Objective Taking Chinese college students as the target group,this study detected the distribution of plantar pressure in different gait groups and analyzed the distribution characteristics of plantar pressure in in-toeing gait populations,to provide references for their orthopedic rehabilitation.Methods Ten subjects with typical in-toeing and normal and out-toeing gaits were selected to participate in the plantar pressure testing experiment.The maximum force,pressure,and contact time during natural standing and during one walking gait cycle were measured using a Zebris foot plantar pressure measurement system.Gait parameters,including step length,step width,step speed,step direction angle,gait center line,and force change curves,were collected,and a hazard analysis was conducted.Results During natural standing,the swaying interval area of the center of pressure was 939.0±252.4 mm2 for the in-toeing gait group and 1 120.2±101.6 mm2 for the out-toeing gait group,which was larger than that for the normal group(240.7±130.6 mm2).The in-toeing gait further weakens the human body's ability to maintain stability.The dynamic and static plantar pressures in the three gait groups exhibited different distribution characteristics.During static standing,the pressure center of the in-toeing gait group shifted to the hindfoot,which accounted for 70%of the plantar pressure and was higher than that of the normal group.During dynamic walking,the absolute value of peak pressure in the tripodal area of the foot in the in-toeing gait group was higher than that in the other two groups.Conclusions The in-toeing gait group had poor static maintenance ability,and to a certain extent,the distribution of plantar pressure in the foot tripodal area and plantar zone pressure were different compared with that of the normal gait.This led to poor stability,easy muscle fatigue,and ankle and knee joint injuries in the in-toeing gait group under equal-intensity exercise conditions.

Foam stability affects the efficacy and incidence of side effects of foam sclerotherapy. Exploring the relationship between foam pressure difference and foam stability can provide ideas and basis for obtaining more stable foam. In the experiment, sodium cod liver oleate foam was selected, and poloxamer 188 (concentration of 0%, 4%, 8%, 12%) was added to realize the change of foam pressure. By using the self-written program to process the foam pictures, the foam pressure difference and the relationship between the foam stability indicators (water separation rate curve, half-life) and the foam pressure difference were obtained. The results showed that at first the foam pressure increased with the increase of the concentration, and then it decreased with the increase of the concentration and reached a peak at the concentration of 4%. The foam pressure difference decreases continuously with the increase of decay time. When the additive concentration is low, the foam average pressure difference increases. And if the additive concentration is too high, the foam average pressure difference decreases. The smaller the foam pressure difference is, the better the foam stability is. This paper lays a foundation for the research on the stability of foam hardener.
Half-Life ; Humans ; Poloxamer ; Sclerosing Solutions/adverse effects* ; Sclerotherapy ; Varicose Veins

Corona virus disease 2019 (COVID-19) has been the focus of global attention since its outbreak. With the rapid spreading of COVID-19, serious challenges including medical management system, medical resources, emergency response, medical devices and instruments gradually occur, revealing many shortcomings among these aspects. Herein, through the principles, viewpoints and methods of biomechanics, this article recognizes and analyzes the existing problems that are urgently needed to be solved, such as the study of in-vitro viability of the virus, the biomechanics of aerosol, the fluid mechanics in public transportation and places, the relationship between respiratory diseases and cardiovascular diseases, the improvement of medical devices, with an objective of taking advantages of biomechanics in epidemic prevention and control, so as to promote the development of biomechanics.

Vascular injury resulting from lower limb amputation leads to the redistribution of blood flow and changes in vascular terminal resistance, which can affect the cardiovascular system. However, there was no clear understanding of how different amputation levels affect the cardiovascular system in animal experiments. Therefore, this study established two animal models of above-knee amputation (AKA) and below-knee amputation (BKA) to explore the effects of different amputation levels on the cardiovascular system through blood and histopathological examinations. The results showed that amputation caused pathological changes in the cardiovascular system of animals, including endothelial injury, inflammation, and angiosclerosis. The degree of cardiovascular injury was higher in the AKA group than in the BKA group. This study sheds light on the internal mechanisms of amputation's impact on the cardiovascular system. Based on the amputation level of patients, the findings recommend more comprehensive and targeted monitoring after surgery and necessary interventions to prevent cardiovascular diseases.
Animals ; Animal Experimentation ; Cardiovascular System ; Cardiovascular Diseases ; Hypertension ; Amputation, Surgical

Lower limb amputation is a significant change in body structure. Loss of muscle, blood vessels, and blood leads to a redistribution of blood flow and changes in resistance at the end of blood vessels. In view of the significant increase in the prevalence of cardiovascular disease after lower limb amputation, the mechanism of which is still unclear, this study aims to establish an animal research model that can verify and explore the effects of amputation on cardiovascular system, and provide the experimental basis for subsequent animal experiments when exploring the effect of different amputation levels on the cardiovascular system. SPF New Zealand rabbits were divided into normal group ( n = 6) and amputation group ( n = 6). The amputation group was treated with above-knee amputation. The changes of low-density liptein cholesterol (LDL-C) and total cholesterol (TC) in serum of all the rabbits were monitored regularly after the surgery. The arterial pathological examination was conducted after the experimental rabbits were executed. The results showed that compared with the normal group, serum LDL-C content and TC content in the amputation group were significantly increased ( P<0.05); The blood vessels of the amputated rabbits had pathological changes such as degeneration and necrosis of smooth muscle cells in the middle membrane layer and rupture of elastic fibers. At the abdominal aorta and aortic arch, the elastic fiber area expression percentage (EFEP) of the experimental group was significantly lower than that of the normal group. The results suggest that the cardiovascular system of rabbits has the tendency of decreased arterial elasticity and lipid deposition in blood after amputation, indicating that the animal research model on the effect of amputation on the cardiovascular system has been successfully established, and can provide an experimental platform for further study on the mechanism of the effect of amputation on the cardiovascular system.
Rabbits ; Animals ; Cholesterol, LDL ; Disease Models, Animal ; Amputation, Surgical ; Myocytes, Smooth Muscle ; Arteries