Abstract

Background: The aim of this study was to investigate whether vibration that is applied to the lateral muscles of the neck induces the illusion that the body is swaying and compensatory body sway during sit-to-stand movements.

Methods: Ten healthy adults participated in this examination. The center of pressure’s position during the sit-tostand exercise was measured immediately after the participant sat for 1 minute with their eyes closed, with or without vibration applied to the right side of the neck. The average center of pressure position in the anteriorposterior and left-right directions during the sit-to-stand exercise after the vibration was compared with and without vibration. After the task, we asked the participants about their sensation of body sway during the sit-to-stand movement, and the ratio of the appearance of the body sway and direction were compared between vibration conditions.

Results: The sensation that the body swayed to the right due to vibration was significantly higher than that without vibration. The center of pressure’s position in the vibration condition was significantly deviated to the left compared with that without vibration.

Conclusion: Our findings indicate that vibration applied to the right side of the neck induces the sense that the body is swaying to the right, although the body is actually swaying to the left. This actual body sway during the sit-tostand motion may compensate for an illusion that is induced by muscle vibrations, and this technique is possibly effective for posture control training.

Keywords: Vibration; Illusion; Body sway; Aftereffect; Sit to stand; Lateral sway; Center of pressure