How kirigami can help us study the muscular activity of athletes

February 12, 2020

The upcoming Tokyo Olympic and Paralympic Games in 2020 represent a big opportunity for governments to promote a healthy lifestyle and sports, and the turn of the decade is a great opportunity to showcase how recent technological developments can be used to help us understand human motion during sports. In this regard, the combination of high-speed cameras and surface electromyographic sensors, which record the electromyographic activity of palm muscles, has been employed to obtain a better understanding on the fine control athletes and sportspeople exert on their palm muscles.

However, conventional devices for surface electromyography employ small electrodes that are attached to the skin and wires, which restrict free movement. All-in-one modules containing electrodes, amplifiers, and wireless transmitters help to solve this issue only to some extent; these modules are not suitable for certain parts of the body, like the palms or soles. During pitching in baseball, for example, the ball is in direct contact with palm muscles, and integrated modules cannot be employed without being a nuisance to the user. Even if skin-like electrodes were used, the high forces and friction involved would break them apart. This has limited electromyographic studies to other parts of the arms and legs.

To address this problem, a joint research team from Waseda University and Kitasato University, Japan drew inspiration from a traditional Japanese artform called kirigami, to prepare a durable skin-like patch for measuring the electromyographic activity of palm muscles, and have published their findings in NPG Asia Materials. Unlike the better-known origami, kirigami crafts contain both paper folds and cuts. Interestingly, it is possible to employ kirigami technique to create ultrathin insulated conductive sheets that are also largely bendable and stretchable. "By cutting a conductive sheet in a special kirigami pattern and sealing it with silicone rubber, we have managed to create elastic and insulated wirings that minimized the mechanical mismatch between skin and device during exercise," reports Dr. Kento Yamagishi from Waseda University (Currently, Singapore University of Technology and Design), the lead author of the paper. These wires were combined with another of their previous inventions - conductive nanosheets that can be used on the palm or soles without problems.

These two devices together form an elastic kirigami patch that can capture electromyographic signals in difficult areas and carry them to a Bluetooth device placed in a less-obtrusive zone, such as the forearm. The research team tested their invention by measuring electromyographic signals from one of the palm muscles of an experienced baseball player when throwing curveballs and fastballs, finding significant differences between both types of throw. "Our elastic kirigami patch will serve as a minimally perceivable device to investigate the activity of the palm muscles of athletes without interfering with their performance," remarks Assist. Prof. Tomoyuki Nagmi of Kitasato University. "This surface electromyographic measurement system will enable the analysis of motion in unexplored palm muscle areas, leading to a better understanding of muscular activity in a wide range of sports and even artistic or musical performances," Assoc. Prof. Toshinori Fujie of Waseda University (Currently, Tokyo Institute of Technology), who led the research, concludes. There are also potential applications in medical research for currently unexplainable motor disorders, such as the yips. It is clear that a better understanding of our own bodies during exercise could help us perform better and lead a healthier lifestyle.

Title of original article: Elastic kirigami patch for electromyographic analysis of the palm muscle during baseball pitching
Authors: Kento Yamagishi, Takenori Nakanishi, Sho Mihara, Masaru Azuma, Shinji Takeoka, Kazuyuki Kanosue, Tomoyuki Nagami & Toshinori Fujie
DOI: 10.1038/s41427-019-0183-1
Journal:NPG Asia Materials

Waseda University

Related Athletes Articles from Brightsurf:

51% of Americans agree paying college athletes should be allowed
More Americans than not believe that college athletes should be allowed to be paid more than what it costs them to go to school, a new national study of nearly 4,000 people suggests.

Menstrual dysfunction is more common among young athletes than among non-athletes
Menstrual dysfunction is more prevalent in young Finnish athletes than it is among non-athletes of a similar age, but athletes experience less body weight dissatisfaction than non-athletes do.

Athletes don't benefit from relying on a coach for too long
Athletes increasingly relying on a coach over the course of a season may be a sign that they aren't progressing in their development, according to new research from Binghamton University.

Olympic athletes should be mindful of their biological clocks
Biological clocks have sizeable effects on the performance of elite athletes.

Female athletes at risk for nutritional deficiencies
Two decades of research among female athletes over the age of 13 years shows that a lack of nutrition knowledge about what they need to eat to stay healthy and compete may contribute to poor performance, low energy and nutrient intake, and potential health risks, according to a Rutgers Robert Wood Johnson Medical School study.

Electrocardiogram shows value in college athletes' screens
Research published today indicates that screenings that incorporate an ECG are more effective at detecting cardiac conditions that put athletes at risk, and more efficient in terms of cost-per-diagnosis of at-risk players, than screenings involving only a physical exam and patient history.

How kirigami can help us study the muscular activity of athletes
Scientists devise an elastic and durable skin-contact patch for measuring the electromyographic activity of the palm muscle inspired by ancient Japanese paper crafts.

Study examines attitudes toward transgender athletes
As several states draft legislation that would force student-athletes to play as their gender identified on their birth certificate instead of on a team that matches their gender identity, a team of political scientists investigated underlying factors that drive public opinion on transgender athletes.

The mind-muscle connection: For aesthetes, not athletes?
The 'mind-muscle connection.' Ancient lore for bodybuilders, latest buzz for Instragram fitness followers.

Sudden cardiac arrest in athletes: Prevention and management
It's marathon season, and every so often a news report will focus on an athlete who has collapsed from sudden cardiac arrest.

Read More: Athletes News and Athletes 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