Analysis of plantar pressure and postural balance during different phases of pregnancy

Objective: To analyze plantar pressure and postural balance during the three trimesters of pregnancy, and also to correlate these with anthropometric characteristics. Method: Sixty volunteers participated in this study, with a mean age of 23.3 +/- 5.5 years. There were 15 subjects in each group: non-pregnant, (C), first trimester (IT), second trimester (2T) and third trimester (3T). Evaluations were performed in bipedal stance with open eyes, using,a pressure platform. The following variables were analyzed in the right and left feet: peak pressures in the whole foot (W-FP), forefoot (FFP) and hindfoot (HFP); distance between the medial borders of the foot (width of support base); the distance from the center of force to the anterior (COF-A) and posterior (COF-P) limits of the foot; anteroposterior (AP) and mediolateral,(ML) COF displacements; and the contact area (CA). Results: There were no differences in peak contact pressures and COF-A and COF-P distances between the groups. The AP displacement.., was greater (p< 0.05) in 3T than in IT. There was no difference (p> 0;05)between the groups regarding ML displacement. There, was a positive correlation between weight gained, during pregnancy and CA for the 2T group, and between weight gain and WFP in the right feet in the IT group. Conclusion: The results demonstrate the:influence of the anatomical and physiological changes inherent to pregnancy on plantar pressure. They also,suggest that postural, equilibrium decreases in the third trimester, associated with greater AP displacement during this phase.