Research in Sport Medicine and Technology

The purpose of this study was to examine the difference between two types of
the soccer instep kick in temporal sequence of motion and muscle
electromyography, during forward swing phase of the kick. Ten elite soccer
players, volunteered as subjects in the study. To culculate the kinematics data,
we used DLT method with two video camera that filmed five markers fixed on
anatomical points of lower body, at 240 fpm. Moreover the electromyography of
rectus femoris, vastus medialis and tibialis anterior were estimated. Kinematic
data from ten players was extracted using image processing toolbox of
MATLAB software. Using these results, we compared sequences of joint motion
and progression of activation muscle in low drive and high drive kick. The
results indicate that there was a difference in ranks of muscle activation
between two kick, but there were no difference in muscles activation time and
sequence of joint motion between low drive and high drive kick. Furthermore
both kicks have a similar proximal-distal pattern and interaction in muscles
contraction and joints motion

Objective: The aim of this study was to investigate the effect of non- stability surface of support leg on the instep kicking kinematics in soccer players. Materials and Methods: 30 male soccer players participated in this study. After the measurement of static and dynamic balance tests by the Biodex System, 20 players were selected who were at a desired level of the balance. Data were recorded using the three- dimensional motion analysis system with 6 optoelectronic cameras (200 HZ). The kinematic parameters in three critical moments of kicking (Forward swing of hip, Contact to ball, Follow through) were compared by using repeated measures of variance and independent t- test (0/05). Results: The results showed that the values of maximum angular velocity and displacement of hip and velocity of ball at the kicking over stability surface was significantly higher from the kicking over non- stability surface. Conclusion: These results indicate that the kicking over non- stability surface causes the lower of kinematic parameters in the more of the kicking skill phases and the movement prime velocity of ball

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.