Winter/Spring 2008

NEW TECHNOLOGY is positioning an old injury-prevention program at the cutting edge of the poultry industry.

Researchers Jonathan Holmes and Sergio Grullon demonstrate operation of the Ergonomic Work Assessment System.

Nearly 10 years ago, scientists from the Georgia Tech Research Institute (GTRI) collaborated with Georgia Tech’s School of Applied Physiology to create the Ergonomic Work Assessment System (EWAS) to track the positioning and arm movements of workers as they deboned poultry. The idea was to identify and then avoid the factors leading to repetitive-stress injuries.

The improved EWAS, developed in cooperation with the poultry industry, provides a more accurate and detailed assessment by taking advantage of technology that wasn’t available in the ‘90s – namely position-tracking technology typically used to create computer animation.

“It measures arm position in three dimensions,” says GTRI research engineer Jonathan Holmes. “You strap the system onto your arm and move your arm around, and you can watch it moving on a screen beside you.”

The system measures forearm and wrist orientation as well as upper arm and shoulder activity. Separate modules provide a global reference for the position sensors. Muscle response is monitored through electromyography, a procedure for determining the level of electrical activity in muscles. Grip force on the knife is calculated by a technique developed by Liberty Mutual Research Institute for Safety, which is teaming up with the Georgia Tech design team for that part of the system development.

The aggregate data of shoulder and arm position, muscle response and grip force of a worker cutting poultry are transmitted wirelessly to a computer for analysis. EWAS will be used in field studies to assess the dynamics of muscle group interactions in job rotation schemes designed to reduce repetitive-motion disorders such as carpal tunnel syndrome.

“By monitoring these forces and positions, you can put numbers to physical motions and get a better idea of what is good and what is risky,” says Holmes. “You can hopefully determine if someone is using certain muscles too often, or if they are bending their wrists too far. This opens the door for studies that can eventually help us determine which risk factors are more likely to lead to injuries.”

The group is also investigating the development of a second system to monitor the back. They ultimately hope to pursue studies that can help reduce back injuries resulting from back-instability conditions.

— Gary Goettling