Trajectory Playback

A technique in haptic interfaces where a force-feedback device physically guides a user's hand through a predefined path or shape. The system applies forces to move the user along a trajectory, allowing them to perceive spatial information through proprioception and kinesthetic feedback rather than vision. Trajectory playback is used in accessibility applications to teach shapes, gestures, and handwriting to blind users, in rehabilitation to guide therapeutic movements, and in skill training (such as calligraphy or surgical procedures). Research shows that combining trajectory playback with audio feedback significantly improves shape learning for visually impaired users compared to haptic-only approaches.