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Rechargeable batteries, which are used for renewable energy storage, have paved the way for reducing the enormous pressure of the energy crisis and environmental pollution. Recently, promising electrode materials with high energy and power density and favorable electrochemical performance for energy conversion and storage have been developed to meet the ever-growing demand for renewable power for electric vehicles or grid applications. MXenes, which constitute an impressive two-dimensional transition metal carbide/carbonitride family, exhibit great energy storage potential based on their ideal specific surface area, excellent electrical conductivity, and superior chemical durability in batteries. The recent advances in MXenes and their composites for metal-sulfur batteries (specifically lithium-sulfur and sodium-sulfur batteries) and metal-air batteries (specifically lithium-air and zinc-air batteries) are comprehensively and systematically summarized in this review. Furthermore, the performance management strategies, next-stage research prospects, and remaining practical challenges for MXene-based materials in battery applications are discussed in detail. This review may provide some guidance for the development and application of MXene-based electrode materials in renewable electrochemical energy storage.

Altering plantar load using foot orthoses (FOs) may alter the mechanical work required of internal structures and change the size of muscle and connective tissues. Skin sensitivity might also change as a result of altering mechanoreceptor stimulation. This study investigated the effects of FOs on foot soft tissue morphology and skin sensitivity over three months of use. Forty-one healthy participants wore pre-fabricatedprefabricated FOs (n=23) or no insert (n=18) for three months. The FOs were prescribed specific to each participant, using criteria of a change in peak pressure of 8% in the medial arch (pressure increase) and medial heel (pressure decrease). Ultrasound images were recorded pre- and post-FOs use to derive cross-sectional area and thickness of: abductor hallucis, flexor hallucis brevis, flexor digitorum brevis and the Achilles tendon at the insertion and mid-portion. Plantar fascia thickness was measured at the insertion and midfoot. The minimal detectable difference was established in piloting (n=7). Skin sensitivity was measured with monofilaments at the dorsum (between the hallux and second toe), medial and lateral heel, medial and lateral arch and the 1st metatarsal head. The FOs increased peak pressure by 15% in the medial arch and reduced it by 21% in the medial heel. None of the changes in soft tissue measurements was greater than the minimal detectable difference and there were no effects of group and time. Skin sensitivity decreased over time at the 1st metatarsal head for both groups, but there was no group effect. Using FOs over three months did not change the foot tissues nor skin sensitivity. This study challenges the notion that FOs make muscles smaller.

In order to improve the diagnosis and classification effect of pituitary tumors, this paper combines the current common machine learning methods and classification prediction methods to improve the traditional machine learning algorithms. Moreover, this paper analyzes the feature algorithm based on the feature extraction requirements of pituitary tumor pictures and compares a variety of commonly used algorithms to select a classification algorithm suitable for the model of this paper through comparison methods. In addition, this paper carries out the calculation of the prediction algorithm and verifies the algorithm according to the actual situation. Finally, based on the neural network algorithm, this paper designs and constructs the algorithm function module and combines the actual needs of pituitary tumors to build the model and verify the performance of the model. The research results show that the model system constructed in this paper meets the expected demand.

Organic semiconductor materials are widely used in the field of organic electronic devices due to their wide variety, low price, and light weight. However, their developments are still restrained by their low stability and carrier mobility. Density functional theory (DFT) was used to study the influence of doped oxygen group elements (O, S, Se, and Te) on the properties of organic semiconductor materials (seven-membered benzothiophene, o-pentacene, thiophene derivatives, and pentacene) in this paper. Based on the calculation of EHOMO, ELUMO, ΔE, and total energy, the performances of organic semiconductor materials without and with doped elements were compared, and it was found that the doping of multi-element Te makes the material have high stability and potential high mobility. For these studied organic semiconductor materials, when the atoms of the doped site change in the order of O, S, Se, and Te, the carrier mobility gradually increases, and the molecules show a tendency of stability. In this paper, promising doping elements and doping methods for these studied molecules are determined through calculations and screening out suitable materials more efficiently and economically without a large amount of repetitive experimental work, which may provide a theoretical basis and guidance for preparing high-performance organic semiconductor materials.

In the family of inorganic perovskite solar cells (PSCs), CsPbBr3 has attracted widespread attention due to its excellent stability under high humidity and high temperature conditions. However, power conversion efficiency (PCE) improvement of CsPbBr3-based PSCs is markedly limited by the large optical absorption loss coming from the wide band gap and serious charge recombination at interfaces and/or within the perovskite film. In this work, using density functional theory calculations, we systemically studied the electronic properties of niobium (Nb)-doped CsPbBr3 with different concentration ratios. As a result, it is found that doped CsPbBr3 compounds are metallic at high Nb doping concentration but semiconducting at low Nb doping concentration. The calculated electronic density of states shows that the conduction band is predominantly constructed of doped Nb. These characteristics make them very suitable for solar cell and energy storage applications.

The presence of organic pollutants in the world is harmful to our existence and the environment. So efficient and energy-saving methods for the degradation of organic pollutants present in the environment are important and beneficial for humans and the environment. The use of emerging photocatalytic technology using semiconductor materials to degrade organic pollutants is an effective method with potential prospects for the future. In this work, quantum chemical calculations and classical molecular dynamics simulations are employed to investigate the performances and related reactivities of sulfide semiconductor materials for the photocatalytic degradation of several common organic compounds. The reactivity of the organics is studied using quantum chemical calculations. The adsorption behaviors of several types of organic compounds on the surfaces of sulfide semiconductors in the gas phase were investigated, then similar adsorption processes in the aqueous phase were studied, and then CdS semiconductors were used to explore the influence of different crystal planes on the adsorption behavior of organic matter. Based on adsorption energy calculations, the best adsorption performance for a specific type of organic matter on a sulfide semiconductor was explored, together with an adsorption comparison in the gas and water phases. The results of this study may provide theoretical guidance for sulfide semiconductor photocatalysis technology and give ideas for subsequent experiments.

Lead halide perovskite has in recent years gained widespread interest due to its excellent physical and chemical properties, as well as superior optoelectronic performance. However, some restrictio...

Foot orthoses (FOs) are used to treat clinical conditions by altering the external forces applied to the foot and thereafter the forces of muscles and tendons. However, whether specific geometric design features of FOs affect muscle activation is unknown. The aim of this study was to investigate if medial heel wedging and increased medial arch height have different effects on the electromyography (EMG) amplitude of tibialis posterior, other muscles of the lower limb and the kinematics and kinetics at the rearfoot and ankle. Healthy participants (n = 19) walked in standardised shoes with i) a flat inlay; ii) a standard shape FOs, iii) standard FOs adjusted to incorporate a 6 mm increase in arch height, iv) and standard FOs adjusted to incorporate an 8° medial heel wedging and v) both the 6 mm increase in arch height and 8° increase in medial wedging. EMG was recorded from medial gastrocnemius, peroneus longus, tibialis anterior and in-dwelling tibialis posterior muscles. Motion and ground reaction force data were collected concurrently. Tibialis posterior EMG amplitude reduced in early stance with all FOs (ηp = 0.23-1.16). Tibialis posterior EMG amplitude and external ankle eversion moment significantly reduced with FOs incorporating medial wedging. The concurrent reduction in external eversion moment and peak TP EMG amplitude in early stance with medial heel wedging demonstrates the potential for this specific FOs geometric feature to alter TP activation. Medial wedged FOs could facilitate tendon healing in tibialis posterior tendon dysfunction by reducing force going through the TP muscle tendon unit. [Abstract copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.]

Objective: Stand-to-sit task is an important daily function, but there is a lack of research evidence on whether knee osteoarthritis (knee OA) affects the postural balance during the task. This study aimed to compare individuals with knee OA and asymptomatic controls in postural balance and identify kinematic and lower extremity muscle activity characteristics in individuals with knee OA during the stand-to-sit task.Methods: In total, 30 individuals with knee OA and 30 age-matched asymptomatic controls performed the 30-s Chair Stand Test (30sCST) at self-selected speeds. Motion analysis data and surface electromyography (sEMG) were collected while participants performed the 30sCST. To quantify postural balance, the displacement of the center of mass (CoM) and the peak instantaneous velocity of the CoM were calculated. The kinematic data included forward lean angles of the trunk and pelvic, range of motion (RoM) of the hip, knee, and ankle joints in the sagittal plane. The averaged activation levels of gluteus maximus, vastus lateralis, vastus medialis, rectus femoris, biceps femoris (BF), tibialis anterior (TA), and medial head of gastrocnemius muscles were indicated by the normalized root mean square amplitudes.Results: Compared with the asymptomatic control group, the knee OA group prolonged the duration of the stand-to-sit task, demonstrated significantly larger CoM displacement and peak instantaneous CoM velocity in the anterior-posterior direction, reduced ankle dorsiflexion RoM, greater anterior pelvic tilt RoM, and lower quadriceps femoris and muscles activation level coupled with higher BF muscle activation level during the stand-to-sit task.Conclusion: This study indicates that individuals with knee OA adopt greater pelvic forward lean RoM and higher BF muscle activation level during the stand-to-sit task. However, these individuals exist greater CoM excursion in the anterior-posterior direction and take more time to complete the task. This daily functional activity should be added to the rehabilitation goals for individuals with knee OA. The knee OA group performs reduced ankle dorsiflexion RoM, quadriceps femoris, and TA activation deficit. In the future, the rehabilitation programs targeting these impairments could be beneficial for restoring the functional transfer in individuals with knee OA.

Objectives:\ud Beside pathophysiological factors, pain is believed to play a crucial role in the progression of patellofemoral pain (PFP). However, the isolated effect of pain on biomechanics and quadriceps function has not been investigated in PFP. Thus, this study aimed to investigate the effect of pain on quadriceps function and lower limb biomechanics in individuals with PFP.\ud Methods:\ud Twenty-one individuals with PFP (11 males and 10 females, age: 29.76 ±6.36 years, height: 1.74 ± 0.09m, mass: 70.12 ±8.56kg) were measured at two different occasions: when not and when experiencing acute pain. Peak quadriceps torque (concentric, eccentric and isometric) and arthrogenic muscle inhibition (AMI) was assessed. Three-dimensional motion analysis and surface electromyography of the quadriceps and hamstrings muscles were collected during running, a single-leg-squat and step-down task. The normality was assessed using the Shapiro-Wilk test and a MANOVA was performed at the 95% confidence interval. \ud Results:\ud AMI increased significantly in acute pain. The net muscle activation of the knee extensors and flexors decreased during running in acute pain. The lower limb biomechanics and the quadriceps torque did not change in acute pain. \ud Discussion:\ud It appears that even if individuals with PFP experience pain they can still deliver maximal quadriceps contractions and maintain their moving patterns without biomechanical changes. However, the overall reduced activation of the quadriceps and the increased AMI indicate the presence of quadriceps inhibition in acute pain. \ud Key words: patellofemoral pain, knee, PFP, AKP, inhibition, quadriceps, strength, pain

The high cost of hole transporting materials (HTMs) and noble metal electrodes limits the application of perovskite solar cells (PSCs). Carbon materials have been commonly utilized for HTMs and noble-metal-free PSCs. In this paper, a more conductive 2D MXene material (Ti3C2), showing a similar energy level to carbon materials, has been used as a back electrode in HTMs and noble-metal-free PSCs for the first time. Seamless interfacial contact between the perovskite layer and Ti3C2 material was obtained using a simple hot-pressing method. After the adjustment of key parameters, the PSCs based on the Ti3C2 electrode show more stability and higher power conversion efficiencies (PCE) (13.83%, 27% higher than that (10.87%) of the PSCs based on carbon electrodes) due to the higher conductivity and seamless interfacial contact of the MXene electrode. Our work proposes a promising future application for MXene and also a good electrode candidate for HTM and the noble-metal-free PSCs.

Objective\ud \ud Trials testing promising interventions in knee osteoarthritis (OA) often fail to show pain reductions. This may be due to change in activity whereby a person’s pain decreases, leading them to increase their activity levels, in turn increasing pain back to baseline levels. Using data from a trial of a beneficial treatment for knee pain, we explored whether activity changes might mask a treatment’s effect on pain, by looking at whether activity levels increased with effective treatment and whether change in activity level related to change in pain.\ud \ud Design\ud \ud During the InRespond trial (ISRCTN55059760) participants wore an accelerometer for 7 days before and during treatments. We assessed change in pain on treatment using scores for overall knee pain and pain in a nominated pain-aggravating activity both in the last week and evaluated change in different types of activity using accelerometer data. Principal components analysis tested whether change in activity and pain outcomes were correlated and created composites combining them. We then tested whether activity, pain or the composites showed a treatment effect, and examined their responsiveness.\ud \ud Results\ud \ud In the 61 participants (mean age 64.5 years, 38% women, mean overall knee pain score 5.08 (0-10)), activity levels mostly decreased during the trial. Principal component analyses suggested that pain and activity did not correlate highly, loading on different components. Treatment that showed significant effects on pain did not show similar effects on either activity (e.g. the active treatment had a slightly greater reduction in total steps taken than the control treatment (difference 1942.6 steps/week, p =.42) nor on composites combining activity and pain. Pain outcomes were the most responsive; static loading (standing) outcomes were the most responsive activity outcome.\ud \ud Conclusion\ud We found no evidence to support the hypothesis that activity levels increase during effective OA treatment and might account for the negligible pain effects of OA treatments.

IntroductionStair ascent and descent require complex integration between sensory and motor systems; individuals with knee osteoarthritis (KOA) have an elevated risk for falls and fall injuries, which may be in part due to poor dynamic postural control during locomotion. Tai chi exercise has been shown to reduce fall risks in the ageing population and is recommended as one of the non-pharmocological therapies for people with KOA. However, neuromuscular mechanisms underlying the benefits of tai chi for persons with KOA are not clearly understood. Postural control deficits in performing a primary motor task may be more pronounced when required to simultaneously attend to a cognitive task. This single-blind, parallel design randomised controlled trial (RCT) aims to evaluate the effects of a 12-week tai chi programme versus balance and postural control training on neuromechanical characteristics during dual-task stair negotiation.Methods and analysisSixty-six participants with KOA will be randomised into either tai chi or balance and postural control training, each at 60 min per session, twice weekly for 12 weeks. Assessed at baseline and 12 weeks (ie, postintervention), the primary outcomes are attention cost and dynamic postural stability during dual-task stair negotiation. Secondary outcomes include balance and proprioception, foot clearances, self-reported symptoms and function. A telephone follow-up to assess symptoms and function will be conducted at 20 weeks. The findings will help determine whether tai chi is beneficial on dynamic stability and in reducing fall risks in older adults with KOA patients in community.Ethics and disseminationEthics approval was obtained from the Ethics Committee of the Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine (#2018KY-006–1). Study findings will be disseminated through presentations at scientific conferences or publications in peer-reviewed journals.Trial registration numberChiCTR1800018028.

Environmental catalysts and sensors have gained great attention due to their important roles in sensing and understanding the environment as well as pollution abatement and prevention. Power supply to run the environmental sensors, drive environmental catalysis, and store energy harvested from the environment bring opportunities for rechargeable batteries for environmental applications. Li-ion (Li–S) batteries and Na-ion (Na–S) batteries have clear fundamental advantages based on their energy density, cycle life, and efficiency in renewable energy storage. However, continued researches are urgently needed relating to the investigation of new electrodes with lower cost, high energy density, high-power density, as well as excellent life cycle and safety for their large-scale commercial applications. Therefore enormous efforts have been made to explore nanomaterials for Li-ion (Li–S) and Na-ion (Na–S) batteries to realize the requirements of large-scale commercial applications. Benefitting from the investigations of nanomaterials for Li-ion (Li–S) and Na-ion (Na–S) batteries, their energy density, power density, as well as life cycle and safety were significantly enhanced with lower costs.

// Kaishu Li 1, 2, 5, * , Leping Ouyang 1, * , Mingliang He 1, 2, * , Ming Luo 2, 3 , Wangqing Cai 1 , Yalin Tu 4 , Rongbiao Pi 4 , Anmin Liu 1, 2 1 Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, PR China 2 Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou 510120, PR China 3 Department of Oncology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, PR China 4 Department of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510080, PR China 5 Department of Neurosurgery, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan 511500, PR China * These authors have contributed equally to this work Correspondence to: Anmin Liu, email: liuanmin@mail.sysu.edu.cn Ming Luo, email: luoming2@mail.sysu.edu.cn Keywords: IDH1, Nrf2, NQO1, temozolomide, chemotherapy Received: October 12, 2016 Accepted: February 13, 2017 Published: March 03, 2017 ABSTRACT Purpose: Numerous studies have reported that glioma patients with isocitrate dehydrogenase 1(IDH1) R132H mutation are sensitive to temozolomide treatment. However, the mechanism of IDH1 mutations on the chemosensitivity of glioma remains unclear. In this study, we investigated the role and the potential mechanism of Nrf2 in IDH1 R132H-mediated drug resistance. Methods: Wild type IDH1 (R132H-WT) and mutant IDH1 (R132H) plasmids were constructed. Stable U87 cells and U251 cells overexpressing IDH1 were generated. Phenotypic differences between IDH1-WT and IDH1 R132H overexpressing cells were evaluated using MTT, cell colony formation assay, scratch test assay and flow cytometry. Expression of IDH1 and its associated targets, nuclear factor-erythroid 2-related factor 2 (Nrf2), NAD(P)H quinine oxidoreductase 1 (NQO1), multidrug resistant protein 1 (MRP1) and p53 were analyzed. Results: The IDH1 R132H overexpressing cells were more sensitive to temozolomide than WT and the control, and Nrf2 was significantly decreased in IDH1 R132H overexpressing cells. We found that knocking down Nrf2 could decrease resistance to temozolomide. The nuclear translocation of Nrf2 in IDH1 R132H overexpressing cells was lower than the WT and the control groups after temozolomide treatment. When compared with WT cells, NQO1 expression was reduced in IDH1 R132H cells, especially after temozolomide treatment. P53 was involved in the resistance mechanism of temozolomide mediated by Nrf2 and NQO1. Conclusions: Nrf2 played an important role in IDH1 R132H-mediated drug resistance. The present study provides new insight for glioma chemotherapy with temozolomide.

Visual signal (i.e., images and videos) coding is to compress digital visual data to be as small in size as possible in order to make use of limited bandwidth of networks and cater for compact storage, by exploring various data redundancy. It exploits the redundancy in signal itself (statistical redundancy, i.e., spatial-temporal redundancy and spectral/color redundancy). Since the human visual system (HVS) is the ultimate receiver and appreciator of most processed visual signal, we should also consider the redundancy due to the human vision properties (i.e., perceptual/psycho-visual redundancy) in the course of coding. The effectiveness of image and video coding methods is traditionally evaluated with their rate-distortion (RD) performance where rate is the number of bits required for the compressed visual signal (or its variants such as bits per pixel (bpp) and bits per second) and distortion is usually measured as peak signal to noise ratio (PSNR). However, it has been found that PSNR is not always in accordance with the human judgment and therefore the measurement for perceptual distortion is an active research area. Firstly, in this work, we discuss the statistical redundancy of video and then propose a novel optimal compression plane (OCP) based video coding scheme. In the sense of data structure, video is nothing more than a three dimensional data matrix, and the distinction among X (a spatial dimension), Y (the other spatial dimension), and T (the temporal dimension) is not absolutely necessary. We ignore the physical meaning of X, Y, and T axes for a video during the video coding process; frames are allowed to be formed in the TX (or TY) plane rather than the traditional XY plane to exploit the redundancy more effectively, and therefore better coder performance is achieved. Secondly, the model reflecting the masking characteristics of the HVS is studied as it is fundamental for perceptual redundancy exploring and visual distortion (quality) measurement. Just noticeable difference (JND) accounts for various masking effects of the HVS. We improve the pixel domain JND model by better contrast masking (CM) evaluation and appropriately accounting for the difference of CM for textural and edge regions. We also investigate into the application of the perceptual models (i.e., visual attention model and JND model) in the context of adaptive sampling based low-bit-rate image coding and JND based histogram adjustment for visually lossless image coding. Lastly, an effective and efficient metric of visual quality/distortion evaluation is proposed. The metric is based on the similarity between the gradient profiles of the reference and distorted signals which accounts for both the high level premise of the HVS (i.e., high sensitivity to image edges and structure) and the masking property. This new metric is with simple calculation and high accuracy (verified with extensive cross-database tests); it is robust to various distortion types and can be easily embedded in coding systems (as well as other visual signal processing algorithms). DOCTOR OF PHILOSOPHY (SCE)

Background:\ud External devices are used to manage musculoskeletal pathologies by altering loading of the foot, which could result in altered muscle activity that could have therapeutic benefits.\ud \ud Objectives:\ud To establish if evidence exists that footwear, foot orthoses and taping alter lower limb muscle activity during walking and running.\ud \ud Study design:\ud Systematic literature review.\ud \ud Methods:\ud CINAHL, MEDLINE, ScienceDirect, SPORTDiscus and Web of Science databases were searched. Quality assessment was performed using guidelines for assessing healthcare interventions and electromyography methodology.\ud \ud Results:\ud Thirty-one studies were included: 22 related to footwear, eight foot orthoses and one taping. In walking, (1) rocker footwear apparently decreases tibialis anterior activity and increases triceps surae activity, (2) orthoses could decrease activity of tibialis posterior and increase activity of peroneus longus and (3) other footwear and taping effects are unclear.\ud \ud Conclusion:\ud Modifications in shoe or orthosis design in the sagittal or frontal plane can alter activation in walking of muscles acting primarily in these planes. Adequately powered research with kinematic and kinetic data is needed to explain the presence/absence of changes in muscle activation with external devices.\ud \ud Clinical relevance:\ud This review provides some evidence that foot orthoses can reduce tibialis posterior activity, potentially benefitting specific musculoskeletal pathologies.

© 2019, American College of Rheumatology Objective: Lateral wedge shoe insoles decrease medial knee loading, but trials have shown no effect on pain in medial knee osteoarthritis (OA). However, loading effects of insoles are inconsistent, and they can increase patellofemoral loading. We undertook this study to investigate the hypothesis that insoles would reduce pain in preselected patients. Methods: Among patients with painful medial knee OA, we excluded those with patellofemoral OA and those with a pain rating of

The conjugate bridge plays an important role in the D–π–A sensitizers, which affects the optical properties, energy levels and electron transfer from donor to acceptor unit. The transfer and securing abilities of conjugate bridge is a necessary conditions to raise the red-shift absorption band, light harvesting ability. In this paper, the effect of conjugate bridge in the D–π–A sensitizers, such as benzene, thiophene, bithiophene, 4-(thiophen-2-yl)benzo[c] [1,2,5]thiadiazole, 4-(thiophen-2-yl)benzo[c] [1,2,5]thiadiazole, terthiophene and so on, which were studied to predict the photoelectric properties of molecules. The ground-state structure and excited-state properties of the dyes and dyes/TiO2 were calculated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The short circuit density (J sc), open-circuit voltage (V oc), fill factor (FF), and photo-to-electric conversion efficiency (η) are critical factors for dye-sensitized solar cells (DSSCs). Then, this method not only considered the relationship between macroscopic phenomena and macroscopic properties but also reasonably selected the dye molecules suitable for dye batteries.

The decent power conversion efficiency (~20%), ultra-low cost, and 1-year stability make carbon-based perovskite solar cells (C-PSCs) one of the most promising candidates for commercialization in the field of perovskite photovoltaics. However, the stability of C-PSCs still lags behind that of the commercialized silicon and thin-film photovoltaics. Although there have been many reviews of the long-term stability of perovskite solar cells (PSCs), none has specifically focused on the long-term stability of C-PSCs. Herein, we summarize the environmental risks and strategies for ensuring the long-term stability of C-PSCs, highlighting also the various contributions of our research group. The most important factors affecting long-term stability are analyzed according to the environmental risks (i.e. moisture, oxygen, light, and thermal stress) of device degradation. The proposed strategies chiefly center around improving the intrinsic stability and strengthening encapsulation. In our conclusions, we also present an outlook on future work concerning stability improvement and commercial development of C-PSCs. Our work provides a clear guideline for future research on C-PSCs.

Background: Knee valgus braces are used to reduce knee load and varus deformities in individuals with medial compartment osteoarthritis (OA). The purpose of this study was to determine whether the kinematics and kinetics of the knee are improved when wearing a knee-ankle-foot orthosis (KAFO) compared with knee valgus braces while walking and stair climbing. Materials and Methods: One male individual (with 10° of knee varus) was assessed with a control shoe, custom, and off-the-shelf (OTS) Unloader knee valgus braces, and a custom-made KAFO in situ during walking and stair climbing. Results: The KAFO significantly reduced the knee varus angle compared with the shoe and both knee valgus braces during walking and stair climbing, as well as the first peak of the external knee adduction moment (EKAM) during walking and the knee adduction angular impulse (KAAI) during ascending compared with the shoe. No significant differences were noted between the custom and OTS knee valgus braces in any measures. Conclusions: Knee-ankle-foot orthoses may be recommended for individuals with high knee varus angles.

Background: Abnormal biomechanics, especially hip internal rotation and adduction are known to be associated with patellofemoral pain (PFP). The PowersTM strap was designed to decrease hip internal rotation and to thereby stabilise the patellofemoral joint.\ud \ud Objectives: This study aimed to investigate whether the PowersTM strap influenced pain and lower limb biomechanics during running and squatting in individuals with PFP.\ud \ud Methods: 24 individuals with PFP were recruited using advertisements that were placed at fitness centres. They were asked to perform a single leg squat task (SLS) and to run on an indoor track at their own selected speed during two conditions: with and without the PowersTM strap. Immediate pain was assessed with the numeric pain rating scale. Three-dimensional motion and ground reaction force data were collected with 10 Qualisys cameras and 3 AMTI force plates.\ud \ud Results: Immediate pain was significantly reduced with the PowersTM strap (without the PowersTM strap: 4.04±1.91; with the PowersTM strap: 1.93±2.13). The PowersTM strap condition significantly increased hip external rotation by 4.7° during the stance phase in running and by 2.5° during the single leg squat task. Furthermore, the external knee adduction moment during the SLS and running increased significantly.\ud \ud Conclusion: This study assessed the effect of the PowersTM strap on lower limbs kinematics and kinetics in individual with PFP. The results suggest that the PowersTM strap has the potential to improve abnormal hip motion. Furthermore, the PowersTM strap demonstrated an ability to significantly reduce pain during functional tasks in patients with PFP.

The tumor microenvironment is partially characterized by a state of chronic inflammation, and radiologic features are related to the tumor's biological behavior. This study was conducted to explore whether peripheral blood inflammatory markers combined with radiologic features could predict proliferation potency.This study retrospectively reviewed 183 patients with a primary diagnosis of glioma. Clinical characteristics, preoperative peripheral full blood count data, and brain magnetic resonance imaging findings were reviewed to analyze the expression of inflammatory markers neutrophil lymphocyte ratio (NLR), monocyte lymphocyte ratio, and platelet lymphocyte ratio (PLR), as well as radiologic features such as location, peritumor edema, and contrast enhancement. Immunohistochemical staining was performed to determine the proliferation index (i.e., expression of Ki-67). Receiver operating characteristic curves for cutoff value, various bivariate tests, and binary logistic regression analyses were applied.Proliferation index was highly associated with tumor grade, showing a gradually increasing tendency. A Ki-67 cutoff value9% predicted high-grade glioma (HGG). Mean NLR and PLR were significantly higher in the HGG group compared with the low-grade glioma group (NLR: 3.11 ± 0.59 vs. 4.27 ± 1.13; PLR: 133.07 ± 13.17 vs. 161.51 ± 38.99; P0.01 for both). Contrast enhancement was more likely in the HGG group, but there was no significant between-group difference in peritumor edema. Logistic regression analysis identified the following risk factors for prediction of proliferation potency: age, Karnofsky Performance Score, NLR, PLR, and contrast enhancement. However, age43 years, NLR3.68, and positive contrast enhancement independently predicted a higher proliferation rate.NLR and contrast enhancement were positively correlated with the proliferation potency of gliomas.

A heat source model is the key issue for laser welding simulation. The Gaussian heat source model is not suitable to match the actual laser weld profile accurately. Furthermore, fiber lasers are widely recognized to result in good-quality laser beam output, a narrower weld zone, less distortion, and high process efficiency, compared with other types of lasers (such as CO2, Nd : YAG, and diode lasers). At present, there are few heat source models for fiber laser welding. Most of researchers evaluate the weld profile only by the bead width and depth of penetration, which is not suitable for the laser keyhole welding nail-like profile. This paper reports an experimental study and FEA simulation of fiber laser butt welding on 1 mm thick A304 stainless steel. A new heat source model (cylindrical and cylindrical) is established to match the actual weld profile using Marc and Fortran software. Four bead geometry parameters (penetration depth, bead width, waist width, and depth of the waist) are used to compare between the experimental and simulation results. The results show that the heat source model of cylindrical and cylindrical can match the actual shape of the fiber laser welding feasibly. The error range of the penetration depth, bead width, waist width, and depth of the waist between experimental and simulation results is about 4.1 ± 1.6%, 2.9 ± 2.0%, 13.6 ± 7.4/%, and 18.3 ± 8.0%, respectively. In addition, it is found that the depth of penetration is more sensitive to laser power rather than bead width, waist width, and depth of the waist. Welding speed has a similar influence on the depth of penetration, weld width, waist width, and depth of the waist.

Altering plantar load using a foot orthosis (FO) may alter the work required of internal structures. Intrinsic foot muscles can change size after loading of the foot is altered using footwear (John...

Image retargeting is to re-represent the image, usually with a different image size to cater for the display size of the end-user (e.g., computer, smartphone). In this paper, we propose an image retargeting quality assessment scheme based on four quality factors and support vector regression. The accounted quality factors are of two categorizes: 1) shape distortions, they are visual unpleasant artifacts introduced by retargeting, e.g., a straight line may be retargeted as a curve, a circle may be retargeted as an ellipse, etc.; 2) visual content changes, they mainly refer to the loss of visual information due to retargeting. Both spatial and frequency information are used toward a complete assessment. The spatial quality factors measure shape distortions and visual content changes separately and independently, and therefore it is possible to control their relative importance to the overall assessment. Since spatial quality factors need image matching which may cause measurement error, another quality factor in frequency domain is also used. The overall image retargeting quality is contributed by the four quality measures collectively and machine learning is used accounts for such a combination, corresponding discussions are also provided for each factor. The effectiveness of the proposed scheme is verified with the publicly-available subject-rated database (comprising of diverse images and retargeting methods) and better performance (in terms of both accuracy and complexity) is achieved in comparison with the state of the art schemes. Formulated major quality factors (in both spatial and frequency domains) into IRQA.Identified shape distortion and proposed a measure for it.Proposed frequency domain estimator to alleviate the measurement error in spatial domain.Used machine learning to integrate different quality factors.

Background The development of heart failure after acute myocardial infarction (MI) was related to left ventricular (LV) pathological remodeling and dysfunction. Cardiac stem cells (CSCs) provided a new option to treat acute MI. This study was to investigate the effects of CSCs on structural and functional alteration in acute MI. Methods Acute MI was induced in 20 Sprague-Dawley rats by ligation of the left anterior descending coronary artery. Two weeks after MI, animals were randomized into CSCs or control group. LV geometry and function were echocardiographically measured at baseline, 2, 4, and 6 weeks after MI. After measuring hemodynamics at 6 weeks after MI, hearts were harvested for tracing CSCs stained by PKH26 and testing expression of VEGF-α/TGF-β1 by RT-PCR and ELISA. Results Two weeks after MI, there were significant decreases in interventricular septal systolic and diastolic thickness (IVSTs/d), while increases in LV systolic and diastolic dimension (LVDs/d). Consequently, this contributed to decreases in ejection fraction (EF) and fractional shorting (FS). With the treatment of CSCs for 4 weeks, significant better ejection fraction (EF) and fractional shorting (FS) were achieved in CSCs group accompanied by the reduction in LV systole and diastole dimension (LVDs/d). Besides, a significant improvement in the maximal rate of LV pressure development and decline (peak +dP/dt and -dP/dt, respectively) was observed. Moreover, significantly higher VEGF-α was expressed in CSCs group rather than TGF-β1. Conclusion CSCs significantly prevented structural and functional deterioration after MI with increasing expression of VEGF-α.

Oxidative stress and blood-brain barrier (BBB) disruption play important roles in cerebral ischemic pathogenesis and may represent targets for treatment. Earlier studies have shown that osthole, a main active constituent isolated from Cnidium monnieri (L.) Cusson, could be considered as an attractive therapeutic agent in the treatment of ischemic stroke. However, the mechanism underlying the protective effect remains vague. In this study we aimed to investigate the effect of osthole on transient cerebral ischemia as well as its mechanism(s) in C57 BL/6 J mice. Mice were subjected to transient global cerebral ischemia induced by bilateral common carotid artery occlusion for 25 min. Behavioral test was performed at 4 days after ischemia, followed by assessment of neuronal loss in hippocampal CA1 region. Osthole significantly improved the cognitive ability and enhanced the survival of pyramidal neurons in the CA1 region of mice after lesion. Further studies showed that osthole attenuated the permeation of BBB, which may contribute to antioxidative effect by increasing the superoxide dismutase activity and decreasing the malondialdehyde level in model mice. Further studies revealed that osthole obviously up-regulated the protein levels of nuclear factor erythroid 2-related factor 2/heme oxygenase 1 in HT22 cells. In conclusion, our findings indicated that osthole exerts neuroprotective effects against global cerebral ischemia injury by reducing oxidative stress injury and reserving the disruption of BBB, which may be attributed to elevating the protein levels of Nrf2 and HO-1.

Bracing and patellar taping are common interventions for patellofemoral pain (PFP), reducing pain by 56% to 80%. It has been proposed that these effects may be due to altered lower-limb biomechanics. To date, there have been no comparative investigations into the effect of patellofemoral taping and patellofemoral bracing on knee mechanics during ambulation to determine whether they both have a mechanical application. This article aimed to address this gap in the literature. Three-dimensional movement analysis was performed on 12 healthy subjects during walking under three randomized experimental conditions: control (no intervention), patellofemoral bracing (Bioskin™ Q-Brace), and patellofemoral taping. Compared with patellofemoral taping or control conditions, the patellofemoral brace significantly increased knee flexion at heelstrike (p < 0.001) and loading response (p = 0.002). There were also significant changes in the knee valgus angle during heelstrike (p = 0.004) and loading response (p = 0.047.) A significant increase in knee flexor moment throughout the stance phase was also observed comparing patellofemoral bracing with control (p < 0.05) and patellofemoral taping (p < 0.05). Patellofemoral bracing and patellofemoral taping have been reported to be beneficial for treatment of PFP, but this effect may be due to more than solely altered knee mechanics because these results indicate that only patellofemoral bracing altered knee biomechanics in certain parts of the gait cycle. The patellofemoral brace does seem to influence biomechanical results more than the patellar tape does and may therefore have value in treating the biomechanical consequences of PFP.

In this paper, we introduce a new environmentally friendly silver electroplating bath, employing 5,5-dimethylhydantoin (DMH) and nicotinic acid (NA) as complexing agents, based on the prediction of computational chemistry. An excellent silver electrodeposit with properties suitable for application in electronics packaging was obtained from the newly developed silver electroplating bath, and the electroplating bath is simple and stable. Moreover, the silver(I)-complexes in this bath possessed good complex stability. As a consequence, mirror-bright silver electrodeposits on copper substrates with excellent leveling capability, smooth and compact morphologies, high purity and conductivity, as well as excellent welding property could be realized by adopting this unique bath. Based on the performances of the plating bath and silver deposit, the introduced silver plating bath is a promising candidate for silver electrodeposition applied in microelectronics to replace the conventional cyanide silver electroplating baths.

Aim To investigate the effect of rollover footwear on walking speed, metabolic cost of gait, lower limb kinematics, kinetics, EMG muscle activity and plantar pressure. Methods Twenty subjects (mean age-33.1 years, height-1.71 m, body mass-68.9 kg, BMI 23.6, 12 male) walked in: a flat control footwear; a flat control footwear weighted to match the mass of a rollover shoe; a rollover shoe; MBT footwear. Data relating to metabolic energy and temporal aspects of gait were collected during 6 min of continuous walking, all other data in a gait laboratory. Results The rollover footwear moved the contact point under the shoe anteriorly during early stance, increasing midfoot pressures. This changed internal ankle dorsiflexion moments to plantarflexion moments earlier, reducing ankle plantarflexion and tibialis anterior activity after initial contact, and increasing calf EMG activity. In mid stance the rollover footwear resulted in a more dorsiflexed ankle position but less ankle movement. During propulsion, the rollover footwear reduced peak ankle dorsiflexion, peak internal plantarflexor ankle moments and the range of ankle plantarflexion. Vertical ground reaction loading rates were increased by the rollover footwear. There were no effects on temporal or energy cost of gait and no effect of elevated shoe weight. Conclusion Investigating all proposed effects of this footwear concurrently has enabled a more valid investigation of how the footwear effects are interrelated. There were concurrent changes in several aspects of lower limb function, with greatest effects at the foot and ankle, but no change in the metabolic cost of walking.

To assist balance and mobility, older adults are often prescribed walking aids. Nevertheless, surprisingly their use has been associated with increased falls-risk. To address this finding we first need to characterise a person's stability while using a walking aid. Therefore, we present a generalisable method for the assessment of stability of walking frame (WF) users. Our method, for the first time, considers user and device as a combined system. We define the combined centre of pressure (CoPsystem) of user and WF to be the point through which the resultant ground reaction force for all feet of both the WF and user acts if theresultant moment acts only around an axisperpendicular tothe ground plane. We also define the combined base of support (BoSsystem) to be the convex polygon formed by the boundaries of the anatomical and WF feet in contact with the ground and interconnecting lines between them. To measure these parameters we have developed an instrumented WF with a load cell in each foot which we use together with pressure-sensing insoles and a camera system, the latter providing the relative position of the WF and anatomical feet. Software uses the resulting data to calculate the stability margin of the combined system, defined as the distance between CoPsystem and the nearest edge of BoSsystem. Our software also calculates the weight supported through the frame and when each foot (of user and/or frame) is on the floor. Finally, we present experimental work demonstrating the value of our approach.

Abnormal biomechanics, especially dynamic knee valgus, a combination of femoral adduction, femoral internal rotation, external knee rotation, tibial abduction, and ankle eversion is known to be associated with patellofemoral pain (PFP). To stabilise the patellofemoral joint during leisure and sporting activities by increasing the hip external rotation and hip abduction, researchers in the USA invented the Powers™ strap.

In this paper, we introduce a novel just noticeable difference (JND) estimation model based on the unified brain theory, namely the free-energy principle. The existing pixel-based JND models mainly consider the orderly factors and always underestimate the JND threshold of the disorderly region. Recent research indicates that the human visual system (HVS) actively predicts the orderly information and avoids the residual disorderly uncertainty for image perception and understanding. Thus, we suggest that there exists disorderly concealment effect which results in high JND threshold of the disorderly region. Beginning with the Bayesian inference, we deduce an autoregressive model to imitate the active prediction of the HVS. Then, we estimate the disorderly concealment effect for the novel JND model. Experimental results confirm that the proposed JND model outperforms the relevant existing ones. Furthermore, we apply the proposed JND model in image compression, and around 15% of bit rate can be reduced without jeopardizing the perceptual quality.

Reduced-reference (RR) image quality assessment (IQA) aims to use less data about the reference image and achieve higher evaluation accuracy. Recent research on brain theory suggests that the human visual system (HVS) actively predicts the primary visual information and tries to avoid the residual uncertainty for image perception and understanding. Therefore, the perceptual quality relies to the information fidelities of the primary visual information and the residual uncertainty. In this paper, we propose a novel RR IQA index based on visual information fidelity. We advocate that distortions on the primary visual information mainly disturb image understanding, and distortions on the residual uncertainty mainly change the comfort of perception. We separately compute the quantities of the primary visual information and the residual uncertainty of an image. Then the fidelities of the two types of information are separately evaluated for quality assessment. Experimental results demonstrate that the proposed index uses few data (30 bits) and achieves high consistency with human perception.

Sitting cross-legged as an activity of daily living and its kinematics have significantly different demands on the arthroplasty of hip and knee, which can be referred in the design of joint arthroplasty.The purpose of this study was to obtain the kinematics of the lower limb in Chinese people during cross-legged sitting.This study identified the necessary requirements for joint arthroplasty to carry out sitting cross-legged activity.A total of 40 healthy Chinese participants (average age = 23.8 years) performed six cross-legged sitting trials per person. Three-dimensional kinematic data of ankle, knee, and hip joints were collected; the means of the three-dimensional angles of these three joints were calculated.At the hip, the range of motion of the flexion was 101.7°, the abduction reached 43.2°, and the range of motion of the external rotation was 36.4°. At the knee, the range of motion of the flexion was 131.9° and the range of motion of the internal rotation reached 32.4°. At the ankle, the range of motion in three planes was not great.Such motion ranges were likely to result in prosthetic dislocation. The results would provide valuable references for prosthesis design in the Chinese population.

Lateral wedged insoles are a common treatment in individuals with medial tibiofemoral osteoarthritis of the knee joint. One concern has been the potential for increased foot and ankle pain due to increased eversion. The purpose of this study was to assess the biomechanical effectiveness of a typical lateral wedged insole and a combined insole with a lateral wedge and off-the-shelf anti-pronatory device in shoes while walking. A cross-over randomized design was used where each insole was worn by fifteen healthy subjects while three-dimensional motion data were collected in three different conditions: (1) control condition (with standard shoes), (2) with an insole with a lateral wedge and additional off-the-shelf anti-pronatory support (supporting), and (3) with an insole with a lateral wedge with no additional support (unsupported) in the standard shoes. The unsupported insole significantly increased the amount of ankle/subtalar joint complex eversion than the other experimental conditions, with the supporting insole reducing the ankle/subtalar joint complex eversion, and was found to be more comfortable. Both the supporting and unsupported lateral wedged insoles significantly reduced knee loading (external knee adduction moment reduction 8.5% and 9.1%, respectively), the knee adduction angular impulse. This new design of lateral wedge may offer increased adherence in future osteoarthritis population studies while offering reductions in joint loading.

Modifications in shoe outer soles are frequently made with the intention of altering biomechanics of the foot inside the shoe. These modifications are however, generally based upon intuition with l ...

Functional electrical stimulation has been shown to be a safe and effective means of correcting foot 12 drop of central neurological origin. Current surface-based devices typically consist of a single channel stimulator, 13 a sensor for determining gait phase and a cuff, within which is housed the anode and cathode. The cuff-mounted 14 electrode design reduces the likelihood of large errors in electrode placement, but the user is still fully responsible 15 for selecting the correct stimulation level each time the system is donned. Researchers have investigated different 16 approaches to automating aspects of setup and/or use, including recent promising work based on iterative learning 17 techniques. This paper reports on the design and clinical evaluation of an electrode array-based FES system for 18 the correction of drop foot, ShefStim. The paper reviews the design process from proof of concept lab-based study, 19 through modelling of the array geometry and interface layer to array search algorithm development. Finally, the 20 paper summarises two clinical studies involving patients with drop foot. The results suggest that the ShefStim 21 system with automated setup produces results which are comparable with clinician setup of conventional systems. 22 Further, the final study demonstrated that patients can use the system without clinical supervision. When used 23 unsupervised, setup time was 14 minutes (9 minutes for automated search plus 5 minutes for donning the 24 equipment), although this figure could be reduced significantly with relatively minor changes to the design.

OBJECTIVE Ventriculoperitoneal (VP) shunt treatment is the main treatment method for hydrocephalus. The traditional operative approach for peritoneal catheter insertion is mini-laparotomy. In recent years, laparoscopy-assisted insertion has become increasingly popular. It seems likely that use of an endoscope could lower the incidence of shunt malfunction. However, there is no consensus about the benefits of laparoscopy-assisted peritoneal catheter insertion. METHODS A systematic search was performed using the PubMed, Embase, ScienceDirect, and Cochrane Library databases. A manual search for reference lists was conducted. The protocol was prepared according to the interventional systematic reviews of the Cochrane Handbook, and the article was written on the basis of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. RESULTS Eleven observational trials and 2 randomized controlled trials were included. Seven operation-related outcome measures were analyzed, and 3 of these showed no difference between operative techniques. The results of the meta-analysis are as follows: in the laparoscopy group, the rate of distal shunt failure was lower (OR 0.41, 95% CI 0.25–0.67; p = 0.0003), the absolute effect is 7.11% for distal shunt failure, the number needed to treat is 14 (95% CI 8–23), operative time was shorter (mean difference [MD], −12.84; 95% CI −20.68 to −5.00; p = 0.001), and blood loss was less (MD −9.93, 95% CI −17.56 to −2.31; p = 0.01). In addition, a borderline statistically significant difference tending to laparoscopic technique was observed in terms of hospital stay (MD −1.77, 95% CI −3.67 to 0.13; p = 0.07). CONCLUSIONS To some extent, a laparoscopic insertion technique could yield a better prognosis, mainly because it is associated with a lower distal failure rate and shorter operative time, which would be clinically relevant.

Objective video quality assessment (VQA) is the use of computational models to evaluate the video quality in line with the perception of the human visual system (HVS). It is challenging due to the underlying complexity, and the relatively limited understanding of the HVS and its intricate mechanisms. There are three important issues that arise in objective VQA in comparison with image quality assessment: 1) the temporal factors apart from the spatial ones also need to be considered, 2) the contribution of each factor (spatial and temporal) and their interaction to the overall video quality need to be determined, and 3) the computational complexity of the resultant method. In this paper, we seek to tackle the first issue by utilizing the worst case pooling strategy and the variations of spatial quality along the temporal axis with proper analysis and justification. The second issue is addressed by the use of machine learning; we believe this to be more convincing since the relationship between the factors and the overall quality is derived via training with substantial ground truth (i.e., subjective scores). Experiments conducted using publicly available video databases show the effectiveness of the proposed full-reference (FR) algorithm in comparison to the relevant existing VQA schemes. Focus has also been placed on demonstrating the robustness of the proposed method to new and untrained data. To that end, cross-database tests have been carried out to provide a proper perspective of the performance of proposed scheme as compared to other VQA methods. The third issue regarding the computational costs also plays a key role in determining the feasibility of a VQA scheme for practical deployment given the large amount of data that needs to be processed/analyzed in real time. A limitation of many existing VQA algorithms is their higher computational complexity. In contrast, the proposed scheme is more efficient due to its low complexity without jeopardizing the predict- on accuracy.

In this paper, we propose a new image quality assessment (IQA) scheme, with emphasis on gradient similarity. Gradients convey important visual information and are crucial to scene understanding. Using such information, structural and contrast changes can be effectively captured. Therefore, we use the gradient similarity to measure the change in contrast and structure in images. Apart from the structural/contrast changes, image quality is also affected by luminance changes, which must be also accounted for complete and more robust IQA. Hence, the proposed scheme considers both luminance and contrast-structural changes to effectively assess image quality. Furthermore, the proposed scheme is designed to follow the masking effect and visibility threshold more closely, i.e., the case when both masked and masking signals are small is more effectively tackled by the proposed scheme. Finally, the effects of the changes in luminance and contrast-structure are integrated via an adaptive method to obtain the overall image quality score. Extensive experiments conducted with six publicly available subject-rated databases (comprising of diverse images and distortion types) have confirmed the effectiveness, robustness, and efficiency of the proposed scheme in comparison with the relevant state-of-the-art schemes.

In just noticeable difference (JND) models, evaluation of contrast masking (CM) is a crucial step. More specifically, CM due to edge masking (EM) and texture masking (TM) needs to be distinguished due to the entropy masking property of the human visual system. However, TM is not estimated accurately in the existing JND models since they fail to distinguish TM from EM. In this letter, we propose an enhanced pixel domain JND model with a new algorithm for CM estimation. In our model, total-variation based image decomposition is used to decompose an image into structural image (i.e., cartoon like, piecewise smooth regions with sharp edges) and textural image for estimation of EM and TM, respectively. Compared with the existing models, the proposed one shows its advantages brought by the better EM and TM estimation. It has been also applied to noise shaping and visual distortion gauge, and favorable results are demonstrated by experiments on different images.

Reliable computational foot models offer an alternative means to enhance knowledge on the biomechanics of human foot. Model validation is one of the most critical aspects of the entire foot modeling and analysis process. This paper presents an in vivo experiment combining motion capture system and plantar pressure measure platform to validate a three-dimensional finite element model of human foot. The Magnetic Resonance Imaging (MRI) slices for the foot modeling and the experimental data for validation were both collected from the same volunteer subject. The validated components included the comparison of static model predictions of plantar force, plantar pressure and foot surface deformation during six loading conditions, to equivalent measured data. During the whole experiment, foot surface deformation, plantar force and plantar pressure were recorded simultaneously during six different loaded standing conditions. The predictions of the current FE model were in good agreement with these experimental results.

The aim of this work was to use bone anchored external markers to describe the kinematics of the tibia, fibula, talus, calcaneus, navicular, cuboid, medial cuneiform, first and fifth metatarsals during gait. Data were collected from six subjects. There was motion at all the joints studied. Movement between the talus and the tibia showed the expected predominance of sagittal plane motion, but the talocalcaneal joint displayed greater variability than expected in its motion. Movement at the talonavicular joint was greater than at the talocalcaneal joint and motion between the medial cuneiform and navicular was far greater than expected. Motion between the first metatarsal and the medial cuneiform was less than motion between the fifth metatarsal and cuboid. Overall the data demonstrated the complexity of the foot and the importance of the joints distal to the rearfoot in its overall dynamic function.

Magnetic resonance (MR) imaging is becoming increasingly important in the study of foot biomechanics. Specific devices have been constructed to load and position the foot while the subject is lying supine in the scanner. The present study examines the efficacy of such a newly developed device in replicating tarsal kinematics seen during the more commonly studied standing loading conditions. The results showed that although knee flexion and the externally applied load were carefully controlled, subtalar and talo-navicular joint rotations while lying during MR imaging and when standing (measured opto-electrically with markers attached to intracortical pins) did not match, nor were they systematically shifted. Thus, the proposed MR protocol cannot replicate tarsal kinematics seen during upright standing. It is concluded that specific foot loading conditions have to be considered when tarsal kinematics are evaluated. Improved replication of tarsal kinematics in different postures should comprehensively consider muscle activity, a fixed hip position, and a well-defined point of load application.