درخت حوزه‌های تخصصی

The current research aimed to develop a freelancing model in Iran's sports industry. This study is applied in terms of purpose and qualitative in terms of methodology. The statistical population consisted of experts in entrepreneurship, management, and sports management. A purposive snowball sampling method was used, and 19 participants were selected based on theoretical saturation. Semi-structured interviews were conducted to collect data. The data were analyzed using the grounded theory approach and Glaser's emergent method. Coding was performed in two stages and three steps: actual coding (open and selective coding) and theoretical coding, through which the research components were identified. In total, 160 codes and 41 categories were extracted across 10 dimensions at three levels: macro, meso, and micro. The findings indicate that at the macro level, cultural, political, social, economic, and legal factors are influential; at the meso level, educational, technological, and media factors play a role; and at the micro level, behavioral and psychological factors are significant. Given the unemployment rate among graduates of sports science and physical education, it is recommended that managers and policymakers take coordinated steps to leverage freelancing capacities to improve employment and entrepreneurship in the country's sports sector.

Background: Dynamic knee valgus (DKV) is due to the weakness of the thigh abductor muscles and the vastus medialis muscle, which increases the internal rotation of the thigh and increases the possibility of anterior cruciate ligament (ACL) injury. The amount of DKV in women is higher than men, which is one of the reasons for the possibility of more injury in women. Aim: The aim of the present study was the effect of acute soccer functional fatigue on knee and trunk kinematic factors in female soccer players with and without DKV during single leg landing. Materials and Methods: The present study is quasi-experimental research conducted on 28 female soccer players who were selected using purposeful and convenience sampling. They were classified into two groups with and without DKV. The subjects performed a single leg soccer landing, and the kinematic changes of the participants' trunk and knees were recorded through high-speed video cameras (SONY camera) in two sagittal and frontal planes and analyzed by Kinovea software. The data were analyzed in SPSS-26 software using a mixed ANOVA statistical test.Results The results revealed a significant interaction effect between fatigue conditions and groups on knee and trunk joint angles in frontal plane in the initial contact with the ground in single leg landing. The results showed that fatigue significantly reduced knee flexion and increased knee valgus and trunk lateral flexion increased significantly after fatigue. Conclusion: The results indicated the acute effect of fatigue on knee and trunk kinematics of female soccer players with DKV. Therefore, by increasing the amount of knee and trunk flexion and correcting the landing technique, the possibility of ACL injury in fatigue can be reduced.