Designed to relieve stress on the lower back, exoskeletons are said to contribute to brain fatigue by preventing it from functioning in harmony with the rest of the body.
- The exoskeleton, which is attached to the user’s chest and legs, is designed to help control posture and movement during the lift to protect the lower back and reduce the risk of injury.
- The exoskeleton tries to anticipate your movements, but it doesn’t go well, so you fight with the exoskeleton, and it causes this change in your brain.
It is a device intended to relieve what would lead to physical fatigue. Exoskeletons are devices designed to spare their users the stress of the lower back, especially for workers who have to carry heavy loads. The problem, reveals a study published on June 11 in the journal Applied Ergonomics, is that it leads to fatigue of the brain. According to the American scientists from the Ohio State University who conducted the research, these devices generate a lack of harmony between the body and the brain which is subject to an additional load of reflection.
Like dancing with a bad partner
The exoskeleton, which is attached to the user’s chest and legs, is designed to help control posture and movement during the lift to protect the lower back and reduce the risk of injury. However, the extra strain it causes on the brain would help negate its potential physical benefits. “It’s almost like dancing with a very bad partnersummarizes William Marras, professor of integrated systems engineering and lead author of the study. The exoskeleton tries to anticipate your movements, but it doesn’t go well, so you fight with the exoskeleton, and it causes this change in your brain that alters muscle recruitment – and could cause higher forces on the lower back, which could lead to possible pain and injury.”
For the study, researchers asked 12 people, six men and six women, to repeatedly lift a medicine ball in two 30-minute sessions. During the first session, participants wore an exoskeleton while they spent the second without the device. The researchers used infrared sensors to assess participants’ brain activity and measured the force exerted on each participant’s lower back during each session. They also counted the number of times the volunteers successfully lifted the medicine ball during each session. In separate sessions, they asked these same participants to perform the same exercise by adding a mental task: they asked participants to subtract 13 from a random number between 500 and 1000 each time they lifted the ball.
The confused brain
The results showed that when the participants simply lifted and lowered the ball, the exoskeleton slightly reduced the load on the volunteers’ lower back. When participants had to do calculations in their heads while lifting and lowering the ball, those advantages disappeared.
“Although exoskeleton users on an assembly line might not have to do calculations in their heads, any type of mental strain such as psychological stress or the instructions they have to follow could have the same effect.assures William Marras. When we looked at what was happening in the brain, there was more competition for these resources. The person was doing this mental math, but the brain was also trying to figure out how to help the body interact with the exoskeleton, and it confused how the brain was recruiting the muscles to do the task..”
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