Engineers combined the science of biomechanics and advances in wearable technology to create a smart, mechanized undergarment that serves as a back-assist exosuit. The clothing-like device supports human movement and posture and can reduce fatigue by an average of 29 to 47 percent in lower back muscles. The exosuit was designed for individuals who work in physically demanding fields and are at risk for back pain including medical professionals and frontline workers.
The device consists of two fabric sections — made of nylon canvas, Lycra, polyester, and other materials — for the chest and legs. The sections are connected by sturdy straps across the middle back, with natural rubber pieces at the lower back and glutes. It does not rely on motors or batteries. Instead, the low-profile, elastic exosuit applies assistive forces that cooperate with the low back extensor muscles to relieve strain on the muscles and spine and to help reduce injury risks.
The device is designed so that users engage it only when they need it. A simple double tap to the shirt engages the straps. When the task is done, another double tap releases the straps so the user can sit down and the device feels and behaves like normal clothes. The device also can be controlled by an app — users tap their phones to engage the smart clothing wirelessly via Bluetooth.
The engineers used surface electromyography techniques to measure changes in low back muscle fatigue in male and female participants, who were given physical tasks to perform both with and without the exosuit. The study showed that wearing the exosuit made holding a 35-pound weight (the average weight of a 4-year-old child) less tiring on the back than holding a 24-pound weight (the average weight of an 18-month-old baby) without the exosuit.
The team discovered that the latissimus dorsi muscles (“lats”) — those that adduct, extend, and medially rotate the shoulder joint — affect low back mechanics. While previous research has shown that the lats generally do not contribute much to supporting the low back, the team found that, as people get tired, they may suddenly recruit the lats to offload the main back extensor muscles to a significant degree. The elastic bands in the exosuit work the same way to help sustain endurance and strength.
The suit was designed with both male-and female-specific fits.