مهدی خالقی تازجی

Background: Perturbation training which is in the context of volleyball routine practice is a type of neuromuscular exercises that is useful in overhead sports; leads to contraction responses through unpredictable perturbation. Aim : The present study aims to investigate the effects of perturbation training on volleyball players strength proprioception and performance. Materials and Methods: Twenty-four volunteer male volleyball players (age: 24.42±2.15 years; height: 181.46±3.00m; Weight: 73.87±3.77kg; BMI: 22.43±0.80) were recruited and randomly assigned into perturbation and control groups, Before the intervention, a set of isokinetic dynamometry was carried out to measure shoulder proprioception as well as rotator cuff muscles strength, what is more, the upper extremity performance was evaluated using Y-Balance Test. For a course of 6 weeks, players of the perturbation group implemented perturbation trainings, 3 times weekly while the control group performed its routine training. The dynamometry was repeated at the end of training period to compare trainings outcome. The Repeated Measures ANOVA statistic was used to find differences between groups. Results: A significant difference in shoulder proprioception, as well as the YBT-UQ test, was observed between the groups; Also, the ANOVA showed a significant difference ( P <0.05) in functional strength ratio followed by 6 weeks of perturbation training. Conclusion: Perturbation trainings might have benefit to volleyball players conditioning by improvement rotator cuff strength, shoulder proprioception and upper extremity performance. Given this adopting kind of training as a part of regular basic training for volleyball players is highly recommended.

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.