Showing 9 results for Biomechanic
Dr. Amir Fatollahi, Dr. Amirali Jafarnezhadgero, Dr. Hamidreza Maghami,
Volume 0, Issue 0 (11-2019)
Abstract
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 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.
, , ,
Volume 12, Issue 7 (4-2014)
Abstract
The main purpose of the present study was to investigate the kinematics and kinetics of successful versus
unsuccessful basketball free throw shots. Six professional basketball players (age= 23±2.09 years members
of Iranian premier basketball league participat in test. Kinematics of arm motion during basketball free throws
were recorded by two Casio zr200 camera in frequency of 240 Hz. Wilcoxon test was used for significant
differences between successful versus unsuccessful free throws (p ≤ 0/05). Angular velocity of the wrist was
found to be significantly higher in successful versus unsuccessful shots at the time of ball release (p ≤ 0/028).
Wrist (p ≤ 0/008) and shoulder (p ≤ 0/023) joints were found to have significantly more flexion in successful
versus unsuccessful shots while elbow (p ≤ 0/002) remained significantly less flexed in successful shots.
Angular displacement of wrist (p ≤ 0/034) and elbow (p ≤ 0/004) was shown to be significantly greater in
successful versus unsuccessful shots. Integrated EMG of Anterior Deltoid (AD), Triceps Brachii (TB) and
Flexor Carpi Radialis (FCR) muscles was more in successful free throw versus unsuccessful free throw, but
the only significant difference was observed in the Integrated EMG of the Triceps Brachii muscle (p ≤ 0/034).
In summery, increasing the wrist angular velocity and activity of triceps brachii muscle affected successful
free throws.
Mr Mostafa Haj Lotfalian, Dr Mahdi Kargarfard, Dr Heydar Sadeghi, Mr Sajjad Mohammadi,
Volume 14, Issue 12 (10-2016)
Abstract
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.
Razie Yaqoubi, Heydar Sadeghi, Ali Yaqoubi,
Volume 16, Issue 15 (9-2018)
Abstract
Since the anthropometric and biomechanical parameters role is effective in improving the quality of sports skills, researchers and sports scientists are interesting to identify and communicate between these factors. The purpose of this study was making relationship between some of anthropometrical and biomechanical parameter of girl swimmers in swimming breast strokes. Twenty girl Swimmers (mean±SD: age 12±2 years; heights 147.50±11.23 cm; weights 39.53±9.58 kg) performed in this study. After compeletting the personal and satisfaction form anthropometric charactrastics, motion domain, power swimmer’s record along with information about the number of arm and leg kicks in distance of 25 meters was measured. Descriptive statics (mean, Standard deviation) and deductive statics (pearson corrolation, principle component analysis (PCA) to the determine the main parameters influencing and multiple regression to determine the role of main parameters selected) were used for data analysis. Results indicate the relationship between weight and length with swimmers stroke length in swimming breast stroke. Also there was a relationship between body type (endo morph, mezzo morph) with some of swimmers biomechanical parameters (speed, number of legs kicks, top power, hyper extension, motion domin of thigh). The given results indicate that there was a relationship between percentage of the anthropometric and biomechanical parameters in swimmers, and some of biomechanical parameters predictors of back and front crawl swimming in the same swimmer were different.
, , Elham Shirzad,
Volume 19, Issue 21 (9-2021)
Abstract
Despite the importance of talent for sports, but it has yet received little attention. The purpose of this study was to present a pattern design for talent identification in karate based on artificial intelligence algorithms. Subjects divided to adolescent elite karate athletes (n = 19) and non-karate athletes adolescent (n=20) by convenience sampling. Besed on previous literature, we selected and measured biomechanical and anthropometric variables. The normal distribution of all data was analyzed using Shapiro-Wilk test. Principal component Analysis (PCA) was performed to reduce the number of variables and identify the most important anthropometric and biomechanical variables. Then, for modeling, the neural network algorithm was used with three input layer (10 neurons), middle (7 neurons) and output (2 neurons). The results showed the most important anthropometric variables of adolescent elite karate athletes were thoracic subcutaneous fat, height, jump, static balance, grip strength, chest circumference, ankle circumference, abdominal subcutaneous fat and apparent length leg respectively. Also, percentage of correct classification and sensitive of data was high and 87% and 85% respectively. According to the results of this study, this method can be used for talent karate athletes along with other methods.
Golnaz Mousavi, Mehdi Varsei , Abosaeed Rashidi, Reza Ghazisaeidi,
Volume 19, Issue 21 (9-2021)
Abstract
The purpose of this article is to biomechanically simulate athlete's leg and compression garment to measure the pressure on a young athlete's leg in order to apply more optimal and uniform pressure distribution while providing a greater sense of comfort when wearing.
The body condition and body shape of the athlete are measured by anthropometric method. Although Using a CT scan of the athlete's body (athlete's limb) and the mechanical properties of the pressure garment (leggings) that made of elastane spacer fabric was simulated by finite element technique. The results of measuring the real pressure on the young athlete's foot were measured and compared by a kikuhime device. The values of pressure applied by the leg in the real state and simulation indicate a maximum error of 14/44 percent (Cross section below the knee and the point behind the leg), a minimum error of 8 percent (Cross section of the ankle and the front point of the leg). Despite the assumptions and sources of error in this simulation, the results show that measured pressure values in the simulation mode with the real mode with incredible accuracy
Marjan Asadi, Heydar Sadeghi,
Volume 19, Issue 21 (9-2021)
Abstract
Knowledge of the relationship between performance and range of motion, helping to design training programs, comply of individual with the needs of children is, therefore, The aim of research the relationship between some of the lower extremity range of motion and biomechanical parameters of the boys was performed. Hundred students in this study were randomly selected. After measuring the range of motion of lower extremity, test speed, power, balance and agility of the subjects were recorded. By descriptive statistics to determine the mean and standard deviation of the method of multiple correlations to assess the relationship between the selected range of motion and biomechanical parameters of subjects were used. Hip flexion by speed, hip abduction and knee flexion by balance and hip flexion, hyper adduction and ankle dorsi flexion significant positive correlation by the agility, the rate of hip and knee flexion by power a significant negative correlation and with other lower extremity range motion parameters showed a significant positive association. According to the research findings, seem to be characteristics of the children lower extremity range of motion and identify performance indicators for various athletic field, can be used.
Leila Nazari, Saba Rahmati,
Volume 19, Issue 22 (12-2021)
Abstract
One of the most important issues in community is health and progress people. Because of durability of a community depends on health each person. In this regard, the present study aims to compare anthropometric, biomechanical and psychological factors between university student and student girls done. Subjects of the study were 86 girls 15-17 years old and 113 university student 18-24 years old, took part randomly in this study. Measure anthropometric, biomechanical characteristic also psychological characteristics including general health (GHQ-28) and personality (NEO-FFI) were measured. The result of independent t-test showed that between percent fat and lean body mass, static balance and muscular endurance and all of the general health factors, there are significant differences between the two groups. In generally the subjects are in the border abdominal obesity and high risks associated health them. Doing prevention programs are essential. One of the most important proceedings for this group doing of physical activity and fitness and have a regular exercise program.
Nafise-Sadat Shahamiri, Dr Mohammad-Ali Soleiman-Fallah, Dr Foad Feizolahi,
Volume 20, Issue 24 (3-2023)
Abstract
The aim of this study is the effect of one period core stability exercise with and without kinesio taping on biomechanical effective factors in lower cross syndrome on female. 36 female between 30 to 40 were randomly divided in to 3 groups (control, with taping and without taping). each group consist 12 participant. To measure Pelvic slope, Hip and Knee ROM, Isometric strength of flexors and extensors, Abdominal muscle endurance, Flexibility of spine extensors, Endurance of core muscles, respectively was used Inclinometer, Goniometer, Dynamometer, Body flection test, Body straightening test and Planck test to the side. To evaluate research hypotheses, if there is a significant difference between them we was used analysis of covariance test and multiple comparison in averages with post hoc bonferroni test. The result of the survey indicate that difference between taping and control groups were significant in pelvic slope, hamstring and rectus femoris flexibility, knee and hip flexors muscle strength )p≥0/05(. Difference between without taping and control groups were significant in pelvic slope, rectus femoris and spine extensors flexibility (p≥0/05(. Difference between with and with¬out taping groups were significant in hamstring and iliopsoas flexibility, knee flexors, hip flexors, extensors, adductors strength, core muscles endurance )p≥0/05(. The results show that training with taping has an effective role on reducing lower cross syndrome. So it is suggested that taping can be used as an non-aggressive and low-cost method at the same time with exercise.
