The effect of continuous I week bed rest during traction on bone metabolism were studied in patients with femoral neck fracture. Bone demineralization was assessed by measuring serum calcium (Ca), phosphorus (P), and alkaline phosphatase (AlkP) before, during, and after l week-bed rest with skeletal traction. In addition, 24-hour urinary excretion of calcium and phosphorus were measured. Serum Ca did not change significantly before, during, and after bed rest, whereas serum P increased after I week bed rest and postoperatively remained significantly elevated. Serum AlkP did not increase with bed rest, but became elevated postoperativefy. Urinary Ca excretion increased from 105.8±15.2 to 138.0±15.4 mg/24h after 1 week of bed rest, and remained elevated postoperatively. In contrast, urinary P excretion initially increased 495.1±65.0 to 610.8±87.7 mg/24h, and subsequently decreased to a level significantly less than the admission level. These results suggest that I week bed rest for the patients with femoral neck fracture resulted in bone atrophy and demineralization.

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Cardiovascular and body temperature responses during submaximal exercise (25% and 50% Vo₂max) were investigated using female subjects (n=6) in two separate experiments ; one with head cooling and heating and the other with torso heating with and without head cooling. To supply the heat load, a liquid conditioned cap and vest were used. In the first experiment, a significant decrease in heart rate, oxygen intake (Vo₂) and cardiac output (Q) at relative work intensity of 50% Vo₂max was observed by head cooling. These results show that head cooling is very effective to reduce the physiological strain. In the second experiment, was a function of Vo₂ during torso heating was decreased by head cooling. However, the tympanic membrane temperature during head cooling at 15°C was significantly higher than that at 20°C and it was almost the same level with torso heating without head cooling. The results suggest that excess head cooling is not beneficial in terms of improving the body heat dissipation.

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The dependence of cooling-induced decrement in muscular performance on several physical characteristics was studied. The characteristics were : the amount of subcutaneous fat, body weight, height and surface area, maximal aerobic capacity and maximal voluntary isometric contraction of the trunk flexors. Ten male subjects wearing shorts and jogging shoes were exposed to 27°C and 10°C for 60 min. The cooling resulted in a decrease of 6.8±0.3°C (mean±SE) in mean skin temperature. The temperatures of m. triceps and m. deltoideus were de-creased by 2.8±1.0°C and 5.1±0.4°C, respectively. Rectal temperature was virtually unaffected. A significant negative correlation (r=-0.785) was found between the amount of subcutaneous fat and decrease in mean skin temperature after cooling. After the exposures to 27°C and 10°C, the subiects performed an overhead ball throwing test to measure muscular performance. The test was performed in a standing position using both arms. Five balls weighing from 0.27kg to 3.0kg were thrown. On the average, cooling decreased muscular performance 7.6%. The decrease correlated significantly only with the amount of subcutaneous fat (r=-0.710). The results indicate that from the measured physical characteristics, varying within normal range, only subcutaneous fat had significant effect on thermal responses. Accordingly, the decrease in muscular performance correlated only with the amount of subcutaneous fat.

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This study was conducted to examine the relative differences in the muscular strain of the hand-arm-shoulder system in the repetitive arm movements which would directly depend on the layout of devices at teller counter. The subjects were five young male adults. The manual handling task was standardized and the repetition frequency was in self-pace. The arm movements were characterized by the different direction measured from the frontal plane of the subject between 0° to 150° combined with the distance measured from the acromion to the fixed points of 300, 500 and 700mm. The movements to all of the fourteen points tested were evaluated on both sides of the arms and shoulders by the integration of the EMG signals (IEMG) as to m. deltoid pars media and clavicularis, m. trapezius pars descendens, m. pector-alis maior pars clavicularis and m. extensor carpi radialis brevis. It was found that IEMG of the deltoid muscles were sensitive to the direction and distance of the arm movements while the trapezius muscle showed the relative lower dependence on the direction. There were significant combined effects of the direction and distance in all muscles ; i.e. effect of reach distance was greater with decreasing the arm angle, which was obvious at distance longer than 500mm in the arm abduction. When IEMG was divided by the task time in self-pace which increased in the arm abduction, the peak value was observed at the angle of 30°. It was suggested that if the repetitive movement was required at the same frequency as at the angle of 30° the position near the arm abduction (the angle of 0°) would become the most expensive working direction.

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This study was performed to evaluate the physical resources for elite male cyclists of senior high school. Nine track cyclists (mean age, 17.4 years) and seven road cyclists (mean age, 17.3 years) were examined for body composition and cardiorespiratory function (VO₂ max and O₂ debt max), from 1988 to 1992. These measurements were compared with those of elite junior cyclists, and the progress of physiological function due to one-year training was examined for 7 cyclists. The results were as follows : 1. The mean parameters for track cyclists were recorded : percentage body fat (%Fat) : l0.3% ; Iean body mass (LBM) : 56.5kg ; VO₂ max : 3.93l/min, 62.5ml/kg·min ; O₂ debt max : 8.81l, 139.1ml/kg.

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To determine the effects of chronic hypoxia on oxidative capacity in skeletal muscle, 10-week-old Wistar male rats were exposed continuously to normobaric hypoxia (l0% O₂) for 4 weeks. To unify the level of activity in skeletal muscle of the lower limbs, some rats were treated by surgical sciatic denervation. After the experimental period, rats were anesthetized and their plantaris and soleus muscles were removed. Muscle samples were homogenized and analyzed for the mitoc.hondrial enzymes malate dehydrogenase (MDH) and 3-hydroxyacyl-COA dehydrogenase (HAD) activities by spectrophotometer. Sciatic denervation caused a decrease in MDH and HAD activities in both the plantaris and the soleus. Hypoxia also reduced MDH activity in the denervated plantaris muscle. As the ATP demands in the plantaris of hypoxic rats might be equal to that of normoxic rats, the reduction of MDH Ievels by hypoxia was not caused by a decreased level of muscle activity during hypoxic exposure. Our results indicate that chronic hypoxia has a negative effect on the oxidative enzyme MDH activity in rat skeletal muscle

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In walking exercise the human body is exposed bo external forces. Some of them are produced by constraints such as surface, shoes or opponent. In kick action of walking, the ground reaction force (GRF) is the most important external force. The magnitude of the GRF, its direction, and point of application have an influence on the load on the human body. The purpose of this study is to clarify the role of forefoot joint (artt. metatarsophalangeae) at the force exerted upon the floor during kick action of walking. The device used in this study to analyze the GRF and its three components consists of Kistler's force platform. Output from force transducer was collected online with a TEAC data recorder and MEM-4101 minicomputer. The impact force measurements were taken from the anterior-posterior force time curves at the take-off for I subject walking 10 trials at 2 m/sec with 2 different pairs of shoes (Shoes I : thin sole of 4mm, and Shoes 2 : thick sole of 40mm) and without shoes. High speed (200f/sec) cinematography was also used to analyze the angular displacement of forefoot joint at the take'off of walking exercise.

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The purpose of this study was to examine the relationship between physical fitness and mental health in men and women. Twenty-five students (12 men and 13 women) aged 19 to 23 years participated in this study as subjects with low life stress who did not participate in competitive sports. Their physical fitness level was determined according to VO₂max test results obtained using a cycle ergometer, and their mental health status according to the results of psychological measurement using the Profile of Mood States (POMS) and Spielberger's State-Trait Anxiety Inventory (STAI). In the men, there was significant correlation of VO₂max with each of the POMS subscores for tension (r=-0.61), depression '(r=-0.61), fatigue (r=-0.60), and total mood disturbance (r=-0.59), as well as with STAI state (r=-0.66) and trait (r=-0.76) anxiety scores. On the other hand, no similar correlation was found in the women. These results suggest that the relationship between physical fitness and mental health in men differs from that in women.

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