The effects of stretching, sport massage, light exercise (80% of the subjects' anaerobic threshold), and hot pack on the recoveries of work capacity and blood lactate (La) after strenuous exercise were compared with the resting recovery conditions. In each experiment for the four recovery strategies, twelve male physical education students participated as subjects. The subjects performed 5-s maximal effort cycle ergometer exercise bouts, repeated 8 times with 20-s rests (W 1) . A 33-min rest period was given after W 1, and then the same exercise as W 1 was performed again (W 2) . During the rest period (from 9 to 19min after W 1), one of the recovery strategies was practiced for 10min. The subjects also participated in a control experiment (rest recovery) on another day. Blood samples were taken from the earlobe to determine La. The rate of work capacity recovery was significantly higher than the control when stretching was performed, but no significant difference was observed in the recovery rate of La. The same tendency was also observed in the case of sport massage. In the case of light exercise, on the other hand, the recovery rate of La was significantly higher than the control, whereas the recovery rate of work capacity was not significantly different. Many of the subjects complained that the intensity of light exercise was too hard. No significant differences were found in the recovery rates of both work capacity and La by application of a hot pack. These results suggest that stretching and sport massage are effective for accelerating recovery of work capacity. Light exercise was not effective in this study. However, considering previous investigations which showed light exercise to be effective, it might be effective if an abequate work intensity is given. A hot pack is suggested not to be effective. No significant correlation was observed between the recovery rate of La and that of work capacity. Thus it seems that the recovery of work capacity is regulated by factors other than La.

  When subacute elderly patients are transferred from an acute hospital to a rehabilitation facility, the likelihood is that the environmental change will decrease the patients' ability to perform the basic activities of daily living (ADLs). In this study, we assessed the effects of the ambient changes on ADLs by the use of the Barthel Index, the reliability as well as validity of which is rated high for assessing the patient's fundamental ability. Our subjects consisted of the patients with hemiplegia who had undergone medical treatment of stroke and those who had been operated on for femoral neck fracture (FNF) in Toride Kyodo General Hospital. They were transferred to the convalescent rehabilitation ward (CRW) of Aida Memorial Rehabilitation Hospital, affiliated with our hospital. We compared the BI scores given to the patients by physical, occupational and speech therapists, when discharged from our hospital, and those scores given by nurses within one week after the patients moved to the CRW. Differences between BI scores given at Toride Hospital and those at the rehabilitation hospital averaged -5.9±16.0 points for stroke patients and -7.3±14.1 points for FNF patients. Spearman's rank correlation coefficient of BI scores in the acute hospital and in the CRW for stroke patients was 0.91 (p<0.001) and 0.69 (p<0.001) for FNF. There was no significant difference in changes in BI scores between stroke and FNF. However, there was a tendency for the patients' functional ability in daily living to be assessed lower in the FNF patients than in the stroke patients. This was probably because the former were older than the latter on the average. The average age of the FNF patients was 81.4 years and that of the stroke patients was 68.5 years.

Some factors influencing the tension development of human muscles at the maximal exertion was analyzed in order to find out some desirable indicators of the characteristics of the voluntary exertion of muscle force.
1) The isometric tension development of the maximal exertion of hand-gripping and arm-bending was recorded simultaneously with the measurement of electromyogram, respiratory curve, electrocardiogram and reaction time. The subjects were all male and 22 to 61 years old.
2) The length of time needed to exert muscle force from 20 to 80% of each recorded maximal force exerted maximally was nearly constant so far as the interval and number of repetition was less than 5 sec and 30 respectively. The correlation coefficient between the standard deviation of the undulating descending curve of the decrease in maximal muscle force during repetition described above and that of this length of time from 20 to 80% definded here was +0.64.
3) The values of tan θ and tan ψ calculated from the (P_max-P) -log t relation were in some cases found to decrease during repetitive exertion under the same conditions as mentioned above, but the decrease was in most cases not so remarkable. The values of tan θ and tan ψ ranged from 0.1 to 0.2 (kg/msec) and from 0.3 to 0.5 (kg) respectively.
4) The maximal force of hand gripping was measured immediately after a conditioning exertion of force of various intensity (i.e.25, 50 and 75% of the maximal force of hand gripping exerted maximally by each subject prior to the measurement) . The tan ψ and tan θ were maximal when no conditioning was loaded, and they decreased with increasing intensity of conditioning exertion.
5) The tan θ of the test exertion of hand gripping exerted maximally was larger when a very short time of pause was interposed between the conditioning and the test exertion than that without conditioning exertion at all.
6) Both tan ψ and tan θ were larger when the condition exertion was done by antagonistic muscle of hand gripping than without conditioning exertion at all.
7) The maximal force of flexion of the one arm was not influenced by the simultaneous maximal exertion of flexion of the other arm.
8) When a constant time interval (i.e. 0.5, 1.0 and 2.0 sec) was interposed between the time of beginning of the maintained maximal exertion of the one arm and that of the other arm, the decrease in the tension of the maximal flexion of the first arm due to the maximal flexion of the second arm was larger than that due to the maximal extension of the second arm. This decrease in tension was larger when the first arm was the left one than that when the first arm was the right one. This decrease in tension was also larger when the length of the time interval mentioned above was arbitrarily chosen by the subject than that when the time interval was prescribed.
On the basis of the results mentioned above, the characteristics of the voluntary exertion of muscle force was discussed.

The purpose of the present study is to investigate the influence on postural sway of such condition as fatigue resulting from muscular work. Twelve of the male adults (26.7±6.2 yrs old) of a certain airport ground service company were served as the experimental subjects. The measurement of postural sway has been made by measuring the weight at two points of the supporting platform. The degree of postural sway was calculated by using an electronic computer (HITAC-10) . The measurement was carried out before and after the work on each day during the experimental days. The following results were obtained.
On the 1st day with eyes open the ratio of the postural sway after the work to that of before the work (‘after’/‘before’) was 1.25, with eyes closed 113, respectively. On the 2nd day with eyes open it was 1.38, with eyes closed 1.53, respectively. On the last day with eyes open it was 147, with eyes closed 1.23, respectively. The amount of postural sway after the work was greater as compared with that of before the work. The statistical analysis showed that these difference in postural sway was significant (P<0.05-0.001) . The influence of several factors on the changes in postural sway was discussed, together with the experimental results obtained by other authors. In conclusion, these results suggest that balance impairment is mainly due to work-related fatigue.

The purpose of the present study is threefold : first, to observe simultaneously the changes in both the frequency of motor unit (MU) discharges and the amplitude of surface electromyogram (EMG) during the prolonged and sustained voluntary efforts; and second, to demonstrate the effects of arterial occlusion on the frequency of MU discharges ; lastly, to discuss the mechanism of motor control in the light of the present results and others'. Two male adults participated in the experiment. They were with no nervous disorders, right-handed, aged 24 and 33 years. Each subject was seated with both eyes closed in a chair in an electrically shielded room. He held a weight of 1 kg on his wrist during periods of about 45 minutes. The angle of his elbow joint was maintained at 90 degrees during the course of the experiments. The impulses of MU and the surface EMG were led off from muscles biceps brachii of the left upper arm by using coaxial needle electrodes and surface ones respectively. Discharge intervals of MUs were recorded as ordinate by means of ‘Electro-tachograph’. The action voltages of single MU was monitored for differentiation from that of others with a cathode-ray oscillograph and with a loud speaker. The subject's complaints were noted during the course of the experiments. The following results were obtained.
1. The patterns of changes in the frequency of discharges of MUs were divided into three types. The first pattern showed the steep decrease in the frequency of discharge for short period, and at last the discharge disappeared, the second the gradual prolongation of discharge intervals and the increase in both irregular fluctuation and slow undulation, the third constant frequency of discharge even immediately before the exhaustion of voluntary effort.
2. The undulation and prolongation of discharge intervals appeared during the abolition of blood supply to the arm. It did not recover for about 1 minute even though the arterial occlusion was released.
3. The gradual increase in the amplitude of direct EMG in muscles biceps brachii was observed during holding a weight of constant load.
4. The rotational activity of MU was suggested to exist in the case of prolonged, sustained and voluntary muscular contraction.
5. The gradual increase in prolongation and undulation of MU seems to come from the decrease in number of afferent impulses resulting from fatigue.

The purpose of the present study is to investigate the changes in postural sway (PS) related to age quantitatively. The movement in the center of gravity of the body projected into the base of support was used as a criterion of PS. It was measured in 45 subjects, 23 males and 22 females, ranging in age from 22.1 to 68.1. The subjects maintained erect posture with feet together for about 2 minutes with eyes open, and thereafter with eyes closed respectively. The measurement of PS has been made by measuring the weight at two points of the supporting platform. The degree of PS was calculated by using an electronic computer (HITAC-10-II) . The following results were obtained.
1. The displacements of body's center of gravity per 1 minute with eyes open as well as with eyes closed increased with age. The PS, however, showed a gradual increase with eyes open, and then it did a steep increase with eyes closed from the age of fifties.
2. The PS was reduced to two components, i.e., lateral (X) and antero-posterior (Y) ones. The ratio of the Y component to the X one (Y/X) with eyes open as well as with eyes closed showed a gradual decrease with age.
3. The ratio of X component with eyes closed to that with eyes open was calculated as well as the ratio of Y component. At all ages the ratio in X component was larger than that in Y component.
4. Judging from both the steep increase in PS with eyes closed and the gradual increase with eyes open with age, there seems to exist the modification of static equilibration mechanism in the aged, especially the much degradation of some regulatory function other than visual one.

It is described that climate is changeable by inadvertent effect of atmospheric pollution. Particularly effects of increasing CO₂ and particulate matters in the atmosphere on climate are discussed.