Japanese Journal of Physical Fitness and Sports Medicine 

About: Japanese Journal of Physical Fitness and Sports Medicine is an academic journal published by Japanese Society Of Physical Fitness And Sports Medicine. The journal publishes majorly in the area(s): Physical fitness & Athletes. It has an ISSN identifier of 0039-906X. It is also open access. Over the lifetime, 2040 publications have been published receiving 3866 citations. The journal is also known as: Japanese journal of physical fitness and sports medicine & Japanese journal of physical fitness.

Walking ability of older adults in the community

Abstract: Four-year longitudinal changes in walking ability were examined in 510 older adults in a rural community in Japan. The participants walked on an 11-m walkway at their preferred and maximum speeds, and velocity, step length, step rate, and walk ratio (step length/step rate) were measured. Physical performance, including muscle strength, balance, and manual skill, was examined concur rently. An age-related decline in all variables except for step rate was confirmed in the longitudinal as well as cross-sectional data. The longitudinal decline accelerated for participants in their seventies and over, as compared to those in their sixties. Grip strength, balance, and manual speed, measured at the baseline, predicted relative changes in walking velocity over four years. The risk of mortality and instrumental ADL decline in four years were also predicted by maximum walking velocity at the baseline. These results suggest that the walking test has discriminant and predictive validities for assessing the physical functioning of community-dwelling older adults. (Jpn, J. Phys. Fitness Sports Med. 1998, 47 : 443•`452) key words : Longitudinal study, Aging, Walking, Instrumental ADL, Mortality.

Effect of aging on motor ability in men aged 18 to 83 years

Abstract: A study was conducted to determine the effect of aging on motor ability and to establish a test battery for physical fitness in the elderly. The subjects were 150 men aged 18 to 83 years. The test items examined were selected, according to Fleishman's list of motor abilities; (1) trunk flexion, (2) grip and isometric knee extension strength, (3) postural sway with eyes open and closed, (4) step test, (5) walking test at preferred and maximum speeds, (6) simple visual reaction time, (7) peg-board test, (8) finger tapping test at maximum rate and in time to metronome sounds. Performances for the test items, except for preferred walking speed and coefficient of variation in finger tapping at 5 Hz, showed significant decreases with aging. The decrease in motor performance at age 80 years relative to the level at age 20 years was less than 30% for finger dexterity and reaction time, 4060% for muscle strength, maximum walking speed and the step test, and over 70% for trunk flexion and postural sway with eyes closed. A test battery composed of trunk flexion, grip strength, knee extension, step test, walking as fast as possible, postural sway with eyes closed, and finger tapping, is therefore recommended for assessing the effect of aging on physical fitness. (Jpn. J. Phys. Fitness Sports Med. 1994, 43: 343351) key words : motor ability, aging, elderly

Relationship between reduction of hip joint and thigh muscle and walking ability in elderly people

Abstract: The purpose of this study was to investigate the hypothesis that the reduction in walking ability is due to muscle atrophy in the lower limb muscles with aging using equational structure modeling as well as investigate the influence of muscle on walking ability. The subjects consisted of 127 per. sons (57 males and 70 females) aged 2084 year, who were grouped into 6 age brackets of 20-39, 40--49, 5059, 60-V69, 70.74, and 75 or older. Using MRI, muscle cross-sectional area was measured on psoas major and thigh muscle (divided into extensor and flexor). For walking patterns , each subject walked along a 7-m walking passage at normal speed for VTR-recording of the motion. The resulting pictures were used to analyze stride length, trunk inclination and walking speeds. Walking speeds showed a statistically significant decrease in value from the 50's age group in males and the 60's age group in females when compared with the 20•`39 age bracket (p<0.05). In males, a significant co-relationship was observed only between the muscle cross-sectional area of thigh extensor and walking speed (p<0.01) while in females, a significant co-relationship was found between the muscle cross-sectional area of psoas major (p<0.001) /thigh muscle extensor (p<0.01) and walking speed. These results indicate that the muscle atrophy with aging in psoas major and thigh muscle extensor is a factor responsible for the decrease in walking speed. Meanwhile, a differ. ence in sex was observed between the muscle cross-sectional area of psoas major and walking speed. It was considered that the muscle atrophy rate of the female's psoas major being higher than the male's influenced this. Furthermore, it was suggested possibility that the decline of walking ability is due to decreased muscle mass of the lower limbs with aging. (Jpn. J. Phys. Fitness Sports Med. 2000, 49 : 589•`596) key word : aging, muscle cross-sectional area, psoas major, walking speed

Architectural properties and specific tension of human knee extensor and flexor muscles based on magnetic resonance imaging

Abstract: 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. (Jpn. J. Phys. Fitness Med. 1995, 44:267•`278) key words : muscle architecture, muscle volume, physiological cross-sectional area, specific tension, magnetic resonance imaging, human