ABSTRACT
The purpose of this study was to investigate the relative growth of thigh muscle thickness and development of ball kicking performance in junior male soccer players.The study participants included 235 Japanese male soccer players aged between 10 and 18 years. Subjects were classified into 10 groups on the basis of their body height every 5 cm. The thickness of the anterior and posterior thigh muscles (MTA and MTP, respectively) were measured using B-mode ultrasonography. The ball distance (BD) and ball velocity (BV) were measured using a tape measure and a speed gun, respectively. By using a custom-made speed meter, we measured the maximal swing velocity of the lower limb (SV) while the players were kicking the ball. These parameters, along with the height, were plotted on a logarithmic graph to obtain the allometric equation y = bx<sup>a</sup>.There was a sharp bend in the graph showing the relationships between MTA, MTP, BV, SV, and body height. The growth indexes "a" of MTA and MTP were increased at 157.3 cm and 159.9 cm, respectively. The development indexes "a" of BV and SV were increased at 144.3 cm and 146.1 cm, respectively. However, there were 2 sharp bends in the graph showing the relationships between BD and body height. The development index "a" of BD showed the highest value from 150.5 to 171.2 cm.These results suggested that the developmental spurt in ball kicking performance was faster than the growth spurt in muscle thickness of the thigh.
ABSTRACT
The purpose of this study was to clarify the relationship between left ventricular muscle mass, skeletal muscle volume and vessel structures in elderly women (n=15, 76.0±5.4 years). We measured the thigh muscle thickness, and brachial and common carotid arterial diameter using B-mode ultrasound method. Posterior wall thickness, interventricular septal thickness, left ventricular end-diastolic internal diameter, and aorta artery were measured by B-mode echocardiography. No significant relationship was obtained between brachial and common carotid arterial diameters, and aortic diameter. On the other hand, significant correlation coefficients were obtained between cardiac muscle thickness and thigh muscle thickness (r=0.674, p<0.01). A significant correlation coefficient was also obtained between the estimated skeletal muscle volume and left ventricular mass [LVmass](r=0.542, p<0.05). The slope of regression equation between estimated thigh muscle volume and LVmass in elderly women in this study was (y=0.11x+75.65) steeper than in children (y=0.06x+14.02) reported previously. These results indicate that the ventricular muscle (LVmass) is closely related to the skeletal muscle volume in ordinary elderly women and skeletal muscle mass at a given LVmass is smaller in elderly women than children.