Pneumatically actuated softwareable robotic elbow exoskeleton that reduces muscle activity and perceived workload

For workers whose jobs involve hours of lifting and repetitive movements, even small innovations can make a big difference in preventing future musculoskeletal disorders.

That’s why engineers at the University of Texas at Arlington have developed a soft robotic exoskeleton that literally takes the load off by reducing strain on the arms and elbows.

The device, called the Pneumatically Actuated Soft Elbow Exoskeleton (PASE), uses lightweight silicone “pneumatic actuators” (soft, air-filled mechanisms that help move the arm) to aid movement during everyday industrial tasks such as lifting, assembly, and drilling. Its flexible design aims to lower the risk of developing work-related musculoskeletal disorders, which account for approximately 30% of all workplace injuries in the United States and cost workers an estimated $45 billion to $54 billion annually in compensation and recovery.

“Our goal was to create a preventive, supportive device that reduces muscle strain before an injury occurs,” said Eshwara Prasad Sridhar, a graduate research assistant in the Department of Industrial, Manufacturing, and Systems Engineering. “By using overhead pneumatic systems that are already available in most manufacturing facilities, we can easily implement this exoskeleton in real-world environments.”

This interdisciplinary project brought together Mahmudur Rahman, PI, assistant professor in the Department of Industrial, Manufacturing, and Systems Engineering; Muthu Wijesundara (Co-Principal Investigator), Principal Investigator and Head of the Department of Biomedical Technology, UTA Research Institute; Veisel Erel, Research Scientist III at UTARI. And Shridhar.

The team designed PASE as an integrated pneumatic actuator to maximize comfort and freedom of movement while minimizing weight and mechanical complexity. The device is made of silicone and attached to a carbon fiber onyx baseplate with a soft neoprene outer layer, providing precise assistance with natural elbow movements.

In the study, which involved 19 participants between the ages of 18 and 45, researchers tested the exoskeleton across three tasks: manual weight lifting, basic assembly, and power drilling. Exoskeleton support reduced biceps and triceps muscle activity by up to 22% during lifting tasks, and participants using NASA’s Task Load Index reported an 8-10 point reduction in perceived physical and mental workload compared to when the support was off.

“Delaying or preventing even one workplace injury makes a huge difference,” said Dr. Erel, who leads UTARI’s soft robotics efforts. “Projects like this show that engineering can directly improve people’s quality of life by reducing fatigue, preventing strain, and creating a safer working environment.”

The study, “Design, development, and evaluation of a pneumatically actuated softwareable robotic elbow exoskeleton to reduce muscle activity and sensory workload,” was published in the Journal of Rehabilitation and Assistive Technologies Engineering.

Based on this success, the research team submitted a National Science Foundation proposal to expand this concept into a complete upper limb exoskeleton that can assist the elbow, wrist, and fingers simultaneously.

“This type of interdisciplinary research is central to UTA’s mission,” Errell said. “By combining our expertise in robotics, mechanical engineering and human factors, we are creating important solutions for both industry and everyday life.”