Development of sizing structure for fall arrest harness design

Abstract

Updated harness designs are needed to accommodate diverse populations in the current workforce. This paper determined an improved fall-arrest harness sizing scheme and strap-length configurations for harness design. A 3-D elliptic Fourier analysis (EFA) procedure with 123 coefficients was developed to quantify torso-shape effect on harness fit, based on 3-D data of 108 women and 108 men. The EFA coefficients were then applied to 600 representative body scans from a national database of 2382 participants to establish an improved sizing system. Study outcomes suggested a more upward back D-ring location for women than current unisex designs to accommodate female torso form and mitigate their fit problem. Results also suggested an improved system of three sizes for women and three sizes for men. New harness sizing charts for women and men were proposed accordingly. Using the most current 3-D whole-body digital scanning technology, this study assembled data from a US workforce to establish an improved fall-arrest harness sizing system and strap configurations for men and women. The information is useful for new generation harness designs to reduce the risk of worker injury.

Anthropometric Procedures for Protective Equipment Sizing and Design

“…In the harness design application, the additional clothing that workers wear in the winter time needs to be accounted for; harness users usually want one harness for all seasons. An additional 2.5 cm range for back strap, 2.5 cm for front cross-chest strap, and 7.5 cm for thigh-hip strap (i.e., gluteal furrow arc, thigh circumference, and trochantercrotch in combination) would therefore be necessary (Hsiao, Friess, et al, 2009). Some specialized designs may require an additional 7 cm for the thigh-hip area for improved mobility.…”

“…The first part identified the relationship between body shapes and harness fit using 216 participants and developed equations for predicting the best-fit harness size for any given 3D torso scan. The second part established an improved harness sizing system based on the equations developed in Part 1, using 600 3D torso scans (Hsiao, Friess, et al, 2009). …”

“…For instance, Elliptic Fourier Analysis-based shape-expression methods have already resulted in improved PE fit quantification and PE design. A notable example of this is in fall-arrest harness sizing design (Hsiao, Friess, Bradtmiller, & Rohlf, 2009). …”

“…Twenty components, accounting for over 96% (96.1% for men and 96.4% for women) of the total variance were retained. The sizing prediction equations were and where PC1, PC2, ‖, PC20 are the 20 principal component factors (Hsiao, Friess, et al, 2009). …”

“…Elliptic Fourier coefficients of torso outlines: A three-dimensional extension to the Elliptic Fourier Analysis approach (Hsiao, Friess, et al, 2009) was used to quantify body configuration (size and shape) variation and to determine the correlation between body configuration and harness size and fit. The EFA approach is based on the mathematical decomposition of a curve into a series of ellipses that can be described by coefficients and constants (Kuhl & Giardina, 1980;Lestrel, 1997).…”