Motor Coordination of Instep Soccer Kick in Elite Soccer Players After ACL Re-Construction Surgery

The aim of this study was to investigate Motor coordination of lower extremity in instep soccer kick. The participant of this study were 24 elite soccer players of professional Iran league which weren't have any injury in last 6 months. Twelve healthy subject (age 25.87±1.2years, height180.7± 4.6cm, and weight 77.25 ± 5.1 kg) and twelve ones (age25.25± 1.39 years, height181.37 ±5.0cm, weight 76.12±8.02kg) were the players who at least 2 years passed of their ACL reconstruction surgery. After 10 minutes of warm-up and performing five instep kicks, fifteen 14 mm spherical reflective marker were installed on specific anatomical points in the lower extremities; Then subjects performed instep kicks for three times. For performing each kicks subject keep out 3 steps from ball, then approach to the ball with 30° angle and kicks the specific goal are with dimension of 1.5mₓ1.5m, 5m distance to the ball and 0.5-meter distance from the ground. The kicks were records by motion analysis system with five digital cameras (Viconvcam 460) with a frequency of 200 Hz. Angels and ranges of motion of the hip, knee, ankle, foot& also thigh and shank angular velocity were calculated by using of Vicon work Station and Excel-2007 in the setting of MATLAB software. Data analysis were done in SPSS-18 software and by using of MANOVA test at significance level of 0.05.Significant difference results indicated in hyper extension angle of the hip, knee and ankle angle (P<0.05)but there was no significant difference in range of motion of the hip and thigh angle before ball impact (P>0.05). and also, there was no significant difference between the angular velocity of the hip of two groups (P=0.63). However, significant difference were found in the angular velocity of the shank in both groups (P=0.00). According to these results it can be concluded that reconstructed ACL surgary would change the mechanism of control& motor program of instep soccer kick and would have the most effective in the ankle & knee angle and have the lowest impact on the movement of the hip. Therefore, it is recommended that coaches& those who involved in sports teams should pay attention to these results.