The effect of shoe toe box shape and volume on forefoot interdigital and plantar pressures in healthy females

Ill-fitting footwear can be detrimental to foot health with the forefoot being an area for most discomfort. Studies on footwear have primarily examined sports or orthopaedic prescription shoes and little is known about the effects that everyday flat shoes have on the forefoot. The aim of this study was to investigate the effect of toe box shape in a popular slip-on pump on dorsal and plantar pressures with particular interest around the forefoot in a healthy female population

COMPARISON OF ENERGY EXPENDITURE ON NORMAL SUBJECTS FOR DIFFERENT FOOTWEAR

Energy expenditure differs in accordance with the physical activity and with the appliances used to support the activity.Footwear is one of the prime supporting appliances for physical activity. An attempt is made to quantify and compare the work efficiency of eight normal male subjects with and without two different types of footwear A VICON movement analysis setup with an AMTI force platform was used to study the ground reaction forces.Mechanical work uttered by the body was derived from the reaction forces. External Mechanical work can be defined as the force exerted on the body.times the displacement of the centre of mass of the body. Energy expenditure was calculated with the values of mechanical work. The energy expenditure values for walking barefooted and with footwear are calculated and the results are reported. A comparative study on the material. and design aspect of soles have also been discussed

Low-Complexity Detection/Equalization in Large-Dimension MIMO-ISI Channels Using Graphical Models

In this paper, we deal with low-complexity near-optimal detection/equalization in large-dimension multiple-input multiple-output inter-symbol interference (MIMO-ISI) channels using message passing on graphical models. A key contribution in the paper is the demonstration that near-optimal performance in MIMO-ISI channels with large dimensions can be achieved at low complexities through simple yet effective simplifications/approximations, although the graphical models that represent MIMO-ISI channels are fully/densely connected (loopy graphs). These include 1) use of Markov Random Field (MRF) based graphical model with pairwise interaction, in conjunction with {\em message/belief damping}, and 2) use of Factor Graph (FG) based graphical model with {\em Gaussian approximation of interference} (GAI). The per-symbol complexities are $O(K^2n_t^2)$ and $O(Kn_t)$ for the MRF and the FG with GAI approaches, respectively, where $K$ and $n_t$ denote the number of channel uses per frame, and number of transmit antennas, respectively. These low-complexities are quite attractive for large dimensions, i.e., for large $Kn_t$. From a performance perspective, these algorithms are even more interesting in large-dimensions since they achieve increasingly closer to optimum detection performance for increasing $Kn_t$. Also, we show that these message passing algorithms can be used in an iterative manner with local neighborhood search algorithms to improve the reliability/performance of $M$-QAM symbol detection

Equipartition of Current in Parallel Conductors on Cooling Through the Superconducting Transition

Our experiments show that for two or more pieces of a wire, of different lengths in general, combined in parallel and connected to a dc source, the current ratio evolves towards unity as the combination is cooled to the superconducting transition temperature Tc, and remains pinned at that value below it. This re-distribution of the total current towards equipartition without external fine tuning is a surprise. It can be physically understood in terms of a mechanism that involves the flux-flow resistance associated with the transport current in a wire of type-II superconducting material. It is the fact that the flux-flow resistance increases with current that drives the current division towards equipartition.Comment: Revised version of J.Phys. Condens.Matter; vol. 18(2006) L143-L147 14 pages including 3 figures; provided an explanation in terms of the physical mechanism of flux flow induced resistance that is proportional to the impressed current. We are adding a simple, physically robust derivation of our equipartition without taking resort to the minimum dissipation principl

Shore hardness is a more representative measurement of bulk tissue biomechanics than of skin biomechanics.

To support the effective use of Shore hardness (SH) in research and clinical practice this study investigates whether SH should be interpreted as a measurement of skin or of bulk tissue biomechanics. A 3D finite element model of the heel and a validated model of a Shore-00 durometer were used to simulate testing for different combinations of stiffness and thickness in the skin and subcutaneous tissue. The results of this numerical analysis showed that SH is significantly more sensitive to changes in skin thickness, relatively to subcutaneous tissue, but equally sensitive to changes in the stiffness of either tissue. Indicatively, 25% reduction in skin thickness (0.3 mm thickness change) or in subcutaneous tissue thickness (5.9 mm thickness change), reduced SH by 7% or increased SH by 2% respectively. At the same time, 25% reduction in skin stiffness (10.1 MPa change in initial shear modulus) or of subcutaneous tissue (4.1 MPa change in initial shear modulus) led to 11% or 8% reduction in SH respectively. In the literature, SH is commonly used to study skin biomechanics. However, this analysis indicates that SH quantifies the deformability of bulk tissue, not of skin. Measurements of skin thickness are also necessary for the correct interpretation of SH

Equipartition of current in parallel conductors on cooling through the superconducting transition

Our experiments show that for two or more pieces of a wire, of different lengths in general, combined in parallel and connected to a dc source, the current ratio evolves towards unity as the combination is cooled to the superconducting transition temperature Tc, and remains pinned at that value below it. This redistribution of the total current towards equipartition without external fine-tuning is a surprise. It can be physically understood in terms of a mechanism that involves the flux-flow resistance associated with the transport current in a wire of type-II superconducting material. It is a fact that the flux-flow resistance increases with the current that drives the current division towards equipartition

Footwear Choices for Painful Feet

Introduction Footwear has been identified as a key component in the aetiology of foot pain in the general public. Females appear to suffer more than males with the forefoot being the highest reported location of footwear related pain. Choices of footwear styles in young healthy females are led by comfort and activity, but it is not clear as to what footwear choices are made by women who suffer from foot pain. Method Two focus groups were conducted with three women who suffered with foot pain aged 40-59 years, and four women aged 60-80 years, regarding the choices made when buying footwear. Discussions focused around type of shoe purchased and the choices made when purchasing that shoe. Data were analysed using thematic analysis. Results Themes generated included style, brand, emotions, available choices and restrictions when buying shoes. While the older group chose shoes for comfort and fit, the younger group were more influenced by fashion and matching to dress choice. Colour was important to both groups and a key factor when buying new shoes. Foot pathology was the main restriction in buying desirable shoes in the older group. Conclusion As women age, the choices made for fashionable footwear may be overridden by the need to fit a shoe to existing foot pathology. Older women may be willing to alter the style of shoes to accommodate problems and ensure comfort. However, younger females with foot pain may wear fashionable shoes even if they cause discomfort

Effects of footwear variations on three-dimensional kinematics and tibial accelerations of specific movements in American football

American football is associated with a high rate of non-contact chronic injuries. Players are able to select from both high and low cut footwear. The aim of the current investigation was to examine the influence of high and low cut American football specific footwear on tibial accelerations and three-dimensional (3D) kinematics during three sport specific movements. Twelve male American football players performed three movements, run, cut and vertical jump whilst wearing both low and high cut footwear. 3D kinematics of the lower extremities were measured using an eight-camera motion analysis system alongside tibial acceleration parameters which were obtained using a shank mounted accelerometer. Tibial acceleration and 3D kinematic differences between the different footwear were examined using either repeated measures or Friedman’s ANOVA. Tibial accelerations were significantly greater in the low cut footwear in comparison to the high cut footwear for the run and cut movements. In addition, peak ankle eversion and tibial internal rotation parameters were shown to be significantly greater in the low cut footwear in the running and cutting movement conditions. The current study indicates that the utilization of low cut American football footwear for training/performance may place American footballers at increased risk from chronic injuries