Exoskeletons have a problem: They can strain the brain
Exoskeletons—wearable devices used by workers on assembly lines or in warehouses to alleviate stress on their lower backs—may compete with valuable resources in the brain while people work, canceling out the physical benefits of wearing them, a new study suggests.

The study, published recently in the journal Applied Ergonomics, found that when people wore exoskeletons while performing tasks that required them to think about their actions, their brains worked overtime and their bodies competed with the exoskeletons rather than working in harmony with them. The study indicates that exoskeletons may place enough burden on the brain that potential benefits to the body are negated.

For the study, researchers asked 12 people—six men and six women—to repeatedly lift a medicine ball in two 30-minutes sessions. For one of the sessions, the participants wore an exoskeleton. For the other, they did not.

The researchers used infrared sensors to evaluate the participants' brain activity and measured the force on each participant's lower back during each session. They also tracked the number of times each participant was able to lift the medicine ball in each session.

Then, in separate sessions, they asked those same participants to perform that same task—lifting a medicine ball for 30 minutes, in one session wearing an exoskeleton—but added a mental task: They had the participants subtract 13 from a random number between 500 and 1,000 each time they lifted the ball.

They found that when the participants were simply lifting and lowering the ball, the exoskeleton slightly reduced the load on the participants' lower backs. But when the participants had to do math in their heads while lifting and lowering the ball, those benefits disappeared.

Although exoskeleton users on an assembly line may not have to do math in their heads, any kind of mental strain such as psychological stress or instructions they must follow could have the same effect, the author said.

Applied Ergonomics
Source: https://doi.org/10.1016/j.apergo.2021.103494