2005 年 4 巻 1 号 p. 1-9
The objective of the present study was to estimate extremity muscle mass using a BI-based muscle mass analyzer and to investigate relationships of muscle mass to muscular strength system and cardiopulmonary functions. Subjects were 15 healthy adult men who did not exercise regularly (mean age, 19.5±1.4 years; height, 174.0±6.5 cm; weight, 65.1±7.4 kg). For estimation of body composition, including extremity muscle mass, a 12-lead BI muscle analyzer (Muscle-α, 50 kHz, 500, μA) was used. Maximum anaerobic power exhibited significant correlations to muscle mass of each body segment (r=0.549-0.854) and relative parameters such as extremity muscle mass/height ratio (r=0.539-0.853). Leg extension power exhibited significant correlations to muscle mass of the arm, thigh, leg and all extremities (r=0.518-0.700). Grip strength exhibited significant correlations to muscle mass of each body segment (r=0.719-0.865). Maximum oxygen uptake exhibited significant correlations to absolute mass of the thigh, lower leg and leg and relative parameters such as extremity muscle mass/height, upper arm muscle mass/upper arm length and lower leg muscle mass/lower leg length (r=0.564-0.840). In addition, maximum oxygen uptake relative to body weight exhibited significant correlations to leg muscle mass/arm muscle mass ratio and leg muscle mass/arm muscle mass relative to body weight (r=－0.598, p<0.05). Leg muscle mass/arm muscle mass ratio may thus represent a useful index related to maximum oxygen uptake. In this manner, when investigating relationships between body composition, muscular strength system and cardiopulmonary function, estimation of muscle mass and muscle mass balance can yield valuable information. Muscles are biological tissues that are affected by activities of daily living, but measuring muscle mass has not previously been easy. Now that muscle mass can be estimated using convenient techniques such as the BI method, relationships of muscle mass to physical fitness, motor abilities and activities of daily living can be readily assessed.
