درخت حوزه‌های تخصصی

Aim and background: The aim of this study was to investigate Kinematics and kinetics Symmetry of Lower Limbs during running at a constant speed. Methods: 28 Elite runner (age: 34.75±6.63years) participated in this study. Running at constant speed was conducted by each subject at 2/5 m.s-1 on treadmill while kinematic and kinetic data were captured at 150 Hz and 300 Hz, respectively. The peak of joint moments and flexion angles in sagittal plane were calculated. The normality and homogeneity of variances assumptions of the dependent variables was tested using Bartlett and Leven’s test. Independent t tests were conducted to examine the symmetry of hip, knee and ankle moments between dominant and non-dominant joints during stance phase of running (p<0.05). Results: results of the present study showed no significant difference exists between dominant and non-dominant lower joints regarding the peak moments of Hip, Knee and ankle in sagittal plane during stance phase (p>0.05) as well as between peak flexion angles during running. Conclusion: Symmetry exists in lower joints sagittal moments and flexion angle during running at the constant speed. According to the results dominant and non- dominant lower joints play propulsive and absorbent roles cooperatively.

Transference of professional sports clubs to private sector involves the necessary conditions for private sector activity. Therefore, the aim of this study was to determine the prerequisites for the transference of professional football clubs in Iran with emphasis on economic requirements. Statistical population included all CEOs and members of board of directors from professional football clubs, chairmen of committees and officials of provincial football boards, sports management and economics professors as well as football reporters. The research tool was a valid and reliable researcher-developed questionnaire. Factor analysis and Friedman ranking test were employed to analyze the research data. According to the results, the prerequisites for privatization were categorized in seven factors including cultural, executive, programming, motivational, legal, economic, and structural. Moreover, economic requirements (4.20) were the most important category, followed by executive (4.14), structural (4.04), motivational (4.02), legal (3.99), programming (3.97), and cultural requirements (3.62), respectively. Among the economic requirements, the transparency of financial information from country's football clubs, presence of strong sponsors and the creation of supportive funds for financial guarantee of private sector are in the first to third ranks, respectively. According to the findings the most important priority is to solve the financial problems and revenue generation of the clubs.

Background: Low back pain is a common debilitating condition and a major clinical and socio-economic problem in the most industrialized and non-industrialized countries. Aim : The aim of this study was to compare the effect of motor control exercises and PNF exercises on postural control, strength, endurance and proprioception in women with chronic non-specific low back pain. Materials and Methods: Forty-five women with non-specific chronic low back pain selected by convenience sampling and randomly divided into three groups of 15 (motor control exercises, PNF exercises, and control group). The pre-test included posture control, flexor and extensor muscle strength of the trunk, trunk muscle endurance, and proprioception using Y balance, dynamometer, McGill, and Goniometer tests, respectively. The subjects of the experimental groups performed the training program for 8 weeks under the supervision of the instructor and according to the training protocol. Then, the post-test was performed. Paired t-test and analysis of covariance at the significance level of 0.05 were used to collect data. Results: The results showed that motor control and PNF exercises improved proprioception, postural control, endurance, and strength of trunk flexor and extensor muscles in women with non-specific chronic low back pain (α≤0.05). The results also showed that there was no significant difference between the effects of motor control and PNF exercises on proprioception, postural control, flexor muscle endurance, and extensor muscle strength (α≥0.05). Discussion: Motor control and PNF exercises are effective in improving the proprioception, postural control, endurance, and strength of flexor and extensor muscles of the trunk with non-specific chronic low back pain, and both training methods are effective in treating chronic non-specific low back pain.

Background: Hyper kyphosis is a common postural issue that affects many women, often leading to negative body image. Aim: The purpose of this research was to investigate the impact of an 8-week corrective exercise program on the body image of women with hyper kyphosis. Materials and Methods: The research method used in this study was quasi-experimental. The study population consisted of female students aged 18 to 26 years with hyper kyphosis at Shahid Rajaee University. Participants were randomly assigned to either the experimental group (n=20) or the control group (n=20). Hyper kyphosis was measured using a flexible ruler, while body image was assessed using the Body-esteem Scale for Adolescents and Adults. The questionnaire had a reliability coefficient of 0.83 as measured by Cronbach's alpha. After 8 weeks of corrective exercise, both the experimental and control groups completed the questionnaire again. The control group did not receive any training during this time. The data were analyzed using the mixed ANOVA method with SPSS-26 software at a significance level of 95%. Results: The results of the mixed ANOVA analysis showed that the main effect of the training group and the interaction between the group and test stages were significant in the post-test stage for the dependent variable of total body image (F=6.82, P =0.013), appearance (F=6.72, P =0.014), attitude (F=8.81, P =0.005), and kyphosis angle (F=18.91, P =0.000). However, there was no significant effect of training on weight satisfaction. Conclusion: The results of this study indicate that eight weeks of corrective exercise significantly reduced the hyper kyphosis angle ( P =0.01), resulting in an improvement in the subjects' posture and a decrease in deformity. This improvement in appearance led to an increase in satisfaction with their appearance, as demonstrated by improvements in their body image.

This study aimed to identify and analyze the factors affecting the athletic commitment to train and compete in the armed forces. The research method was applied, and the study's statistical population consisted of athletes affiliated with the Armed Forces across the country, of whom 290 were selected as the sample. For data collection, in the beginning, the qualitative method and interview with elites were used, then the quantitative method containing a demographic questionnaire and sport commitment questionnaire (researcher-made) with 33 questions is used. The questionnaire comprises six dimensions: facilities, incentives, rules and regulations, financial and personal factors, and enjoyment and satisfaction. Collected data through equation modeling were analyzed using Amos 21 software and SPSS 22 software to identify the factors affecting the variables. The results showed that the research model had a good fit, and a positive and significant relationship existed between facilities and incentives, incentives, rules and regulations, finances, personal factors, and enjoyment and satisfaction with sport commitment. Finally, it is recommended that the physical education managers of the armed forces take advantage of all the national facilities to increase their athlete's athletic commitment.