中高齢男性における支持基底面を基準とした有効支持基底面の割合の足隔条件間差および日間信頼性

―２種類の動作による検証―

抄録

　The ratio of limits of stability (LOS) to base of support (BOS) should be large. However, balance tests often inadequately address LOS and tend to overlook BOS. Moreover, higher difficulty levels may hinder some middle-aged and elderly individuals from performing these tests. This study aims to explore variations in foot breadth (0 cm, 10 cm) and the day-to-day reliability in rate of LOS per BOS (LPB) of two motions, examining relationships between LPBs in ten middle-aged and elderly males. A pressure-sensitive mat and force platform measured BOS and LOS, respectively, with the former positioned on top of the latter. Subjects, following BOS measurements, assessed LOS through circular (rotational motion) and four-directional tilting motions. These measurements spanned three days. Two-way analysis of variance demonstrated no significant interaction differences for both motions; however, there was a notable main effect of the breadth factors. LPB for both motions was consistently higher at 10 cm than at 0 cm throughout the study. All intraclass correlation coefficients were >0.80. Relationships between LPBs were >0.87. In conclusion, day-to-day reliability demonstrated a moderate or larger extent. The LOS for rotational motion was <40% of BOS (0 cm: 33.5%, 10 cm: 36.6%), whereas for tilting motion, was approximated 50% of BOS (0 cm: 50.2%, 10 cm: 53.9%). Ultimately, LPB increased with the widening of foot distance in both motions. Furthermore, there was a strong relationship between the LPBs.