2025 年 13 巻 4 号 p. 393-404
In conventional instruction for beginning soccer players, the instructor often teaches by demonstration and feeling, making it difficult for the learner to grasp the proper posture correctly and understand how to improve their own instance. In this study, we introduce and investigate two types of visual augmentation for soccer kicking posture instruction: Spot projection directly on the ball surface and on the ground for guiding foot positions, and Portrait playback providing skeletal motion in the scene at free point of view. Both augmentations can also display shadow instruction from an expert simultaneously. We conducted a user study (N = 48) to verify how the two types of augmentation would affect the soccer learners in the learning process. The results showed that Spot Projection could help to understand the posture of the axis leg, while Portrait Playback could help to understand the example of the upper body and leg movements.