中高年者における左右下肢別重心動揺測定の意義

Abstract

若年者および中高年者を対象とし，静止立位時の左右下肢荷重値および左右下肢別重心動揺測定値と総合的重心動揺測定値との関連性について検討した．その結果，中高年者では総合的重心動揺検査における前後方向単位軌跡長の増加と左右別下肢荷重検査における一側下肢への荷重偏位，荷重側重心の前方変位，荷重側の外周面積増加という立位姿勢の特徴が示唆された．また若年者は荷重側重心後方型で重心動揺は減少し，中高年者では荷重側重心前方型で重心動揺は減少する傾向を示した．

The present study investigated relationships between general gravity-center sway and weight-bearing volume and differences in gravity-center sway between right and left legs during static standing. Subjects comprised an elderly group (n=50; mean age, 63.6 ±6.8 years) and a younger group (n=25; mean age, 22.7 ±2.3 years) . A Twin-Gravicorder combined with 2 force plates was used to measure 15 parameters, such as mean sway velocity along the X and Y axes from the general gravity-center sway test; mean volume of weight-bearing; envelope area, such as mean sway along the X and Y axes from the weight test distinguishing between the right and left legs. Weight rates ? 50％ were used to define the weight-bearing side, and weight rates <50％ represented the non-weight bearing side. We determined the weight-ratio difference for right and left sides by subtracting weight rate on the non-weight-bearing side from weight rate on the weight-bearing side. Moreover, 3 categories of weight-bearing type according to center of gravity were defined: posterior type, anterior type, and middle type on the weight-bearing side using measurements of Weight-Balance and mean sway along the X axis for Location-Balance. The results suggest characteristic postural standing in elderly patients, with increased mean sway velocity along the Y axis, increased volume of the weight-bearing side, anterior shift of the center of gravity on the weight-bearing side, and increased envelope area on the weight-bearing side. In addition, while gravity-center sway increased for posterior weight-bearing type center of gravity on the weight-bearing side for the younger group, the elderly group showed a tendency for increased gravity-center sway for anterior weight-type center of gravity on the weight-bearing side.