title: Postural responses accompanying Achilles tendon vibration stimulation during various phases of sit-to-stand movement.
abstract: The aim of this study was to determine the postural response accompanying Achilles tendon vibration stimulation during various phases of the sit-to-stand movement. Twelve healthy young adults performed the sit-to-stand movement in response to an auditory signal 2 s after a first one. Vibration stimulation with a 100 Hz frequency was applied to both Achilles tendons during the following phases: (1) 10 s of sitting before standing up; (2) 10 s plus a period until the standing position was achieved; and (3) 5 s after standing. The postural response after standing was analyzed with the center of foot pressure in the anteroposterior direction. Forward-leaning responses were identified in 78.3% and 63.3% of trials under conditions 1 and 2, respectively. Backward-leaning responses were identified in 93.3% of the trials under condition 3. Response latency (+/- standard deviation) was significantly longer under conditions 1 and 2 than under condition 3 (1: 872 +/- 576, 2: 1026 +/- 542, and 3:555 +/- 322 ms; ps < 0.05). Sensory information at the standing point might be anticipated based on sensory information received while sitting. Consequently, postural response as a compensatory movement would occur via the sensory reference system within the supraspinal nervous system.
authors.affiliation: Department of Physical Therapy, Gumma Paz College, 1-7-1 Tonya-machi, Takasaki 370-0006, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Kurokawa
authors.affiliation: Department of Human Movement and Health, Graduate School of Medical Science, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8640, Japan.
authors.forename: Katsuo
authors.initials: K
authors.lastname: Fujiwara
authors.affiliation: Department of Rehabilitation Science, Osaka Health Science University, 1-9-27 Tenma, Kita-ku, Osaka 530-0043, Japan.
authors.forename: Naoe
authors.initials: N
authors.lastname: Kiyota
mesh_terms: D000125:Achilles Tendon / Q000502:physiology*; D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D014732:Vibration; D016474:Weight-Bearing / Q000502:physiology