درخت حوزه‌های تخصصی

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.

Introduction: The present research aimed to compare and follow-up the effect of 8-week corrective exercises with and without the myofascial release on functional kyphosis deformity in young adults. Methods: It was a randomized controlled trial in the university laboratory. Forty-five male students suffering from abnormal hyperkyphosis deformity (kyphosis of more than 42°) were selected and randomly assigned to three groups: corrective exercises, combinational exercises (corrective and myofascial release), and control. The Mean±SD age, height, and weight of the study sample were 22.12±2.88 years, 175.44±6.80 cm, and 71.21±7.31 kg, respectively. The study groups did the exercises for 8 weeks, under the direct observation of the researchers. The kyphosis angle of the participants was measured using a flexible ruler, at the baseline, post-test, and follow-up (4 weeks after the end of the exercises) stages. The collected data were analyzed with repeated measures Analysis of Variance (ANOVA) and Analysis of Covariance (ANCOVA) tests. Results: After 8 weeks of exercises, the degree of kyphosis in the post-test and follow-up stages was significantly lower than that in the pre-test, in both training groups. The results of the ANCOVA test demonstrated that the thoracic kyphosis degree in the combinational exercises group was significantly lower than that of the corrective exercises group (P≤0.05), in the post-test and follow-up stages. Conclusion: According to the results, the corrective exercises program in combination with the myofascial release is more effective than the corrective exercises alone, in correcting the thoracic kyphosis deformity.

Introduction: Wrestling is one of the most popular Olympic sports in Iran. Therefore, preseason screening and the prevention of sports injuries are very important. This study aimed to investigate the relationship between the history of injury and Functional Movement Screen (FMS) scores of the national team wrestlers and determine the cut-off point. Methods: The statistical sample included 136 national team wrestlers. The obtained data were analyzed using the Pearson correlation coefficient, t-test, ROC curve, and contingency table. Results: The results showed that FMS scores were higher in the wrestlers without previous injury compared to the injured ones. The t-test results demonstrated no significant difference between deep squat, straight and active leg raise, trunk stability push-up, and rotatory stability. According to the results, there is a poor negative, but statistically significant, the relationship between the number of previous injuries and FMS scores. Based on the ROC curve for FMS, the cut-off point of 16.5 was reported with the sensitivity and specificity values of 0.587 and 0.658, respectively. Conclusion: The results indicated that FMS can be used for fast and accurate control of injury probability in wrestling athletes. Therefore, besides the medical tests, FMS tests should be employed by wrestling coaches as a valid tool for injury prevention and the identification of athletes prone to injury.

Introduction: Nowadays, the use of artificial turf fields has become widespread. Given the high prevalence of noncontact injuries among female soccer players and high contribution of the Anterior Cruciate Ligament (ACL) injury, this research was conducted to compare biomechanical risk factors in the incidence of ACL injury for elite female soccer players during shearing maneuver and header on the natural grass and artificial turf fields. Methods: Sixteen players were selected from U-14 women’s national team by the convenience sampling method and started to perform the skills. Knee joint information was calculated by a 3D imaging system and a force plate. Statistical differences were reported using the dependent t-test at a significant level of 0.05. Results: The findings showed that the biomechanical behavior of the lower extremity while performing soccer skills on the natural grass was affected differently from that on the artificial turf. Results also demonstrated that the torque applied to the knee joint on the natural grass was higher than that on the artificial turf (P=0.039). Angular velocity on the artificial turf was also higher than that on the natural grass (P=0.006). Conclusion: The higher knee joint torque and the lower angular velocity on natural grass may result in a higher risk of ACL injury on the natural grass than on the artificial turf. Therefore, the use of prevention programs for ACL injury is crucial to minimize the incidence of lower extremity injuries.

Purpose: Low back pain is one of the most common health problems of the world. Very different causes can cause back pain. Approximately 85% of people who are examined for low back pain the cause is not specific. The purpose of this study is to investigate the effects of the knee abnormalities on pain intensity and functional fitness in middle aged men with the chronic nonspecific low back pain. Method: The statistical community of this study includes 30 people of patient’s male with nonspecific chronic low back pain in the age range of 30-50 years with one of the abnormalities of genu varum or genu valgum. Results: The research findings were analyzed using descriptive and inferential statistical methods (dependent t and independent t tests). The research findings indicate that both the pain and disability of the experimental groups have significantly decreased after applying selected of corrective programs (Stretching muscles and short elements and strengthening weakened muscles). Sitting frog, walking with the inner edges of the legs, pressure to enter the wall with the outer edges of the legs to modify the genu varum. passing legs from one side to another in the form of scissors in liner mode, passing the medicine ball to the wall with the inside of the legs, walking with the outer edges of the legs to modify the genu valgum (p<0.05). While the two variables in the control group did not differ significantly (p>0.05). Conclusions: According to the results and considering the conditions prevailing on the research samples, it can be concluded that knee abnormalities (genu varum and genu valgum) affected by pain intensity and functional fitness efficacy in nonspecific chronic low back pain patients and Corrective exercises of these abnormalities has had a significant effect on reduce pain and disability index.

The purpose of this study is to investigate the effect of brand, design and price on the perceived quality and re-intention of consumers to buy sport brand shoes. This is an applied research conducted as a descriptive correlational study in field form. The statistical population of this study included all physical education students across different educational levels in Iran. In this research, 720 questionnaires were collected by random cluster sampling. Structural Equation Modelling (SEM) with PLS software was used to analyse the data of this research. The results of this study show that design with a coefficient of 0.36, price with 0.27, and brand with 0.26 have a significant effect on quality perceived by customers. The results of this research also show that perceived quality with an effect coefficient of 0.49 has a significant effect on customers’ purchase intention. Generally speaking, it can be concluded that the components of design, price, and brand of sport shoes for Iranian physical education students are very important. Famous brands in the world need to pay particular attention to these components to tap into this lucrative market in Iran and increase their re-purchasing intention by influencing consumers’ perceived quality.