Background During pregnancy, a number of changes affecting venous blood flow occur in the circulatory system, such as reduced vein wall tension or increased exposure to collagen fibers. These factors may cause blood stagnation, swelling of the legs, or endothelial damage and consequently lead to development of venous disease. Objectives The aim of this study is to evaluate the effect of special footwear designed to improve blood circulation in the feet on venous blood flow changes observed during advancing phases of pregnancy. Methods Thirty healthy pregnant women participated in this study at 25, 30, and 35 weeks of gestation. Participants were allocated at random to an experimental group (n = 15) which was provided with the special footwear, or a control group (n = 15). At each data collection session, Doppler measurements of peak systolic blood flow velocity and cross-sectional area of the right popliteal vein were performed using a MySonoU6 ultrasound machine with a linear transducer (Samsung Medison). The differences were compared using Cohen’s d test to calculate effect size. Results With advancing phases of pregnancy, peak systolic velocity in the popliteal vein decreased significantly in the control group, whereas it increased significantly in the experimental group. No significant change in cross-sectional area was observed in any of the groups. Conclusions Findings in the experimental group demonstrated that wearing the footwear tested may prevent venous blood velocity from reducing during advanced phases of pregnancy. Nevertheless, there is a need for further investigation of the beneficial effect on venous flow of the footwear tested and its application.

Plantar pressure sore occurrence is an indicator of increased plantar pressures which may develop into subsequent foot problems and pain. Therefore, the aim of this study was to assess the effect of special footwear on plantar pressure sore distribution. 67 healthy pregnant women participated at all data collection session at their 27, 32 and 37 gestational weeks. At each data collection session, the plantar pressure sore distribution was assessed for both feet. During the first data collection session participants were randomly divided into a control and experimental group. Experimental group obtained the special footwear. For the control group, the results show an increased in pressure sores occurrence in the medial edge of thumb and first metatarso-phalangeal joint. The special footwear introduction in the experimental group increased the pressure sore occurrence at the edge of the heel, probably associated with the plantar pressure redistribution more to the heel area. The distribution of pressure sore areas of the control and experimental group is in accordance with our hypothesis that the special footwear redistributes the plantar pressures, however, the trend of these changes is not clear as there are many factors influencing the foot condition during advanced stages of pregnancy.

Purpose: The primary aim of this study was to analyse the COP characteristics and force-time changes during walking between weeks 27 and 36 of pregnancy. The secondary objective was to verify the influence of the specific orthopaedic shoes that were given to the experimental group. The experimental group wore patented J Hanák R biomechanical footwear and insoles, which are designed to help with redistribution of forces acting on foot, to support both longitudinal and transverse arches of the foot and to strengthen the foot muscles during movement.Methods: Seventy-three pregnant women participated in this study. This group was random divided into the experimental group (35 pregnant women) wearing specific orthopaedic shoes and the control group (38 pregnant women). The motor task consisted of five gait trials where two foot prints for each leg were always recorded. The participants started barefoot walking 3 m ahead of the pressure platform and finished the trial 1 m after the end of the platform in order to preserve acceleration and deceleration in gait. Participants walked at their own preferred velocity. All pedobarometric parameters were registered by Emed walkway - trademark of novel gmbh in Munich, Germany. Data processing was divided to two scrips. The first script processed data to these variables (COP characteristics): Centre of pressure index (COPI), centre of pressure excursion index (COPEI), distance (D) of COP, maximum velocity (MaV) and mean velocity (MeV) of COP. The second script processed data for ten pre-defined areas of the foot: hindfoot, midfoot, MH1-5 – metatarsal heads, big toe, second toe, toes 3, 4 and 5 with these applied variables (force-time characteristics): Force-time integral (FTI) and contact time (CT).Results: For the experimental group, in comparison between 27th week and the 36th week of gestation, we can find lower COPI for both feet, significantly only for the left foot (p=0.04). Also, significant difference in COPEI (p=0.03, p=0.03) for both feet was found. In comparison pre and post measurement we found higher values of parameters COPI and COPEI and that indicates more lateral weight shifting during the last trimester. We can distinctly register extension of D, especially for the left foot (p=0.04). Changes in velocity of COP indicate that MaV was increased for both feet (p=0.00, p=0.00) and MeV was significantly increased only for the right foot (p=0.00) in the 36 week of pregnancy. For the control group, we found no significant changes in COPI, COPEI or COP. MaV and MeV of COP were significantly increased for both feet in the 36 week of pregnancy (p=0.02, p=0.00, p=0.01, p=0.00). Higher values of MaV and MeV indicate that pregnant women accelerated their walking in the 36 week of pregnancy. Further, force-time characteristics in most cases did not reveal statistically significant changes in the last trimester.Conclusion: Over the last three months of pregnancy, significant observable changes can be found, especially through COP parameters of the experimental and the control group. We found out that the specific orthopaedic shoes given to the experimental group influenced the trajectory of COP, which could have positive health aspects. Further, certain conflicting results of our study in comparison with other similar studies only confirm that individual biomechanic and physiological developments in pregnancy affect the kinematic and kinetic aspects of walking differently.Key Words: Center of pressure, pregnancy, gait, feet