I started as a Mechanical Engineer in the defence sector, testing armour materials. I transitioned into the ergonomics MSc program. where I am investigating the comfort of body armour systems and further exploring as a new PhD researcher.
I started as a Mechanical Engineer in the defence sector, testing armour materials. I transitioned into the ergonomics MSc program. where I am investigating the comfort of body armour systems and further exploring as a new PhD researcher.
Introduction
Body armour (BA) is critical for military, law enforcement, and security personnel, offering essential protection in hazardous environments. However, wearability remains a concern as discomfort from poorly designed BA systems can hinder performance and well-being. Wearability encompasses factors like ease of movement, thermal comfort, pressure distribution, and overall comfort. Previous studies indicate that discomfort from BA can limit mobility and increase fatigue, especially during prolonged use.
This study aims to evaluate the wearability of BA during sub-maximal activities, focusing on both overall and local comfort sensations. By using subjective comfort scales and body mapping techniques, this research seeks to identify predictors of overall wearability and potential areas for BA design improvement. The study also assesses the usability of the developed methodology for evaluating BA wearability.
Objectives
The primary objective is to evaluate BA wearability using subjective comfort scales and body mapping. The research aims to answer:
The study investigates the relationships between comfort variables such as ease of movement (EoM), pressure comfort (PC), and thermal sensation (ThermSen), and their role in predicting wear discomfort (WC).
Methods
Five male participants completed three circuits of six activities, simulating postures and movements common in military or security tasks, such as standing upright, leaning forward, arm movements, lying prone and supine, and walking on a treadmill. Each participant wore three different clothing conditions: no BA (control), a police-style stab vest (4kg), and a military-style ballistic vest (12kg). The weight of each vest was evenly distributed to minimize the effects of asymmetrical loading.
Subjective scales measured wear discomfort (1-7), ease of movement (0-12), pressure comfort (1-7), and thermal sensation (-10 to 20). Texture (TextSen) and stickiness (StickSen) were assessed during the walking task. A body map divided the torso into seven regions—neck, chest, shoulders, upper abdomen, lower abdomen, upper back, and lower back—to assess localised discomfort.
Data was collected in Microsoft Excel and analyzed using IBM SPSS V.29, with statistical significance set at p < 0.05. Correlation and regression analyses explored relationships between comfort variables and overall WC. Heatmaps visualized regional discomfort for each BA condition.
Results
EoM and PC were the strongest predictors of overall WC, with both showing strong correlations (p-values < 0.001). EoM explained 88.8% of WC variance, and PC explained 92.1%. ThermSen was also significant (p < 0.001) but accounted for only 48.5% of the variance. TextSen was strongly correlated with WC during walking, but StickSen showed only a moderate correlation.
Multiple regression analysis confirmed that PC was the most significant predictor of WC, followed by EoM. ThermSen was not significant when combined with other variables (p = 0.283). Heatmaps revealed that the military vest caused discomfort around the chest, upper back, and shoulders, while the police vest resulted in moderate discomfort in the frontal chest and upper back areas. The control condition showed minimal discomfort.
Discussion
The results highlight that EoM and PC are key indicators of BA wearability, with the military vest exerting more pressure on the shoulders and chest, leading to discomfort and restricted movement. In contrast, the police vest caused less restriction, although discomfort was still present. The significance of ThermSen was evident during physically exerting tasks like walking but was less important in neutral temperature conditions.
The usability assessment scored 34 out of 50. The study design was efficient and easy for participants to follow, but the results were potentially affected by anchor bias, where participants may have based their responses on earlier comfort scores. To reduce bias, future studies should alter the reporting frequency and simplify the body map to maintain participant engagement and accuracy.
Conclusion
This study developed a reliable method for assessing BA wearability, identifying pressure comfort and ease of movement as critical predictors of overall comfort. The body mapping and subjective scales provided insights into regional discomfort, which can inform design improvements. However, future research should increase the sample size, improve BA fit, and investigate weight distribution effects on shoulder discomfort. Additional studies can refine the method, ensuring more reliable and consistent results in BA wearability assessments.