The Association Between Sleep and Musculoskeletal Injuries in Military Personnel: A Systematic Review

Oral habits and temporomandibular joint disorders according to stress levels among military personnel in South Korea: A cross-sectional study

BACKGROUND

Military personnel suffer from stress-induced temporomandibular joint disorders (TMD). No previous studies have evaluated the oral habits and TMD in military personnel based on their stress levels.

OBJECTIVES

To examine the correlation between oral habits and TMD based on stress levels. In addition, we assessed the relationship between stress levels and TMD by military rank as well as the impact of oral habits on TMD.

METHOD

This cross-sectional survey included 89 military personnel who visited the Armed Forces Medical Center in Korea with discomfort in the temporomandibular joint (TMJ) discomfort. Oral habits, stress level, TMD and general characteristics of the subjects were investigated. A questionnaire was distributed to the subjects who agreed to the study, and they were asked to respond in a self-written form. Multiple linear regression analysis was performed to examine the factors that affect oral habits and TMJ symptoms.

RESULTS

Stress scores and oral habits were highest in the 'Private' rank. In contrast, temporomandibular joint symptoms were highest in the 'Corporal' rank. Additionally, the high-risk stress group exhibited higher scores in oral habits and TMD compared to the potential stress group. Furthermore, there was a positive correlation between an increase in high-risk stress scores and a rise in oral habits. And individuals with more oral habits are at an increased likelihood of experiencing TMD.

CONCLUSION

Our study findings suggest that military personnel with prevent TMD and improve oral habits by addressing stress levels.

Sleep Quality as a Mediator of Burnout, Stress and Multisite Musculoskeletal Pain in Healthcare Workers: A Longitudinal Study

This study aimed to verify whether sleep quality is a mediator of the relationship between burnout, stress and multisite pain in healthcare workers in a longitudinal study with 12 months of follow-up during the COVID-19 pandemic. Online questionnaires were used for data collection. The sociodemographic questionnaire contained personal and occupational data. The short version of the Copenhagen Psychosocial Questionnaire (COPSOQ II-Br) was used to assess burnout and stress. The Pittsburgh Sleep Quality Index (PSQI-Br) assessed sleep quality over one month. The Nordic Musculoskeletal Questionnaire (NMQ) aimed to identify the presence of multisite musculoskeletal pain in the last 12 months and the last 7 days. Mediation analysis was used to verify whether the effect of the predictor variables (burnout and stress) on the dependent variable (number of pain sites in the last 12 months and 7 days) was due to an intervening variable (sleep quality). Stress and burnout were associated with multisite pain in healthcare workers in the last 12 months and the last 7 days. Sleep quality was a significant mediator of this association in the last 12 months, indicating that some of the association between burnout, stress and multisite pain can be explained by poor sleep quality. Thus, a comprehensive approach to long-term multisite pain should consider psychosocial aspects such as burnout, stress and sleep quality.

Short sleep duration is associated with a wide variety of medical conditions among United States military service members

OBJECTIVES

This cross-sectional study investigated self-reported sleep duration and its association with a comprehensive range of clinically-diagnosed medical condition categories (CDMCs), as well as the relationship between short sleep duration (≤6 h) and demographic/lifestyle factors, among United States military service members (SMs).

METHODS

A stratified random sample of SMs (n = 20,819) completed an online questionnaire on usual daily hours of sleep and demographic/lifestyle characteristics. CDMCs for a six-month period prior to questionnaire completion were obtained from a comprehensive military electronic medical surveillance system and grouped into 33 CDMCs covering both broad and specific medical conditions. Prevalence of CDMCs was compared among three sleep duration categories (≤4, 5-6 and ≥7 h).

RESULTS

SMs reported a mean ± standard deviation of 6.3 ± 1.4 h of sleep per day. After adjustment for demographic/lifestyle characteristics, shorter sleep duration was associated with higher odds of a medical condition in 25 of 33 CDMCs, with most (n = 20) demonstrating a dose-response relationship. The five CDMCs with the largest differences between ≤4 vs ≥ 7 h sleep were: diseases of the nervous system (odds ratio [OR] = 2.9, 95% confidence interval [95%CI] = 2.4-3.4), mental/behavioral diseases (OR = 2.7, 95%CI = 2.3-3.2), diseases of the musculoskeletal system (OR = 1.9, 95%CI = 1.6-2.1), diseases of the circulatory system (OR = 1.7, 95%CI = 1.3-2.2), and diseases of the digestive system (OR = 1.6, 95%CI = 1.2-2.0). Six hours of sleep or less was independently associated with older age, less formal education, race, Hispanic ethnicity, higher body mass index, smoking, and military service branch.

CONCLUSIONS

In this young, physically active population, reporting shorter sleep duration was associated with a higher risk of multiple CDMCs.

Assessment of Training Load, Sleep, Injuries, and Operational Physical Performance During Basic Military Qualification

INTRODUCTION

Optimizing training load (TL) and sleep is essential to maximize physical performance and prevent musculoskeletal injuries (MSKIs) for Canadian forces recruits during the 10-week basic military qualification (BMQ) course. The purpose of this study was to assess the TL, sleep duration, the occurrence of MSKIs during the BMQ, and the operation fitness performance during the BMQ.

MATERIALS AND METHODS

Forty Canadian recruits, eight females and 32 males, (age 24 ± 5 years; height 176.4 ± 10.4 cm), were monitored with an accelerometer (GENEActiv) on their wrist between weeks 1 and 9 to evaluate the TL and sleep duration. During weeks 2 and 10, the recruits completed an operational fitness evaluation. Injury surveillance was performed over 10 weeks.

RESULTS

TL intensity was significantly different (P = 0.0001) from week to week. The weekly average total time of moderate and vigorous physical activity was 189.7 ± 48.1 min and 44.7 ± 15.2 min, respectively. The average sleep duration was 5.4 ± 0.4 h per night and decreased to 4.2 h ± 0.4 during field exercises. A significant difference in sleep duration was observed between recruits with and without a MSKI. The recruits accumulated a total of 95 days under medical restrictions with an average of 3.8 consecutive days. The VO2peak estimated from the Fitness for Operational Requirements of Canadian Armed Forces Employment job-based simulation test significantly improved from weeks 2 to 10 (pre, 47.1 ± 6.3; post: 50.2 ± 5.8; P = 0.001).

CONCLUSIONS

TL is of high magnitude and varies from week to week. The reported mean sleep duration per week may perhaps negatively impact the occurrence of MSKI. No significant improvement was detected in operational fitness by the end of the BMQ.