Understanding the musculoskeletal injury risk of women in combat: the effect of infantry training and sex on musculoskeletal injury incidence during British Army basic training

Abstract

IntroductionUntil recently, women were excluded from British combat roles. Their risk for musculoskeletal injury during basic training is two to three times higher than men. To better understand the musculoskeletal injury risk of women in British Army infantry basic training, we compared injury incidence between (1) men in standard entry training and men in infantry training, to assess the risk of infantry training; and (2) men and women in both standard entry and officer basic training, to assess the risk in women compared with men.MethodsThe incidence of musculoskeletal injury was determined from defence medical records for all men entering infantry training, and for all men and women entering standard entry and officer training, between April 2015 and March 2016.Results7390 men (standard entry, n=4229; infantry, n=2683; officer, n=478) and 696 women (standard entry, n=626; officer, n=70) entered basic training. Men in infantry training had a lower incidence of musculoskeletal injury (391 vs 417 per 1000 personnel, OR 0.90 (95% CI 0.81 to 0.99), p=0.028) and a higher incidence of stress fracture (14 vs 5 per 1000 personnel, OR 2.80 (95% CI 1.64 to 4.80), p<0.001) than men in standard entry training. Women had a higher incidence of musculoskeletal injury than men in standard entry training (522 vs 417 per 1000 personnel, OR 1.53 (95% CI 1.29 to 1.81), p<0.001) and a higher incidence of stress fracture than men in officer training (114 vs 19 per 1000 personnel, OR 6.72 (95% CI 2.50 to 18.07), p<0.001).ConclusionWomen in infantry training may be at similar risk for musculoskeletal injury, but at higher risk for stress fracture, compared with their non-infantry counterparts. Women in infantry training may be at higher risk for musculoskeletal injury and stress fracture compared with men in infantry training.

Energy Deficiency in Soldiers: The Risk of the Athlete Triad and Relative Energy Deficiency in Sport Syndromes in the Military

“…Stress fractures at weight-bearing sites are common during basic military training (25,118,119), more so in women than in men (120,121). Skeletal injuries are indicative of the high mechanical stresses of military activities, but decreased bone formation and increased bone resorption with low energy availability could decrease mechanical strength of bone and increase the propagation of microcracks with repeated loading.…”

“…Men make-up most of the military, and women have only recently been permitted to enter combat roles in several countries including the UK and US. Women in these combat roles are likely to experience higher physical demands (29,196,211), have poorer physical performance (211), a higher incidence of musculoskeletal injuries and stress fractures (121), and increased risk of reproductive disturbances with low energy availability (102), compared with men. Better understanding of the effects of low energy availability on the health and performance of women in military roles, including combat roles, is an important area of future study.…”

Dietary Intake and Nitrogen Balance in British Army Infantry Recruits Undergoing Basic Training

“…This study is not without its limitations. Firstly, only male participants were included, therefore the protein requirements in women during British Army infantry BT remain unknown and should be investigated as women are at a greater risk of musculoskeletal injury compared to men during BT [ 6 ]. Secondly, this study used the nitrogen balance method which has been suggested to underestimate protein requirements [ 55 ] due to an underestimation of nitrogen excretion [ 51 ].…”

“…Both courses are characterised by high daily physical demands [ 1 , 2 ] which contribute to high rates of musculoskeletal injuries in recruits [ 3 , 4 , 5 ]. High daily physical demands combined with other risk factors such as high mechanical loading, sleep restriction, psychological stress, smoking and poor vitamin D status likely exacerbate injury risk in recruits [ 6 ]. Men undergoing the CMS have a greater incidence rate of injury compared to their CIC counterparts (417 vs. 391 injuries per 1000 recruits) [ 6 ].…”

“…High daily physical demands combined with other risk factors such as high mechanical loading, sleep restriction, psychological stress, smoking and poor vitamin D status likely exacerbate injury risk in recruits [ 6 ]. Men undergoing the CMS have a greater incidence rate of injury compared to their CIC counterparts (417 vs. 391 injuries per 1000 recruits) [ 6 ]. The high incidence rates of injury in both courses has a detrimental effect on recruit wastage and organisational effectiveness [ 5 ].…”