Estimating flight trajectories of breaking balls from four-seam fastballs.

It is widely acknowledged that understanding the physical mechanics of the flight trajectories of four-seam fastballs and breaking balls is crucial for players and coaches to enhance pitching performance. The characteristics of the flight trajectories of four-seam fastballs and breaking balls have been revealed; however, the relationship between them has not been examined. Here, we show the characteristics of the flight trajectory of breaking balls from the four-seam fastballs. We found that the direction of the deviation of the curveballs could be generally predicted from that of the four-seam fastballs. We also found that the limits of the deviation of the sliders can be determined from the direction of the deviation of the four-seam fastball. This study revealed the deviation of the breaking ball from the four-seam fastballs, which clearly showed the differences in the characteristics between curveballs and sliders. This study moved forward with the description of the physical properties of each pitch type and allowed us to obtain valuable insights and practical implications.

Observation of Clinical Efficacy of Dong’s Pushing Epiglottis Cartilage Method for the Treatment of Children Food Retention / 中国中医药信息杂志

Objective To observe the clinical efficacy of Dong’s Pushing Epiglottis Cartilage Method for the treatment of children food retention through randomized, parallel and controlled clinical trial.Methods Totally 72 children diagnosed with children food retention were randomly divided into treatment group and control group, 36 cases for each group. Children of the treatment group were treated with Dong’s Pushing Epiglottis Cartilage Method, while children of the control group were treated with acupuncture Four Seam. The clinical symptoms, gastric half-emptying time and antral contraction frequency of the two groups before and after the treatment were compared. Results After treatment, integral of clinical symptom in both groups were obviously improved compared with before treatment (P0.05). After treatment, gastric half-emptying time and antral contraction frequency of the both groups were obviously improved, with significant difference (P0.05). The total effectiveness of the treatment group was 97.2% (35/36) and the control group was 94.4% (34/36), with no significantly difference (P>0.05).Conclusion Dong’s Pushing Epiglottis Cartilage Method has relatively good clinical efficacy for the treatment of children food retention.