The effects of visual information about object size on grip force programming were investigated. Fifteen subjects (26.1±7.6 yrs) repeated lifts of a cube-like grip apparatus (30×30×30 mm, 30g) using a thumb and index finger, while three boxes of different sizes but equal weight (small : 10×10×60 mm, medium : 30×30×60 mm, large : 60×60×60 mm, 25g) were pseudorandomly presented by attaching beneath the grip apparatus. Lifting tasks were performed in two visual conditions. In the full-vision condition, subjects could perceive the box size prior to the lift-off of the grip apparatus, similar to normal everyday conditions. In the obstructed-vision condition, subjects could not perceive the box size due to the placement of a screen during the initial lifting phase, and only the grip apparatus were visible over the screen. The grip apparatus measured grip and load forces during the trial and we found that the grip and load force applied to the grip apparatus in the full-vision condition significantly increased with box size regardless of equal weight. In contrast, when the size information was removed in the obstructed-vision condition, the force applied for a given box of any size was always that adequate for the largest box, suggesting that the scaling of fingertip force by utilizing size information may be achieved by reducing forces for the smaller boxes on the basis of the force output applied for the largest box, but not by increasing forces on the basis of the force output applied for the smallest box.

The effects of insulin administration on the normal growth of mouse skeletal muscle and its effect on induction of muscle hypertrophy by tenotomy were investigated in this experiment.
1) The influence of insulin dosage on rat body weight was investigated.
The results of examining the influence of insulin dosage on body weight showed significant increases in body weight in the 8.0U/Kg dosage group and 16.0 U/Kg dosage group compared to the control group.
2) The influence of insulin dosage on rat blood glucose levels was investigated.
The blood glucose values of the 1.0 U/kg dosage group were significantly lower than in the control group. They were significantly lower in the 1.0 U/kg dosage group than in the other dosage groups. The positive utilization of glucose in the peripheral organization was suggested.
3) The effect of insulin dosage on skeletal muscle weight was tested.
ANOVA shows a significant difference in soleus muscle weight as the insulin dosage rose. Soleus muscle weight at the 1.0 U/kg dosage was significantly higher than in the other groups. By contrast, no significant differences in muscle weight were observed in the control group as the dose insulin increased. The weight of fast muscle was unaffected by the size of the insulin dosage.
4) The influence of insulin dosage on the compensatory muscle hypertrophy was examined.
The influence of insulin dosage to the compensatory muscle hypertrophy was examined after one week. A 75% increase in soleus muscle after tenotomy was observed in the control group. Although the plantaris muscle showed an average 30% increase, the difference was not significant. A tendency for the weight of soleus muscle and plantaris muscle to increase after tenotomy was observed in the 2.0 U/kg dosage group, but the increments were not significantly different. Effect of tenotomy was observed weight of the soleus from an average of 7.3% in the 16.0 U/kg dosage group, but the increment was not significant. On the other hand, plantaris muscle weight increased about 65% and the increment was significant.

We applied Fast Fourier Transform to monopolarily recorded surface myoelectric signals from m. biceps brachii to obtain the turning frequency (TF) at which the signals divide into high and low frequency components. Then using the TF as a cut-off point, the raw myoelectric signals were divided into high frequency component (HFC) and low frequency component (LFC) .
1) TF values were constant at every recording position along muscle fibers. And there was no considerable relationship between developed tensions and TF values.
2) Cross-correlation analysis was done to obtain the phase relationship between LFCs, and between HFCs at four different recording positions along muscle fibers. LFCs appeared in phase in all combinations below the tension of 10%MVC and also in HFCs. Above 20%MVC, LFCs represented the time delay depending upon the electrode distance in six subjects. The conduction velocity calculated from the relationship between time delay and distance in LFC was too high (16.1 m·s^-1-33.3 m·s^-1) compared with the muscle fiber and/or motor unit conduction velocity. But LFCs in other subjects remained in phase. HFCs showed no considerable relationship above 20%MVC in six subjects, while other subjects remained in phase between HFCs.
The present results differ from the recent investigation in m. vastus medialis (Kamo & Morimoto, 2000) . Our proposal on the construction mechanism of surface myoelectric signals could not be adapted to the electrical signals from m.biceps brachii. The present results suggest the different in architecture of muscle fibers and the innervation of the motor nerve in a motor unit between two muscles.

The purpose of this study was to compare the thigh muscle oxygenation state of competitive road cyclists and non-cyclists during varied pedaling frequency cycling. Six male college road cyclists (CY group) and five male students (NC group) performed four sets of cycling bouts, consisting of 2 minutes of warm up (60 rpm, 50 watts) followed by 5 minutes of pedaling (150 watts) using an electro-magnetic braked cycle ergometer at 40, 60, 90, and 120 rpm. Oxygenated hemoglobin and/or myoglobin (Oxy-Hb/Mb) and deoxygenated Hb/Mb (Deoxy-Hb/Mb) concentrations in the vastus lateralis were measured by near infrared spatially resolved spectroscopy. The Oxy-Hb/Mb level was significantly higher in the CY group than the NC group. But there was no significant intraction effect of the group and pedaling rate on the Oxy-Hb/Mb level. These results suggest that the changes in muscle oxygenation state according to pedaling cadence do not differ between cyclists and non-cyclists. And though the whole body work efficiency decreased according to increasing pedaling cadence, Oxy-Hb/Mb and Deoxy-Hb/Mb levels in the vastus lateralis remained unchanged up to 90 rpm. However, at 120 rpm, the Oxy-Hb/Mb level decreased remarkably and the Deoxy-Hb/Mb level increased. These results suggest that deoxygenation in the vastus lateralis at 120 rpm was higher than that for lower frequencies. And, conversely, oxygen uptake in the vastus lateralis might have increased steeply at 120 rpm. It may be that the maximum pedaling cadence that would not reduce work efficiency in the vastus lateralis is around 90 rpm.

Body shape, daily physical-activity, cardiovascular risk factors and disease complications of diabetic patients were analyzed by the survey of mailed questionnaires. Of the 6, 800 men who were randomly selected, 1, 731 responded. The subjects were divided into two groups according to age (middle-aged group ; 40-60 yrs, old-aged group ; over 60 yrs) .
The physical-activity performed by the diabetic patients was similar to that of non-diabetic patients in the middle-aged group. IIowever, in the old-aged group the diabetic patients performed significantly less physical-activity than that of the non-diabetic cohort. The prevalence of coronary heart disease of diabetic patients in the old-aged group was significantly higher than their age-matched non-diabetic cohort. Also, in the old-aged group, the age at onset of hypercholesteremia of diabetic patients occurred significantly earlier than that of non-diabetic cohort.
The onset of the cardiovascular complications (hypertension and hypercholesteremia) of diabetes mellitus in patients with an earlier onset (40-49 yrs) of diabetes mellitus was related to their obesity, in diabetic patients with a later-onset (over 60 yrs) of diabetes mellitus there was no relationship with obesity and physical-activity throughout life are important in preventing onset and progression of coronary heart disease of the diabetic patient.

The present study was performed to investigate heart rate responses and occurrence of arrhythmias caused by various diving maneuvers and swimming in infants. Forty four healthy infants (mean age 2.5±1.1, mean ±SD) served on this study. Condition of telemetry electrocardiograph recording was 1) rest on the land and in the water, 2) diving, 3) swimming and 4) “pass in water (PW) ”. Moreover, diving styles was classified for five patterns by presence of body movement or expiration (Apneic not move diving, Expiratory not move diving, Apneic kick diving. Expiratory kick diving and Underwater swimming) . “Diving bradycardia” was observed during diving and PW, and the magnitude of heart rate reduction was grater in diving without body movement than diving combined with body movement. Presence of expiration did not influence on the level of bradycardia during diving. Any kinds of arrythmias was observed 13 out of 44 subjects. In premature contractions, supraventricular premature contraction (SVPC, 7 subjects) was observed more often than ventricu-lar premature contraction (PVC, 3 subjects) . Another arrhythmias observed was atrioventricular junctional rhythm (AVJR, 1 subject), atrioventricular junctional escaped beat (AVJEB, 3 subjects) and wandering pacemaker (1 subject) . The danger arrhythmias which is necessary to restrict on exercise or swimming was not observed in this study.

We investigated whether the autonomic nervous system (ANS) modulation contribute to the bradycardia induced by endurance training. First, the meta-analysis approach was used to collect group mean values of maximal oxygen consumption (Vo₂max) and heart rate variability (HRV) from 14 studies involving 30 groups and 485 subjects. Subsequently, we performed a cross-sectional (n=116) and intervention (n=training group : 10 and control group : 6) studies. In both studies, ANS modulation was estimated by spectral analysis of HRV. In the meta-analysis and cross-sectional study, HR and natural logarithmic high frequency power (In HF power) were correlated with Vo₂max or peak oxygen uptake (peak Vo₂) . The significant negative correlations were found between HR and In HF power (meta-analysis and the cross-sectional study ; r² = 0.42 and 0.44, respectively) . Endurance training in the intervention study increased peak Vo₂ and resting In HF power, and decreased resting HR. These results strongly suggest that endurance training induces an increase in resting ANS modulation especially parasympathetic modulation. Furthermore, about half of the variability of resting HR can be accounted for by difference in parasympathetic modulation.

The purpose of this study was to analyze the relationship between activity pattern and temporal changes in the oxygen dynamics of human femoral medial vastus muscles. Oxygen dynamics were evaluated from the surface of the body by near-infrared spectroscopy (NIRS) . Arterial occlusion tests were performed in the femoral region at a cuff pressure of 300 mmHg. Exercise type and speed were controlled by CYBEX 6000. The exercise types examined were concentric contraction (CON) and eccentric contraction (ECC) . The 3 angular velocities of 90, 120 and 180 degrees were used as the exercise speeds. Exercise was performed continuously 60 times at maximum effort. The subjects were 7 healthy males with a mean age of 19.6±0.5 years. A transient decrease in oxygen concentration was observed during circulatory occlusion ; and rapid hyperemia occurred immediately after the removal of pressure. Oxygen concentration peaked above the control level and then returned to the initial level. In the CON exercise, the initial decrease in oxygen concentration was the largest at CON 90, and a gradual increase in oxygen concentration was clearly observed during exercise. In the recovery stage, after exercise at CON 90, 120 and 180, oxygen concentration exceeded the control level before exercise, then peaked and returned to the initial level. In the ECC exercise, an initial decrease in oxygen concentration was similar to that in the CON exercise, but a gradual increase in oxygen concentration was not observed during the exercise ; nor did oxygen concentration exceed the control level in the recovery stage after the exercise.
These results indicate that an increase in oxygen level after the removal of arterial occlusion, during and after the CON exercise was much higher than the control level before the exercise, sug-gesting the involvement of reactive hyperemia and exercise hyperemia.

The purposes of this study were 1) to determine cardiac output and active limb blood flow responses to unilateral and bilateral dynamic handgrip exercises and 2) to investigate the effects of exercise intensity and a change in active muscle mass on the relationship between limb blood flow and cardiac output. Five physically active women performed dynamic handgrip exercises with the right hand (right handgrip exercise ; RHG), with the left hand (left handgrip exercise ; LHG), and bilaterally (bilateral handgrip exercise ; BHG) . Exercise intensities were 10%, 30% and 50% of the subjects' maximum voluntary contraction (MVC) and the exercise frequency was 60 contractions per minute. The 10%MVC exercise duration was 10 min, while the 30% and 50%MVC exercise conditions were performed to exhaustion. During exercise, stroke volume (SV) and heart rate (HR) were measured using Doppler ultrasound and electrocardiogram (ECG), respectively. Cardiac output (Q_sys) was calculated as the product of SV and HR. Blood flow to the forearm (Q_foream, ) was measured by venous occlusion plethysmography. Q_sys, did not differ significantly between RHG, LHG and BHG. However, SV was lower in BHG than in RHG and LHG. Reciprocally, HR was higher during BHG than RHG and LHG. The increase in the Q_forearm, was significantly lower during BHG than RHG and LHG exercise (p<0.05) .
These results suggest that Q_sys, does not differ between unilateral and bilateral handgrip exercise, despite the increase in active muscle mass. The unchanged Q_sys could be explained by the Q_forearm reduction during BHG. The Q_forearm was lower during BHG than during the unilateral handgrip exercises, possibly due to vasoconstriction induced by BHG exercise.