It is thought that for some sports so called the “agility” accomplishes the key role from the viewpoint of the improvement of the performance and the injury prevention. Therefore we examined the influence of bite up with the oral appliances on the agility.Tested sporting event were cervical retroflexed force. EVA mouthguard and resin splint were used for the oral appliances. Reaction time was measured as a response to stimulated light by the activating time of the masseter muscle and activating time of the main muscle.It is found the reaction time of neck muscles movement tends to be shortened by wearing of the oral appliances.These results were seemed to be based on decrease of a free way space by the bite up with the oral appliances resulted in shortening the reaction time of the masseter and the stabilized occlusion.(141 words)

Recently, the problem of the high incidence of throwing injuries in young people has been gaining attention. Identifying high-risk players before the onset of the throwing injury is important for prevention. One of the most widely used screening tests for sports-related injuries is the Functional Movement Screen (FMS), which assesses the quality of movement; however, its correlation with throwing injuries has not been established. The purpose of this study was to investigate the correlation between the FMS score and throwing injuries. The FMS was used during the medical check for two hundred and thirty junior high school baseball players. We allotted those who had experienced throwing injuries multiple times to the injury group and those who had never experienced throwing injury to the control group. We then calculated the FMS cutoff value using the receiver operating characteristic curve. In addition, we investigated differences in the incidence of throwing injury between above and below the cutoff value using chi-square test. The FMS cutoff score was 17. Players who scored ≤17 had a significantly higher incidence of throwing injuries than those who scored ≥18. Conclusion: We believe that FMS score is correlated to throwing injuries. In addition, the results suggest that throwing injuries might be prevented in junior high school baseball players who scored ≤17 on the FMS if they undergo training in the correct movement patterns.

OBJECTIVESThe purposes of this paper were to evaluate the serum leptin levels in healthy adolescents and to establish standard age variation curves.

METHODSNine hundred six (414 boys and 492 girls) healthy adolescents were investigated. The maximum increment age in height (MIA) was identified in 124 boys and 130 girls. The menarcheal age (MA) was obtained for 130 girls. Fasting leptin levels were measured by enzyme immunoassay. The MIA was calculated by proportional allotment of yearly height increments.

RESULTSSerum leptin levels did not change in boys and girls from the ages of 9 to 11. They decreased after the age of 11 in boys, while they increased in girls. Stepwise multiple regression analysis revealed that serum leptin levels were closely related to pubertal stage. The levels decreased remarkably after MIA in boys and increased remarkably after MA in girls. We drew standard age variation curves of serum leptin levels by calculating the 25th, 50th and 75th percentiles for each age in both boys and girls. The percentile curves for boys were divided into pre-MIA and post-MIA curves. Those for girls were divided into pre-MA and post-MA curves.

CONCLUSIONWe have devised a potentially useful method for evaluating serum leptin levels in adolescents considering the effects of gender and growth.