OLGA A SYSTEM FOR AUTOMATIC-RECORDING AND ANALYSIS OF KINEMATIC AND DYNAMIC MOVEMENT PARAMETERS APPLICATIONS IN SPORT

Abstract

INTRODUCTION In sport biomechanics research applications and in modern coaching there is a need for data acquisition and elaboration systems that can be used in normal field situations. With this in mind, we developed a system devoted to the analysis of sport movements, evaluation of biomechanical performance criteria and to direct influence of training conduction. METHODS OLGA means On-Line Graphics Analysis. Essentially it consists on a hardware and a software design. The hardware configuration combines signals coming from videocamera with analog signals originating from different measuring devices (i.e. force plates, electrogoniometers, EMG ). The main components are: a PC IBM-AT3 microcomputer, a videodigitizing card 4 (512x512~12 bit) connected to a special high resolution memory-monitor CCIR, a Nec Multisync monitor, a CCD-Camcorder (50 Hz) for acquisition of videosignals. To acquire analog data, up to 32 analog signals may be multiplexed into an analog-to-digital 8 bit converter ( A / D ) . In addition a digital-to-analog function 3x8 bit is provided. The software is designed according to the following criteria: automatic digitalisation of the passive markers; minimization of-calibrating procedures; independent setting of the sampling frequency for video and analogue signals respectively, to assure an appropriate resolution: automatic and/or semiautomatic diagnostic routines according to the specificity of the movement to be investigated; intercommunication modules for statistical elaborations; interactive menus for application of biofeedback methods. RESULTS The application possibilities of the system are shown in the case of competitive weightlifting and in strength training schedules. The following examples will be presented : # analysis of the kinematics and kinetics of the centre of gravity of the barbell, of the body and of the bar- . bell-body system; # analysis of the kinematics of the leg motion during specific strength training exercises; # analysis of external and internal dynamic structure (i.e. net muscle moment) in lower limb; # application of biofeedback technique using acustical signal referring to a chosen threshold of an essential parameter.