New lightweight, portable robotic suit to increase running and walking performance

October 21, 2019

While walking may not seem like a burden for most people, for others, this simple task can often feel exhausting. For patients recovering from surgery or stroke, those with Parkinson's Disease, those with restricted mobility, and even for soldiers or firemen carrying heavy loads over difficult terrain, walking or running can be a struggle. Many researchers have pondered over this problem over the years, developing a number of external devices that, once worn by users, allow them to move, walk, and run much more easily than they normally would. A variety of these "robotic exoskeletons" or robotic suits have been developed over the years, with an aim to decrease users' energy expenditure (or metabolic rate) when walking and running. So far, however, as Prof Giuk Lee from Chung-Ang University says, "Robotic exoskeletons tend to be bulky and heavy; and while walking experiments have shown promising results, the energy spent running with the added weight of the device outweighs the benefits of robotic assistance."

The problem, as Prof Lee and colleagues explain in their paper published in Science, lies in the fact that "Walking and running have fundamentally different biomechanics, which makes it challenging to develop devices that assist both gaits." Tackling this challenge, the scientists showcase their newly developed exosuit, mostly made of a fabric vest, belt, and thigh wraps, just like clothes that we wear in everyday life. These components are connected by wires, and fitted with batteries and a motor-like device (an actuator). The device weighs just 5 kg, conveniently fitted around the waist to assist hip extension muscles and allow a greater range of movement. What's more, this exosuit can switch the assistance mode automatically between walking and running gaits to achieve maximum efficiency of assistance. The scientists tested their prototype on treadmills and on outdoor courses with different terrains to examine the energy savings achieved by the exosuits in different conditions. They used an algorithm to classify gait (walking or running), which provided feedback to the device and adjusted the assistance mode accordingly. This allowed the exosuit to match the movement initiated by the actuator to the gait identified by the algorithm, and therefore to maximize energy savings. Indoor and outdoor testing revealed that the algorithm was able to correctly identify walking and running gaits more than 99.98% of the time.

Once they had confirmed the algorithm's accuracy, the scientists looked at the metabolic savings achieved by the exosuit's assistance functionalities. They found that exosuit assistance decreased the energy cost of walking at a speed of 1.5 meters per second (4.8 km per hour) by 9.3%, equivalent to the user shedding off 7.4 kg. They were also successful in securing energy savings during running tasks (speed of 2.5 meters per second or 9 km per hour), where the assistance function reduced metabolic rate by 4%, equivalent to a weight loss of 5.7 kg. Such energy savings might seem insignificant, but according to Prof Lee and colleagues, "Although the changes in metabolic rate are relatively modest, they are of similar magnitude to those that have been proven sufficient to improve maximum walking and running performance. Therefore, we think that these energy savings could result in proportional increases in maximal performance, for example, over a cross-country course." Finally, unlike previous exosuits, which relied heavily on knee function, this new device uses hip extension to drive the leg movement, making the exosuits particularly relevant for above-knee amputees and other people lacking complete knee function. By harnessing the power of the hip extension, users of this robotic suit will be able to achieve higher athletic performance in a variety of terrain, seamlessly switching between running and walking as needed.

To conclude, Prof Lee says, "We are expecting that this 'wearable robot' will have many uses, such as in aiding rehabilitation training for senior patients and enhancing the work efficiency of soldiers or firemen. In the long term, we envision this exosuit as hanging in a closet all the time, just like the clothes we wear every day."
About Chung-Ang University

Chung-Ang University is a private comprehensive research university located in Seoul, South Korea. It was started as a kindergarten in 1918 and attained university status in 1953. It is fully accredited by the Ministry of Education of Korea. Chung-Ang University conducts research activities under the slogan of "Justice and Truth." Its new vision for completing 100 years is "The Global Creative Leader." Chung-Ang University offers undergraduate, postgraduate, and doctoral programs, which encompass a law school, management program, and medical school; it has 16 undergraduate and graduate schools each. Chung-Ang University's culture and arts programs are considered the best in Korea.


About Professor Giuk Lee from Chung-Ang University

Dr Giuk Lee is an assistant professor at Chung-Ang University's School of Mechanical Engineering in Seoul, South Korea. After being awarded a PhD from Seoul National University in 2014, he worked as a senior researcher at Seoul National University, then as a postdoc at the Korea Institute of Science and Technology and Harvard University. His research interests revolve around developing wearable robotic exosuits to help people with restricted mobility achieve a greater performance. His publication record includes 14 journal articles and 21 international conference papers.

Media contact:

Chung Ang University

Related Weight Loss Articles from Brightsurf:

Weight loss shouldn't be the goal of PE
For adults, the goal of exercise is often to shed some pounds, but new research from the University of Georgia suggests the objective should be different for kids.

How long should you fast for weight loss?
Two daily fasting diets, also known as time-restricted feeding diets, are effective for weight loss, according to a new study.

Green tea may help with weight loss efforts
In an analysis published in Phytotherapy Research of randomized controlled trials, individuals who consumed green tea experienced a significant decline in body weight and body mass index.

Changing weight-loss strategies, attempts
The proportion of adults who tried to lose weight in the previous year increased from 1999 to 2016 but the findings of this observational study suggest the results may have been unsatisfactory.

Quality of life changes after weight loss
Obesity increases a number of adverse health consequences including reduced health-related quality of life.

Weight loss medicines underutilized by veterans
Despite the availability of new weight management medications and several clinical guidelines recommending their use as part of a comprehensive treatment plan for obesity, a new study has found that their use is extremely low (about one percent) among eligible Veterans.

Is the most effective weight-loss strategy really that hard?
Dietary self-monitoring is the best predictor of weight-loss success. But the practice is viewed as so unpleasant and time-consuming, many would-be weight-losers won't adopt it.

Study: Faster weight loss no better than slow weight loss for health benefits
Losing weight slowly or quickly won't tip the scale in your favor when it comes to overall health, according to new research.

Mindfulness training may help support weight loss
Mindfulness training may improve the effectiveness of intensive weight management programs, according to a small study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

Does weight loss before surgery provide benefits?
For obese and overweight patients, it is common for various surgical procedures to be deferred until they have lost weight through diet and exercise.

Read More: Weight Loss News and Weight Loss Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to