Association of anthropometric characteristics of law enforcement officers with perceived ratings of fit, comfort, and pain in the use of body armor

Abstract

Knowledge gaps exist on association between law enforcement officer (LEO) anthropometric characteristics and perceived body armour fit, armour discomfort, and armour-caused pain. This study assessed the correlation and identified influential torso dimensions for armour sizing and design applications. Nine-hundreds and seventy-four LEOs across the U.S. participated in a national study on LEO armour use and body dimensions. Perceived ratings of armour fit, armour discomfort, and body pain were found moderately correlated with each other. In addition, armour fit ratings were associated with certain torso anthropometric characteristics, such as chest circumference, chest breadth, chest depth, waist circumference, waist breadth (sitting), waist front length (sitting), body weight, and body mass index. LEOs who reported armour poor fit, armour discomfort, and armour-caused pain had a larger mean of body dimensions than the "armor good fit" group. More women than men had poor fit, discomfort, and body pain in the use of body armour.Practitioner summary: The identified influential body measurements can be used as the "drivers" for multivariate analyses to develop an improved armour sizing system to further LEO protection. The study also suggests consideration of gender specific armour sizing systems to accommodate differences in torso configurations between male and female officers and to resolve the concern that more female officers had poor armour fit than male officers.

Keywords: Police; armour fit; body armour; body size; torso; vest.

Figure 1.

Ballistic- and stab-resistant body armour provides coverage and protection for the vital organs, which safeguards LEOs against various kinds of threats (a). It consists of a front ‘panel’ overlapping the back ‘panel’ and is held in place on the wearer’s torso by a carrier to protect the torso (b). A panel includes the ballistic materials and an enclosure that covers the materials, which fits in the carrier (c) (Picture credits: TurboSquid.com and National Institute of Justice (NIJ)) 2014).

Figure 2.

Sizing vests with adjustments in front width, front length, back width, and back length are being used to help officers in determining adequate armour sizes (side view – standing, front view – seated, and back view – standing) (Credit: drawings based on figures on the Armour Express Inc. web page).

Figure 3.

A moderate positive correlation was found (r = 0.56) between armour fit and armour comfort. The colour theme shows nonparametric density of data with a fit line and a density ellipse of 0.95.

Figure 4.

U.S. army soldier waist-front length (sitting) and chest breadth distribution (N=6068) against the dimensions/sizes of armour ballistic test panels (the five rectangles) specified in the NIJ Standard – 0101.06.

Figure 5.

LEO waist-front length (sitting) and chest breadth distribution (N=974) against the dimensions/sizes of armour ballistic test panels (the five rectangles) specified in the NIJ Standard – 0101.06.

Figure 6.

The probability of a body dimension of women in predicting armour fit through simple logistic regression. Chest circumference, chest depth, body mass index (BMI), stature, waist breadth (sitting), waist circumference, and chest breadth are important dimensions in predicting armour fit in the ranking order (in dark colour). Sitting height, weight (kg), waist front length (sitting), and front lateral length (standing) are not good predictors (in gray colour).