AN INVESTIGATION OF LOWER EXTREMITY CONTROL OF ADOLESCENT FOOTBALL PLAYERS

ABSTRACT The aim of the present experiment is to make a combined kinematics and dynamic analysis of test movements in adolescent football players and to perform an assessment of the muscle control of the lower limbs. 22 adolescent (12-years old) football players have been researched by means of a complex method for simultaneous registration of dynamometric and kinematic parameters of motor control. Two video cameras and a tens platform were used. The researched persons have been performing two test movements landing on the tens-platform from a standardized height of 35 centimeters and a jump and landing on the tens-platform. The analysis was effectuated by joining a software program for kinematic analysis “KINOVEA” and the dynamometric one by a specialized computer dynamometric system by a measuring platform. At the moment of maximum exertion, the angle between the thigh and the shank was measured. The distance between the knees at the moment of amortization was shot by means of the video camera placed in front. The juxtaposition of the change of the distances between the knee joints with the initial values shows a medialization in all researched persons. This is an indication of a deficit in the muscle control of the lower limbs. The coefficient of variation and the range demonstrate the presence of significant differences in the distance between the knee joints in different persons. The values in both tests prove to be rather close landing from a standardized height and a jump from a platform. In the angle of flexion at the moment of the maximum foothold reaction upon landing from a standardized height there are no big differences in the studied persons. In the jump from a platform the maximum values of the flexion are greater and the range of the values as well. This indicated to a greater individual dependency of the amortization phase of the landing on the very jump.