درخت حوزه‌های تخصصی

Background: The immune properties of mothers’ milk are well known. But the effects of physical activity on humeral immune properties of mothers’ milk is still undetermined. Therefore, reports on the impact of exercise on IgA concentrations of mothers’ milk is controversial. The purpose of the present study was the investigation of the effects of selected aerobic exercises in maximum intensity of 60-70% of heart rate reserve on IgA concentrations in breast milk as well as body composition. Method: In this research, 28 sedentary women (29±5.7 years; VO2max 36±4 ml/Kg/min), divided into two exercise and control groups through random sampling, took part. The exercise group performed some particular exercises for 10 weeks whereas the control group did not do so. Milk samples were taken from both groups and measured by the ELISA method. Body composition was also measured in different stages of the study. Results: In the rest status, the two groups were identical in terms of IgA concentrations (p= 0.549) and body composition (p=0.204). IgA concentrations under exercise load of 60% (p=0.060) and 70% (p= 0.001) of the HRR respectively showed a significant increase as compared to the resting status mean values in the two groups. Body composition variables were only of significant values in terms of comparing the general effects, only in the factors of group (p=0.003) and reciprocal effect of the grouping - the duration of the exercises (p=0.024). Conclusions: The results of this research show that, under the effects of moderate intensity exercise, the mothers’ secretory immune system experiences some changes. Therefore, IgA concentrations in the milk increase. In addition, with the reduction of fat weight, the decrease of fat mass percentage, and increase in the body density, the level of the mothers’ aerobic fitness is increased, which is in no contradiction with their lactation performance.

Introduction: Since people experience fatigue after anterior cruciate ligament injury during exercises, it is important to understand how fatigue affects the biomechanical movement patterns. Therefore, this study aimed to investigate the effect of fatigue on ground reaction force variables during single-leg landing in athletes with a history of an anterior cruciate ligament sprain. Methods: it was a case-control study conducted in the University Laboratory. The sample consisted of 36 male athletes who were divided into three groups: 12 people with Anterior Cruciate Ligament Reconstruction (ACLR), 12 people with Anterior Cruciate Ligament Deficiency (ACLD), and 12 people as the control group. Fatigue was induced via the repetitive sets of double-leg squats (n=8), which were interspersed with the sets of countermovement jumps (n=2) and single-leg landings (n=3) until squats were no longer possible. A 2×2 repeated-measures multivariate analysis of variance was used to detect the main effects of group (ACLD, ACLR, control) and fatigue state (prefatigue, postfatigue) on the ground reaction forces variables. Results: The results showed a significant decrease in the peak vertical force and internal-external ground reaction force in the ACLD group after fatigue. Regardless of the fatigue state, the peak vertical ground reaction force in ACLD and ACLR groups was significantly lower than that in the control group. Conclusion: The athletes with the ACL injury, regardless of the selective treatment type, use compensatory strategies to reduce the contact forces on the lower extremity, compared with healthy athletes.

Background and Purpose: Increasing participation in sports activities has increased the incidence of sports injuries. Considering the short and long term complications of sports injuries, the need to prevent them is one of the most important goals. The purpose of this study was to evaluate the effects of ankle bracing on the ankle plantar flexor muscles activity in different foot position during drop landing with and without fatigue. Method: Fourteen female college athletes participated in this study. Five models of 5 and 10 degrees medial, lateral and normal wedged insoles were used to simulate the position of the feet on the ground at the wrong landing technique. The Medial Gastrocnemius (MG) and Peroneus Longus (PL) muscles activity 100 ms before and 100ms after landing in different foot position before and after muscles fatigue with and without ankle bracing was recorded with surface electromyography. Repeated measures ANOVA was used for statistical analysis (p≤0.05). Results: The results showed that the effect of time on the activity of MG and PL muscles in landing with brace was significant, so that the MG muscle before landing and PL muscle after landing had a higher activity in both times before and after fatigue (p≤0.001). The activity of this muscles was not significant when using the ankle brace during landing in different positions (p˃0.05). Conclusions: According to the results of this study, lace-up brace can help to increase muscles activity when they were fatigue, while the using of brace does not affect muscle activity when landing perform in different positions without fatigue. According to the results, In the case of a suggestion to use brace for athletes, all aspects of using this equipment should be considered.

Purpose: The purpose of this study was to investigate the dimensions of brand impact on sports, economic and professional experts, managers and experts in Kermanshah province. Method: This is a descriptive-survey research. The statistical population consisted of 120 experts, managers and experts in sport and economic in Kermanshah province who were selected by random sampling. In this study, 87 experts including experts, managers and experts in two fields of sport and economics completed a researcher-made questionnaire assessing the dimensions of sport brand effectiveness. The measurement tool was a questionnaire of sport brand management whose reliability and validity were tested for this research. The Cronbach's alpha value for all factors is 7 or higher, indicating the appropriateness of the questions posed to assess each of the dimensions affecting sport brand management. SPSS software version 20 was used for data analysis. The results of the tests showed that all four sectors (managerial, economic, cultural and social) influenced sport brand management. Results: Finally, the overall summary of the tests shows that social media management brand with a mean of 3.09 and cultural management factor with a mean of 1.82 have the highest and lowest priority in influencing sport brand, respectively. Conclusions: The research results show that the social sector of the brand has a higher priority and microeconomic and macroeconomic indicators should be recognized.