Falls are the leading cause of fatalities in the construction industry — with an average of 362 fatal falls per year, according to OSHA. Could part of the reason for this be poor-fitting fall-arrest harnesses?

A recent study found that current fall-arrest harnesses did not properly fit at least 24 percent of the men and 31 percent of the women in the study.

Published in Human Factors: The Journal of the Human Factors and Ergonomics Society, the study found that current sizing for commercial harnesses is derived from 1970s-1980s anthropometric (human body) measurements of members of the military services. These data, says the study, do not represent today's civilian worker population, which is more diverse and now includes more women. The result is greater variation in workers’ range of body dimensions and shapes.

The authors of the study — human factors/ergonomics researchers from the National Institute for Occupational Health and Safety (NIOSH), Total Contact Inc. and the University of Michigan — obtained anthropometric data from 216 white, Hispanic, African-American, and multiracial men and women age 18 to 56 who had selected harnesses they felt fit them the best. These participants were then scanned with a 3-D full-body scanner, first while standing and then while being suspended by the harness.

After integrating criteria established for the harness manufacturing industry with the body measurement data from the study participants, the researchers created a comprehensive test for assessing the overall fit of the harnesses. They then derived eight models, which provided unique 3-D anthropometric information for better defining harness size groups. The goal was to develop harnesses that would fit 96 percent of the population.

The researchers' alternative fitting system would replace the existing four unisex size options with two sizes for women and three for men. The researchers believe that by adopting this new system harness manufacturers can help the construction industry reduce the risk of injuries and fatalities from improper size selection and fit.