Physical education and sports sciences
Dissertation to receive a master's degree. M.A»
Abstract
The purpose of this research was to determine the effect of sports shoes and medical insoles on shooting on the feet in people with flat feet. For this purpose, 30 active students in the field of football with an average age of 16.16 years with flat feet were selected and participated in this study. In this research, the subjects shot the ball from 20 and 30 meters away, and the range of the ball and the accuracy to the target were measured and recorded. The shots were made with two types of soccer shoes with and without soles. The collected data was analyzed using SPSS software and ANOVA with repeated measures at a significant level (p ? 0.05). The findings of the research showed a significant difference between the time the subjects used sports shoes compared to the time they used non-sports shoes (p=0.00). These results indicate that sports shoes have an effect on the range of the ball and the accuracy of the target in people with flat feet. Also, there was a significant difference between the time when these people used medical insoles compared to the time when they did not use insoles (p=0.00). These results indicate that medical insoles have an effect on the shooting performance of people with flat soles.
Key words: shooting, flat feet, soccer shoes, medical insoles
-1-Introduction
Football is the most popular sport in the world. Shooting skill is the most important in football. The shooting performance of football athletes usually depends on the accuracy and speed of the shot (Lees & Nolan, 1998). Among the different shots used in football, the leg shot is considered the most powerful shot. Ball speed is the main biomechanical indicator of successful shooting, which can affect ball speed as a result of various factors such as technique, speed, contact angle, contact surface, age, gender, dominance, characteristics of ball and foot contact, muscle strength and type of impact. Foot speed and impact angle are one of the effective factors in the range of the ball (Kellis and Katis 2007).
Among the mentioned factors and variables, usually the biomechanical analysis of shot accuracy has received less attention. The accuracy of the shot can be checked in the angle between the direction of the shot and the intended path. The accuracy of the shot depends on the speed of the angle of impact of the foot. When players shoot at their own speed, their shots will be more accurate. The maximum speed of the shot will have the minimum accuracy. (Kellis and Katis 2007)
Flat foot is a muscular-skeletal problem that is mostly seen due to the reduction of the inner longitudinal arch of the foot and the full contact of the sole with the ground during weight bearing. (Murley et al 2009)
Among the treatment methods or the use of corrective interventions, attention to orthoses has a special place, which is often It is used to eliminate a wide range of lower limb abnormalities (GROSS et al 1991)
1-2- Statement of the problem
In sports biomechanics and performance training of people who engage in sports activities, it is considered and analyzed. The main goal of sports biomechanics is to improve performance in exercise or sport. One of the ways to improve performance is to modify sports equipment or use appropriate equipment. For example, in most sports, shoes are one of the main accessories used by athletes, which can affect performance directly or by preventing injuries (Mamari, 2013). One of the most important and variable structural features of the foot is the height of the internal longitudinal arch when bearing weight (Cavanagh 1987).Flat feet is one of the common deformities in which the height of the inner arch of the foot is lost or reduced (Van Borum 2003). Due to the bio-mechanical changes of the lower limb, flat feet cause changes in the individual's performance and affect important variables such as muscle activity, and as a result, in addition to the fatigue of walking and running, it affects the performance of the lower limb in general (Nawoczenski 1999). Using orthosis and shoes that support the longitudinal arch of the foot is one of the common ways to improve the function of the lower limbs in people with flat feet (Noll 2001). Definitely, in achieving this goal, having a strong shooting ability is one of the main success factors in football (Nambakhsh 1377). Success in executing a proper shot, especially a shot on the feet, depends on several factors. According to the position of the sports team, skills can be diverse and complex (Lees, 1996). The biomechanical study of foot shot has a long history. Since 1960, results have been obtained from partial analysis of the body and 2D analysis to the analysis of the whole body with a 3D system. One of the common methods that have been used in biomechanical studies is the standing foot shot. The biomechanical research of the foot shot has been started by analyzing 2D films. And these studies started in late 1970 and continued until 1990. In these studies, the parameters of ball speed, joint position change, joint angles and angular velocity have been used. (Lees, Nolan 1998 & Asami, Nolte 1983 & Zernicke, Roberts 1978)
Palagenhoef showed that improper control of foot movement is often due to muscle damage. It should be noted that the foot shot is an open movement chain, any change in one part affects other parts. (Plagenhoef 1971) .
The shot on the foot is composed of 6 main steps: the contact angle, the forces of the planted foot, the swing of the loaded limb, the bending of the thigh and the opening of the knee, the collision of the foot with the ball and the pulling of the foot after the ball. (Barfield 1998). (Lees 2010) The movement of the ball resulting from a soccer shot is ultimately determined by the central character of the interaction between the foot and the ball, which lasts about 0.1 second. (Tsaousidis & Zataroski 1996). Stability has been investigated. However, the effect of its performance on the shot is unique (Henning & Sterzing 2010).
Most of the researches in the field of shooting on the feet have been in healthy people, and most of their attention has been paid to the evaluation of the shot among skilled and beginners, women and men with superior and non-superior feet, and the effect of different types of shoes in stationary and moving conditions. Injuries of the lower limbs affecting the shot have been discussed. Many researches have been done in the field of flat soles and its effect on movement factors, physical fitness and ground reaction force. So far, no research has been found that shows that flat soles have an effect on the foot in the shot. Therefore, this research can evaluate the effect of sports shoes and insoles on the feet.
1-3 - Necessity and importance of research
According to the statements of motor behavior experts, children's motor skills are a prerequisite for a successful experience and a factor in enjoying organized movement activities (Wong et al 2005)). Skeletal-muscular abnormalities, especially in the lower limbs, are among the factors that affect the superiority of children, which can affect the bio-mechanics of the human body, especially the bio-mechanics of running, walking, and in general, the movements of human movement (Twomey 2010) and Science 2015. (
According to the research literature, a change in the alignment of the foot causes inappropriate biomechanical performance in the lower limb and affects walking, agility, balance, agility, speed and other physical fitness factors (Khoshdel Ahmadi 87).
The shape, type, weight and material of the shoe on the quality of the foot hitting the ball and the impact point It is effective. The success of the shot (accuracy, duration of flight) depends on the speed of the foot contact with the ball.