KARATECH: A Practice Support System Using an Accelerometer to Reduce the Preliminary Actions of Karate

Area of Science:

• Sports Science
• Biomechanics
• Motor Control

Background:

• Kumite sparring involves offensive and defensive techniques, with pre-actions potentially revealing technique timing to opponents.
• Reducing pre-actions is crucial for improving kumite performance, but difficult for beginners and intermediate practitioners to identify and correct.
• Existing methods lack effective tools for practitioners to understand and reduce pre-actions.

Purpose of the Study:

• To develop a practice support system for karate practitioners to identify and reduce pre-actions in kumite.
• To enable beginners and intermediate players to better understand their pre-action tendencies.
• To improve overall kumite performance by minimizing detectable pre-actions.

Main Methods:

• Proposed a method to estimate the presence or absence of pre-actions in forefist punches using acceleration data.
• Compared acceleration data of punches against a dataset of punches without pre-actions to detect anomalies.
• Developed KARATECH, a system visualizing pre-action presence via video and graphs.

Main Results:

• The proposed method achieved 86% accuracy in estimating the presence or absence of pre-actions in forefist punches.
• The KARATECH system successfully demonstrated the presence or absence of pre-actions to users.
• Karate practitioners using KARATECH showed a reduced rate of pre-actions compared to a control group.

Conclusions:

• The developed method and KARATECH system are effective in helping karate practitioners reduce pre-actions.
• This approach offers a novel way to provide objective feedback for skill refinement in kumite.
• Further research can explore application to other techniques and skill levels in martial arts.