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University of Michigan Innovation Partnerships
University of Michigan Innovation Partnerships

Don Chaffin’s Groundbreaking Work in Ergonomics


As part of his PhD thesis at the University of Michigan in 1967, Don Chaffin developed a 2D mechanical model of the human body. Little did he realize that what he created would be the basis for a powerful tool that would change the approach to ergonomics for decades to come.

Chaffin’s thesis work resulted in a way to predict injurious levels of stress on the human back when lifting weighted objects of different sizes and weights.

Following graduation, Chaffin went to work as a biomechanics engineer at Western Electric where many employees were required to lift and move a variety of heavy objects. At its plant in Chicago, more than 30 percent of its workforce was on a medical work restriction. Needless to say, “Western Electric had a huge economic and production problem,” Chaffin explained.

Chaffin’s solution? Discover the limits on what people could physically do. He started strength assessments of the major muscle groups by asking for 50 male and 50 female volunteers to be evaluated, with the goal of understanding the limits on what people could safely lift and push.

Following his time at Western Electric, Chaffin returned to the University of Michigan with a grant to continue to develop these strength testing norms. The ubiquitous nature of the problem resulted in Chaffin being able to recruit seven other companies to participate in his studies. At the conclusion of this work, his team had tested over 3,000 people.

In the early 1980’s, with the support of the Ford Motor Company and the United Auto Workers (UAW), Chaffin continued his research, bringing U-M faculty and PhD students together to develop more ergonomically based designs for the workplace. Ford and the UAW adopted his findings and began training autoworkers to follow the guidelines of his research.

These experiences provided the basis for Chaffin and several other University faculty members to found the Center for Ergonomics at U-M. With the aid of the Center’s continuing education program for engineers, Chaffin’s human strength model became available to more users by reconfiguring the code to run on personal computers. Chaffin and his PhD students also began work on the next generation model that would take in to account twisting and movement. It eventually became a 3D model – dubbed 3DSSPP (Three-Dimensional Static Strength Prediction Program) – and included a graphic interface that engineers could use to see the body in the exact posture they were analyzing.

In 1997, with the assistance of U-M Innovation Partnerships, 3DSSPP became a licensed product, and the students, faculty, and staff who’d worked to develop it all agreed to direct all of the royalties from the sales of the product to reinvest in the Center. As a result, 20 years later, engineering students under the supervision of research engineer Charles Woolley are still making improvements to make the model and software function better, and workplaces safer. To date, over 3,000 users have licensed the software from the University of Michigan, making 3DSSPP one of the most impactful software programs ever distributed by the University.