Are female soldiers satisfied with the fit and function of body armour?

Clothing and Equipment Fit Among Male and Female Canadian Armed Forces Members

INTRODUCTION

The fit of military clothing and equipment is essential for the health and safety of military operators. Given the aim of increasing the proportion of women and the known biological and morphological differences between male and female soldiers, an understanding of fit across different items of kit is needed. The aim of this study was to quantify subjective fit ratings of 8 items of military clothing and equipment, including combat shirt, combat pants, rucksack, small pack, tactical vest, fragmentation vest, helmet, and ballistic eyewear as a function of relative stature and occupational group among male and female Canadian Armed Forces members.

MATERIALS AND METHODS

An online survey was distributed to male and female Canadian Armed Forces members, where fit was reported by participants according to a 7-point Likert acceptability scale. Participants were binned into 1 of 6 (3 males, 3 females) standing stature categories based on percentiles in a male and female distribution that included (1) under 35th percentile stature, (2) 35th to 80th percentile stature, and (3) over 80th percentile stature. Additionally, participants were separated according to occupational group: Group A: Infantry, Combat Engineer, Artillery, Armored; group B: Signals, Medical Technician, Intelligence, Signals Intelligence/Cyber Ops; group C: Supply Technician, Weapons Technician, Vehicle Technician, Electronic-Optronic Technician, Ammunition Technician; other: Not in other groups, examples include: Financial Services Administrator, Cook. This study was approved by the Defence Research and Development Canada Human Research Ethics Committee under protocol 2019-048, Amendment 2.

RESULTS

There were significant effects attributable to stature category and occupational group on the fit of equipment. Specifically, fit acceptability of the rucksack helmet, small pack, and tactical vest was significantly affected by occupational group. Differences between stature categories were detected in all items with the exception of the small pack.

CONCLUSIONS

Military equipment fit has previously been shown to have implications for protection, performance, and mobility. The results of the investigation demonstrate different patterns of fit acceptability in male and female soldiers across items of clothing and equipment and may require different solutions.

The comfort and functional performance of personal protective equipment for police officers: a systematic scoping review

This scoping review aimed to identify and summarise evidence on the comfort and functional performance of police officer personal protective equipment (PPE). The Arksey and O'Malley (2005) five-stage framework for scoping reviews was followed. PubMed, CINAHL, Scopus, and Web of Science were searched, and 35 articles were included in the review. The findings show that increased police PPE mass increases heart rate, metabolic energy expenditure, and perceived exertion in response to exercise. Unisex armour designs cause increased discomfort for females with larger bra sizes. PPE reduces joint-specific range of motion, with the design and location impairing movement more than mass. Jumping and sprinting performance is decreased with heavy PPE but unaffected by lighter protection, while agility is compromised with most forms of protection. Future research is needed on the fit and function of PPE for specialist police units, such as mounted police, along with further investigations on how fit can affect functional performance.

Occupational Safety and Health for Adult Saudi Arabian Women: Utilizing National Anthropometric Data

In the last five years, the female labor force has increased rapidly in Saudi Arabia. This is due to the new government's vision to empower women. For many decades, Saudi females were excluded from working in certain fields due to cultural restrictions. Nowadays, Saudi women are not only joining the service workforce but are currently employed in more physically demanding careers, such as manufacturing and military jobs, which were previously dominated by males. It becomes necessary to design workplaces, tools, and equipment to safely accommodate the female physical attributes, which include body dimensions. This study presents the anthropometric measurements of Saudi Arabian adult females. In total, 504 female subjects aged 20-70 participated in the study. Thirty-eight body measurements, including weight and triceps skinfold, were taken in sitting and standing postures. The main contribution of this study is to provide a national anthropometric database of Saudi females, which is very limited, especially for females in the age groups under study. The availability of such data will allow foreign and local manufacturers to design usable and safe products and workspaces for a wide range of Saudi adult females. The findings reveal that there are no significant differences in the body dimensions of Saudi females across all age groups, except for stature height, eye height, chest depth, skinfold (mm), sitting height, buttock-knee length, and hip breadth. The study also reveals that Saudi females' body sizes are different from other Asian, Middle Eastern, and British nations, which invalidates the assumption of using other nations' body measurements to estimate Saudis' body measurements. Utilizing the supermarket cashier workstation to assess the appropriateness of commercial station fit for Saudi females' body dimensions, the results underscore the crucial role of anthropometric measurements in addressing differences between product design and the unique body dimensions of Saudi females. The identified anthropometric mismatch highlights potential risks, emphasizing the threat to the working safety of Saudi females. Moreover, the data can be used by health professionals as a base to evaluate the health of Saudi adult females. Descriptive statistics and extreme values are determined. The data are presented in standard anthropometric tables.

Comparison of In-service Reduced vs. Full Torso Coverage Armor for Females

INTRODUCTION

Body armor and torso-borne equipment are critical to the survivability and operational effectiveness of a soldier. Historically, in-service designs have been predominantly designed for males or unisex, which may be disadvantageous for females who are shaped differently and, on average, smaller in stature and mass than their male counterparts. This study assesses the biomechanical and performance impact of two Canadian in-service armors and fighting load conditions on females.

MATERIALS AND METHODS

Four tasks (i.e., range of motion, treadmill march [×2], and a wall obstacle) were performed in a Baseline condition and two in-service torso-borne equipment conditions; the full torso coverage (FTC) condition has full upper torso soft armor with the fighting load carried in a separate vest, while the reduced coverage (RC) has a plate carrier with fighting load integrated into the armor carrier, bulk positioned higher, and less torso coverage. Both used identical combat loads and front and back armor plates. Trunk range of motion, march lower limb kinematics, march shoulder and hip skin pressures, perceived discomfort after the march, and time to traverse a wall obstacle were captured. Data were collected to assess the biomechanics and usability of the systems for eight females, representative of military recruits. Linear mixed-effects models were created, and analysis of variances (ANOVAs) were then performed on all the outcome measures (P < .05). Tukey's post-hoc procedures were performed when appropriate (P < .05).

RESULTS

There were significant differences between the RC and FTC for the sit and reach test (P < .001), lateral bend test (P < .001), and wall traverse time (P < .01). In all cases, the RC outperformed FTC. There were no differences between the two in-service conditions with respect to hip, knee, and ankle flexion/extension. The RC average skin pressure was higher than the FTC at the left and right shoulders by 103% and 79%, respectively, and peak skin pressure at the left shoulder by 75%. Both in-service conditions showed decrements in performance from Baseline for sit and reach (P < .001), lateral bend (P < .001), and peak hip and knee flexion (P < .01) with the FTC showing decreases in trunk rotation (P < .001) and wall traverse time (P < .01).

CONCLUSIONS

Improved outcomes for the RC can be attributed to design differences. The lower placement of bulk in FTC may act as a physical barrier during range of motion tasks and the wall obstacle. The presence of shoulder caps on FTC provides another physical barrier that likely impedes full movement through the arms and shoulders. While the narrower shoulder straps of the RC remove the barrier, it causes more concentrated skin pressures on the shoulder that can lead to injury. The results suggest that the RC offers a potential for increased operational effectiveness in females (and potentially for males) compared to the FTC system. Shoulder pressure, an important predictor of discomfort and injury, is the only measure for which FTC outperformed the RC. Future torso-borne equipment designs targeting this outcome measure could help increase the effectiveness of the RC and other similar systems that reduce torso coverage, though survivability implications must also be considered.

Do thoracoabdominal organ boundaries differ between males and females? Implications for body armour coverage and design

To optimise fit and protection of body armour systems, knowledge of the location of thoracoabdominal organ boundaries is required. The aims of this study were (i) determine the effect of sex on essential and desirable thoracoabdominal organ boundaries, and (ii) compare essential thoracoabdominal organ boundaries with small and large hard ballistic plate sizes from the National Institute of Justice (NIJ) and determine if coverage requirements differ between sexes. 33 males and 33 females underwent supine magnetic resonance imaging of their thoracoabdominal organs. Male participants on average displayed more laterally and inferiorly positioned essential and desirable organ boundaries than females. Based on NIJ plate sizes, insufficient coverage of essential organs was identified for male and female participants. A greater range of body armour sizes and designs that better cater to the diverse anatomy of soldier populations is warranted, but must be considered in the context of ergonomic and performance implications.

Does the fit of personal protective equipment affect functional performance? A systematic review across occupational domains

OBJECTIVE

To explore the effect of personal protective equipment (PPE) fit on functional performance across a range of occupational domains.

BACKGROUND

PPE introduces an ergonomic, human systems integration, and mass burden to the wearer, and these factors are thought to be amplified if PPE is ill-fitting. However, few studies have considered the role of fit (static, dynamic, and cognitive) when evaluating PPE-related performance detriments in occupational settings.

METHOD

A systematic literature review was conducted to identify relevant studies, which were then critically appraised based on methodological quality and collated to compare key findings and present evidence-based recommendations for future research directions across a range of occupational domains.

RESULTS

16 published studies met the inclusion criteria, 88% of which found that the fit of PPE had a statistically significant effect on occupational performance. Poorly sized PPE resulted in slower or increased reaction time; decreased range of motion or mobility; decreased endurance or tolerance; decreased pulmonary function; and altered muscle activation. Limited research met the inclusion criteria and those that did had risks of bias in methodology quality.

CONCLUSION

Future research evaluating the effect of PPE on performance in occupational settings should aim to recruit a more representative population; consider sex as a covariate; quantify and evaluate PPE fit and performance when integrated with all relevant equipment items; include outcome measures related to all three categories of fit (static, dynamic, cognitive); and assess performance of operationally relevant tasks.

Risk factors for injuries in female soldiers: a systematic review

Background

Female soldiers form an integral part of any modern defence force. Previous reports have highlighted that female soldiers report injuries at higher rates than male personnel. One possible reason for this is an actual difference in underlying injury rates, purported to be due to several factors, including levels of fitness. The aim of this review was to determine risk factors for injuries in female soldiers.

Methods

A systematic search was conducted for studies which reported on risk factors for injuries in female soldiers. Databases searched included PUBMED, CINAHL and Medline through OVID. Eligible studies were rated for their methodological quality using the Critical Appraisal Skills Program (CASP) tools and data were extracted and synthesized using a critical narrative approach.

Results

A total of 18 articles were included in this review which reported on 18 risk factors for injury. Smoking, previous injury, no history of deployment, heavy occupational tasks, lower levels of aerobic fitness and lower number of push-up repetitions appear to be risk factors for injuries in female soldiers. Age, height, body fat, high or low BMI and body mass do not appear to be consistent risk factors for injury in female soldiers and there appears to be minimal evidence for current levels of activity, sit-up ability, and other assessments of strength, power, speed, or movement being associated with injury risk. Additionally, neither flexibility nor previous levels of activity appear to be associated with injury risk in female soldiers.

Conclusion

Strategies to improve aerobic fitness and upper limb endurance, reduce smoking, and optimise rehabilitation from injuries and risk management for heavy occupational tasks need to be developed for female soldiers. Such strategies are also likely to reduce risks for male soldiers.

Effect of Torso and Breast Characteristics on the Perceived Fit of Body Armour Systems Among Female Soldiers: Implications for Body Armour Sizing and Design

This study aimed to provide normative data characterising the torsos and breasts of female soldiers and to determine which torso and breast anthropometric measurements contributed to reports of poor body armour fit. Ninety-seven female Australian Army soldiers completed a questionnaire about their experience with current-issue body armour, including perceptions of fit. Participants also attended a single testing session where we took a three-dimensional scan of their breasts and torso and collected several anthropometric measurements to characterise their torso size and shape. Sixteen of the 22 breast and torso measurements collected were significantly related to the perceived fit of current-issue body armour systems. To improve perceptions of fit for female soldiers and, in turn, reduce movement interference, discomfort, and barriers to occupational performance, future body armour systems should cater to the wide range of female breast and torso shapes and sizes.

Can smaller body armour improve thoracolumbar range of motion and reduce interference when female soldiers perform dynamic tasks?

Most female soldiers report that in-service body armour systems are too large. We investigated whether a smaller prototype body armour system could improve thoracolumbar range of motion (ROM) and reduce interference when female soldiers performed dynamic postures. 97 female soldiers completed three ROM tasks and seven dynamic postures wearing no armour, an in-service body armour system, and a smaller prototype system. Feedback on comfort of the prototype system was also obtained. Thoracolumbar ROM and dynamic posture completion were both hindered by using body armour, although the participants' performances were significantly less impeded when they wore the smaller prototype system compared to the in-service system. A smaller body armour system that is better matched to the anthropometric dimensions of female soldiers appears to improve overall fit and function. An increased range of body armour sizes and female-specific designs should be systematically explored to further enhance fit and function of body armour.

Bra-body armour integration, breast discomfort and breast injury associated with wearing body armour

This study investigated whether female soldiers experience bra integration or breast discomfort/injuries related to body armour use and whether these issues were associated with breast size. Ninety-seven Australian Defence Force female soldiers completed a questionnaire and had their breast volume assessed (range: 91-919 ml/breast) using three-dimensional scanning. Twenty-two percent (n = 21) of participants reported integration issues between their bra and body armour, 63% (n = 61) reported breast discomfort while wearing body armour and 27% (n = 26) reported experiencing a breast injury related to wearing body armour. Although bra-body armour integration was not dependent upon breast size, female soldiers with medium-large breasts reported significantly more breast discomfort and injuries when using body armour compared to participants with small breasts. These findings highlight the importance of developing body armour systems that cater to the range of breast sizes of female soldiers in order to improve bra-body armour integration and reduce breast discomfort and injury. Practitioner summary: This exploratory research provides evidence of bra integration issues, breast discomfort and breast injury experienced by female soldiers when wearing body armour. Given the growing representation of women in military organisations, strategies to alleviate these issues for female users of body armour, particularly those with larger breast sizes, are required.

Prediction of military combat clothing size using decision trees and 3D body scan data

AIM

To determine how well decision tree models can predict tailor-assigned uniform sizes using anthropometry data from the New Zealand Defence Force Anthropometry Survey (NZDFAS). This information may inform automatic sizing systems for military personnel.

METHODS

Anthropometric data from two separate samples of the New Zealand Defence Force military were used. Data on Army personnel from the NZDFAS (n = 583) were used to develop a series of shirt- and trouser-size prediction models based on decision trees. Different combinations of physical, automatic, and post-processed measurements (the latter two derived from a 3D body scan) were trialled, and the models with the highest cross-validation accuracy were retained. The accuracy of these models were then tested on an independent sample of Army recruits (n = 154).

RESULTS

The automated measurement method (measurements derived automatically by the body scanner software) were the best predictors of shirt size (58.1% accuracy) and trouser size (61.7%), with body weight and waist girth being the strongest predictors. Clothing sizes that were incorrectly predicted by the model where generally one size above or below the tailor-predicted size.

CONCLUSIONS

Anthropometry measurements, when used with decision tree models, show promise for classifying clothing size. Methodological changes such as fitting gender-specific models, using additional anthropometry variables, and testing other data mining techniques are avenues for future work. More research is required before fully automated body scanning is a viable option for obtaining fast and accurate clothing sizes for military clothing and logistics departments.

Identifying problems that female soldiers experience with current-issue body armour

Despite female soldiers representing a growing user population, military body armour systems are currently better suited to the anthropometric dimensions of male soldiers. The aim of this study was to explore issues that female soldiers experience with current Australian Defence Force (ADF)-issue body armour. Following a sequential exploratory design, an initial questionnaire was completed by 97 Australian female soldiers. Subsequently, 33 Australian female soldiers participated in one of three focus groups. Descriptive statistics of questionnaire data considered alongside thematic analysis of focus group transcripts revealed problems with the design (fit, form and function) of current ADF-issue body armour, as well as problems with the issuance and education surrounding use of the system. It is recommended that anthropometric data of female soldiers be better incorporated into future body armour designs, that these data inform processes surrounding both acquisition and issuance of body armour and that training protocols for body armour use be reviewed.