1.AGE AND SEX DIFFERENCES IN JAPANESE LIFE FITNESS
Japanese Journal of Physical Fitness and Sports Medicine 2003;52(Supplement):9-16
The purpose of the present study is to observe the effect of aging on life fitness in Japanese. Life fitness consists of such parameters as body composition, joint torque (JT), leg extension power (LP) and run power (RP) . Subjects were 719 males and 859 females, from 20 to 80yrs old. The “aged” groups (over 70 years) indicated a higher percentage of body fat, compared to the younger groups. The subcutaneous fat thickness at the arms and legs measured by ultrasonography, was independent of age, while that at the abdomen and back was higher among aged groups. It is therefore considered that the higher percentage body fat observed in the aged groups is due mainly to accumulated subcutaneous fat at the abdomen and back. Muscle volume (MV) at the upper extremity indicated no significant difference among age groups; while that at the lower extremity (especially knee extensor muscle) was significantly lower in the aged groups compared to the younger groups. The ratio of JT to MV, considered as the index of specific tension, was lower for the aged groups than younger groups. Mechanical power performed during ergometer running and leg extension power were significantly lower for the aged groups. It is concluded that aged peoples due to low muscle volume of the knee extensor, experience deterioration in leg extension power, resulting in lower mechanical power for runnine.
2.Influence of muscle fiber composition and muscle cross-sectional area on maximal isometric strength.
TOMOO RYUSHI ; TETSUO FUKUNAGA
Japanese Journal of Physical Fitness and Sports Medicine 1986;35(3):168-174
The purpose of the present study is to investigate the influence of muscle cross-sectional area on maximal isometric strength (M. I. S.), and the influence of muscle fiber composition on the ratio of maximal isometric strength to muscle cross-sectional area in the leg extensor muscles.
Muscle biopsies were taken from the right vastus lateralis of 16 healthy untrained males. Cross-sectional area of the leg extensor muscles were measured by ultrasonic measurements. Maximal isometric strength were determined as peak torques using an isokinetic dynamometer.
Significant positive correlation was observed between muscle cross-sectional area and maximal isometric strength (r=0.61, p<0.05) . The ratio of maximal isometric strength to muscle cross-sectional area was 2.6±0.4 Nm/cm2 (mean±S. D.) with a wide range of values from 2.0 to 3.3 Nm/cm2. No relationship was observed to exist between the ratio of maximal isometric strength to muscle cross-sectional area and muscle fiber composition.
From these results it can be concluded that muscle cross-sectional area plays a more important role in producing a high maximal isometric strength than muscle fiber composition, and that the large variations observed in the ratio of maximal isometric strength to muscle cross-sectional area may be caused by factors other than muscle fiber composition.
3.Reliability of B-mode ultrasound for measuring subcutaneous fat thickness in the cadaver.
KAGEMOTO YUASA ; TETSUO FUKUNAGA
Japanese Journal of Physical Fitness and Sports Medicine 1987;36(1):31-35
The reliability of B-mode ultrasound for measuring subcutaneous fat thickness was evaluated in the cadaver. The ultrasonic device used in this study was the linear type employing a 5 MHz transducer. Ultrasonically determined-measurements of subcutaneous fat thickness was obtained on the upper arm, thigh, leg and abdomen. The border between subcutaneous fat and muscle tissues was able to be distinguish clearly by using this ultrasonic device. The subcutaneous fat thickness obtained ultrasonically were lower than those measured directly with using the slide calipers in the cadaver. Mean difference (standard deviation) between these values was 1.65 mm (0.98 mm) . A statistically significant correlation coefficient of 0.97 (p<0.001) and the linear regression equation of D=1.0963 B+0.9332 was observed between the subcutaneous fat thickness obtained from a B-mode ultrasonic (B) and direct (D) methods. The results suggest that B-mode ultrasonic device may be able to use for measuring subcutaneous fat thickness and a more reliable fat thickness may be able to obtain by revising the ultrasonically determined-measurements.
4.B-mode ultrasonic assessment for the fat thickness distribution pattern on the whole body.
KAGEMOTO YUASA ; TETSUO FUKUNAGA
Japanese Journal of Physical Fitness and Sports Medicine 1987;36(1):36-41
A study was carried out to investigate the distribution pattern of the subcutaneous fat on the whole body. Two helathy males, 31 and 38 years of age, participated as subjects in this study. Subcutaneous fat thickness measurements were made on the trunk, the upper and lower extremities, and the buttock with using B-mode ultrasonic device employing a 5 MHz transducer. The thicker subcutaneous fat were obtained on the portion near navel, outer sites of the lower trunk and the thigh just under the buttock for the both subjects. The thinner portions, on the other hand, were showed on the upper sites of the chest, forearm and leg. On the extremities, fat thickness was relatively remained constant over the whole sites compared with those on the trunk. These results suggest that the fat thickness distribution on the trunk is more significant than those on the extremities in males.
5.Differences in muscle thicknesses of male and female Japanese elite athletes.
YOSHIE ISHIDA ; HIROAKI KANEHISA ; TETSUO FUKUNAGA
Japanese Journal of Physical Fitness and Sports Medicine 1992;41(2):233-240
The pourpose of this study is to investigate the differences in muscle thickness between males and females of Japanese elite athletes. Subjects were 82 males and 65 females who were Japan candidates for the 1986 Asian and the 1988 Olympic Games 8 sports events, e, g., sprinters, middle and long distance runners, throwers, swimmers, gymnasts, volleyball players, basketball players, and oarsmen. Muscle thicknesses were measured by using B-scan ultrasound equipment with a 5 MHz transducer at the follwing sites: forearm anterior, biceps, triceps, subsucapular, abdomen, quadriceps, hamstrings and posterior calf. In results, comparison in muscle thickness between males and females were made at upper extremity (forearm+biceps+triceps), trunk (subsucapular+ abdomen) and lower extremity (quadriceps+hamstrings+calf) . Males showed siginificantly higher values in muscle thickness than females at all sites, except for trunk of distance runners and lower extremity of volleyball players. Relative values of females to males in muscle thickness were 59-84% for upper extremity, 68-89% for trunk, 84-94% for lower extremity. At upper extremity and trunk, Males indicated significantly higher values in muscle thickness per body height (muscle thickness/Ht) execpt for distance runners. At lower extremity, however, there were no siginificant differences in muscle thickness/Ht at lower between males and females except for gymnasts. Relative values of females to males in muscle thickness/Ht were 66-94% for upper extremity, 72-99% for trunk and 89-100% for lower extremity. Males showed significantly higher values in upper/lower extremity ratio of muscle thickness than females, except for sprinters and distance runners. On the other hand, females had significantly higher values in lower/trunk ratio of muscle thickness than males, except for distance runners and gymnasts. These results indicate that the differences in muscle thickness between males and females exist remarkably at upper extremity and trunk commpared to lower extremity. These anatomical differences in the degree of muscle development may be refered to genetic and/or enviromental factors.
6.ULTRASONOGRAPHIC DETERMINATION OF TENDON COMPLIANCE IN HUMAN BICEPS BRACHII MUSCLE
MEGUMI OHTA ; HIROAKI KANEHISA ; TETSUO FUKUNAGA
Japanese Journal of Physical Fitness and Sports Medicine 2004;53(3):337-345
This study aimed to estimate in vivo the compliance of tendon structure in human biceps brachii (BB) muscle for eight healthy male subjects. Elongation of the tendon of BB during isometric elbowflexion was directly measured by ultrasonography. Muscle force of BB (FBB) was calculated from the elbow flexion torque and moment arm of elbow-flexor. When the EBB increased to 80%MVC (maximum voluntary contraction), the tendinous tissue of BB was elongated 10.24±2.52 mm, horizontally. The relationship between tendon length and FBB was curvilinear and consisted of an initial region characterized by a large increase in tendon length with increasing FBB under 50%MVC, immediately followed by a linear region. The compliance of tendinous tissues, estimated from the slope of the linear region, was 0.010±0.005 mm N, and did not show a significant correlation with MVC and muscle volume of the elbow flexors, estimated from muscle thickness. The compliance value observed here was lower than those of the medial gastrocnemius muscle and the tibialis anterior muscle, reported previously using the same ultrasonic method as the present study. This may be related to the functional differences among limb muscles in various human movements.
7.Architectural properties and specific tension of human knee extensor and flexor muscles based on magnetic resonance imaging.
HIROSHI AKIMA ; SHIN-YA KUNO ; TETSUO FUKUNAGA ; SHIGERU KATSUTA
Japanese Journal of Physical Fitness and Sports Medicine 1995;44(2):267-278
The physiological cross-sectional area (PCSA) of knee extensors (KE) and flexors (KF) was determined using magnetic resonance imaging (MRI) in humans. Twenty two healthy male volunteers were assigned to the subjects and MRI was taken to obtained 41-52 consecutive axial images (slice thickness ; 10 mm, interslice gap ; 0 mm) from right-leg thigh. From these images, anatomical cross-sectional area (ACSA) of KE and KF was determined. Muscle volume was calculated from the summation of each ACSA and the distance between each section. Muscle length was determined as the distance from most proximal to most distal images in which the muscle visible. The PCSA of each muscle was calculated as muscle volume times the cosine of the angle of fiber pinnation divided by fiber length, where published fiber length : muscle length ratio were used to estimate fiber length. The isokinetic knee extension and flexion (angular velocity ; 30, 60, 180, 300, 450 deg/sec) was measured to estimate the muscle force at KE and KF. Specific tension of KE and KF was calculated muscle force deviled by PCSA. The mean muscle volume of KE and KF was 2178, 1141 cm3. The ratio of KE : KF was 2.6. The mean fiber length in KE was 7-8 cm, and in KF was 6-42 cm. Peak torque during knee extension was significantly higher than knee flexion at all angular velocities. The specific tension of KF was higher than that of KE at all tendon velocities. Moreover, relationships between specific tension and tendon velocity/fiber length, KF was still higher than that of KE. These results suggest that the capacity of tension development differ between KE and KF under the same shortening velocity per unit of sarcomere.
8.Effect of high-speed resistance training on muscle cross-sectional area and speed of movement.
HIKARU HISAEDA ; YOSHIO NAKAMURA ; SHINYA KUNO ; TETSUO FUKUNAGA ; ISAO MURAOKA
Japanese Journal of Physical Fitness and Sports Medicine 1996;45(2):345-355
A conducted to determine 1) the effect of high-velocity movement in resistance training with a constant load on the velocity of movement after training and 2) the differences in the effect on muscle hypertrophy according to training velocity. Fourteen of the total subjects (male; n=10, female ; n=7) were placed in the experimental group and agreed to participate in 8 weeks of training sessions (4 times a week) . Five of the 17 subjects were in control a group before the training session. Subjects performed elbow extension and flexion exercise using 50% of one repetition maximum (% 1 RM) load. The exercise session consisted of 6 sets of 10 repetitions and 30s of rest was taken between the sets. The subjects in the experimental group trained their arms using two different protocols ; one was high-velocity movement performed as rapidly as possible (Type R), the other was low-velocity movement performed at a constant and slow velocity (Type S) . Isokinetic torque in elbow flexion was measured at angular velocities of 60, 180, 300 deg/s, respectively, during elbow flexion performed under different constant loads of 0, 30, 50% 1 RM, and the muscle cross-sectional area (CSA) of the elbow flexor was determined before and after training. It was found that Type R did not increased isokinetic torque at 300 deg/s significantly after training. However, the increase in angular velocity of elbow flexion in Type R exercise tended to be higher than in Type S exercise. The increase in CSA [Type S; 11.2%, Type R ; 14.2%] was significantly higher in Type R exercise (p<0.05) . These results suggest that high-velocity movement with a constant load in resistance training might increase the angular velocity of movement in the same mode, but might not produce a change in isokinetic strength, which involves a different mode of muscle contraction. Muscle hypertrophy would be induced to a greater extent by high-velocity movement than by low-velocity movement in resistance training with a constant load.
9.Relationships between muscle mass or power and bone mineral density in postmenopausal women.
KIYOSHI SANADA ; TSUTOMU KUCHIKI ; HIROSHI EBASHI ; TAKASHI ABE ; TETSUO FUKUNAGA
Japanese Journal of Physical Fitness and Sports Medicine 1997;46(1):69-76
The purpose of this study was to investigate the relationships between muscle mass or muscle power and bone mineral density in 43 postmenopausal women. Single photon absorptiometry was used to measure the bone mineral density and bone width of the calcaneuse. Isotonic muscle power of knee extensions (KE), knee flexions and incline squats (ISQ) were measured, using the power processor (VINE Co., Ltd.) . Statistical analysis demonstrated a significant positive correlation (p<0.05) between bone mineral density and lean body mass or muscle thickness. Although, bone mineral density was not significantly correlated with body mass index or fat mass, it was significantly corre-lated with leg muscle power. Further, the bone mineral density was also positively correlated with muscle contraction speed in the motion of KE (p<0.01) and ISQ (p<0.05), but not with muscle strength. This data suggest that the bone mineral density is closely related to the muscle power and/or speed rather than the muscle strength in postmenopausal women.
10.THE STRENGTH PER UNIT MUSCLE AREA IN THE GROWING GENERATION
HIROAKI KANEHISA ; TETSUO FUKUNAGA ; NAOYA TSUNODA ; SHIGEKI IKEGAWA
Japanese Journal of Physical Fitness and Sports Medicine 1985;34(Supplement):71-78
Muscle strength per unit muscle area related to age was investigated in normal 131 males and 127 females, 7 to 18 years of age. A cybex machine was used to measure the isometric muscle strength of elbow flexion and extension, knee flexion and extension, respectively. The cross-sectional muscle area of extensor and flexor at right upper arm and thigh were determined by using ultrasonic apparatus. The muscle area in male increased with age from 7 years to 17 or 18 years. Females showed increment in muscle area from 7 to 12 years for elbow flexor muscle, and from 7 to 16 years for another muscles. Muscle strength in both males and females increased with age from 7 to 16 or 17 years. Muscle strength per unit muscle area tended to increase with age in males from 7 to 12 years, and in girls 7 to 9 years except for elbow extension. The strength per area under 12 years of age for males and 9 years of age for females except for elbow extension were significantly lower than that of the above age. There were little differences in the strength per unit area with age among males from 13 to 18 years and females from 10 to 18 years, respectively. These results indicate that under 12 years for boys and 9 years for girls the increment in muscle area with age is not accompanied with the development of muscle function.