Comparison of nordic hamstring exercise and leg curl exercise in hamstring strength development

Developing hamstring strength with the most appropriate exercises plays an important role both in maintaining and improving sportive performance and in preventing sports injuries. In the literature, the effects of different hamstring exercises on hamstring strength development and knee muscle strength balances have been examined, but it has not been clearly stated which exercises are more effective. In this thesis study, is it possible to use nordic hamstring exercise or leg curl exercise in increasing hamstring strength and H/Q ratio and decreasing BLF? It was aimed to examine whether it is more effective. The sample of the study consisted of 38 healthy, sedentary male volunteers studying at Niğde Ömer Halisdemir University, Faculty of Sport Sciences. Participants were randomly divided into 3 groups as the nordic hamstring exercise group (NHEG), the leg curl exercise group (LCEG) doing the nordic hamstring exercise, and the control group (CG) not doing any exercise. Isokinetic knee muscle strength measurements and knee joint range measurements in all groups were repeated twice, before the exercise program and 8 weeks after the first measurement. Knee range of motion was measured 5 days before the exercise program started. 1 TM measurements were applied to determine the training load. Concentric and eccentric isokinetic knee muscle strength test consisting of 10 repetitions at 30°s-1 and 60°s-1 angular velocities was applied with a Cybex brand isokinetic dynamometer. The H/Q ratio has been studied traditionally and functionally in different ways. In the analysis of the data, the difference between the pre-test and post-test was determined with the Wilcoxon signed-rank test. Mixed Anova test was used to determine the efficiency levels of the exercise method applied. As a result, NHE increased eccentric hamstring peak torque, eccentric-concentric H/Q ratio and decreased BLF; Leg curl exercises were determined to be effective in increasing concentric hamstring peak torque, H/Q conventional ratio and reducing BLF. It has been observed that both exercise protocols can be applied as an effective method in hamstring muscle strength development.