According to the U.S. Bureau of Labor Statistics, back injuries count for nearly 40% of all workplace injuries. Many workers wear lift-assist devices that support the back muscles, but these don’t fully prevent improper lifting posture. Researchers from the Biorobotics Laboratory at Seoul National University (SNU) in Korea have developed an exosuit that stops the wearer from stooping from the waist. The research team The exosuit also encourages squatting, a much safer lifting posture, and helps conserve body energy during lifting activities.
Stooping is a natural human tendency when lifting items from a lower level. To intercept this tendency, the SNU team built a locking mechanism into the exosuit. Cables and a large rubberband create a braking resistance when the wearer begins to bend forward at the hips. When the wearer widens their knees in preparation for squatting, the angle of the mechanism changes, allowing the bending movement to continue. The mechanism also enhances the force of the squat as the wearer lifts an object from the floor.
Inspired by the interconnection of human tendons, the team chose not to mirror the actual joint structures of the body. Rather, the exosuit provides an external system that connects the torso, hips, knees, and feet via a tendon-like network. The actions of the suit work entirely in response to the wearer’s movements. It requires no electricity and therefore has no wires or electrical power source.
In an initial study that compared lifting patterns with and without the exosuit in 10 participants, the device improved average lifting posture by 35%. The study also recorded a 5.3% reduction in the average amount of metabolic energy consumed during lifting. The researchers describe the design and testing of the exosuit in a recent paper published in Science Robotics.
Although development is still in the early stages, the SNU engineers intend to bring the exosuit to market by next year. Before then, the team plans to conduct trials in field settings, such as factories, gyms, and physical therapy centers. These trials will examine the long-term effects of wearing the suit during repetitive lifting activities. Eventually, the researchers hope to develop specialized versions of the exosuit for a broad range of sports activities to enhance training and performance.
