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Showing 3 results for Haj Lotfalian

Mr Soroush Bagheri Koodakani, Dr Shahram Lenjan Nejhadian, Mr Mostafa Haj Lotfalian,
Volume 14, Issue 11 (4-2016)

Motion analysis systems are useful and effective equipment in biomechanics research. Unfortunately these systems are available for few researchers because these are expensive equipment. The aim of this study was to design and validation of a practical and inexpensive software, to determine the exact markers position in space and compute the kinematic of movement. In designing the software, the exact image processing algorithms and Direct Liner Transformation (DLT) method were used to calculate markers position in space. To validate the software, the markers position in static, dynamic, linear, angular, 2D and 3D conditions were calculateted by other standard tools and compared with software outputs using Mann-Whitney U test and no significant difference were observed. The validity and reliability of the software was assessed using Pearson Correlation Coefficient and Intraclass Correlations Coefficient and during all test conditions, very high levels of these coefficients were found (≥0.97). In a nutshell, present software, with features such as automatic tracking markers, inexpensive price, the possibility to outdoor use and image processing in 2D and 3D conditions, is valid and reliable software for kinematics analysis

Mr Mostafa Haj Lotfalian, Dr Mahdi Kargarfard, Dr Heydar Sadeghi, Mr Sajjad Mohammadi,
Volume 14, Issue 12 (10-2016)

Support foot position is one of the important factors which can affect instep kick quality and ankle joint injury. The aims of this study were to examine the support foot parameters in maximal instep kicking with the preferred and the non-preferred leg and research on risk factors for ankle joint injury in amateur futsal players. In this semi experimental study, twelve young and novice futsal players performed maximal speed place kicks with the preferred and the non-preferred leg. Average of the subjects individual characteristic have contained, age : 21/2±1/5 years, weight : 67/6±5/5 Kg and height :176±4/2 cm. Athletes were kicking the ball towards the goal from 10 meters. amount of support foot pressure were calculated at 300 Hz. To calculate injury of ankle joint, Forces, impulses, position of the fixed leg and maximum pressure of the lateral and medial portions of the foots were determined. Results indicated a significant difference in amount of subtalar joint range of motion. Higher range of motion in dominant leg were caused by a greater flexibility and coordination in this side of the body. In addition there were no significant different in impact of anterior, middle and posterior portion of fixed legs between two support foot. In contrast the maximum pressure in lateral side of non-preferred leg, was significantly more than other foot. In addition, the maximum force in non-preferred leg occurred prior then other foot. These problems can exacerbate ankle injury risk. Because the subjects were novice and they do not have appropriate neuromuscular coordination, can’t show a good movement pattern in non preferred leg. Hence, the absence of neuromuscular coordination can lead to energy loss and high pressure coming into the body, especially the feet and it can exacerbate injuries.  In a nutshell, amateur subjects indicated higher quality of­ biomechanical parameters in support foot of the preferred leg. Also likelihood of ankle sprain in dominant foot was less than other. Also generalization of these results to semi-professional and professional players, need further research.

Dr Mostafa Haj Lotfalian, Dr Heydar Sadeghi, Mr Soroosh Bagheri,
Volume 21, Issue 25 (9-2023)

The purpose of this study was to examine and compare the difference between inside kick, outside kick, toe foot kick and cheap kick with maximum effort, in some parameters associated with the electromyographic activity of the quadriceps muscle. Eight skilled collegiate soccer players volunteered as subjects in the study. These variables were included the average and maximum activation, activation time (AT), the time which the muscles reached to zenith activity (ZAT) and work (W). In order to calculate electromyography of selected muscles contain, RectusFemuris, VastusMedialis and VastusLateralis, ME6000 apparatus with 1080 Hz sample rate was used. Paired sample t-test was used to analyze data. The results indicate similarity between outside and toe foot kicks in average and maximum activity, activation time and work. thus there was no significant difference in electromyographic activity of the quadriceps muscles between these two kicks. But in many parameters, these two kicks were different with inside and cheap kicks. In a nutshell, according to the results, it can be said, quadriceps muscles during various kicks, adapting different trend of contraction which are dependent on the position of the muscles and limbs interaction during soccer kick. And outside kick could be created maximum stimulation in quadriceps.

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