Engineering an Award-Winning Study of Human Energy and Movement

When the American Society of Mechanical Engineers (ASME) convened in Buffalo, New York, for its annual International Design and Engineering Technical Conferences and Computers and Information in Engineering Conference, more than 50 papers were presented to its Advanced Modeling and Simulation Technical Committee. The jury awarded top honors to “Joint-Space Dynamic Model of Metabolic Cost with Subject-Specific Energetic Parameters,” by Joo H. Kim, an assistant professor of mechanical engineering; his student, Dustyn Roberts, who is listed as the first author on the work and is now a faculty member at the University of Delaware; and Howard Hillstrom, a colleague from New York City’s Hospital for Special Surgery.

The paper, Kim explains, is the first of its kind because it details a novel computational model—which was derived rigorously and mathematically—for human metabolic energy expenditure. (Metabolic energy expenditure is a critical measure of human motion.)

Kim, the recent recipient of a three-year, $350,000 National Science Foundation research grant, approaches the issue from engineering perspectives, integrating the laws of thermodynamics and the principles of multibody system dynamics. In addition to being used to develop more-efficient, lower-cost prosthetic limbs (the work for which he won the grant), the model can be employed by those diagnosing gait disorders—an increasing concern as America’s population grows older, because many of those disorders are age-related—or designing robotic exoskeletons.

Exoskeletons, now commonly being called “wearable robots,” can help soldiers to carry heavy loads over rough terrain, disabled people to walk, and much more. “Our algorithm provides detailed information about how the human body moves and expends energy,” Kim says, “and that has the potential to lead to exciting and important new scientific, clinical, and engineering applications.”