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Mr Amin Mardazad, Dr Amirali Jafarnezhadgero, Mr Sajad Avazzadeh,
Volume 0, Issue 0 (11-2019)
Abstract
Warm up method can be considered as a strategy for improving athlete’s performance. The purpose of this study was to provide a useful data as warm up to improve the performance of athletes, including volleyball players by increasing their jump height. In the present review study by using the following keywords included Post-Activation Potentiation, Squat Jump, Warm-up, Volleyball, Jump Height, Force Plate, and electromyography the search process was done in Google scholar, the Pubmed databases and Scientific Information database and Google scholar. In the identification stage, 387 English and 15 Persian articles related to the mentioned keywords were found. Finally, the number of English articles reached 42 and the number of Persian articles reached 6. The results of this review-descriptive study showed in the final stages of Post-Activation Potentiation warm-up, performing high intensity squats by creating acute changes in neuromuscular system can increase in jump height of athletes including volleyball players in match and practice.
Dr Mohsen Barghamadi, Miss Roghayeh Parsa, Dr Amir Fatollahi,
Volume 0, Issue 0 (11-2019)
Abstract
Volleyball players are looking to apply their force at a short time speed to transfer more diagonal and vertical blows on the ball so that you land on the opposing team's field more quickly and make it difficult for the opposing team players to receive. It seems that various types of resistance training can improwe the vertical force of the spike skill.
Therefore the aim of the current study is to compare the effects of two types of resistance training (exercises with cable machines and exercise with barbells and free weights) on vertical force and impulse caused by diagonal hit on spike skill in college girl volleyball players. The present study method was semi-experimental. The statistical samples in this study included 45 girl volleyball players from university of Mohaghegh Ardabili. In three groups of 15 in groups 1 and 2 strength training intervention for two days a week, in 7 strenght movements with a cable bodybulding machine and barbell, dumbbell, and medicine training tools, observing the principle of overload in three movement intensities: 80%, 5 repetition, 90%, 2 repetition, 100%, one maximum repetition and in the third group in the form of a control group were identified. Strength training as an independent variable and vertical force and impulse as a dependent variable. Bertek force plate was used to record ground reaction forces. The table was used to adjust height, the invisible thread and the ball for the dominant hand shot in the volleyball players. In this study, ANOVA test was used with a significance level of 0.05. The effects of the force resulting from the diagonal impact on the ball in line with the vertical force of the ground reaction were significant in intervention group 1 (p< 0.008) and intervention group 2 was not significant (p< 0.133).The effect of the impulse time factor in the strength training group was significant in the vertical component of the ground reaction in intervention group1 (P<0.030) and in intervention group 2 (P<0.023). The difference between the groups in the intervention group shows the effect of the vertical force factor in the intervention group 1 with the impact factor (v = 0.016) compared to the group 2 also, in the impulse factor, impact factor was effective in intervention group1 (v = 0.190) and strength training in intervention group 2 (v = 0.167). It seems that barbell and medicine ball strength exercises increased force in diagonal strikes and produce the maximum vertical force in the shorter time to the ball in the spike skill of the diagonal strike of the volleyball players.
Mr. Milad Piran Hamlabadi, Dr. Amirali Jafarnezhadgero, Hamed Naghizadeh,
Volume 0, Issue 0 (11-2019)
Abstract
Background and Aims: Running is one of the most important activities for soldiers, and boots play an effective role in this activity. The aim of the present study was to investigate the effects of three types of military boots mileage on ground reaction force variables during running.
Materials and Methods: The current research was a clinical trial. 15 healthy male students (20-25 years old) used three different types of used and new boots. Using Bartec force plate with dimensions (60 x 40 cm2), ground reaction forces were measured in vertical (Fz), anterior-posterior (Fy) and medio-lateral (Fx) directions while running at constant speed. Two-way ANOVA was used for statistical analysis at a significance level of 0.05.
Results: Results demonstrated significant main effects of "Time" for FXHC (P=0.001, d=0.407), FXPO (P=0.001, d=0.674), TTPFXPO (P=0.001, d=0.394) and TTPFYPO (P=0.031, d=0.226). Findings showed significant main effect of group for FZHC (P=0.027, d=0.163) and TTPFYHC (p=0.035, d=0.150). Furthermore, significant group-by-time interactions was found for FZHC (P=0.001, d=0.404) and FXPO (P=0.014, d=0.272).
Conclusion: The results of this research showed that using military boots, the vertical ground reaction force, the medio-lateral force at heel contact and the peak medio-lateral force were increased. The increase of this value can be related to fracture injuries caused by pressure and patella femoral pain. The results of this study showed that the type of boots can be effective in preventing lower limb injuries. Therefore, using new operational boots is suggested for the military application.
Mr. Ali Smaeeli, Dr. Amirali Jafarnezhadgero, Mr. Mansour Jabri,
Volume 0, Issue 0 (11-2019)
Abstract
Background and Aim: This study focuses and reviews the researches that examines the effect of footwear types on torsional, vertical and limb stiffness during running.
Methods: The search for articles in English languages between 2000 and 2024 (until May) was carried out in WOS, Scopus, PubMed, Springer databases and grey literature from Google Scholar. The inclusion criteria included the number of participants being more than one and the availability of the full text of the articles. Exclusion criteria included studies whose participants were under 18 years of age. Review studies and studies that studied an activity other than running.
Results: 586 relevant articles were selected. After examining the articles, 17 articles were selected. Vertical stiffness and limb stiffness in barefoot conditions are significantly greater than in conventional shoes. The torsional stiffness in the ankle and hip joints in conventional shoe conditions was reported to be higher than in barefoot and minimal shoe conditions. In contrast, the torsional stiffness of the knee joint in conventional shoe conditions was lower than in barefoot and minimal shoe conditions.
Conclusion: These findings provide further insight into the susceptibility of runners to different injury mechanisms as a function of footwear.
Dr Shirin Aali, Dr Farhad Rezazadeh, Mr Fariborz Imani, Mrs Parya Sharifi,
Volume 0, Issue 0 (11-2019)
Abstract
This systematic review aimed to investigate the effectiveness of resistance training, particularly exercises designed based on 3D motion analysis, in improving muscle strength and balance function in elderly individuals with early knee osteoarthritis. A comprehensive search was conducted in PubMed, PEDro, Scopus, and Web of Science databases for articles published from January 2000 to December 2024. Selected studies were required to have utilized 3D motion analysis to assess movement deficits and design exercise programs. Out of 84 reviewed articles, 18 were chosen for final analysis. The results indicated that the majority of studies (86%) confirmed the effectiveness of resistance training in ameliorating knee osteoarthritis symptoms. Specifically, significant improvements were observed in functional balance (44% of articles) and reductions in knee pain (48% of articles). Furthermore, 33% of the studies reported superior efficacy for exercises designed based on 3D biomechanical analysis. These findings can significantly enhance the quality of life for patients and promote mobility safety in the elderly by reducing the risk of falls and improving joint stability. In conclusion, the findings suggest that innovative training approaches, particularly those incorporating 3D motion analysis, can play a pivotal role in optimizing rehabilitation and enhancing the quality of life for elderly individuals with knee osteoarthritis.
Saeed Vahedi, Mareft Siah Koohian, Milad Rahati, Negar Rostami, Elaheh Fallahzadeh, Roghayeh Afrondeh,
Volume 20, Issue 23 (9-2022)
Abstract
Covid 19 disease is associated with a wide range of clinical symptoms and long-term complications. For most sports medicine professionals, it's a new challenge for people to resume their previous activities after recovering from Covid 19 after receiving the exercise prescription and care. The aim of this study was to review the appropriate physical activity for those recovering from Covid 19 infection based on the type of involvement they developed during the illness. For this study, a review study method was selected. This is done in three steps. In the first stage, physical activity in Quid, in the second stage, organ involvement in Quid, and in the third stage, sports prescriptions in organ involvement by searching for appropriate keywords in reputable scientific databases such as Pubmed, ACSM, SID. ir and Science Direct were searched, content related to the purpose of the articles were extracted and collected and analyzed for content. Examination of organs after recovery from Covid 19 infection is essential to return to physical activity. Physical activity prescriptions in those recovering from Corona varies from disease to patient, and organ to organ. Exercising in Covid conditions requires consideration. The cardiovascular, respiratory, blood, gastrointestinal, and musculoskeletal systems are affected by Covid 19 infection. Exercise, on the other hand, has different effects on the immune system depending on its severity, and the immune system undergoes changes in Covid 19 disease. The type, intensity, and duration of exercise or physical activity vary according to the patient and the symptoms or side effects left by Quid, and the readiness of the various organs for physical activity should be assessed.
Amir Fatollahi, Amirali Jafarnezhadgero, Hamidreza Maghami,
Volume 22, Issue 27 (8-2024)
Abstract
Biomechanics is the knowledge that shows what forces enter the motion system of the human body and how it causes human movement. Therefore, the aim of this Meta-Analysis study was to review the studies conducted in the field of the effects of training on sand surface on biomechanics and physical fitness factors of human body during translational motions. The current study was a library and systematic review, the search for articles in Persian and Latin was from the beginning of the year 2000 to the end of 2023, which was done in the specialized databases of PubMed, WOS, Scopus, ISC and Google Scholar search engine. 568 related articles were selected based on inclusion and exclusion criteria. Standardized mean differences (SMDs) were calculated using random-effects models. The findings of eight articles indicated the improvement of mucle activity during training on sand. Examining the findings of one article indicated positive effects of kinematic variabls during training on sand. A number of two articles also reported that the reduction of the ground reaction forces and impact shock. In addition, five articles reported the improvement of sports performance in athletes, the increase of physical fitness factors. In general, training on sand surface can have significant positive effects on people's daily and sport life. Further study is warranted.
Amirali Jafarnezhadgero, Arezoo Madahi, Milad Piran Hamlabadi,
Volume 23, Issue 29 (7-2025)
Abstract
Background and Aims: The surface quality and type are an important factor that may influence the risk of sustaining injuries during running. The aim of the present study was to compare forces excreted on the foot while running on the ground and artificial turf in people with pronated and supinated feet.
Materials and Methods: The statistical population of the present study consisted of healthy men with pronated and supinated feet in Ardabil province. A statistical sample of 30 people aged 20-25 years was selected by available sampling and participated in the present study. Statistical samples were divided into three groups. There were 10 patients in the pronated foot group, 10 people in the supinated foot group and the third group of 10 people as the control group. The navicular drop test was used to measure foot type. A Bertec force plate was used to record ground reaction forces while running on ground and artificial turf at constant speed (about 3.2 m/s). The ground reaction forces in the vertical (Fz), anterior-posterior (Fy) and medio-lateral (Fx) directions were recorded during running.
Results: The results revealed greater medio-lateral ground reaction force at the heel contact in males with pronated feet while running on the ground than that artificial grass. In addition, the time to reach the peak of the vertical component at heel contact during running on grass was greater compared to the ground.
Conclusion: The results showed that the use of artificial turf can improve the risk factors for injury in people with pronated and supinated feet.
