Author(s): ICHIYA, F., OHARA, Y., SAKO, H., HORIUCHI, T., TOYA, A., OHASHI, S., OKUSHIMA, D., SHINGA, I., Institution: NATIONAL INSTITUTE OF TECHNOLOGY, MATSUE COLLEGE, Country: JAPAN, Abstract-ID: 1373

INTRODUCTION:
In this study, we developed a measurement system that integrates a high-precision Global Navigation Satellite System (GNSS) receiver with a nine-axis Inertial Measurement Unit (IMU) sensor to capture the kinematic characteristics of rowing.
METHODS:
The system simultaneously records boat position, velocity, acceleration, and angular velocity during each stroke. Using this system, rowing data were collected, and a comparative analysis between athletes was conducted to evaluate its effectiveness.
The system consists of a GNSS receiver mounted on the boat, a compact Arduino-compatible board computer (Sony Spresense), and a GNSS add-on board, enabling high-precision positioning. An LTE extension board was integrated to allow data transmission via LTE-M communication. In addition, an IMU sensor was installed to continuously measure acceleration and angular velocity, including longitudinal and lateral oscillations.
For data visualization, Soracom Harvest Data cloud service was used. The measured data were sampled at 10 Hz and transmitted every 5 s via LTE-M communication.
The experiment was conducted on athletes who regularly trained in single sculls. Participants were instructed to row at maximal effort for 20 strokes at a fixed stroke rate of 24 strokes per minute. The participants were classified as novice rowers (less than one year of experience) and advanced rowers (more than six years of experience).
RESULTS:
Focusing on boat velocity, Athlete A exhibited the highest maximum speed of 4.71 m/s. Athlete A has competed in international competitions as a member of the national age-group team and had the longest competitive experience among the participants in this study. The second-highest maximum speed was observed in Athlete B (4.50 m/s), with a difference of 0.21 m/s between the two athletes.
Furthermore, comparison of the difference between the maximum and minimum velocity within each stroke revealed that Athlete A showed smaller velocity fluctuations than the other athletes. These results suggest that Athlete A was able to maintain a high boat velocity with minimal deceleration.
With respect to acceleration in the direction of motion, Athlete A demonstrated relatively large positive acceleration and small negative acceleration. In contrast, although positive acceleration was observed in the less experienced Athlete C, its magnitude was smaller, and a two-phase acceleration pattern was evident. In addition, Athlete C exhibited greater negative acceleration than Athlete A.
CONCLUSION:
This study developed a measurement system using a high-precision GNSS and IMU sensors to quantitatively evaluate boat velocity and acceleration characteristics during rowing. The results demonstrated that experienced athletes were able to maintain high boat velocity with minimal deceleration and negative acceleration. In contrast, less experienced athletes exhibited fragmented acceleration patterns and increased vertical oscillations, indicating unstable movement characteristics.