درخت حوزه‌های تخصصی

Purpose:  Prophylactic effect of PNF stretching is performed with an expectation to reduce the risk of eccentric exercise-induced muscle damage and enhance drop jump performance.The purpose of this study was to examine the effects of proprioceptive neuromuscular facilitation stretching combined with plyometric training on deep jump in non-athlete male students. Method: The study design was a single blinded, randomized, concurrent parallel trial. Forty-two non-athlete male students were volunteered to participate in this study. Participants were assigned into plyometric (n=21) and plyometric & PNF (n=21) groups. Maximum and minimum vertical displacements, flight time, joint power, maximum landing force, peak take off instantaneous velocity were measured at baseline and 48 hours following the plyometric exercise protocol. A Vicon (200 Hz) motion analysis system with six T-Series cameras and two Kistler force plates (1000 HZ) were used to record kinematic and kinetic data, respectively. A two-way repeatedmeasure ANOVA (group x DOMS) was used to analyze data. Results: There was a significant difference between the pretest and the posttest scores in the intervention group for maximum vertical displacement (p=0.028), flight time (p=0.042), and Power average (p=0.026). Conclusions: This prophylactic treatment on mechanical parameters of deep jump during timing was useful. Eventually, results suggest that preventative treatments can have a significant effect on maintenance functional parameters or even helping to slow exercise-induced muscle damage for alleviating its symptoms.

Purpose: Nowadays, the use of sports and famous athletes in advertising has become one of the most common advertising practices. Therefore, the purpose of this research was to investigate the ability of predicting the indices of attractiveness, expertise, and trustworthiness of the renowned sport endorser on the consumers' willingness to buy sporting and non-sporting goods. Method: This study was a quasi-experimental study on a sample of 150 students of sport science at Ferdowsi University of Iran. The statistical sample was divided into two homogeneous groups; for one month, one group watched the advertisements of an artificial sport product and the other group watched the advertisements of an artificial non-sport product endorsed by the famous sport personality on the telegram. Finally, the results were analyzed by completing standard questionnaires of purchase willingness (Zichkowski, 1985) and advertising celebrities (Ohanian, 1990) and simultaneous regression statistical methods. Results: The results showed that all three indices of attractiveness, expertise, and trustworthiness of the renowned sports endorser have high predictive power for the tendency to purchase sporting and non-sporting goods. Also in the sporting goods group, the expertise, and in the non-sporting goods group, the attractiveness had the highest predictive power of tendency to buy. On the other hand, there is a significant difference between the perception of the popular sport endorsing indices in advertising sporting and non-sporting goods. Conclusions: Through a promotional period for two endorsed sporting and non-sporting products, this study provides useful findings for product and service institutions to select and employ renowned athletes to endorse their products and influence consumers' purchase intention. In the text, the detailed descriptions of the expected results and discussions have been reported.