Military training is physically arduous and associated with high injury incidence. Unlike in high‐performance sport, the interaction between training load and injury has not been extensively ...researched in military personnel. Sixty‐three (43 men, 20 women; age 24 ± 2 years; stature 1.76 ± 0.09 m; body mass 79.1 ± 10.8 kg) British Army Officer Cadets undergoing 44 weeks of training at the Royal Military Academy Sandhurst volunteered to participate. Weekly training load (cumulative 7‐day moderate‐vigorous physical activity MVPA, vigorous PA VPA, and the ratio between MVPA and sedentary‐light PA SLPA; MVPA:SLPA) was monitored using a wrist‐worn accelerometer (GENEActiv, UK). Self‐report injury data were collected and combined with musculoskeletal injuries recorded at the Academy medical center. Training loads were divided into quartiles with the lowest load group used as the reference to enable comparisons using odds ratios (OR) and 95% confidence intervals (95% CI). Overall injury incidence was 60% with the most common injury sites being the ankle (22%) and knee (18%). High (load; OR; 95% CI >2327 mins; 3.44; 1.80–6.56) weekly cumulative MVPA exposure significantly increased odds of injury. Similarly, likelihood of injury significantly increased when exposed to low‐moderate (0.42–0.47; 2.45 1.19–5.04), high‐moderate (0.48–0.51; 2.48 1.21–5.10), and high MVPA:SLPA loads (>0.51; 3.60 1.80–7.21). High MVPA and high‐moderate MVPA:SLPA increased odds of injury by ~2.0 to 3.5 fold, suggesting that the ratio of workload to recovery is important for mitigating injury occurrence.
Abstract
Introduction
Military operations require vigilance and performance under stressful conditions while functioning with little to no sleep. Previous links between marksmanship performance and ...sleep restrictions have been shown primarily in novice Soldier populations, with significant decrements in reaction time and decision making skills rather than lethality, mobility, or weapon handling metrics. Additionally, previous research has focused on isolated static marksmanship tasks in laboratory settings. The research presented here assessed the relationship between changes in Soldier sleep duration as measured by actigraphy, and marksmanship performance when conducting a 72-hour military field training exercise.
Methods
Forty-six volunteers 42 males (age 24.5±4.2y; mean±SD) across three platoons participated in this assessment of Soldier performance during a company-wide mission exercise. Sleep characteristics were collected via actigraphy throughout the mission. Marksmanship performance was assessed during pre-, mid-, and post-mission, utilizing an operationally relevant course that integrated a static self-paced shooting task with a dynamic, fast-paced multiple target task. Marksmanship was assessed in areas of lethality (e.g. accuracy, shot dispersion), mobility (e.g. acquisition, engagement times), and weapon handling stability (e.g. movement of barrel during aiming).
Results
Analysis utilized a multivariate analysis of covariance (MANCOVA) with platoon as the independent variable and total sleep time over the previous 24-hours as the covariant, during the mid-session assessment. The results indicated that prior sleep does significantly modulate marksmanship performance in areas of lethality and stability (ps<.05), but not mobility. Although all individuals received fewer hours of sleep than typical during the mission, those who received less sleep had greater inaccuracy and dispersion in their shot groups, and more barrel movement during weapon handling.
Conclusion
Marksmanship is a key military skill required of all Soldiers. This study has linked degradations in marksmanship lethality and stability performance in the field to naturally occurring sleep restrictions due to platoon-group variances during mission activities. Additionally, it is the first study to link weapon handling stability degradations to sleep loss. Further analysis will explore performance degradations associated with aspects of sleep quality, as well as individual platoon differences, such as leadership, qualifications, and resiliency.
Support
CCDC Soldier Center and Military Operational Medicine Research Program.
Together, electrochemical aptamer sensors and rapidly advancing wearable device platforms (Fig. 1) now place the field in technological position to achieve that long sought-after watershed moment of ...the ability to pursue the continuous measurement of a wide spectrum of small molecule and protein biomarkers. For sweat, the presentation will focus on the need for reliable sweat stimulation, dealing with miniscule sample volumes, effects of variable pH and salinity, and the limited biomarkers that work well in sweat such as small hydrophobic molecules (i.e., drugs, steroid hormones). With biosensing device technology rapidly maturing, and an improved fundamental understanding of what biomarkers are most feasible for blood correlation, interstitial fluid and sweat are now at the point where we can credibly pursue continuous sensing of biomarkers of performance and injury in the warfighter.Fig. 1Two successes currently exist in continuous, minimally invasive, and blood-correlated biosensing: sensing of glucose in dermal interstitial fluid (left1); sensing of ethanol in sweat (right2).Figure 1 Acknowledgements: Biosensor research in Prof. Heikenfeld’s group at the Univ. of Cincinnati has been supported by the U.S. Office of Naval Research, the U.S. Airforce Office of Scientific Research, and the U.S. National Science Foundation.
Abstract
Introduction
Sleep disruption is prevalent among active military personnel. For some, there is the added environmental stressor of repetitive, low-level blast exposures. Though there are ...subjective reports that blasts affect sleep, objective measurement is lacking. In this observational study, we examined sleep across 2-week military training with exposure to blast. Across all training days blast intensity was low (<2psi), except for a single day, Day 7 (peak pressure M=7.99psi, SD=1.66). As such, we predicted that sleep would be acutely fragmented and shortened following that moderate blast exposure.
Methods
Participants were 31 males, aged 25–42 years. Sleep efficiency (SE) and total sleep time (TST) were measured using wrist-worn actigraphy. Peak intensity of blast exposure was captured daily via helmet-mounted pressure sensors. Training Day 5 was selected as baseline as participants were not exposed to blast training or night operations. Pairwise comparisons t-test (TST) and Wilcoxon matched-pairs (SE) were run to compare sleep at baseline to the training days (6–10).
Results
TST was consistently short (daily M≤6hours) and there were no significant differences in TST between the training days. Although SE was significantly different between Day 5 and Day 8 (reflecting sleep following blast on Day 7), this reduction in sleep efficiency did not seem to reflect an acute effect of blast, but a more general decline in SE observed between baseline and Days 7, 8, 9, and 10 (p<.05).
Conclusion
TST was consistently short (daily M≤6hours) and there were no significant differences in TST between the training days. Although SE was significantly different between Day 5 and Day 8 (reflecting sleep following blast on Day 7), this reduction in sleep efficiency did not seem to reflect an acute effect of blast, but a more general decline in SE observed between baseline and Days 7, 8, 9, and 10 (p<.05).
Support (If Any)
This work was supported by the U.S. Army Medical Research and Materiel Command and federal institutional resources of the National Institute of Nursing Research at the National Institutes of Health.
Abstract
Introduction
The research on sleep in the social-psychological domain is sparse. Gordon and colleagues (Gordon, Mendes, & Prather, 2017) proposed a bidirectional relationship between sleep ...and social processes. The current research tests this model in the military by examining the relationship between subjective sleep quality and an important social cognitive process in the contexts of military teams - psychological safety (i.e., an individual’s perceptions of interpersonal threat in their work environment; Edmondson, 1999).
Methods
One hundred and twenty-eight U.S. Army tank crewmen were surveyed prior to (T1), and immediately after (T2), participating in a two-week simulated combat training exercise. Each survey included the seven-item Insomnia Severity Index (ISI; Bastien et al., 2001), which served as a measure of subjective sleep quality (SSQ), and Edmonson’s seven-item Psychological Safety Questionnaire which measured team psychological safety (TPS). A cross-lagged panel model tested the effects of SSQ and TPS over the course of the training.
Results
Both SSQ and TPS were stable over the two time points, SSQT1: M=2.83, SD=.85, α=.83; SSQT2: M=2.63, SD=.83, α=.83; B=.387, SE=.08, β=.397, p<.001, and TPST1: M=3.7, SD=.72, α=.79; TPST2: M=3.67, SD=.75, α=.77; B=.619, SE=.07, β=.600, p<.001, respectively. Although SSQ and TPS were weakly related to one another at both time points, rT1=.122, p=.086 and rT2=.171, p = .028, only the cross-lagged path between SSQT1 predicting TPST2 was significant, B=.129, SE=.06, β=.147, p=.038. The cross-lagged path between TPST1 predicting SSQT2 was not significant, B=-.098, SE=.094, β=-.086, p=.296. Approximately 40% of the variance in CPS, R2=.4 as opposed to 17% in SSQ, R2=.17, was accounted for by the predictors in the model.
Conclusion
These results provide support for a directional (vs bidirectional) link between SSQ and TPS, insomuch that, in the context of military training, SSQ influences TPS, as opposed to the other way around. Elucidating the directionality of this relationship is not only important for advancing theory, but more importantly, it helps practitioners develop programs and policies that precisely address the right mechanism at the right time to maximize team effectiveness and wellbeing.
Support
This work was supported by the Military Operational Medicine Research Program (MOMRP).
Introduction Research has demonstrated that military personnel sleep less and experience poorer quality sleep than the general civilian population and that sleep problems are related to degraded ...performance. However, differences in methodology for measuring sleep quantity and quality, as well as a lack of operationally-relevant performance metrics have led to challenges in demonstrating the importance of sleep in military populations. The goal of this analysis was to examine novel approaches of deriving sleep quality and quantity statistics and their relationships to health and performance outcomes in military settings. Methods Two studies of US Army Soldiers operating in Europe were used in the analysis, one during a training exercise and the other following a combat deployment to Afghanistan. In both studies, Soldiers completed health surveys at multiple time points and wore actigraphs. These data sources were used to examine discrepancies between self-report and objective sleep duration and to examine sleep patterns, including the shifting of sleep onset and offset times. These data, in addition to traditional sleep metrics, were then linked to health and performance outcomes. Results 167 (Study 1) and 87 (Study 2) Soldiers completed the studies. Initial analysis suggests that novel sleep statistics, such as discrepancies between subjectively and objectively-measured sleep and tendencies towards shifting of normal sleep patterns have a greater impact on the health of Soldiers and performance of military tasks than traditional measures of sleep quantity and quality. Conclusion Perceptions of sleep and sleep routines are particularly important factors for maintaining health and optimal performance in Soldiers. A better understanding is needed of the specific aspects and timing of sleep that are most relevant to the unique day-to-day functioning of military personnel in various real-world environments. Training on the impact of insufficient sleep and disruptions to normal sleep routines should be incorporated into the military culture. Support (If Any) Department of Defense Military Operational Medicine Research Program (MOMRP).
Abstract
This article starts with the application of virtual simulation training platform to practical teaching, and analyzes and researches the integration of practical teaching and virtual ...simulation technology. This article briefly describes the significance of integrating virtual simulation training platform into practical teaching, the specific path of applying virtual simulation training platform in practical teaching, and the precautions of virtual simulation training platform in practical teaching application. The author hopes that this article can provide a feasible new path reference for advancing the application of practical teaching in the new era.
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