Risk Factors for Musculoskeletal Injuries in Military Recruits: The Impact of Sex, Body Fat Percentage, and Physical Fitness.

INTRODUCTION

Basic military training is crucial for preparing civilians for military life. This period prepares them with physical and cognitive skills required for military service. However, basic military training is marked by a high incidence of musculoskeletal injuries. In addition, female sex has been identified as a risk factor in military training courses, contributing to higher medical treatment costs and reduced operational readiness.

OBJECTIVE

To investigate the incidence of musculoskeletal symptoms and injuries in male and female recruits during sixteen weeks of Brazilian Marine Basic Military Training, as well as to assess their potential risk factors.

METHODS

A total of 626 military recruits were enrolled in the training period. The study was divided into two phases. Firstly, a cross-sectional analysis included body composition assessment and physical fitness tests. Secondly, a retrospective analysis included the application of the Nordic Musculoskeletal Symptoms Questionnaire (NMQ) at the end of the course to assess the musculoskeletal complaints experienced by the recruits. A logistic regression analysis investigated factors associated with injuries, adjusting for physical fitness variables. Data analysis was performed using Jamovi software, with a significance level set at 0.05.

RESULTS

The NMQ revealed that women had a higher risk in the following categories: any symptom, symptoms that resulted in time loss from duties, symptoms that required medical attention, symptoms in the 7 days preceding the baseline evaluation, trunk injuries, upper and lower limbs injuries. However, after adjusting for physical fitness variables, the fitness-related factors associated with the incidence of musculoskeletal symptoms were body fat percentage and running performance only for symptoms that led to medical consultation or duty restriction. Sex was associated only with the week in which the NMQ was administered. The activities associated with a higher risk of injuries in women were drill and ceremonies, load carriage marching, and obstacle courses.

CONCLUSIONS

The present study identified that sex, body fat percentage, and running performance were risk factors for musculoskeletal symptoms in recruits. Additionally, physical training, loaded marching, and running were the activities most associated with injuries during the training course.