上腕部の筋運動に伴う生体電気インピーダンスと筋厚の変化

抄録

Muscle tissue swelling occurs immediately after exercise. Conventionally, this phenomenon has been evaluated by diagnostic imaging methods such as ultrasonic B-mode imaging. On the other hand, bioelectrical impedance analysis (BIA) is a simpler method to measure this phenomenon. In the BIA, changes in water volume inside and outside of muscle cells during exercise can be evaluated as changes in bioelectrical impedance (BI) . In this study, the local muscle fatigue was effectively measured using BIA by concentrating the current in a narrow area and the results were compared with muscle thickness measured by ultrasonic B-mode imaging. The measurement site was the upper arm, and the exercise condition was four sets of arm curl exercise. Measurements of upper arms were taken before exercise (base line:BL) and after each exercise set (post exercise:PE1-4) . BI was converted into external cell water resistance (R_ECW), internal cell water resistance (R_ICW), and their parallel resistance (R_ICW//R_ECW) . The results showed that R_ECW increased before PE1 and decreased after PE1. Therefore, exercise hyperemia was inferred to be a factor in muscle swelling after PE1. Then, the correlations between R_ECW, R_ICW, R_ICW//R_ECW and muscle thickness were calculated. Subsequently, a significant correlation was obtained between R_ICW//R_ECW and muscle thickness, especially after PE1.