الهام شیرزاد عراقی

Introduction:This study aimed to compare selected kinetic factors during a cross-cutting maneuver in soccer players with athletics groin pain (AGP) and healthy-ones. Materials and Method: twenty-eight soccer players (healthy group (n=14) and AGP group (n=14)) who take-part in the first division league participated in this study. A force-plate via 1000 hertz sampling rate was used to evaluate the ground reaction force, rate of force developments, vertical-impulse, and symmetry index during the cross-cutting maneuver.The independent sample t-test used to compare the results between healthy groups with AGP. Results:The results indicated the significant differences in the peak of ground reaction force (P=0.023), symmetry index (P=0.01), and rate of force development (P=0.031) in the medial-lateral direction of the dominant limb in a group with AGP. The peak of the vertical ground reaction force of none dominant limb was significantly higher in the AGP group (P=0.004). Conclusion:It seems that groin pain changes the kinetic profile, which puts the athletes at the potential risk of overuse in the lower extremities injuries. It is also recommended to utilize the output of the current study as back to sports index, and the rehabilitation progress should be continued to reduce symptoms injuries up to the proper symmetry.

Background: The authors assessed the effect of bandwidth modeling in learning relative timing and absolute timing. Method: Participants were 10 male high school students who volunteered to participate in the experiment (M age = 16 years, SD = 0.942 years). None of the participants had prior experience with the task or was informed about the purpose of the experiment. They had to learn soccer chip shot under either a bandwidth (model delivered when participant’s performance was outside a predefined bandwidth or rang) or yoked (same number of model provided as bandwidth group) modeling procedure. Results: The results show that the bandwidth group was more effective in learning relative timing than the yoked group. Conclusions: It indicated that benefits of feedback frequency reduction is generalizable to observational learning context. The authors propose that this method may be an appropriate method for relative timing learning.