健常人における Body Tracking Test 追随軸の変位について  [in Japanese] The Tracking Axis of the Body Tracking Test  [in Japanese]

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Author(s)

Abstract

私たちは, 動的体平衡機能を定量的に評価する方法である Body Tracking Test (以下, BTT と略す) を用いて, 健常人の追随時の体重心移動のあり方を解析したので報告する. 対象は, めまい・平衡障害の既往がない健常被検者779名で, 平均年齢37.9歳である. 視刺激は, 前後方向定速刺激BTT, 左右方向定速刺激 BTT を用いた. BTT 解析は, 主成分分析法による第一主成分を主軸とした主軸解析にて行った. 主軸方向について, 座標Y軸とX軸の傾きを算出して軸の傾きを評価した. 全年齢の傾き角は, 前後方向 BTT では位置ベクトル・速度ベクトルともに時計方向 (プラス方向) に傾きを示した. 左右方向 BTT では, 位置ベクトル・速度ベクトルともに反時計方向 (マイナス方向) に傾きをもって追随していることがみられた. 年代別にみると, 前後方向 BTT ではゼロ度からの傾き角が有意差をもってプラス方向 (時計方向) を示した. また, 左右方向 BTT では10~30歳代には傾きはみられずX軸に沿った追随を示していた. 追随軸の傾きについては, 重心移動する習慣 (習性) が大きいのではないかと考えられた. 空間知覚には右脳の頭頂葉が主に関与しており, 下肢と体幹の位置関係においては, 身体左側からの体性感覚情報が大きく活用されるものといわれている. 主軸の変位は, 利き足・軸足の関係, そして空間知覚に関与する頭頂葉の働きが関係している可能性があると思われた.

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 antero-posterior (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° 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.

Journal

  • Nippon Jibiinkoka Gakkai Kaiho

    Nippon Jibiinkoka Gakkai Kaiho 116(12), 1308-1314, 2013

    The Oto-Rhino-Laryngological Society of Japan, Inc.

Codes

  • NII Article ID (NAID)
    130003395261
  • NII NACSIS-CAT ID (NCID)
    AN00191551
  • Text Lang
    JPN
  • ISSN
    0030-6622
  • NDL Article ID
    025109907
  • NDL Call No.
    Z19-250
  • Data Source
    NDL  J-STAGE 
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