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Volume 48 (1999)
- Issue 6 Pages 671-
- Issue 5 Pages 547-
- Issue 4 Pages 447-
- Issue 3 Pages 343-
- Issue 2 Pages 245-
- Issue 1 Pages 1-
Volume 48, Issue 5
Displaying 1-11 of 11 articles from this issue
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HIDETOSHI HOSHIKAWA, KEIICHI TAMAKI, HIROSHI FUJIMOTO, YUICHI KIMURA, ...1999 Volume 48 Issue 5 Pages 547-558
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to compare the effect between cyclists and noncyclists of pedal rates on ankle, knee, and hip joint torque during pedaling exercises. Six male cyclists (CY) and seven male noncyclists (NC) pedaled at 40, 60, 90 and 120 rpm with a power output of 200 W. The lower limb was modeled as three rigid segment links constrained to plane motion. Based on the Newton-Euler method, the equation for each segment was constructed and solved on a computer using pedal force, pedal, crank, and lower limb position data to calculate torque at the ankle, knee, and hip joints. The average planter flexor torque decreased with increasing pedal rates in both groups. The average knee extensor torque for CY decreased up to 90 rpm, and then leveled off at 120 rpm. These results were similar to NC. The average knee flexor torque in both groups remained steady over all pedal rates. The average hip extensor torque for CY decreased significantly up to 90 rpm where it showed the lowest value, but increased at 120 rpm. For NC, the average hip extensor torque did not decrease at 90 rpm compared with 60 rpm, and was significantly higher than CY at 120 rpm (CY : 28.1 ± 9.0 Nm, NC : 38.6 ± 6.7 Nm, p<0.05) . The average hip flexsor torque for NC at 120 rpm increased significanly from 90 rpm, and was significantly higher than CY (CY : 11.6±2.9 Nm, NC : 22.6±11.8 Nm, p<0.05) . These results suggest that it would be better for cyclists to select a pedal rate of between 90 to 110 rpm to minimize joint torque, and, as a result, reduce peripheral muscle fatigue.View full abstractDownload PDF (1265K) -
HIROSHI YAMASAKI1999 Volume 48 Issue 5 Pages 559-567
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe present two studies were aimed at investigating the necessity of weight training in elderly patients with myocardial infarction.
Study 1 investigated the muscle strength and incidence of gait disorders in 300 patients with myocardial infarction. The age-and gender-related differences in knee extension peak torque were significant (p<0.01) . Peak torque in the 70-79 and 80-89 yr-old women was extremely low (0.88, 0.75N·mm/kg) . Gait disorders occurred frequently in older patients amounting to approximately 30% of women>70 years of age.
Study 2 was conducted to clarify the effects of combined aerobic and weight training. 35 elderly patients with myocardial infarction were assigned to two groups : Group I performed combined aerobic and weight training (n=18) and group II did not perform physical training (n =17) . Physical training was prescribed for 8 weeks. Weight training of knee extensors was performed at 60% of one repetition maximum and aerobic training was prescribed at the anaerobic threshold (AT) level heart rate. After 8 weeks, the improvement in peak torque and gait speed was significantly greater in group I (32%, 12%) than group II (9%, 3%) . The improvement in peak VO2, exercise time, AT was significantly greater in group I than group II. Increased peak torque was associated with increased gait speed and exercise time (modified protocol) (r=0.71, r=0.53) . On the other hand, increased peak torque was not associated with increased peak VO2 and AT. Combined aerobic and weight training is an effective method for increasing muscle strength, gait speed and exercise capacity.
In conclusion, physical training in the recovery phase of elderly patients with myocardial infarction should include weight training.View full abstractDownload PDF (1058K) -
—DIFFERENT AMOUNT OF THE PRECONTRACTION—MASAKI FUMOTO, YOSHIAKI NISHIHIRA, TATSUO MIYA, ARIHIRO HATTA, MASAHIR ...1999 Volume 48 Issue 5 Pages 569-581
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThis study was carried out to investigate the influence of pre-movement tonic contraction on the Contingent Negative Variation (CNV) and Flexor Carpi Radialis (FCR) H reflex between the warning (WS) and response signal (RS) (foreperiod : FP) . Two levels of contraction were designed and the accompanying FCR Electromyography (EMG) was directly returned to the subject to sustain constant contraction. The subjects were 10 normal volunteers. Either small or middle (7.9±5.6% or 16.0±6.3% of the standard FCR EMG) contraction was sustained and the isometric wrist flexion movement was performed as quickly as possible following the RS.
EMG Reaction time (RT) in the small contracting condition was shorter than that in the resting condition (nothing performed during the foreperiod) in almost all subjects, but in the middle contracting condition EMG RT was not similar. The CNV amplitude for the late period of the FP, which was considered to be related to the motor preparation, was larger in the middle contracting condition than in the resting condition, although the small contracting condition was similar to the resting condition. The H reflex amplitude for the late period of the FP tended to be smaller than the control level in the small and middle contracting conditions, but it was not significant. However, in over half of the subjects, whose CNV amplitude for the late period of the FP increased linearly depending on the conditions, the H reflex amplitude was smaller than the control level in both contracting conditions, but it was not linear. These results indicate that the modulation of the EMG RT was not directly associated with the CNV or H reflex amplitudes for the late period of the FP, and a functional difference in the set for the RS between the spinal and the upper level of the central nervous system was present.View full abstractDownload PDF (1336K) -
TOMOHISA MIYANISHI, YUTAKA MIYANAGA, TOHRU FUKUBAYASHI, NAOTAKA MAMIZU ...1999 Volume 48 Issue 5 Pages 583-595
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThis study was designed to clarify the causes of throwing injuries of the elbow and shoulder joints in baseball. Five varsity-skilled baseball players without pain in the elbow and shoulder joints were subjects for this study. They were fixed to a chair and asked to throw a baseball using three different throwing arm movements (T0, T45, and T90) . These movements were filmed using three-dimensional DLT videography. Linked rigid-body segment inverse dynamics were then employed to determine resultant joint force and torque at the elbow and shoulder joints. Peak varus torque at the elbow joint for T90 was less than for the other movements during the acceleration phase. In the follow-through phase, however, a large anterior shear force (70 N) at the elbow, for elbow extension, was present for T90. These results indicate that T90 was a high risk movement which leads to extension injuries rather than medial tension injuries. After the ball release, a large superior shear force (118 N) at the shoulder joint was present in all movements. This superior force may result from the subacromial impingement syndrome, except for critical zones of impingement caused by the different throwing arm movements. These findings suggest that the mechanisms of throwing arm injuries are closely related to differences in throwing arm movements.View full abstractDownload PDF (1446K) -
KEITARO KUBO, YASUO KAWAKAMI, HIROAKI KANEHISA, TETSUO FUKUNAGA1999 Volume 48 Issue 5 Pages 597-605
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to investigate the viscoelastic properties of tendon structures in humans. Elongation of the tendon and aponeurosis of medial gastrocnemius muscle (MG) was directly measured by ultrasonography, while subjects (N=12) performed ramp isometric plantar flexion up to the voluntary maximum, followed by a ramp relaxation. The relationship between estimated muscle force (Ff) and tendon elongation (dL) was fitted to a linear regression, the slope of which was defined as stiffness of the tendon structures. The hysteresis was calculated as the ratio of the area within the Ff-dL loop (elastic energy dissipated) to the area beneath the load portion of the curve (elastic energy input) . The resulting Ff-dL relationship was non-linear in form, as previously reported on animal and human tendons in vitro. The mean stiffness was 24.0±5.6 N/mm. However, there was a considerable inter-subject variability (15.8 to 36.8 N/mm) . The Young's modulus, i. e., the slope of the stress-strain curve, was 280 MPa, which tended to be lower than the previously reported values for human tendons. It was also found that the strain of the tendon structures was homogeneously distributed along its length. The mean hysteresis (energy dissipation) was 23.4±12.4%. However, again there was a considerable inter-subject variability (8.7 to 39.3%) . The present results indicated that the tendon structures of human MG was considerably compliant and its hysteresis was in accordance with previously reported values.View full abstractDownload PDF (2533K) -
SAWAKO WAKUI, TERUICHI SHIMOMITSU, YUKO ODAGIRI, YUMIKO OHYA, TOSHIHIT ...1999 Volume 48 Issue 5 Pages 607-618
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSWe examined the relationships between exercise, eating disorders, weight loss-related concerns/behaviors and weight-cycling (weight loss and regain ≥10%) . The subjects were comprised of 1123 female college students (aged 18.9 ± 1.1 yrs.) who each completed a questionnaire on eating attitudes [Eating Attitude Test (EAT) ], dieting behavior [Dieting Behavior Scale (DBS) ], purging behavior (self-induced vomiting and use of laxatives) and previous weight-cycling. Subjects were divided into four groups on the basis of their current regular exercise behavior as follows non-exercisers (Ns) (N=704), low-intensity, low-frequency exercisers (LLs) (N=106), moderate/high-intensity, low-frequency exercisers (MLs) (N=184) and moderate/high-intensity, high-frequency exercisers (MHs) (N=129) .
Analyses of variances showed significant differences among the four groups for weight and eating concerns, and weight loss behavior. Not only MHs, but also MLs exhibited higher Dieting subscale score ratings on the EAT than Ns. MHs and MLs also showed higher Structured- and Extraordinary-Diet subscale score ratings on the DBS than Ns and LLs. Significantly more MHs used self-induced vomiting than the other three groups, whereas significantly more MHs and MLs used laxatives than Ns. MHs who had experienced weight-cycling were by far more likely to have unhealthy weight loss behaviors and eating disorders than Ns.
These findings suggest that vigorous exercise in female college students is associated with eating disorder- and weight loss-related concerns/behavior even though the students do not exhibit frequent exercise habits. Though regular exercise is desirable, careful attention must be paid to behavioral factors related to eating and weight loss in exercising female college students.View full abstractDownload PDF (1529K) -
HIDETSUGU KOBAYASHI, SHINICHI DEMURA, FUMIO GOSHI, MASAKI MINAMI, YOSH ...1999 Volume 48 Issue 5 Pages 619-630
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSThe purpose of this study was to examine sex differences in subjective symptoms of fatigue (SSF) in high school and college students by considering the relationship between subjective feeling of fatigue and life habits.
A questionnaire on SSF (54 items), dealing with subjective feeling of fatigue and life habits (frequency of exercise, going to sleep, waking in the morning and physical condition) was administered to 5622 healthy students aged 15-20 yr, and data of 5335 properly completed questionnaires was analyzed.
The following was determined :
1) Sex differences were confirmed in most SSF items. SSF complaints for females was generally higher than that of males.
2) The relationship between SSF and the age was low in both sexes.
3) Subjective feeling of fatigue is somewhat related to SSF.
4) The going to sleep last night influence on SSF was different in both sexes and related largely to the next day SSF in males.
5) Waking this morning and today's physical condition are related to SSF in both sexes.
6) In males, the influence of exercise habits on SSF regarding drowsiness is relatively large.View full abstractDownload PDF (1540K) -
TAKEHIKO FUJISE, KOJI NAGASAKI1999 Volume 48 Issue 5 Pages 631-640
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSSubjects evaluated by percentage body fat as obese, even though they are normal evaluated by BMI (calculated by height and weight), have recently come to be referred to as‘masked obesity’cases. The purpose of this study was to compare the characteristics of anthropometry and physical fitness between controls (20≤BMI<24, percent fat: men<20%, women<30%) and masked obesity (20≤BMI<24, percent fat: men≥20%, women≥30%) cases among young men and women. Subjects included 1985 unversity students among which 1278 were men (age 18.7 ± 0.9 yr) and 707 were women (age 18.6± 1.1 yr) . They performed anthropometry and physical fitness tests. Percentage body fat was calculated from the skinfold thickness of triceps and subscapula. Masked obesity showed up in 5.4% (69 persons) of men and 13.6% (96 persons) of women. The percentage of women with masked obesity was about 2.5 times higher than men. Furthermore, the percentage of masked obesity cases among obese subjects was 30.4% (69/227 persons) of men, and 66.2% (96/145 persons) of women. This value of women was about 2.2 times higher than men. Comparisons of values of control subjects and masked obese subjects were carried out in each BMI group (above 20, BMI 20-group ; above 21, BMI 21-group ; above 22, BMI 22-group; above 23, BMI 23-group) of men and women respectively. For anthropometry in women, the waist and waist-hip ratio of masked obesity cases of the BMI 21 and 22-groups were significantly higher than those of the controls. However the same trend was not found in men. For physical fitness in men, back strength of masked obesity cases in the BMI 20 and 23-groups, and 50 m dash in the BMI 20, 21, 23-groups were inferior to those of the controls. However the same trend was not found in women. These results suggest that masked obesity in women existed 2.5 times more often in men, and women have larger waists and men were inferior in muscle strength and power in comparison with non-obese subjects.View full abstractDownload PDF (1272K) -
KODO OTOKI, SHUICHI KOMIYA, KEISUKE TERAMOTO, TAKASHI MASUDA, MAKOTO U ...1999 Volume 48 Issue 5 Pages 641-649
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSA study was conducted to assess gender differences of body fat distribution (i. e., total body fat mass, subcutaneous fat mass, and internal fat mass) in a homogeneous group of Japanese children. Body composition was estimated in 141 boys and 139 girls (aged 3-6 yr) using bioelectrical impedance analysis (BIA) . All subjects were apparently healthy. Determinations of impedance were made using a four-terminal impedance analyzer (TP-95 K, Toyo Physical, Inc., Fukuoka) . The lean body mass (LBM) was calculated using the equation of Kushuner et al. (1992) and Goran et al. (1993) . Total body fat mass (TFM) was calculated as the difference between body weight and LBM. The subcutaneous fat mass (SFM) was calculated using a modification of the equation derived by Skerjl et al. (1953) . The internal fat mass (IFM) was calculated as the difference between TFM and SFM. From ages 3 through 6 years, the mean LBM increased with age in boys and girls, but showed no significant gender differences. There were also no obvious gender differences in TFM and IFM within the same age range. Percentage body fat decreased in both sexes until the age of approximately 5-yr, and then increased again slightly at 6 yr, although it showed no significant differences between the sexes. The gender-specific pattern of fat accumulation during childhood was characterized by an almost steady increase of SFM in girls. These differences were independent of gender differences in physical characteristics.View full abstractDownload PDF (1128K) -
[in Japanese], [in Japanese]1999 Volume 48 Issue 5 Pages 651-659
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (3382K) -
1999 Volume 48 Issue 5 Pages 661-671
Published: October 01, 1999
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (1672K)
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