title: Postural control during transient floor translation while standing with the leg and trunk fixed.
abstract: Postural movement was restricted above the ankle, and contingent negative variation (CNV) and postural muscle activity were investigated during a transient floor translation (S2) 2s after an auditory warning signal (S1). For 13 healthy young adults, the joints of the knee, hip, and trunk were fixed using a cast brace. Under no-fixation and fixation, a set of 10 translations was repeated at least 4 times, and center of pressure in the anteroposterior direction (CoPap), posterior postural muscle activity of the body (elector spinae (ES), biceps femoris (BF), gastrocnemius (GcM) and soleus (Sol)), and late CNV at Cz were analyzed in the initial two sets (initial set) and last two sets (late set). In the no-fixation, CoPap forward displacement after S2 gradually decreased. In the first trial of the fixation, it had significantly increased, and then rapidly decreased across subsequent trials. CNV peak amplitude was largest in the late set of the fixation. The activity of postural muscles increased just before S2 and in the late set the start time showed high correlations with CNV peak time in all muscles (ES (r=0.88), BF (0.92), GcM (0.80), and Sol (0.89)) under the no-fixation, but exclusively in the GcM (0.84) and Sol (0.88) under the fixation. When postural control was restricted mainly to the ankle, attention would have been focused mainly on processing sensory information from the triceps surae just before the floor translation.
authors: Department of Human Movement and Health, Graduate School of Medical Science, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8640, Japan. Electronic address: fujikatu@med.m.kanazawa-u.ac.jp.
authors: Katsuo
authors: K
authors: Fujiwara
authors: Department of Rehabilitation Science, Osaka Health Science University, 1-9-27 Temma, Kita-ku, Osaka 530-0043, Japan.
authors: Naoe
authors: N
authors: Kiyota
authors: Department of Human Movement and Health, Graduate School of Medical Science, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8640, Japan.
authors: Maki
authors: M
authors: Maekawa
authors: Neurology Department, Krasnoyarsk State Medical Academy, Partizana Zheleznyaka d.1, Krasnoyarsk 660022, Russia.
authors: Semen V
authors: SV
authors: Prokopenko
authors: Neurology Department, Krasnoyarsk State Medical Academy, Partizana Zheleznyaka d.1, Krasnoyarsk 660022, Russia.
authors: Abroskina M
authors: AM
authors: Vasilyevna
mesh_terms: D000161:Acoustic Stimulation; D000222:Adaptation, Physiological; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D004856:Postural Balance; D011187:Posture; D055815:Young Adult
keywords: Contingent negative variation; Joint fixation; Postural control; Postural muscle activity; Transient floor translation