Life would be so much easier if I had an exoskeleton suit. I could carry all the grocery bags in one fell swoop without breaking a nail. I could run rings around my dog without breaking a sweat. I could fight alien queens on my next trip to LV426. The only thing an exoskeleton suit couldn’t improve is my lousy sense of balance. Despite their many advances, robots are notorious for have poor balance skills. This deficiency, however, might be due to reaction time.
Researchers at the Georgia Institute of Technology and Emory University may have discovered the key to improving the balance issue. In an article for The Conversation, the research team said, “People tend to take balance for granted. But every step holds the possibility of a fall, and bad falls are a top reason for health declines when people grow older. If researchers can develop assistive technology to improve balance while getting from here to there, it can prevent falls and enable people to be active for longer.”
“We are biomechanical engineers and rehabilitation physiology researchers who study the neurophysiology of movement. In our study, we sought to answer the question of whether wearable robots – like powered lower-limb exoskeletons or prostheses – can improve balance above and beyond a normal baseline.”
To test their hypothesis, the team placed participants in a pair of ankle exoskeleton boots and positioned them atop a custom-designed platform. The rug was then literally pulled out from under the participants’ feet as the platform moved abruptly to cause the subjects to lose their balance. Only when ankle exoskeleton torque was applied before the body’s natural response did the researchers see an improvement in balance.
The team published their findings in Science Robotics in a paper titled “Exoskeletons need to react faster than physiological responses to improve standing balance.” In the abstract from the paper, the researchers wrote: “Here, we show that exoskeletons need to react faster than physiological responses to improve standing balance after postural perturbations. Delivering ankle exoskeleton torque before the onset of physiological reactive joint moments improved standing balance by 9%, whereas delaying torque onset to coincide with that of physiological reactive ankle moments did not. In addition, artificially fast exoskeleton torque disrupted the ankle mechanics that generate initial local sensory feedback, but the initial reactive soleus muscle activity was only reduced by 18% versus baseline.”