Introduction: GyakuZuki is a major and important skill in karate. The goal is to hit the opponent in a controlled distance and in the possible shortest time. On the other hand, in karate the velocity of performing is taken into account as one of the main fctors. In karate with hit, the opposite and fixing muscles (Brachialis muscle, Armpit, Rhomboid, Trapezius) are not involved until the last moment, so Karatekas gets the peak velocity. Also repeatedly used elite Karatekas the dominant hand over the competition. So in this study, the researcher is seeking what is the difference between dominant and non-dominant hands of Karatekas elite velocity in two with hit and without hit?
Methods: Each subject with dominant and non-dominant hand was performed five GyakuZuki hit with the highest strength and power. For velocity joints, five hits with the best speed of performance were chosen. Also, participants were asked to hit with dominant and non-dominant hand to the Shoot Fist system for five times with their whole power. In these hits, their distance from the Shoot Fist system was equal of their upper limbs. Video was collected through three dimensions. For calculating the peak joint velocity, peak elbow angular velocity and velocity of wrist in contact moment Skill Spector software was used. For checking the data distribution, after ensuring normal distribution by Shapiro-Wilk test data and Kolmogorov-Smirnov, Independen T-test was used for the investigation of the peak joint velocity with dominant and non-dominant hand in the with hit and without hit method velocity of wrist in contact moment with dominant and non-dominant hand the significant level was set at (p≤0.05). For statistical testing, we used a standard software package Spss22.
Results: The test results showed that there was a significant difference between peak joint velocity (shoulder(p<0.001),elbow(p=0.03), and wrist(p=0.02)), peak elbow angular velocity(p <0.001) with and without hit method, between the velocity of wrist in contact moment (p<0.001) between the dominant and non-dominant hand.
Conclusion: According to the results, it seems to be a karate non-dominant hand can achieve higher speeds in technical accomplishments Gyaku Zuki, the opposite and stabilizer muscles should be strengthen in the non-dominant hand.