Angular momentum in skilled kicking pullover performed by elementary school children

Topics in Exercise Science and Kinesiology Volume 3: Issue 1, Article 2, 2022. This study aimed to clarify the differences in body positions and the role of the swing leg, support leg, and head-arm-trunk segment in generating and maintaining angular momentum of the whole body about a horizontal bar as well as how to improve the skill level of successful kicking pullover attempts. Two-dimensional kinematic parameters of successful kicking pullover attempts and body composition indices of 26 fifth-grade elementary school children were collected. Their techniques were classified into excellent and good groups based on the subjective evaluation of three evaluators. Although there were no significant differences in body composition indices between the two groups, the motion phase time during the 4th phase and the total time of the excellent group were significantly shorter compared with the good group. Also, the counterclockwise rotation of the angular momentum of the head-arm-trunk segment and the whole body during the 4th phase was significantly larger in the excellent group than in the good group. These results suggest that maintaining the angular momentum of the head-arm-trunk segment during the 4th phase leads to attempts with shorter time and improves skill levels from the good group to the excellent group. The good group was not able to maintain angular momentum of the whole body during the 4th phase because the peak of the angular momentum of the head-arm-trunk segment and support leg tended to appear earlier than in the excellent group. we newly clarified that teachers need to focus on the body position of the trunk and head during the 4th phase in order for elementary school children to succeed in kicking pullovers more beautifully at a higher level

Tumor suppressor genes in human lung cancer

Lung cancer is the most common cause of cancer death in Japanese males, the incidence having increased markedly in recent years. Carcinogen exposure such as to tobacco-smoke and air pollution are associated with the probability of developing lung cancer. Aquired somatic mutations play an important role in the pathogenesis of environmentally induced lung cancers. Cytogenetic and molecular analysis of lung tumors has made it possible to examine this hypothesis and to search for candidate genes that may be targeted by chronic exposure to these carcinogens. Early studies implicate several distinct chromosomal loci (3p, 9p, 13q, 17p, and others) and suggest sequential genetic events occur during the initiation and progression of lung carcinogenesis. Several suppressor genes including Rb (13q), P53 (17p), and P16 (9p) have been identified and cloned at these chromosomal loci. The identification of putative tumor suppressor gene at chromosome 3p is still under work. Understanding the interaction of P53, RB, cyclins, and protein kinase inhibitors including P16 will be essential to the development of the next generation of diagnostic and therapeutic studies for lung cancer