Vanguard
Attempt to Measure the Immeasurable: Expanding the Frontiers of Sports
Sports engineering has traditionally focused on the analysis of video images, but Associate Professor Yuji Ohgi has been looking at this field from the perspective of measurement. Driven by the desire to spread the joy of sports, he has described how the potential of sports is expanding as things previously considered impossible to measure are now being measured.
OHGI, Yuji
Associate ProfessorGraduate School of Mediaand Governance
From an athlete to a researcher
I first started swimming when I joined
the junior high school swimming club. Swimming is mainly an
individual sport. This meant that if a swimmer practiced harder
he/she could swim faster. I felt quite motivated by this mechanism of
individual sport and quickly became committed to swimming. As my
effort at swimming increased, I often swam for six hours a day. Later
I even participated in the Japanese Olympic trials.When the time came
to enter university, I selected the University of Tsukuba, which
possessed a good swimming environment that could help me to continue
swimming. In the master’s program at the university, I continued
swimming while studying for coaching. Those athletes who pursue
competitive sports during their university education get into many
different fields. Those who think that research in physiology is
important join a physiology lab while those who think that studying
mental aspect of athletes is important enter a psychology lab. I was
interested in conducting research on how to swim faster from the
perspective of biomechanics. As such I joined a sports biomechanics
lab from my undergraduate days. Since then I have continued my
research in the field. I have always enjoyed creating electronic
devices and software. I have really enjoyed conducting research
itself. If I were not doing research at SFC, I would definitely be
doing something similar.
Precise data in real time
In the area of sports engineering
research, researchers often film athletes in motion and then analyze
the images. However, swimming presents some unique challenges. It is
impossible to get a clear image in water due to bubbles and splashes
that the swimmer creates while moving in water. The other problem
with filming athletes, swimmers and other sportspersons is that it
requires filming of a large area according to their fast movement.
This means that the athlete inevitably ends up being small in the
image. Enlarging the picture results in low resolution makes
difficult to analyze the subtle movements of the athlete. As a result
errors may occur. My lab developed a small, lightweight sensor that
athletes can attach to themselves. Instead of filming the athlete, we
measure the movements of the athlete with the sensor. This way we can
acquire precise data on the athlete in motion. 
Recently, I had ski jumpers wear such sensors. The data on their movements while they
were still in the air and data on air resistance they experienced
were sent wirelessly to us on the ground. In the future, I hope to
send such information as digital broadcast content, close to the real
time. If those people watching the sports program on their living
room TV know that the skier they are watching has taken off too fast
or that he/she lost speed because of headwinds, it can make sports
more interesting.Having data in real time would also help with
coaching athletes. For instance, a coach cannot give advice to the
athlete in real time based on the image because the athlete cannot
watch his/her image in motion. That is the reason why we are looking
into using sound. In collaboration with Professor Masaki Suwa and his
lab at SFC that conducts research on cognitive science, we have
started researching on delivering the information as sound. For
example, we could convert movements into sound to let the athlete
know about his/her swing of the baseball bat or tennis racket. The
sound given when the form is correct would differ from the sound
given when it is incorrect. This would let the athlete know that
his/her form is incorrect so that he/she could then correct form
immediately. Since there are many benefits in sports to receive
information in real time, I would like to focus on it and
persistently conduct research.
The joy of measuring the immeasurable
Returning to the topic of aquatic
exercise let me tell you about the work we do in my lab in this area.
We have successfully created the first aquatic pedometer in the
world. Aquatic walking is a suitable exercise for a wide range of
people from young to old. Although not many people enjoy aquatic
walking as it involves repetition of monotonous movements. In order
to make the exercise more enjoyable, we thought it would be useful to
provide information of interest to the person doing the exercise.
Examples of such information include number of steps taken and number
of calories burned. This is one of the reasons why we started the
research. After a process of trial and error, we developed an aquatic
pedometer. It works as follows: The aquatic walker wears goggles to
which a sensor has been attached.
The data is then sent wirelessly from the sensor to a poolside antenna. The number of calories burned
is calculated using the data received and the personal data that has
been entered in advance. Such personal data include height, weight,
age and gender of the athlete. The goggles are also equipped with
bone conduction speakers, which enable information, such as the
amount of calories burnt (for example 80 calories), to be sent
directly to the athlete. Conventional pedometers measure
comparatively large movements on land, and it was believed that
measuring slow movements in water (where there is pressure) would be
impossible. I am always delighted to measure things that everyone
thinks cannot be measured.
Extracting and using the necessary information
As technology advances in the future,
we will be able to obtain large amounts of detailed information about
athletes. The next area of research that needs to be tackled is data
mining. This involves extracting important information from huge
volumes of information and then analyzing key information. Even if we
can obtain information of, for example the stroke of a swimmer or the
gait of a runner, the answer to the question of how to move faster
does not lie in the data obtained. This means that eventually it
would take time to provide useful result to the athlete. It is
difficult to analyze the obtained numerical information and connect
information to purpose. It is expected that a researcher not only has
accurate knowledge of mechanics, but also possesses the experience as
an athlete to analyze such information. Even if researchers were to
find a new method to enhance athletic performance, they would need to
convince the athlete to trust such results. As has been the case with
other findings that are now widely accepted, these findings will
probably take some time to be accepted. We are still in the process
of laying the foundation.
Sharing the joy of sports
In early days of my career I was an
athlete. However, my work is not only meant for athletes but for
everyone. The first aim of my research is to encourage people to play
and enjoy sports. We are now conducting a joint research project with
a corporation. We are doing research on exercise instruction for
elderly persons at nursing care facilities. There are various
programs for elderly in such facilities, and exercise is one of them.
Take the simple exercise of opening and closing hands. Both persons
suffering form dementia or recovering from a stroke conduct the same
exercise. Instructors sometimes wonder if the exercise is effective.
If people who instruct and those who do the exercise understand that
the recommended exercises will improve health, then both will be
motivated. I would like to quantify the effects of such exercises.
The aim of my research is to motivate all, athletes and non-athletes
alike, and help them enjoy sports.
A Brief Background of Associate Professor
Ohgi,Yuji
Associate Professor Ohgi graduated from the School of Health and Physical Education at the University of Tsukuba in 1990 and went on to earn a master’s degree in the Master’s Program in Health and Sport Sciences at the same university in 1992. After completing coursework at the university’s Doctoral Program in Health and Sport Sciences in 1997, he left school and headed SPINOUT, a company he established specializing in experiments, data analysis, and software development for sports. He became a Research Assistant at the Faculty of Environment and Information Studies at Keio University in 1999. After serving as Assistant Professor, he became Associate Professor at the Graduate School of Media and Governance at Keio University in 2005. He earned a Ph.D. in Media and Governance at Keio University in 2003. Associate Professor Ohgi’s specialties include sports engineering and sports biomechanics.He is a member of the executive committee of International Sports Engineering Association. He is currently a member of the Medicine and Scientific Committee of the Japan Swimming Federation and a member of the JOC Scientific Staff. Patents for swimming goggles with bone-conduction speakers, swimming pool lane markers for people with visual impairments, a diagnostic system for analyzing golf-swing form, and an aquatic pedometer.
(26 January 2010)
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