This is a comparative analysis study on the kinetics variables such as time required for movement, CM(center of mass) displacement and velocity, angle of body segment, foot velocity, and GRF(ground reaction force) during the lower turn kick movement targeting the Hapkido experts and non-experts. Experiments of this study have used high-speed camera and force plate, and the data was calculated using the Kwon3D XP. The SPSS 24.0 program was used to verify the difference between Hapkido experts and non-experts, and independent t-test was conducted. At such time, the significance level was set to .05 and the result was derived. The results of this study are as follows.

First, For the total time required for the lower turn kick movement in Hapkido, experts were faster than the non-experts, and there was a significant difference in P3(p<.05).

Second, For the COM left and right displacement during the lower turn kick movement in Hapkido, the movement was made to the right and there was no significant difference. The front and back displacements were shifted in all event and there was no significant difference. For the vertical displacement, experts showed lower displacement than non-experts, and there were significant differences in E3(p<.05).

Third, For the COM left and right velocity during the lower turn kick movement in Hapkido, experts have shown faster velocity and there were significant differences in E 3 and E4(p<.05). There was no significant difference in COM front and back velocity, but experts have shown the fastest velocity in E3. And COM vertical velocity have shown significant differences in E4(p<.05).

Fourth, The right hip joint during the lower turn kick movement in Hapkido has shown big extension for both experts and non-experts and there was no significant difference. The left hip joint has flexion in all event for experts and there was no significant difference. For the right knee joint, there was greater movement for experts than non-experts and showed a significant difference in E4(p<.001). The left knee joints of the experts and non-experts were flexed at P1 and extension at P2. There was no significant difference. For the right ankle joint, experts have shown dorsal flexion in P3, and plantar flexion in P1 and P2. But for non-experts, plantar flexion was shown in P1 and P3, and dorsal flexion in P2, and there was a significant difference in E3 (p<.05). The left ankle which is the supporting foot has shown plantar flexion in all areas for experts, but non-experts have shown dorsal flexion. There was no significant difference.

Fifth, The torsion of trunk angle of experts and non-experts during the lower turn kick movement in Hapkido has shown great deal of change for experts but there was no significant difference.

Sixth, The tilt of trunk angle of experts and non-experts during the lower turn kick movement in Hapkido has shown bigger changes for non-experts tilting towards the back, and there was no significant difference.

Seventh, The foot velocity of kicking for experts and non-experts during the lower turn kick movement in Hapkido has shown faster velocity for experts in all event, and there were significant differences in E3 and E4.

Eight, The Fx(left and right reaction force) of right foot for experts and non-experts during the lower turn kick movement in Hapkido have shown the movement towards the right and there was no significant difference. The Fx of left foot for experts and non-experts have shown the movement towards the right and there was no significant difference. The Fy(front and back reaction force) of right foot have shown the movement towards the back for all experts and non-experts, and there was no significant difference. The Fy of left foot have shown the movement towards the front for all experts and non-experts, and there was no significant difference. The Fz(vertical reaction force) of the right and left foot have manifested vertically upward force in all phases for experts and non-experts, and there were no significant differences in all phases.

Based on the above conclusion, in order to shorten the time required for lower turn kick movement in Hapkido, the COM should velocity up and the angle of supporting foot should be considered. In addition, the knee angle of kicking foot should be given a large change from the time when the knee joint is maximally extended to the time of impact, and the knee joint angle of the supporting foot should be extended at the time of impact in order to maximize the turning force. Both hands and feet that are being supported should manifest proper force in order to maximize the stability.