Showing 7 results for Jafarnezhadgero
Mr. Amirali Jafarnezhadgero, Ms. Arezoo Madahi, Mr. Milad Piran Hamlabadi,
Volume 0, Issue 0 (11-2019)
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.
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.
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 Amir Ali Jafarnezhadgero, Mrs Elham Sorkheh, Mr Goodarz Ghiasvand,
Volume 15, Issue 14 (10-2017)
Abstract
Introduction and aim: Taping is a common method used by athletes to improve muscular function. The aim was to assess the immediate effect of femoral external rotational and abductoral taping on three-dimensional ground reaction force characteristics, their time to peak, impulse, displacement of center of pressure, vertical loading rate, and free moment during stance phase of running. Method: 24 healthy men (age: 24.6±2.5 years; mass: 74.8±6.2 kg; 177.1±7.9 cm) were included in the study. Ground reaction force data was recorded by a Kistler force platform (sampling rate: 1000 Hz). Paired sample t-test was used for statistical analysis. Results: Compared to without taping condition, taping significantly reduced the peak impact and peak active vertical ground reaction forces during stance phase of running (P≤0.05; low to moderate effect size). Taping application increased and decreased the vertical loading rate (19%, P=0.047, moderate effect size) and the peak free moment values (P≤0.001), respectively. The values of the anterior-posterior and vertical impulses during taping condition were greater than that of without taping condition (P≤0.001; low effect size). Conclusion: Femoral external rotational and abductoral taping could improve the values of free moment, but this is not the case in vertical loading rate during the stance phase of running.
A.a Jafarnezhadgero, F Ghorbanlou, S.m Alavi-Mehr, M Majlesi,
Volume 17, Issue 18 (12-2019)
Abstract
Genu varus is one of the malalignment of the lower limbs, the failure to correct it leads to secondary abnormalities in adulthood. The purpose of this study was to investigate the effects of a corrective exercise program on ground reaction forces, loading rates, impulses and free moment during stance phase of walking. 17 children with genu varus were volunteered to participate in this study (Age:11.71±1.68 years, Height:1.40±0.09 meter, Weight:35.14±11.47 Kg, and BMI:17.49±3.61Kg/M2). Ground reaction forces were recorded with two Kisler force plates during pre and post-test. At the dominant limb, the amount of time to peak in the mediolateral ground reaction force component during heel contact decreased by of 61.90% (P=0.011). Also, the time to peak of the vertical ground reaction force component during mid-stance tend to increase significantly by 11.47% during the post-test compared to the pre-test (P=0.063). The values of peak ground reaction force components, loading rate, impulse and free moment did not show any significant differences between pre and post-test. The findings showed that the corrective exercise trainings used in the present study had the most effect on the time to peak components of the GRF, but there were no significant effects on the loading rate, impulses, and free moment components. The corrective exercises used in the present study have had the most effect on the time to peak of ground reaction forces and improve them. On the other hand, these exercises did not have any significant effect on the vertical loading rate, impact and free moment values.
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.
