The purpose of this study was to investigate the injurious influence of aerobic dancing on the lower limbs injuries. Subjects were personally interviewed about exercise hours and the intensity of their classes, together with experience of injury, and their body configurations, alignments, ranges of motion, and muscular strengths were measured. EMG during aerobic dance exercise was measured in subjects with knee Q angles over and under 20 degrees.
The incidence of lower limb injury was 64.3%, and the most frequent injury was shin splint. The injured individuals had significantly more high-intensity classes than normal. As to body configuration, the width in patella per femur was significantly lower and the value of patellar ligament per height was significantly higher in the injured than in the normal subjects. The range of motion of hip external rotation in the injured was significantly smaller than that in the normal subjects. EMG discharge of the vastus medialis in the injured with a knee Q angle of over 20 degrees was markedly greater than that in normal subjects with an angle of less than 20 degrees.

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We evaluated the effect of Tu-Chung (Eucommia ulmoides OLIV.) extract on anabolic action in castrated exercise and non-exercise rats in which the effects of male sex hormone from the testis were excluded. Castration was performed on 32 male Wistar rats aged 4 weeks. The rats were then divided into 4 groups: a non-exercise group treated with Tu-Chung extract (non Ex. Tu-chung G, n = 8), on exercise group treated with the extract (Ex. Tu-Chung G, n = 8), a non-exercise control group not treated with the extract (non Ex. Cont. G, n8), = and an untreated exercise control group (Ex. Cont. G, n=8) .
The Tu-Chung extract was administered orally at a dose of 1g/kg body weight once daily for 4 weeks. Distilled water was given by a similar method to the control groups. As the exercise load, the rats exercised on an animal treadmill at a starting speed of 20 m/min with an increase of 10 m/min every week for 30 min without rest daily for 4 weeks.
The following results were obtained:
1. The relative weight of the adrenal gland (gland weight/100 g body weight ) after 4 weeks was significantly higher in the non Ex. Tu-Chung G than in the non Ex. Cont. G (p<0.001) and in the Ex. Tu-Chung G than in the Ex. Cont. G or the non Ex. Cont. G (p<0.001 each) .
2. The relative weight of the kidneys (kidney weight/100 g body weight) after 4 weeks was significantly higher in the non Ex. Tu-Chung G than in the non Ex. Cont. G (p<0.001) and was slightly higher in the Ex. Tu-Chung G than in the Ex. Cont. G.
3. The relative weight of the musculus levator ani (muscle weight/100g body weight) after 4 weeks was significantly higher in the non Ex. Tu-Chung G than in the non Ex. Cont. G (p<0.001) and also in the Ex. Tu-Chung G than in the Ex. Cont. G (p<0.001) .
4. The 17-KS level in a 24h urine sample after 4 weeks was significantly higher in the non Ex. Tu-Chung G than in the non Ex. Cont. G or the Ex. Tu-Chung G (p<0.001 each) and also in the Ex. Tu-Chung G than in the Ex. Cont. G (p<0.001) .
5. The total urinary nitrogen level after 4 weeks was significantly lower in the non Ex. Tu-Chung G than in the non Ex. Cont. G (p<0.001) or the exercise group treated with the extract (p<0.05) and also in the Ex. Tu-Chung G than in the Ex. Cont. G (p<0.05) .
These results suggest that administration of Tu-Chung extract significantly increases the relative weight of the adrenal gland, enhances androgen secretion from the reticular layer of the adrenal cortex, and promotes protein anabolic action in castrated rats. In addition, this extract appears to increase the adaptation ability of the adrenal cortex to the stress caused by exercise.

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Injury of the anterior cruciate ligament (ACL) occurs frequently in female gymnasts and basketball players. However, there is no effective method for preventing ACL injury. Recently, a fatigue phenomenon of the ligament tissue has been considered to be the main causative factor in ACL injury.
The present study was done to investigate the relationship between knee laxity and general joint looseness in 34 female college basketball players at an orthopedic medical check-up.
Knee laxity was evaluated in terms of the anterior displacement (AD) value measured by a KT-2000 knee ligament arthrometer at 20 lb. General joint looseness was evaluated in terms of the general joint laxity (GL) score including six major joints and the spine.
There was a significant correlation between the AD value and GL score, the correlation coefficients being 0.48 (p<0.01) at the right knee and 0.54 (p<0.01) at the left knee.
The ACL of athletes with a higher AD would always be exposed to higher anterior stress than in athletes with a lower AD, thus possibly leading to a fatigue state. Therefore, we consider that athletes with a high AD are at greater risk of ACL injury. Our results suggest that the easy GL test is an effective screening method for differentiating those with a high AD and a greater risk of ACL injury.

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Using several electrophoretic techniques, this study examined the effects of 3 weeks hindlimb suspension on the patterns of isomyosins, myosin heavy chain (HC) isoforms and myosin light chain (LC) isoforms in the soleus muscle of the rat. The suspended soleus showed a shift in the HC isoform distribution with a marked increase in fast HC isoforms and a commensurate decrease in HCI. In addition, the change in the fast HC isoforms consisted of the expression of HCIId and HC IIb absent in the normal soleus. In contrast to HC isoforms, suspension did not lead to appreciable changes in LC isoform distribution. Analyses of electrophoresis under nondenaturing conditions demonstrated that the normal soleus expressing HCI and HCIIa isoforms contained two isomyooins. Although, of the two isomyosins observed in the normal soleus, the faster migrating band most likely represented the HCIIa-based one (FMas), its mobility was not identical with that of the HCIIa-based isomyosin (FMaf) found in fast-twitch muscles, migrating in the order FMaf>FMas. FMas was designated as intermediate isomyosin (IM) . Some of the suspended soleus contained slow isomyosin (SM) and IM whereas the others comprised FM 3 and/or FM 2 as well as SM and IM. In spite of the expression of HCIIb and HCIId in the suspended soleus, FM 3 and FM 2 observed in these muscles exhibited distinct mobilities from either HCIId-based or HCIIb-based isomyosins comprised in fast-twitch muscles. These results suggest that some of newly expressed HCIId and/or HCIIb isoforms in the suspended soleus are associated with not only fast but also slow LC isoforms and function as a constitutive element of the myosin molecule.

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The relationships were examined between the relative force level and exertion strategy during rapid isometric contractions. Thirteen subjects exerted isometric pinchings as fast as possible at various force levels. Force curves and surface EMGs from the first dorsal interosseous muscle were obtained during the contractions. While the single-peaked force curves remained analogous up to a certain force level, they changed to multi-peaked ones at higher force levels. The critical force level, which could be determined in all subjects as relative force level to MVC, was positively correlated with the %MVC EMG magnitude for unit time, obtained below the critical level. EMG durations were significantly shorter blow than above the critical level. These results suggest that different exertion strategies are utilized in rapid contractions at different force levels, and that individual differences in the critical force level are related to difference in the manner of motor unit activation.

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Generally, sport players of boxing or football who contact roughly with other players use mouth guard during match or game to prevent the breaking of jow boneor bursting of soft oral cavity. Moreover, mouth-guard are used for the purpose to lighter the load to root of teeth and to improve the skill and power of sport's player.
The purpose of this study was to examine the charactaristic of unfitted by H shape-mouth guard compared to U shape mouth guard.
The following results were obtained.
1. The H shape-mouth guard of this study could reduce the impact to 1/7 level.
2. A relative decrease in ventilation level was shown when H shape mouth guard fitted.
3. With reference to respiratory function, reduction of the amount of oxygen up-take was not observed at heart rate lower than 170 beats/min, and in this case a player feells subjective symptom of stiffing.

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This study was carried out to examine the influence of mouthguards on speech intelligibility. Nine male rugby football players with normal personal occlusion and normal speech served as subjects. All players took the speech intelligibility test while wearing self-adapted mouthguards, custom-made mouthguards and without wearing mouthguards.
The ratio of correct judgments for speech intelligibility wearing self-adapted mouthguards was significantly lower than that of wearing custom-made ones or of not wearing one. When misjudged syllables were evaluated by using the manner of production for articulation, plosives had a tendency to be misjudged as flapped sounds or as other plosives while subjects were wearing self-adapted and custom-made mouthguards. When misjudged syllables were evaluated by the points of production for articulation, bilabials and velars had a tendency to be misjudged as alveolar sounds while subjects were wearing self-adapted and custom-made mouthguards, and alveolar sounds had a tendency to be misjudged as various sounds while subjects were wearing self-adapted ones.
The findings showed that speech intelligibility with custom-made mouthguards was better than with self-adapted ones. Speech intelligibility may be better with mouthguards with reduced palatal thickness than with the current ones because points of prodution for alveolars and velars approach the normal points.

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This study examined the secretion capacity of the gonadal and adrenal cortex systems and the morphology of the adrenal cortex in male rats treated with Tu-chung (Eucommia ulmoides O_LIV) extract, the main component of Tu-chung extract, geniposide, or both agents during exercise load testing.
Twenty-four 4-week-old male Wistar rats were used. The rats were divided into four groups : those treated with Tu-chung extract and geniposide (n=7), those treated with Tu-chung extract (n=6), those treated with geniposide (n=7) and a control group treated with distilled water. The dose of each agent was 0.1 ml/100g body weight. The agents were administered orally for 25 days. For the exercise load test, a treadmill for small animals was used, with a tilting angle set at 0. Exercise load testing was performed for 30 min (2-min warm up and 28-min running) daily for 25 days. The running speed was 20 m/min for the first 5 days, and then increased by 5 m/min every 5 days.
The following results were obtained.
1. The relative weight of the adrenal gland (gland weight/100 g body weight) in the group treated with Tu-chung extract and geniposide was significantly higher than that in the group treated with geniposide or the control group (p<0.01) . The relative weight of the adrenal gland in the group treated with Tu-chung extract was significantly higher than that in the group treated with geniposide or the control group (p<0.01, p<0.001) . Furthermore, the relative gland weight in the group treated with geniposide was significantly higher than that in the control group (p<0.05) .
2. In the group treated with Tu-chung extract and geniposide, the group treated with Tu-chung extract and the group treated with geniposide, the relative gland weight of the testis (testis weight/100g body weight) was significantly higher than that in the control group (p<0.001) . However, there were no significant differences among the three groups.
3. The 24-h urinary excretion of 17-ketosteroid (17-KS) in the group treated with Tu-chung extract and geniposide was significantly higher than that in the group treated with Tu-chung extract, the group treated with geniposide or the control group (p<0.01, p<0.01, p<0.001) . In the group treated with geniposide, the 24-h urinary excretion of 17-KS was significantly higher than that in the control group (p<0.05) .
4. In the three groups treated with Tu-chung extract and/or geniposide, serum testosterone levels were significantly higher than those in the control group (p<0.001, p0.05, p<0.05) .
5. Concerning the morphology of the adrenal cortex, the thickness of the reticular layer of the adrenal cortex was most markedly increased in the group treated with Tu-chung extract and geniposide, followed in order by the group treated with Tu-chung extract, the group treated with geniposide and the control group.
Administration of Tu-chung extract and the main component of Tu-chung extract, geniposide, during exercise load testing significantly increased the weights of the adrenal gland and testis, and promoted testosterone secretion in the adrenal cortex reticular layer and testis.
These findings suggest that geniposide plays an important role in the pharmacological action of Tu-chung.

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