141 Energy Saving Footwork that is hard to Slip and Turn over with a Little Physical Load in Power Tennis

Abstract

After seven singles players had retired or withdrawn with injuries at Wimbledon 2013, the All England Club issued an extraordinary statement defending the state of its grass. According to the International Tennis Federation, the seven retirements and walkovers in singles were believed to be the most on the same day at a Grand Slam event in the Open era. All of the slipping and injuries led to questions of why. The suggested culprits included the length of the season, the short time to adjust to grass from clay, and the condition of the courts. There have been several significant falls, the most graphic being when Azarenka twisted her right knee during her first-round that left her lying on the court in tears for several minutes. With so many players being asked about court conditions in news conferences and so many news media requests to speak to the groundskeeper, the All England Club issued a statement about the grass."The court preparation has been to exactly the same meticulous standard as in previous years, and we expect them to continue to play to their usual high quality." It is said that different types of tennis injury have been associated with play on different court surfaces and current knowledge of tennis player and court interactions is limited. Some research with tennis injury incidence, player movements and the biomechanics of slips were begun and a new direction for assessing tennis player-surface interactions has discussed for practical use in the future regulation of tennis courts. On the other hand, in sports, moving body parts around a fixed joint is very popular, but it seems to limit one's power, whereas more power can be generated and the strain on the body is lessen by using the entire body without twisting motion and not resorting to just the fixed joint. This paper proposed the approach for realization of robust physical movements in tennis based on distributed control of physical body in humanoid biped robots, which uses only small active power making full use of equilibrium instability as a source of driving force with simple state transition. Making postures simultaneously by using the entire body produces natural movements.