Sizing and fit of fall-protection harnesses

Abstract

Full-body fall-protection harnesses have been a critical work-practice control technology for reducing the number of fall-related injuries and fatalities among construction workers; yet, very little is known about the fit of these harnesses to the population that wears them. This study evaluated the fit and sizing efficacy of a harness system. Seventy-two male and 26 female construction workers participated in the study. Their body size-and-shape information was measured while they were suspended (with a harness) and standing (with and without a harness), using a 3-D full-body laser scanner and traditional anthropometric calipers. Fisher's discriminant analysis results did not point to the need for a change in the current sizing selection scheme by body height and weight for end users. However, an integrated redesign of harness components is needed because 40% of subjects did not pass fit-performance criteria in either the standing or suspended condition. A multivariate accommodation analysis has identified 15 representative body models for the 'standard-size' harness design. These models can serve as a useful population to test harness design until a larger survey of the nation's construction workers can be done. Finally, further developments in 3-D shape quantification methods are recommended to improve the harness design process; the point-to-point anthropometric information currently used seems to be insufficient for harness design.

Development of sizing structure for fall arrest harness design

“…It is worth noting that Hsiao et al (2003) reported that traditional anthropometric data were not satisfactory in addressing the harness fit issue. In addition, the traditional linear anthropometric data did not correspond well to the harness strap components and thus were not informative in harness design practice (Hsiao et al 2007).…”

“…The same model of scanner was used in study II to register torso images of 600 participants while standing without a harness. The accuracy of the scanning system was tested to an average error of 2.9 mm, ranging from þ6 mm to -6 mm (Hsiao et al 2003). …”

“…The successful design of efficient full-body harnesses relies on quantitative data of human body shape variation. In a previous study on full-body harness fit, Hsiao et al (2003) reported that existing traditional anthropometric data were not satisfactory in establishing good and up-to-date harness design. First, the best available body measurements from the military populations in the 1970s and 1980s do not represent the current civilian worker population due to relatively strict anthropometric entry requirements, which were imposed in the armed forces (Bradtmiller et al 2000).…”

Impact of Harness Fit on Suspension Tolerance

“…The chart must be based on dimensions that are readily known or easily measured by the harness user or vendor. Body weight and stature are well known to individual workers and have fine correlations with harness fit and thus have been widely used as indices by harness manufacturers (Hsiao, Bradtmiller, & Whitestone, 2003). Equations 1 through 4 were simplified to become Equations 5 through 8 in presenting an updated, body-size-based sizing system.…”

“…The accuracy of the scanning system was tested to an average error of 2.9 mm, varying from +6 to −6 mm (Hsiao et al, 2003).…”