Comparison of The Effects of Nordic Hamstring and Single Leg Deadlift Exercises on Hamstring Muscle Strength and Extremity Symmetry Index: An Experimental Study

Objective: The aim of this study is to compare the effects of 8-week Nordic hamstring exercise (NHE) and single leg deadlift exercise (SLDE) on hamstring (H) muscle peak torque (MPT), average power (AP) and extremity symmetry index (ESI). Material and Methods: Thirty competetive male football players between the ages of 18-25 participated in the study. Participants were divided into three groups: control group (CG), Nordic hamstring exercise group (NHEG) and single leg deadlift exercise group (SLDEG). The participants' H muscle strength and ESI values were determined twice with the H-Bord device (IVMES, Türkiye), at the beginning of the training program and at the end of the eight-week program. Repeated Measures Two-Way ANOVA test was used to examine the results of different protocols, pre-post test measurements, and protocol*time interaction effect. Results: A significant difference was found between CG and NHEG in both leg PT and mean power parameters in favor of NHEG. An improvement was determined in all groups in the right leg peak torque and average power parameters in favor of the post-test. In addition, a statistically significant difference was observed in the ESI parameter from the pre-test to the post-test only in NHEG. Conclusion: Eccentric exercises NHE and SLDE are effective in improving H muscle strength with no significant differences.