The purpose of this study was to investigate the head hitting motion according to 3 types of Chudan-sae in kumdo. For this, measured and analysed reaction time, striking time, bamboo sword moving distance, height of knee, stride from start to impact. Twelve middle school kumdo players whose training over two years in Y city and G city, kyung-nam province was divided three group(front, center, back center of gravity: COG) by type of Chudan-sae. The analysis based basic statics, one-way ANOVA was conducted through PC using SPSS/PC+ version 22.0. A significance level of p〈.05 was used for all statistical test. The conclnsions were as follow:
1) Reaction time : Group B(center COG) had fastest on reaction time. The result of post analysis revealed that group B(center COG) was significantly faster than group C(back COG).
2) Striking time : Group B(center COG) had fastest on striking time. The result of post analysis revealed that group B(center COG) was significantly faster than group A(front COG).
3) Bamboo sword moving distance : Group B(center COG) moved shortest distance on bamboo sword moving distance. The result of post analysis revealed that group B(center COG) was significantly shorter than group A(front COG) and group C(back COG).
4) Height of knee : Group B(center COG) had highest on height of knee. There was not revealed significant different by group.
5) Stride : Group A(front COG) had widest stride. The result of post analysis revealed that group A(front COG) was significantly wider than group B(center COG) and group C(back COG).
In conclusion, It was revealed that Chudan-no-kamae of center COG is most efficient type.