Comparison of the effects of paired Nordic hamstring exercise and resistance banded Nordic hamstring exercise applied to taekwondo children on hamstring muscle strength and bilateral strength difference

ABSTRACT MASTER'S THESIS COMPARISON OF THE EFFECTS OF PAIRED NORDIC HAMSTRING EXERCISE AND RESISTANCE BANDED NORDIC HAMSTRING EXERCISE APPLIED TO TAEKWONDO CHILDREN ON HAMSTRING MUSCLE STRENGTH AND BILATERAL STRENGTH DIFFERENCE KAÇGAN, Cengizhan Department of Physical Education and Sport Thesis Advisor: Ass. Prof. Dr. Zait Burak AKTUĞ July, 2024, 47 Pages Nordic hamstring exercise (NHE) is an eccentric strength exercise that is frequently used to increase hamstring strength and sports performance and reduce hamstring injuries. While this exercise is mostly performed in pairs in the literature, no study has been found regarding NHE performed with a resistance band. With this in mind, the aim of the study is to compare the effects of paired NHE and resistance band NHE applied to Taekwondo athletes between the ages of 12-14 on hamstring muscle strength and bilateral strength difference. Thirty-two licensed athletes in the Taekwondo branch participated in the study. The participants were divided into three groups: the group that only did Taekwondo training (CG) (n=12), the group that did Taekwondo training in addition to paired NHE (PNHG) (n=10), and the group that did Taekwondo training in addition to resistance bands NHE (RBNHG) (n=10). Exercise groups applied NHE three days a week for six weeks. Hamstring strengths of the participants were determined twice with the H-Bord device, at the beginning of the study and at the end of the six-week exercise program. Repeated measures two-way ANOVA test was used to examine the results of different protocols, pre- and posttest measurements, and protocol*time interaction effect. As a result of the analysis, an increase was found in the right leg peak torque and average power parameters in favor of the post-test in the exercise groups, and a difference was detected between PNHG, RBNHG and CG in favor of the exercise groups. While a difference was detected in favor of PNHG and RBNHG posttest in the left leg peak torque parameter in all groups,in the right leg relative force parameter, a difference was determined in favor of RBNHG between RBNHG and CG. In the bilateral force difference parameter, no significant difference was determined between the pre-test and post-test and between the groups. It is also seen that the training volume of RBNHG is higher than that of PNHG. It is recommended to perform this exercise method with the help of a resistance band due to the reasons such as ensuring the correct position while performing NHE, the longer time spent under tension during NHE, and the widening of the hamstring breaking point in NHE. Key words: Nordic hamstring, bilateral difference, taekwondo, strength, resistance band