| Summary: | 碩士 === 國立成功大學 === 體育健康育與休閒研究所 === 96 === Tai Chi (or Tai Chi Chuan, Taijiquan) is a kind of physical exercise developed from traditional Chinese martial arts. Tai Chi exercise is suitable for the elderly because it has been proven to be effective in preserving health and decreasing the risk of falling. Biomechanical analyses of the lower limbs and pushing movements of Tai Chi forms have shown the characteristics of Tai Chi exercise including lower center of gravity (COG), whole body coordination, conforming to kinetic chain, and larger range of motion. To date, biomechanical researches of Tai Chi lack three-dimension motion analysis, ground reaction force measurement on each foot, and activation patterns of major muscle groups. In addition, although Push Hands are more advanced movements, no biomechanical analyses of interactive Push Hands have been found.
To analyze the kinematic, kinetic and electromyographic characteristics of Tai Chi Push Hands, an experienced master was asked to defend and attack against two other subjects for three trials. Movements were videotaped and digitized using a motion analysis system with electromyography and two force plates.
The results indicate that when the master encountered pushing forces from the opponents, his COG moved downward and toward the rear foot to defend. During normal pushing, the master used his lumbar and upper limbs muscle to push, but could not move the opponents. In Tai Chi pushing, the master’s rear rectus femoris was highly activated during the whole movement process, but the upper limbs were only activated at the instant of pushing over the opponent. Although the vertical and horizontal force components of the rear foot in Tai Chi pushing were lower than those in normal pushing, the master could push over the opponent by Tai Chi pushing. In the evading with pushing technique, because the master first received the pushing force from the opponent, and then contracted his abdomen with twisting his waist to push over the opponent. The master’s erector spinae activation was higher than those in the upper limbs. Moreover, in this technique the ground reaction force on the rear foot is higher than that in Tai Chi pushing because the master received an additional pushing force from the opponent.
Regardless of the variety in Push Hands skills including resisting, pushing, or the evading with pushing techniques, they are conformed to the martial arts classics: “root on the feet, create force from the legs, be controlled by the lumbar, and finally appear in the fingers.” Because well experienced Tai Chi masters are rarely seen, the suggested future work is to recruit more non- and slightly experienced subjects for biomechanical comparison and statistical analysis. It is expected that the mechanisms for balance maintenance and falls prevention can be found, which will be valuable information for the elderly and Tai Chi novices.
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