The voluntary exercises consist of different automatized levels and are mostly a combination of the upper limbs and the lower limbs exercises. This study was to examine the interference of the upper limbs exercise to the periodic lower limbs exercise with different automatized levels. Seven male university students, aged 19 and 20 yrs., served as subjects. The periodic lower limbs exercises were the stepping (walking on the place) and the alternate plantar-flexion of the right and left foot while standing. The frequencies of the lower limbs exercises were 120, 160 and 200 times/min, The stepping, which is similar to the motion of the lower limbs in walking or running, may be performed more frequently in daily life than the plantar-flexion in which only the ankle angle was changed. Therefore, we assume that the stepping is a higly automatized exercise compared with the plantar-flexion. Upper limbs exercise, which was combined with the lower limbs exercise, was the simultaneous tapping of one time by both hand. The interference degree was evaluated by the change of step intervals of the lower limbs exercise. The results were: 1) The fluctuation of step intervals on the plantar-flexion was greater than the fluctuation on the stepping and the smallest in the frequency 120 compared with that in the other frequencies. 2) When the tapping was combined with the lower limbs exercises, one step interval at that time was lengthened and one step interval immediately before the tapping was shortened. This change of step intervals was greater in the plantar-flexion than that in the stepping. The change in the plantar-flexion was the smallest in the frequency 120 compared with that in the other frequencies. The above mentioned findings suggest that the automatized level of the lower limbs exercise can be clearly evaluated by the interference degree of the upper limbs exercise to the periodic lower limbs exercise.
A new method for estimation of total body water in human subjects by measurement of bioelectrical impedance is described. Determinations of impedance (Z) were made in 24 healthy women aged 35.9±15.39 yr using an electrical impedance analyzer (T-1988 K, Toyo Physical Inc.) with a four-electrode arrangement that delivers a painless signal (500 μA at 50 kHz) into the body. The mean coefficient of variation for ten impedance measurements in 4 male subsamples was 0.8% (range, 0.2-1.2%) . Total body water determined by deuteriumdilution was 26.1±2.44l. The estimation equation was developed by regression analysis of data from 24 women. Height2/resistive impedance was the most significant variable for prediction of deuterium-dilution space (TBW) and yielded r=0.804 (p<0.001) with a SE of estimate= 1.41l. The regression equation generated was Total Body Water=0.5294 (Ht2/Z) + 2.5139. These data indicate that bioelectrical impedance measurement is a reliable and valid approach for the estimation of total body water in human subjects. This noninvasive method, which is safe, simple, rapid and convenient, should prove useful in a clinical setting, and also for epidemiological and exercise physiology studies.
A study was conducted to investigate the influence on the shoulder joint of throwing during water polo. One hundred sixty-seven water polo players were interviewed about injuries caused by water polo, and 70 players claimed to have had shoulder pain. In 21 players, clinical examinations were performed, and in 31 players, assessment of external rotation stability was made. Then three-dimensional analysis of hand-to-hand shoot motion was performed in 7 players. The results were as follows; 1. The painful phases of the throwing motion were the take-back phase and the acceleration phase, the pain being present at the anterior and lateral portions of the shoulder joint, 2. Assessment of stability revealed that the external rotation displacement on the affected side was significantly larger than that on the control side in the injured players. 3. Analysis of hand-to-hand shoot motion revealed that the external rotation angle in the acceleration phase was significantly larger in non-injured subjects than in the injured. 4. The external rotation angle after ball contact was increased in the injured, but decreased in the non-injured. 5. To prevent injury, it appears important to catch and throw the ball using the upper extremity and rotation of the trunk in a high body position in the water, and to strengthen the muscles of the shoulder.