title: [Tracking axis of the body tracking test(BTT)].
abstract: We report herein on the use of the body tracking test (BTT), which is a method for quantitatively evaluating dynamic body balancing function, and how the body center moves during tracking by healthy subjects. We investigated 779 healthy subjects with no history of vertigo or balance disorder and a mean age of 37.9 years. Breakdown is as follows. Under 10 years old is 81 (37 boy and 44 girl), 10 years of age is 162 (73 boy and 89 girl), 20 years of age is 110 (43 men and 67 women), 30 years of age is 73 (44 male, 29 female), 40 years of age is 79 (49 men and 30 women), 50 years of age is 77 (40 men and 37 women), 60 years of age is 100 (53 men and 47 women), 70 years of age is 73 (27 men and 46 women), 80 years of age is 24 (15 men and 9 women). For the visual stimulus, we used a constant-speed antero-posterior (A-P) stimulus BTT and a constant-speed lateral BTT. BTT analysis involved principal axis analysis, in which the principal axis was the first principal component according to a principal component analysis technique. The axis tilt in the principal axis direction was assessed by calculating the coordinate Y-axis and X-axis tilt. In the anteroposterior (A-P) BTT, subjects of all ages exhibited an angle of tilt in the clockwise direction (the "plus" direction), together with the position vector and velocity vector. In the lateral BTT, we observed that the subjects tracked with a tilt in the counter-clockwise direction (the "minus" direction), together with the position vector and velocity vector. In terms of the subjects' ages, the angle of tilt from 0 degree in the antero-posterior (A-P) BTT showed the clockwise direction (the "plus" direction). In the lateral BTT, subjects 10 to 30 years of age exhibited tracking along the X-axis, with no observable tilt. Movement of the center of gravity may be a major acquired ability (practice) with respect to the direction of tilt of the tracking axis. Spatial sensory ability primarily involves the right parietal lobe of the brain, and somatosensory information from the left side of the body is believed to be used more for the positional relationships between the legs and the torso. Deviation of the principal axis appears to be related to the relationship between the dominant foot and the pivot foot, as well as to the functions of the parietal lobe that are involved in spatial sensing.
authors.affiliation: Department of Otolaryngology, Toho University School of Medicine, Sakura.
authors.forename: Tomoe
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Department of Otolaryngology, Toho University School of Medicine, Sakura.
authors.forename: Fuyuko
authors.initials: F
authors.lastname: Ikemiyagi
authors.affiliation: Department of Otolaryngology, Toho University School of Medicine, Sakura.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ikemiyagi
authors.affiliation: Department of Otolaryngology, Toho University School of Medicine, Sakura.
authors.forename: Toshitake
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Otolaryngology, Toho University School of Medicine, Sakura.
authors.forename: Taro
authors.initials: T
authors.lastname: Takanami
authors.affiliation: Department of Otolaryngology, Toho University School of Medicine, Sakura.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Tamura
authors.affiliation: Department of Otolaryngology, Toho University School of Medicine, Sakura.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of Otolaryngology, Toho University School of Medicine, Sakura.
authors.forename: Mitsuya
authors.initials: M
authors.lastname: Suzuki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003939:Diagnostic Techniques, Otological; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006112:Gravitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000502:physiology; D010775:Photic Stimulation; D004856:Postural Balance / Q000502:physiology*; D025341:Principal Component Analysis; D014785:Vision, Ocular / Q000502:physiology; D055815:Young Adult