Sports training equipment is increasingly equipped with all kinds of technologies: electronics, mechanics, digital, statistics, etc. At the service of sport, these new technologies allowed to have a feedback on the performance of athletes and thus to learn the perfect gesture, move or strategy. In competitive sports, these technologies have become a necessity in order to reach and stay at the top level. Some sports are even almost exclusively technological, such as motor sports (Formula 1, WEC, WRC etc.).
However, there are some disciplines in which technology is hardly explored, such as Martial Arts, which are very much rooted in their traditions and Asian culture.
Among these martial arts, karate is the most practiced in the world and will make its debut at the Tokyo Olympic Games originally planned for 2020.
One of the most ancestral instruments of karate training is the Makiwara. It is originally composed of a simple wooden board buried in the ground with a straw-covered head. Today, the straw is most often replaced by leather to form the strike area. It is used to find the right striking distance and to work on the roughness of the hands.
I therefore decided to design a Makiwara whose head is equipped with a technology that makes it possible to quantify and visualize the position and intensity of the punches it receives.
State of the Art
The uses of technology in the service of sport are legion. First of all, they can be seen in our everyday life, for example in our treadmills, indoor bikes or running applications, which use a large number of sensors to carry out simple statistical studies in order to guide us in our training.
But it is in the professional field that this phenomenon is most obvious. For example, the technology can be seen in new refereeing systems, such as fencing suits that detect hits, or tennis nets that detect contact with the ball. Another example is Photo-Finish, a technology that has been used to separate competitors in racing sports since 1955.
But 'High Tech' is also becoming more and more present in the daily training of most top athletes.
In swimming, Motion Capture is used to maximize swimmers' performance. The CRI (Centre de Recherche Interdisciplinaire), works a lot in the field of sport, for example in their HITBOX projects (February 2020) or in their Augmented Gymnasium (January 2019). Within the DVIC, there is the Snook project, an interactive pool table that uses Deep Learning and Reinforcement Learning to improve player performance. In the field of martial arts, there are very few projects with a technological focus. One example is the Punch Acceleration Sensor project (2010), in which an accelerometer is integrated into a Makiwara to give an idea of the striking force.
Contributions / Evaluations
The first step to design the Makiwara is to adapt it for indoor use without floor fixation. So I decided to screw the Makiwara onto a large wooden board on which the karateka will stand.
Flexibility is a crucial issue when making a Makiwara. It must be able to bend under the effect of the punches before coming back into place immediately, without breaking. In order to reproduce the suppleness of a traditional (buried) Makiwara, I have stuck short wooden planks on the base of the base as follows.
To be able to quantify the force and position of an impact on the strike area, we must look into the sensors. However, this area is a critical design point since it is subject to repeated violent impacts. Most sensors have weak areas, particularly on the welds, which would not have withstood these stresses. However, there is one type of sensors that is particularly suited to this situation: flexible sensors. Several tutorials
and articles on this site are dedicated to sensors and flexible robotics. To make the pad (striking zone) of the Makiwara, I was inspired by the Skin-On Interfaces technology developed by Marc Teyssier in 2019. I readapted and reshaped this process in the form of a colorless flexible sensor which alone constitutes the strike area. The working principle of this sensor is detailed in the following article: Skin-On Interfaces
, Marc Teyssier, 2019.
The pad is therefore made up of a matrix of wires trapped between two layers of silicone. The thickness and nature of the silicone were chosen to reproduce the firmness of the striking area of a Makiwara as faithfully as possible.
Technology applied to sport is a booming field, but there are still some paths that have not yet been explored. Flexible sensors are also in full development and open up fascinating new possibilities. In the future, the Makiwara will allow a faster, funnier and more optimized skill development for young karateka’s. Projects such as this one are changing the practice and the vision of these martial arts in today's society.