Watanabe, Y, Yamada, Y, Yoshida, T, Matsui, T, Seo, K, Azuma, Y, Hiramoto, M, Miura, Y, Fukushima, H, Shimazu, A, Eto, T, Saotome, H, Kida, N, and Morihara, T. Relationship between physical fitness at the end of preseason and the inseason game performance in Japanese female professional baseball players. J Strength Cond Res 33(6): 1580–1588, 2019—This study examined anthropometric and fitness profiles of Japanese female professional baseball players and investigated the relationship between players' physical fitness and inseason game performance. Fifty-seven players who were registered in the Japan Women's Baseball League (JWBL) participated. Height, body mass, grip strength, back strength, knee extension and flexion strength, hamstring extensibility, vertical jump height, and horizontal jump distance were measured at preseason (February and March) in 2013. Game performance during the 2013 season (March–November) was obtained from official JWBL statistics. Vertical jump height showed significant positive correlations with individual performance records (e.g., total bases [r = 0.551], slugging percentage [r = 0.459], and stolen bases [r = 0.442]). Similar relationships were observed between horizontal jump distance and performance statistics in most cases. By contrast, grip, back, and lower-limb strength, as well as hamstring extensibility were not significantly correlated with game performance. Stepwise regression analysis selected vertical jump height as an independent variable, significantly correlating with several game performance measures (e.g., total bases: adjusted R 2 = 0.257). Also, vertical jump height and body mass index were identified as independent variables significantly associated with stolen bases (adjusted R 2 = 0.251). Maximal jump performance, rather than simple isometric muscle strength or flexibility, is a good performance test that can be used at the end of preseason to predict inseason batting and stolen base performance. Our findings demonstrate the importance of constructing preseason training programs to enhance lower-limb muscular power that is linked to successful inseason performance in female baseball players.

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The rotational range of motion (ROM) in the upper extremities, trunk, and lower extremities is important for throwing motion. However, unlike for the shoulders, the differences relating to age and throwing-side in trunk and lower extremity ROMs in baseball pitchers are unknown. This study examined the effects of age and dominance on the ROMs of the trunk and upper and lower extremities. Methods: The study included 356 young baseball pitchers aged 9-17 years who participated in off-season baseball camps. The subjects comprised 155 youth pitchers (aged 9-14 years) and 201 high-school pitchers (aged 15-17 years) who were able to throw at full force without pain. The neck, shoulder, trunk, and hip rotational ROMs on the dominant and non-dominant side were measured by well-trained physical therapists. The differences between throwing sides and between age groups were examined using two-way analysis of variance. Results: Shoulder external rotation on the dominant side was greater than that on the non-dominant side. Shoulder external and internal rotational ROMs were maintained regardless of age, whereas the trunk rotational ROM significantly increased with age. Conclusions: The effects of age and dominance on ROMs of the neck, trunk, and upper and lower extremities in Japanese youth and high-school baseball pitchers were clarified. These data could be used as a specific reference and as target values for the rehabilitation of throwing injuries in young athletes.

Abdominal draw-in is a functional transversus abdominal muscle exercise to acquire the contraction. However, it is difficult for even healthy subjects to selectively contract the deep transversus abdominal and internal oblique muscles without over-contraction of the superficial rectus abdominis and the external oblique muscles. This study examined whether the transversus abdominal muscle is selectively contracted by our taping method. The subjects were 20 healthy males. Using ultrasound, we compared the thickness of external oblique, internal oblique, and transversus abdominal muscle among no taping, kinesio taping and abdominal muscle activation taping in the standing position. The thickness of transversus abdominal muscle significantly increased in the activation taping more than the other methods. This study showed that abdominal musculature activation taping made it possible to contract the transversus abdominal muscle selectively.

Pitching motion is made up by three-dimensional whole body movement. Pelvic and trunk rotation movement is important for the prevention of throwing injuries. Throwing is not a simple rotation movement. Evaluation should reflect muscle strength, coordination, and pitching motion characteristics. We have devised throwing rotational assessment (TRA) similar to throwing as the new evaluation of total rotation angle required for throwing. The purpose of this study was to introduce the new method and to examine the characteristics of players with throwing disorders. The subjects were 76 high school baseball pitchers who participated in the medical check. Pain-induced tests were elbow hyperextension test and intra-articular shoulder impingement test. Pitchers who felt pain in either test were classified as disorder group. TRA evaluation was performed as follows. In the positions similar to the foot contact phase, rotation angles of the pelvis and trunk were measured. In the position similar to follow through phase, the distance between the middle finger and the second toe was measured. All tests were performed in the throwing and opposite direction. Twenty five pitchers were classified as disorder group. All TRA tests in healthy group were significantly higher in the throwing direction than in the opposite direction, but there was no significant difference in the disorder group. Disorder group had significantly lower average rotation angles of the pelvis and trunk in the throwing direction and rotation angle of trunk in the opposite direction than the healthy group. Restrictions on TRA reflecting the complex whole body rotation movement may be related to the throwing disorder. This evaluation is a simple method. It would be useful early detection of throwing disorder and systematic evaluation in medical check, as well as self-check in the sports field.