compared with male soldiers but significantly lighter absolute loads. With the loads required to remain extant for combat operations regardless of sex (65), the removal of sex restrictions will likely lead to an increased absolute load for female soldiers (commensurate with those carried by male soldiers) and hence a greater relative load. This supposition is supported by research in law enforcement (4). A study in U.S. law enforcement officers by Baran et al. (4) found that although female officers wore and carried similar absolute loads to those of male officers, female officers wore and carried significantly heavier relative loads. With combat loads increasing, the numbers of female soldiers exposed to these heavy loads increasing, and the potential for these loads to be relatively greater for female soldiers, it is of no surprise that load carriage is considered one of the major physical challenges for female soldiers seeking to demonstrate competence in combat arms professions (65). There are significant differences between men and women in average muscular and cardiovascular fitness, and heavier combat loads are likely associated with increased risk of injury in female soldiers in particular. Given that physiological differences between women andmen are taken into consideration when training athletes (88), similar considerations should be given to female soldiers who are required to carry, and be conditioned to carry, heavy loads during their military service. The purpose of this article is to review the physiological, biomechanical, and injury risk factors associated with load carriage on the female soldier. Also, these facts will recommend conditioning strategies and sex-specific issues impacting on the female athlete and soldier to make recommendations regarding approaches to conditioning of female soldiers for load carriage. LOAD CARRIAGE AND ITS PHYSIOLOGICAL IMPACT The greater the load carried, the greater the energy cost of standing and moving (11,78,85). With female soldiers wearing and carrying combat loads, whether standing at a vehicle check point or patrolling, the weight Address correspondence to Dr. Robin M. Orr, [email protected].