The plantar pressure and shear force measurement, the function and effect of joints, bones and ligaments of foot during running and walking, and the modeling and finite element analysis of human foot are three important aspects in biomechanical study of foot. They are also the basis of the study of rehabilitation. In this paper, studies on the three aspects are reviewed, and further promising developments are proposed.
Biomechanical Phenomena ; Diabetic Foot ; physiopathology ; Exercise ; physiology ; Finite Element Analysis ; Foot ; physiology ; Humans ; Pressure

The purpose of this study was to investigate the effect of different backpack load on the plantar pressure of people during walking. By using three-dimensional force platform system, we collected the ground reaction force data from 20 college students, who were carrying different loads on their backs, and then we transformed the data into a characteristic two-peak curve. Seven characteristic parameters on the curve were selected and analyzed by using statistical methods. The results indicated that the peak ground reaction forces increased as the loads increased. Furthermore, in consideration of different genders, the amount increased was different. For the male subjects, when backpack load reached 17% body weight, changes in ground reaction force began to take place until the backloads reached 20% body weight changes in ground reaction force induced a significant difference. Por the female subjects, changes in ground reaction force began to take place with loads up to 14% body weight and while it reached 15% body weight it induced a significant difference.
Back ; physiology ; Biomechanical Phenomena ; physiology ; Female ; Foot ; physiology ; Humans ; Male ; Pressure ; Stress, Mechanical ; Walking ; physiology ; Weight-Bearing ; physiology ; Young Adult

The present paper is to study the center line of the plantar pressure of normal young people, and to find the relation between center line of the plantar pressure and gait stability and balance. The paper gives the testing principle and calculating methods for geometric center of plantar pressure distribution and the center of pressure due to the techniques of footprint frame. The calculating formulas in both x direction and y direction are also deduced in the paper. In the experiments carried out in our laboratory, the gait parameters of 131 young subjects walking as usual speed were acquired, and 14 young subjects of the total were specially analyzed. We then provided reference data for the walking gait database of young people, including time parameters, space parameters and plantar pressure parameters. We also obtained the line of geometry center and pressure center under the foot. We found that the differences existed in normal people's geometric center line and the pressure center line. The center of pressure trajectory revealed foot movement stability. The length and lateral changes of the center line of the plantar pressure could be applied to analysis of the plantar pressure of all kinds of people. The results in this paper are useful in clinical foot disease diagnosis and evaluation of surgical effect.
Foot ; physiology ; Gait ; Humans ; Pressure ; Reference Values ; Walking

Chronic wounds pose a clinical challenge. Such wounds may present all over the body although the majority appear on the lower extremities. In the main, wounds are caused by hypertension (venous or arterial), diabetes, although infection, trauma, and animal bites can result in non-healing wounds. It is vital to have a reliable diagnosis in order to plan treatment. Despite advances in diagnostics and the development of standard care packages, chronic wounds present a growing burden to all societies. One of the problems faced is the poor understanding of the pathophysiology of wounds; it is commonly accepted that microcirculation is impaired in lower extremity chronic wounds. This paper is focused on the significance and assessment of impaired microcirculation.
Diabetic Foot ; pathology ; Humans ; Microcirculation ; Wound Healing ; physiology

For the study of muscle function and features during exercise, a multi-channel data acquisition system was developed, the overall design of the system, hardware composition, the function of system and so on have made a detail implements. The synchronous acquisition and storage of the surface EMG signal, joint angle signal, plantar pressure signal, ultrasonic image and initial results have been achieved.
Electromyography ; instrumentation ; Exercise ; Foot ; Humans ; Motion ; Muscle, Skeletal ; physiology

In the long time of natural evolution, the bodies of some animals, such as feline, that live in the wild and complicate surroundings have evolved to possess outstanding buffering characteristics, which make the animals adapt to the environment perfectly. These animals generally have well-developed paw pads under their soles to play an important role in attenuating the intensity of impact when they land on the ground. Investigating the buffering characteristics of these animals' paw pads could help us to design "bionic" buffering and energy-absorption devices. In this paper, based on observations of animal jumping test, a simple mass-spring-buffer model was proposed to explore the buffering characteristics of the animals' paw pads. By analytically solving the differential equations of this model, the parameters concerned with paw pads functions were discussed and some significant results were obtained.
Adaptation, Physiological ; Animals ; Biomechanical Phenomena ; Felidae ; anatomy & histology ; physiology ; Foot ; anatomy & histology ; physiology ; Models, Theoretical

This paper presents a system of foot pressure measuring system based on LabVIEW. The designs of hardware and software system are figured out. LabVIEW is used to design the application interface for displaying plantar pressure. The system can realize the plantar pressure data acquisition, data storage, waveform display, and waveform playback. It was also shown that the testing results of the system were in line with the changing trend of normal gait, which conformed to human system engineering theory. It leads to the demonstration of system reliability. The system gives vivid and visual results, and provides a new method of how to measure foot-pressure and some references for the design of Insole System.
Biomechanical Phenomena ; Foot ; physiology ; Gait ; physiology ; Humans ; Monitoring, Physiologic ; instrumentation ; methods ; Signal Processing, Computer-Assisted ; Software

It has been shown from medical researches that many diseases are major causes of foot morbidity, which are deeply related to the abnormality of the plantar pressure distribution. In this respect, we made a new type of conductive rubber sensor and designed a dynamic contact pressure measuring system of plantar-pressure distribution with 251 testing points successfully. It includes the multipoint conductive rubber sensor, the interface circuit and the computer data collecting and progressing system. The measuring system can give the intuitional and full-scale image results with the full-court, real time testing. Also in this paper are introduced the design of the system, the testing results, and its applications in primary medical studies.
Biomechanical Phenomena ; Equipment Design ; Foot ; anatomy & histology ; physiology ; Humans ; Pressure ; Stress, Mechanical ; Transducers, Pressure ; Walking ; physiology

Both genetic and environmental factors are involved in establishing a behavior. An animal study was done to determine the characteristics of interaction between genetic (nature) and environmental (nurture) factors. Delivery of footshocks (0.8 mA x 60 times, at random) early in life was used as the environmental stimulus. As the footshock was delivered repeatedly, a rat showed helplessness behavior and the number of shocks necessary to elicit helplessness was measured to quantify the trait of an animal in coping with the aversive environmental stimulus. The nocturnal ambulatory activity at adulthood was measured as a behavioral expression of the nature-nurture interaction. Although the experience of footshocks early in life did not significantly alter average activity levels at adulthood, the activity was positively correlated with the number of shocks necessary to elicit helplessness (nature) while receiving footshocks (nurture) on postnatal day 14. Additionally, a second exposure to identical shock parameters on postnatal day 21 reversed the relationship. These results clearly showed that an interaction between nature and nurture during infancy leads to substantial behavioral alterations later in life, and suggest that the nature-dependent determination of an adult behavior can be modified in different directions by the conditions of an environmental experience early in life.
Aging/physiology* ; Animal ; Animals, Newborn/physiology* ; Animals, Newborn/growth & development ; Electroshock* ; Foot* ; Motor Activity/physiology* ; Rats ; Rats, Sprague-Dawley

Some 3D finite element systemic models are currently established and used to simulate the foot biomechanical state. However, during most of these 3D foot finite element static analyses, ligaments and plantar fascia are generally defined by connecting the corresponding attachment points on the bones, and the spaces between the bones are fused together by solid elements with given cartilage stiffness to simulate the connection of bones. This "connection of bones" takes the place of the real interactions between neighbored bones and enhances the structure of foot, which possibly leads to the result that the effects of ligaments and other soft tissues are completely replaced by the effect of articular cartilages. Thereby, ligaments and other soft tissues maybe not play an inherent role in the finite element analysis. The objective of this study was to estimate whether there exists the effect of ligaments and plantar fascia on the biomechanical behaviors of the foot tissue stress distribution and foot structure deformation during the balanced standing stance and static finite element analysis.
Adult ; Biomechanical Phenomena ; Computer Simulation ; Fascia ; physiology ; Foot ; diagnostic imaging ; physiology ; Humans ; Ligaments ; physiology ; Male ; Models, Biological ; Radiography ; Stress, Mechanical