SCULLING TECHNIQUES IN SYNCHRONIZED SWIMMING

The purpose of this study was to investigate sculling techniques in synchronized swimming based on three-dimensional motion analysis. Movements during sculling for ten elite synchronized swimmers were analyzed using a three-dimensional direct linear transformation method. Sculling! techniques for more advanced synchronized swimmers included holding the elbows and upper arms stationary and changing the attack angles of the hands smoothly and evenly. When swimmers were given a 1.5-kg load, scull tempo increased and range of motion of the forearms was reduced

Estimating Hydrodynamic Forces Acting on the Hand during Sculling in Synchronized Swimming

The characteristics of the hydrodynamic farces acting on the hand at different loads during sculling in synchronized swimming was estimated using a pressure distribution measuring method. One cycle of flat scull in a back layout position and support scull in a vertical position for one female national-level synchronized swimmer were analyzed. Results showed, at small loads in the flat scull, larger hydrodynamic force was observed during out-scull. As load increased, the hydrodynamic force increased during in-scull, and the values were observed to equalize between in-scull and out-scull. At all loads in the support scull, the larger value was observed during in-scull. It was apparent that in both sculls, the hydrodynamic force increased as the load increased, and the pressure on the dorsum of the hand decreased when large hydrodynamic force was generated

Prenylated Quinolinecarboxylic Acid Derivative Prevents Neuronal Cell Death Through Inhibition of MKK4

The development of neuroprotective agents is necessary for the treatment of neurodegenerative diseases. Here, we report PQA-11, a prenylated quinolinecarboxylic acid (PQA) derivative, as a potent neuroprotectant. PQA-11 inhibits glutamate-induced cell death and caspase-3 activation in hippocampal cultures, as well as inhibits N-Methyl-4-phenylpyridinium iodide- and amyloid β1-42-induced cell death in SH-SY5Y cells. PQA-11 also suppresses mitogen-activated protein kinase kinase 4 (MKK4) and c-jun N-terminal kinase (JNK) signaling activated by these neurotoxins. Quartz crystal microbalance analysis and in vitro kinase assay reveal that PQA-11 interacts with MKK4, and inhibits its sphingosine-induced activation. The administration of PQA-11 by intraperitoneal injection alleviates 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced degeneration of nigrostriatal dopaminergic neurons in mice. These results suggest that PQA-11 is a unique MKK4 inhibitor with potent neuroprotective effects in vitro and in vivo. PQA-11 may be a valuable lead for the development of novel neuroprotectants

<実践研究>大学体育水球授業モデルの開発 : 水球を教材とした大学体育授業の実践に関する効果と課題の検討を通して

The water polo is thought to be an ideal teaching material to master swimming skills and ball game skills at once for students, but in fact there are very few physical education classes in which the water polo is teaching at Japanese universities. Therefore, the aim of this study was to design teaching plans using the water polo for physical education classes in the university, and to verify the educational effects and problems of this class. The lesson was held in an indoor 50m swimming pool at University of Tsukuba, and a total of 6 students participated the class. The two-day water polo intensive program was consisted of an actual training in the water and a classroom lecture. After the two-day water polo intensive program, participants’ skills relevant to the water polo, in particular treading water, dribbling the ball and reciprocate swimming were improved. According to the students’ description, they thought that they were able to improve their basic techniques about the water polo, but they felt a difficulty to use the basic techniques during the actual game. An overall evaluation by the students about the intensive course was quite high and the two-day program was too short to learn. From the above, it is suggested that water polo is a good material for learning swimming skills but also water safety and communication in the water. However the water polo is so tough the class should be held once a week like another classes. Based on these effects and problems, new teaching plan for water polo in the university was presented

多段階の泳速度におけるクロール泳中の自己推進時抵抗とストリームライン姿勢中の受動抵抗の比較

The purpose of this study was to compare active drag during front-crawl swimming performed by competitive swimmers with passive drag acting on the same group of swimmers with a streamlined position at various velocities. Seven male competitive swimmers participated in this study, and the testing was conducted in a swimming flume. Active drag was evaluated for front-crawl swimming with upper and lower limb motion using a methodology that estimates the drag in swimming using measured residual thrust values (MRT method). Passive drag was measured by a load cell connected to the swimmers with a streamlined position using a stainless-steel wire. In each case, drag was estimated at six staged velocities ranging from 1.0 to 1.5 m/s. To compare the drags at various velocities, we calculated coefficients a and b by applying the measured force value at each velocity to the equation D = a vb (D: drag, v: velocity). The active drag estimated from the MRT method (a = 35.7 ± 5.3, b = 2.80 ± 0.22) was larger than passive drag (a = 23.6 ± 3.1, b = 2.08 ± 0.23). Furthermore, the difference between active and passive drag was large at high velocities. Therefore, it is possible that the effects of factors other than posture and/or body shape have a large influence on active drag, especially at high velocity

The influence of sound waves and musical experiences on movement coordination with beats

Synchronizing movement with external stimuli is important in musicians and athletes. This study investigated the effects of sound characteristics, including sound with harmonics (square wave) and without harmonics (sine wave) and levels of expertise in sports and music on rhythmic ability. Thirty-two university students participated in the study. The participants were divided into sixteen music education (ME) and sixteen physical education (PE) majors. They were asked to perform finger tapping tasks with 1,2 and 3 Hz beat rates, tapping in time with the sine and square wave beat produced by a metronome. The relative phase angle of finger tapping and the onset time of metronome sound were calculated using circular statistics. The results showed that type of wave and music experience affected the rhythmic ability of participants. Our study highlights the importance of types of waves on rhythmic ability, especially for participants with no background in music. The square wave is recommended for athletes to learn to synchronize their movement with beats.</p

Japan\u27s Lagging Gender Equality

autho