Body Pose Estimation Integrated With Notational Analysis: A New Approach to Analyze Penalty Kicks Strategy in Elite...

Area of Science:

• Sports Science
• Biomechanics
• Computer Vision

Background:

• Penalty kicks in football are crucial, with player body orientation offering insights into success.
• OpenPose is a widely-used open-source technology for pose estimation from video data.

Purpose of the Study:

• To validate OpenPose's ability to extract relevant body orientation angles from elite football penalty kick videos.
• To investigate the correlation between these body angles and observable behaviors/strategies analyzed via the observational system for penalty kick analysis in football (OSPAF).

Main Methods:

• Analysis of 34 elite football penalty kick videos using OpenPose for body angle extraction.
• Utilized the validated OSPAF system to analyze observable behaviors and strategies.
• Employed logistic regression to examine relationships between OpenPose variables, OSPAF variables, and penalty kick strategies.

Main Results:

• OpenPose demonstrated high reliability (0.976) and confidence scores (0.80 ± 0.14) in measuring body orientation.
• Goalkeeper anticipation, measured by OpenPose, significantly correlated with goalkeeper strategy, increasing prediction accuracy to 97%.
• Lower goalkeeper anticipation, awaiting tactics, and slower run-up speeds were linked to kicker-dependent strategies.

Conclusions:

• OpenPose is a reliable tool for analyzing body orientation in elite football penalty kicks.
• Body orientation analysis via OpenPose offers practical insights into goalkeeper strategies.
• While OpenPose effectively analyzes goalkeeper strategy, it did not significantly associate with penalty taker strategy in this study.