COMPARATIVE ANALYSIS OF THE GROUND REACTION FORCES, DURING THE SUPPORT PHASE, IN A GROUP OF PREGNANT WOMEN ON THEIR 3RD TRIMESTER OF PREGNANCY AND IN A GROUP OF NOT PREGNANT WOMEN Análise comparativa de forças de reação do solo durante a fase de apoio em um grupo de mulheres grávidas no 3º trimestre de gestação e em um grupo de mulheres não-grávidas

PURPOSE: To analyze and compare the Ground Reaction Forces (GRF), during the stance phase of walking in pregnant women in the 3rd trimester of pregnancy, and non pregnant women. METHODS: 20 women, 10 pregnant and 10 non pregnant, voluntarily took part in this study. GRF were measured (1000 Hz) using a force platform (BERTEC 4060-15), an amplifier (BERTEC AM 6300) and an analogical-digital converter of 16 Bits (Biopac). RESULTS: The study showed that there were significant differences among the two groups concerning absolute values of time of the stance phase. In what concerns to the normalized values the most significant differences were verified in the maximums values of vertical force (Fz3, Fz1) and in the impulse of the antero-posterior force (Fy2), taxes of growth of the vertical force, and in the period of time for the antero-posterior force (Fy) be null.