فهرست مطالب mohialdin bahari

Single-leg landing is a difficult task for the lower limbs. This movement is very common in basketball and is one of the main causes of lower limb injuries, especially anterior cruciate ligament injuries. Single-leg landing causes a ground reaction force and torque to the lower limb. By increasing the internal torque and controlling the reaction force at the level of its application, the muscular strength of the lower limb can control the ground reaction force of the surface applied to the limb. This study aims to investigate the effects of 8 weeks of strength training on the ground reaction force in single-leg landing

In this study, 20 semi-professional male basketball players were divided into two equal groups of test and control. The samples of both control and test groups were asked to perform three single-leg landings from a 40-cm platform on the force plate. Then, the test group underwent 8 weeks of lower limb strength training, and after the end of the training, the members of the test and control groups were asked to repeat the landing movement. An average of three movements per person was considered. For data analysis, the paired t test was used for intra-group comparison, and the 1-way ANCOVA method was used to compare inter-group effects. Statistical analysis of the study was performed using SPSS software version 20, at a significance level of 0.05 for all tests.

The results showed that the training program had no significant effects on the ground reaction force in the X direction in both internal and external directions, as well as, in the Y direction in the anterior and posterior directions, both within the group and between the groups. But, the training program had a significant and incremental effect on both within the group (P=0.005) and between the groups (P=0.002) in the Z direction.  

The strength training program lacks enough effect to reduce ground reaction force applied to semi-professional basketball players during a single-leg landing movement.

The aim of this study was to prioritize the effective factors in the marketing of sports products. The present study was a mixed research (qualitative-quantitative). The statistical population in the qualitative section included marketing experts and sports management professors who had articles or writings in the field of research, and in the quantitative section were consumers of sports products. Statistical sample was selected in the qualitative section of 11 experts until the theoretical saturation was reached using theoretical targeted techniques and snowballs. In the quantitative section, between 5 and 10 samples were required for each item, so 308 samples. Formed statistics. The data collection tool was a semi-structured interview in the qualitative part and a researcher-made questionnaire in the quantitative part. The reliability of the interviews was 0.85 by intra-subject agreement study. Content validity in terms of experts and construct validity (exploratory factor analysis) was used. Finally, six factors, namely business ethics, creativity and innovation, citizenship rights, utilitarianism, surprise advertising, and rules and regulations, influence the marketing of sports products. Therefore, novelty and attractive design in advertising, non-social discrimination, attention to citizenship obligations, creating and strengthening social norms, sustainability of advertising, increasing the desire to share advertising in the audience, cultural utilitarianism are suggested.

The aim of the present study was to investigate the effect of a course of central stability training and water training on balance, flexibility of the trunk area and lower limb function of trainable mentally retarded girls. Research

The research samples included 30 female mentally retarded female students of the exceptional school of the mafia system who were randomly divided into two experimental groups (20 people) and control (10 people). Then, the experimental group performed their exercises in the pool environment for 8 weeks (3 sessions per week) and the control group avoided any activity during the study.

Statistical findings showed that in measuring static and dynamic balance, the effect of central stability exercises was more than water exercises (P <0.05). Also, in flexibility, the effect of exercises in water was more than central stability exercises (P <0.05) and in lower limb function, the effect of central stability exercises was more than in water exercises (P <0.05).

It was observed that exercises for central stability as well as exercises in the aquatic environment increase static and dynamic balance in mentally retarded children. Central stability training can be effective for mentally retarded children by strengthening the deep muscles of the body in the abdomen, pelvis and thighs, as well as the stability and strength of these areas. Since central stability training does not require a lot of equipment and a large space, it can be done with the least facilities.

This research compares the psychological skills of the national team players in different disciplines over a period of twelve years. To this end, the 2006 study was considered as a reference. Samples are athletes from the national team who attended the 2018 Asian Games. The number of samples is 148 men and 31 women. The Ottawa Questionnaire (Omsat-3) was used to measure mental skills. The results of single-sample T-test showed that the mean of Relaxation, imagery and mental practice skills increased from 2006 and Knowledge and the athletes' use of these mental skills is greater. The average concentration of psychological skills, Focusing, Refocusing, Fear control, Stress Reaction and Self-confidence declined from 2006, Also, there was no significant difference between the mean of Goal Setting, Commitment, Activation and Competition planning in 2006 and 2018.These results are important for psychologists and sports planners, and they need to pay more attention to these skills.

The purpose of this study was to examine the effect of eight weeks of aerobic exercise on self-harm symptoms in adolescent girls. The method of the present study is applied in nature and is quasi-experimental with pretest-posttest and a control group. The data were collected in the field, and the statistical population of the study includes all ninth grade female students in the first half of 2018 in city of Karaj. These included thirty female adolescent students who had high symptoms of self-harm and a history of self-harm. With the cooperation of researchers, counselors and school teachersthe subjects were selected from 3 selected schools in one of the cities of the province as a convenience and purposive sample and the subjects were randomly divided into two experimental (15 people) and control groups (15 people). The instrument was included a demographic questionnaire, a 22-item self-harm inventory (Shi) (Sansone, Wiederman 1998). The experimental group participated in the aerobic exercise protocol for 8 weeks (three one-hour sessions per week). The results of two-way analysis of variance showed that eight weeks of aerobic exercise had no significant effect on self-harm in adolescent girls (P=0.153). However, it led to a significant reduction in the number of adolescent girls’ self-harm (P=0.010). Therefore, we conclude that aerobic exercise can reduce the frequency of self-harm in adolescent girls.