Dispositivo para monitoramento de ângulos e movimentos repetitivos em atividades físicas

Abstract

The present work aims to develop a device for identification of angulation, range of motion and that performs the counting of repetitions using an inertial sensor to acquire raw data of acceleration and velocity. Through the analysis of data obtained from repetitive movements of the forearm, it was possible to define methods for the creation of algorithms for calculating angular amplitude and counting repetitions. For the identification of absolute angles, an aluminum support and a protractor were used, performing the alignment in specific positions and checking the error between the value read on the protractor and that obtained by the device. The identification of amplitude and time of simple movements, in addition to the use of the support, used the device attached to the forearm. To count repetitions, the device was attached to the torso for abdominal tests, on the back for flexion tests and also, in the same way as before on the arm. A maximum absolute error of 2.4° was obtained for identification of angle and a maximum absolute error of 8º for identification of simple range of motion. For repetitions, counting errors of at most two movements were found. It was then observed that the device does not appear to have sources of errors associated with the speed direction indication and thus can be used to identify the direction and repetition of the movement. In addition, it appears that the work developed is successful in counting the repetition of movements, which may be useful for application in physical tests or rehabilitation of patients in recovery.