ملیحه حدادنژاد

Introduction: The present study aimed to compare hip muscle resistance training with and without feedback on trunk, pelvis, and lower extremity motions in frontal and sagittal planes among active females with dynamic valgus. Materials and Methods: Twenty-Nine active females (Mean±SD age: 22.8±2.4 years, height: 1.70±0.6 m, weight: 69±7.1 kg) were randomly assigned to a hip muscle resistance training with feedback group (n=15) or a hip muscle resistance training without feedback group (n=14). Both training programs lasted 6 weeks (3 sessions/week). The peak angles of lateral trunk flexion, contralateral pelvic drop, hip flexion, knee flexion, and valgus during single-leg drop landing and single-leg vertical drop jump were assessed in the research participants at baseline and 6 weeks post-training. Unipodal functional screening tests were captured with two standard digital video cameras. Results: After 6 weeks, significant differences were observed in knee valgus and lateral trunk flexion, contralateral pelvic drop, and knee flexion angles, i.e., compared between hip muscle resistance training with feedback and hip muscle resistance training without feedback (P<0.05), except for non-dominant leg hip flexion in single-leg vertical drop jump (P>0.05). Conclusion: In the explored active females with dynamic valgus, hip muscle resistance training with feedback seems to be better at improving trunk, pelvis, and lower extremity motions in frontal and sagittal planes, compared to hip muscle resistance training without feedback; however, no significant difference was observed concerning hip flexion during single-leg vertical drop jump between the study groups.

Background: Trunk control defect is one of the neuromuscular defects that can cause sports-related injuries in athletes. Aim: This research investigated whether neuromuscular training affects several kinetic parameters in male athletes who had trouble controlling their trunks during a change-of-direction movement. Materials and Methods: The present study used a pre-test-post-test design and was conducted semi-experimentally. Purposefully chosen male athletes (n= 29) with trunk control defects were randomly divided into two groups: control (n= 14) and experiment (n= 15). A Kistler force plate was used to quantify kinetic variables. The exercises were performed for 6 weeks, 3 sessions per week (30 min each session). To analyze the data, dependent t-test and analysis of covariance and SPSS software version 21 were used at the significance level of P <0.05. Results: The findings indicated a significant decrease in the time to peak anterior-posterior force ( P =0.010), time to peak mediolateral force ( P =0.001), time to peak vertical force ( P =0.003), and rate of loading ( P =0.001) of the experimental group. The differences in all control group variables were insignificant, P >0.05. Conclusion: Performing neuromuscular training is likely to improve the direction change mechanism and prevent injury in athletes with trunk control defects.

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.