THE EFFECT OF LOAD CARRIAGE AND SCHOOLBAG DESIGN ON LATERAL TRUNK POSTURE DURING STAIRS DESCENT IN CHILDREN

The aim of this study was to investigate the way that the schoolbag weight combined with carrying method effects the trunk posture laterally during stairs descent. Thirteen male children performed stairs ascending and descending on a 33-step staircase at their natural cadence for three complete cycles with athletic bag and backpack, each with loads of 0%, 10%, 15% and 20% of their body weight. The trunk posture of one complete gait cycle during every descent was analyzed. Significant load effects on trunk posture were found when the load was increased from 0% to 15% when carrying athletic bag, and when the load was increased to 20% when carrying backpack. For loads of 10%, 15% and 20% the body weight, a backpack design significantly reduced the trunk posture alternation compared with athletic bag

CHANGES OF GAIT PATTERN ON SLIPPERY WALKING SURFACES IN SIMULATED CONSTRUCTION WORKSITE ENVIRONMENTS

This study aimed to investigate the gait pattern when walking on potential slippery surfaces. Twelve male subjects performed level walking at their natural cadence and without slips under sixteen simulated construction site walkway conditions with different floorings, contaminants and footwear. Gait pattern parameters were collected by video cameras and were analyzed by motion analysis system (APAS). Dynamic coefficients of friction (DCOF) of the walkway conditions were determined in a mechanical slip resistant test. Signifkant correlations were found with the DCOF for stance, swing and stride time. Significant increase in stance time, swing time and stride time, decrease in stride length and heel velocity at contact, and slower mean propagation speed were found when slippery potential increased. Further study is suggested to provide a more comprehensive explanation of human adaptation to slippery walking surface which helps proposing occupational safety in worksit

BIOMECHANICS ANALYSIS OF ANKLE SUPINATION SPRAIN INJURY

One male athlete accidentally sprained his ankle with a supination mechanism while performing a series of cutting motion trials in a laboratory. The injury was immediately diagnosed as a grade one mild anterior talofibular ligamentous sprain, and was simultaneously recorded by three calibrated cameras and a pressure insole system at 100 Hz. For the injury trial, results showed that the foot and ankle was more internally rotated and greatly inverted at foot strike, followed by a fast plantarflexion and shift of center of pressure to forefoot. The rearfoot was lifted and swung to the lateral aspect, thus increasing the moment arm and the ankle joint torque. The ankle joint finally reached an orientation of 66 degrees dorsiflexion, 48 degrees internal rotation and 103 degrees inversion

A PILOT STUDY ON COMPARISON OF CUSHIONING ABILITY OF CLOTH SPORT SHOE WITH OTHER ATHLETIC FOOTWEAR

Previous studies assessed the cushioning ability of different athletic footwear including running shoes and court shoes. In recent years, concern about the protective function of cloth sport shoe, a kind of low-price and popular athletic footwear in the youth generation for sport activities, has become popular in Hong Kong and the People's Republic of China. However, the cushioning ability of cloth sport shoe was still left uninvestigated. The purpose of this study was to give a preliminary assessment on the cushioning performance of cloth sport shoe compared with other types of sport shoes

Translation to Bundle Operators

We give explicit formulas for conformally invariant operators with leading term an m-th power of Laplacian on the product of spheres with the natural pseudo-Riemannian product metric for all m

ESTIMATING COMPLETE GROUND REACTION FORCES AND ANKLE JOINT TORQUES FROM PRESSURE INSOLE DATA IN WALKING AND RUNNING

This study described a method to estimate complete ground reaction forces and ankle joint torques from only pressure insole sensor data. One subject performed 56 valid steps during heel-toe walking and running in canvas shoes at different speeds (0.85-4.00m/s). Motion data, ground reaction force data and plantar pressure data were simultaneously recorded. Six parameters of ground reaction forces and ankle joint torques were obtained, and were trimmed from touchdown to takeoff. Pressure values at each of the 99 sensors were used to predict these six parameters by linear stepwise regression. Prediction models with 80% or more explained variance were constructed. Estimated values were obtained from these models, and the prediction accuracy was reported. Comparison to a previously developed method was done

AN IN-SHOE ANKLE SUPINATION TORQUE MEASURING METHOD IN RUNNING

This study presented an in-shoe ankle supination torque measuring method in running. One subject performed 56 valid steps during heel-toe walking and running in canvas shoe at different speeds (0.85-4.00m/s). Motion data, ground reaction force data and plantar pressure data were simultaneously recorded. Ankle joint torques in dorsiflexion / plantarflexion and inversion / eversion directions were obtained, and were trimmed from touchdown to takeoff. Pressure values at each of the 99 sensors were used to predict these two parameters by linear stepwise regression. Prediction models with 80%, 85%, 90% and 95% explained variance were constructed. A 9-sensor system is suggested for further development of an in-shoe ankle supination torque measuring device

Networks of noisy oscillators with correlated degree and frequency dispersion

We investigate how correlations between the diversity of the connectivity of networks and the dynamics at their nodes affect the macroscopic behavior. In particular, we study the synchronization transition of coupled stochastic phase oscillators that represent the node dynamics. Crucially in our work, the variability in the number of connections of the nodes is correlated with the width of the frequency distribution of the oscillators. By numerical simulations on Erd\"os-R\'enyi networks, where the frequencies of the oscillators are Gaussian distributed, we make the counterintuitive observation that an increase in the strength of the correlation is accompanied by an increase in the critical coupling strength for the onset of synchronization. We further observe that the critical coupling can solely depend on the average number of connections or even completely lose its dependence on the network connectivity. Only beyond this state, a weighted mean-field approximation breaks down. If noise is present, the correlations have to be stronger to yield similar observations.Comment: 6 pages, 2 figure

Electrochemical capacitance of a leaky nano-capacitor

We report a detailed theoretical investigation on electrochemical capacitance of a nanoscale capacitor where there is a DC coupling between the two conductors. For this ``leaky'' quantum capacitor, we have derived general analytic expressions of the linear and second order nonlinear electrochemical capacitance within a first principles quantum theory in the discrete potential approximation. Linear and nonlinear capacitance coefficients are also derived in a self-consistent manner without the latter approximation and the self-consistent analysis is suitable for numerical calculations. At linear order, the full quantum formula improves the semiclassical analysis in the tunneling regime. At nonlinear order which has not been studied before for leaky capacitors, the nonlinear capacitance and nonlinear nonequilibrium charge show interesting behavior. Our theory allows the investigation of crossover of capacitance from a full quantum to classical regimes as the distance between the two conductors is changed

A Model Behind the Standard Model

In spite of its many successes, the Standard Model makes many empirical assumptions in the Higgs and fermion sectors for which a deeper theoretical basis is sought. Starting from the usual gauge symmetry $u(1) \times su(2) \times su(3)$ plus the 3 assumptions: (A) scalar fields as vielbeins in internal symmetry space \cite{framevec}, (B) the ``confinement picture'' of symmetry breaking \cite{tHooft,Banovici}, (C) generations as ``dual'' to colour \cite{genmixdsm}, we are led to a scheme which offers: (I) a geometrical significance to scalar fields, (II) a theoretical criterion on what scalar fields are to be introduced, (III) a partial explanation of why $su(2)$ appears broken while $su(3)$ confines, (IV) baryon-lepton number (B - L) conservation, (V) the standard electroweak structure, (VI) a 3-valued generation index for leptons and quarks, and (VII) a dynamical system with all the essential features of an earlier phenomenological model \cite{genmixdsm} which gave a good description of the known mass and mixing patterns of quarks and leptons including neutrino oscillations. There are other implications the consistency of which with experiment, however, has not yet been systematically explored. A possible outcome is a whole new branch of particle spectroscopy from $su(2)$ confinement, potentially as rich in details as that of hadrons from colour confinement, which will be accessible to experiment at high energy.Comment: 66 pages, added new material on phenomenology, and some new reference