Plantar Vibrational Stimuli Modify Dynamic Posture Control in Response to Translational Perturbations

Norio Kato, Toshiaki Tanaka, Takeshi Tsuruga, Yoshimi Tanahashi, Kouki Kuwano, Yasuhiro Nakajima, Takashi Izumi, Yusuke Maeda

Declining superficial and deep sensory function, in addition to muscular weakness and other decreases in motor function, reduces balance in elderly people. In previous research comparing dynamic postural control following sensory disruption in young and elderly people, elderly participants took longer to achieve center of pressure (COP) recovery (i.e., to return to an upright standing position after perturbation cessation). We conducted the present study to determine how dynamic postural control in young and elderly people was affected by plantar sensory feedback with vibrational stimuli in accordance with the load acting on the soles. Six elderly people and five young people participated. With the participants standing on a motion platform, postural responses were analyzed following random translational perturbations in one of four directions (forwards, backwards, left, and right). The study combined four directions of translational perturbation with or without plantar vibrational stimulation for eight different conditions. In both groups, COP recovery was significantly quicker when vibrational stimuli were provided. This finding suggests that plantar sensory feedback with vibrational stimuli could help keep elderly people from falling.