Fig. 4.

Experimental sequence. All subjects were allocated into the three groups randomly. Then, the subjects observed the model image for 30 seconds. They practiced for 30 seconds to properly imitate the model movement. The MO group observed the model image, the SO group observed the video of self-practice images that was recorded at last-minute, and the MSO group observed the video of model and self-practice image at the same time. This was repeated 5 times a day, for a total of 5 days.

MO: model-observation; SO: self-observation; MSO: model and self-observation