The effect of instructions regarding gaze direction on stability of movements and accuracy of trajectory control during cycling.

In real-world locomotion, manipulation of visual information influence movement. It has been suggested that both near and distant visual information are used to control locomotion. However, it has not yet been clarified whether the two archetypal conditions of visual behavior differently affect dynamic balance during cycling. Therefore, our study aimed to investigate the effect of instructions regarding gaze direction on stability of cycling movements and accuracy of cycling trajectory. Twenty participants rode as straight as possible along a 20-m straight line at a low speed (2.4 ± 1.4 m/s), performing five trials for each condition. Participants were instructed to gaze at a far target at eye level (distant-upper condition), at a far target on the ground (distant-bottom condition), and at the line on the cycling path (near condition). The results showed that the standard deviation (SD) of the steering angle in the distant-bottom condition was smaller than that in the near condition. The SDs of lateral head flexion in the distant-upper and distant-bottom conditions were smaller than that in the near condition. The accuracy of the cycling trajectory was highest for near, followed by distant-bottom and distant-upper conditions, in that order. These findings suggest that directing gaze toward the far area during cycling enhances the stability of movements, whereas directing gaze toward the near area contributes to the control of the position in the path.