Assessment Of COP Characteristics And Force-Time Changes During Walking In The Third Trimester 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. This study represents the second part of a research project that processed the same group of pregnant women in order to acquire extended information about gait during pregnancy.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.Results: 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). 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 both groups. 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, feetPurpose: 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 the feet, 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 tasks consisted of five gait trials where two foot impacts for each leg were always recorded. The participants started barefoot walking 3m ahead of the pressure platform and finished the trial 1m 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 scripts. The first script processed data of the 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 found 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 indicated 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 36th 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 36th 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

Plantar Pressure Sore Formation During Advanced Phases Of Pregnancy And The Effect Of Special Footwear

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 at 27, 32 and 37 gestational weeks participated in data collection sessions. 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 were given the special footwear. For the control group, the results show an increase in pressure sore occurrences 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 due to an association with the plantar pressure redistribution more towards 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 plantar pressure. However, the trend of these changes is not clear as there are many factors influencing the foot condition during advanced stages of pregnancy

Analysis of the effect of catalytic additives in the agricultural waste combustion process

This paper presents the research results of the effect of using calcium oxide and potassium permanganate on the combustion of pellets from wheat bran and beet pulp. The measurements were performed in the technical laboratory of the Centre of Energy Utilization of Non-Traditional Energy Sources in Ostrava. The research examined the effect of the use of chemical substances on the amount of air pollutants from biomass thermal conversion in a low-power boiler and the process temperature. First, we performed technical and elementary analyses of agricultural waste. The raw material was then comminuted, mixed with a selected additive, pelletized, and finally burned in a low-power boiler. The additive was added in three proportions: 1:20, 1:10, and 1:6.67 (i.e., 15%) relative to the fuel weight. The combustion process efficiency was measured using a flue gas analyzer and three thermocouples attached to the data recorder. From the measurement results, we were able to determine the percentage reduction of pollutant emissions into the atmosphere (CO, NOx, and SO2) due to the use of additives. Because emission standards are becoming increasingly stringent and fuel and energy prices are rising, the results presented in this article may be useful to agri-food processing plants that want to manage these materials thermally.Web of Science1510art. no. 352

Characterization of syngas produced from biomass gasification

This conference paper presents biomass (wood chips from the production process of sawmills) as a renewable energy source to produce electric energy by gasification. Executed measurements from the gasifier with a fixed bed and properties of produced syngas are described in this paper. The goal is to use the produced syngas at co-generation units with piston combustion engines to produce electric energy and heat. The syngas composition is the final result of these measurements. The syngas from gasification contains pollutants which cause technical difficulties during its use in engines with internal combustion and for this reason it is necessary to choose an adequate system of syngas cleaning

Assessment of distribution of plantar pressures and foot characteristics during walking in pregnant women

The main purpose of this research was to analyse the distribution of plantar pressures and foot characteristics during walking between weeks 27 and 36 of pregnancy. The secondary purpose was to test the effect of the customized orthopaedic shoes that were worn by the experimental group. Methods: Pregnant women (n = 73) were divided into 2 groups, control group (n = 38) and experimental group (n = 35) which completed 5 gait trials on a walkway (1.55m) at a self-selected velocity of gait, where force, pressure and remaining foot characteristics were sampled and displayed by Novel database pro m (version 25.3.24). Results: Analysis of foot characteristics did not reveal important changes. Analysis of the distribution of plantar pressures revealed few changes in the pre- and post-measurement of the experimental and control groups between weeks 27 and 36 of pregnancy. In the last measurement, there is a significant increase of peak pressure only in the midfoot area of the left foot (151.1 ± 41.2 kPa) and in the hindfoot area of the right foot (346.3 ± 104.1) of the experimental group. The control group exhibits similar pressure development for both of foot. Conclusions: Monitored parameters demonstrated in certain areas notably development of force and contact area. Results of foot characteristics did not reveal a significant changes. As both groups registered similar values in certain areas in a comparison of pre/post measurement characteristics, the influence of specific orthopaedic shoes cannot be conclusively demonstrated in the experimental group

Characterization of syngas produced from biomass gasification

This conference paper presents biomass (wood chips from the production process of sawmills) as a renewable energy source to produce electric energy by gasification. Executed measurements from the gasifier with a fixed bed and properties of produced syngas are described in this paper. The goal is to use the produced syngas at co-generation units with piston combustion engines to produce electric energy and heat. The syngas composition is the final result of these measurements. The syngas from gasification contains pollutants which cause technical difficulties during its use in engines with internal combustion and for this reason it is necessary to choose an adequate system of syngas cleaning

Organovermiculite as regenerable nanostructured adsorbent for treatment of heavily polluted waste water from coke industry

Organically modified vermiculites can be used as nanostructured adsorbents of organic compounds from waters or gaseous phases similarly as organically modified smectites or bentonites. There is a large amount of research data focused on adsorption properties of organoclays, however only a little information is about their post-sorption treatment. This work is focused on study of two possible ways of subsequent processing of organovermiculite after its use as sorbent for heavily polluted waste water. At first, the vermiculite modified with hexadecylpyridinium ions was used in batch static sorption against phenol ammonium water from the coke industry to get highly contaminated sorption material, especially containing organic hydrocarbons and their derivatives. The sorbent is known to have excellent sorption properties; however ecotoxicological characteristics of original material showed that sorbent had hazardous properties even before its utilization. For that reason, it was necessary to design a post-sorption treatment. Two possible methods of treatment were investigated, specifically solvent treatment (with dichloromethane) and thermal treatment (thermodesorption) at temperatures of 300 and 1100 degrees C, respectively. The treated materials were studied using infrared spectroscopy, X-ray diffraction and carbon phase analyses. The solvent treatment confirmed that it is possible to reuse modified vermiculite as adsorbent several times, although adsorption capacity after each extraction decreases. The thermal treatment at 300 degrees C was not sufficient to remove all organic compounds from the vermiculite structure; however at 1100 degrees C the only presence of magnesium silicate, magnesium aluminate and ferric oxide confirmed the formation of an inert material convenient for an environmentally harmless disposal of used adsorbent.Web of Science1952574256

Comparison of selected oxidative methods for carbon nanotubes: structure and functionalization study

Alterations induced by oxidative functionalization treatments of commercially available multi- wall carbon nanotubes Nanocyl NC7000 using HNO3, KMnO4, H2O2, H2SO4 and NaOCl was studied. The efficiency of used oxidizers at different concentrations and temperature was evaluated, using analytical methods for structural analysis (FTIR and Raman spectroscopy) and carbon phase analysis. The interpretation of obtained results contains the level of oxidation, functional groups presence and metallic impurities removal. Suggestions for selection of the treatments to fulfill tailored needs for the final product are included.Web of Science1687825782

Changes in lower extremity blood flow during advancing phases of pregnancy and the effects of special footwear

Abstract 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

Adsorption of nerve agent simulants onto vermiculite structure: Experiments and modelling

Chemical warfare agents are still a threat to humanity despite the existence of a ban on their production and use. There are many new materials that have been experimentally verified to be effective in degrading and eliminating various chemical warfare agents; however, clay minerals still remain very effective, environmentally friendly and not expensive. Vermiculites modified with hexadecylpyridinium, hexadecyltrimethylammonium and tetramethylammonium cations were used for static sorption of vapours of two simulants of nerve agents: dimethyl methyl phosphonate and diethyl ethyl phosphonate. The materials before and after sorption were characterized using infrared spectroscopy, X-ray diffraction and carbon phase analysis. The breakthrough time and capture of simulants were measured using dynamic sorption test. Molecular modelling was used to confirm the experimental results and provide a deeper insight into the structure of the materials and sorption processes.Web of Science382art. no. 12100