Central Body Research Articles

Physiological complexity of body sway during dual-task gait in faller older adults

Background: The impact of simultaneous cognitive demand on gait’s physiological complexity in community-dwelling older adults with and without self-reported falls is yet unknown. Objective: To analyze whether the physiological complexity of body sway during dual-task and single gait is worse in once-only fallers than in non-faller older adults. Methods: A total of 58 community-dwelling older adults aged 60 to 80 participated in this study, of whom 21 had self-reported a single fall in the previous 12 months (fallers) and 37 matched participants with no fall self-reported (non-fallers). An inertial sensor (Physilog® 5, Gait Up, Switzerland) was used to acquire the time series of the body center of mass (CoM) sway in the anteroposterior (AP), mediolateral (ML) and vertical (V) directions during single gait (ST) and the gait under dual task (DT). The composite refined multiscale fuzzy entropy method was used to calculate the physiological complexity index (CI) in a MATLAB environment. SPSS (IBM; v.25.0) was used to analyze the effects of group (Fallers vs. Non-fallers), condition (ST vs. DT), and interaction (group vs. condition), using generalized linear mixed models, with an alpha of 5%. Results: No interaction or group effect was observed for the CI. However, when comparing DT with ST, a main effect of the condition was observed for the AP direction (F = 62.394; p < .001) with a reduction of 0.53 (95% CI: -0.66 to -0.39), ML (F = 4.724; p = .034) with an increase of 0.22 (95% CI: 0.17 to 0.42), and V (F = 6.457; p = .014) with a decrease of 0.17. Conclusion: Just one fall in the previous 12 months does not deleteriously influence the body’s physiological complexity during gait under concurrent cognitive demand (dual task). On the other hand, DT significantly affects the gait physiological complexity in community-dwelling older adults.

Coordinated referral and scheduling decisions for specialized healthcare services

This paper studies the coordination of referral and scheduling policies where access to specialized medical services, such as surgical procedures, imaging or other consultations, is managed through a centralized intake system. In this increasingly common mode of operation, a central body makes decisions regarding the allocation of patients between a set of providers, followed by the provider taking control of the scheduling and delivery of the required service. To study the coordination of the allocation and scheduling policies we present a sequential optimization model where both referrer and provider attempt to maximize the proportion of a heterogeneous set of patients receiving treatment within a targeted wait time. Motivated by observations of performance thresholds in queueing systems, we introduce an achievable region model which permits study of providers who vary in ability to coordinate scheduling different patient streams. We characterize optimal referral and scheduling policies for a range of demand patterns and operational abilities. We find that the optimal referral policy can result in large discrepancies in outcomes for different patient types but that the discrepancy in outcomes is muted when operational abilities are higher. In situations where operational abilities are low, it is optimal for the providers to prioritize patients by stream. Low capacity for both providers results in an optimal referral and scheduling policy where certain patients streams are deprioritized and with certainty will not be seen within their wait time targets. We also study the cost of enforcing parity between patient classes and find that the cost is reduced when providers have higher operational abilities. This paper illustrates how operational constraints lead to incentives to prioritize different patient streams. In particular, we show that when operations are challenging, a more hands-on design is required to ensure clinical intake systems maintain equitable access to the service.

A Practical Approach for Estimating Drag Increase due to Volume Increase in the Center Body of a High-Speed UAV

High-speed unmanned aerial vehicles are used for many purposes in aviation. High-speed aircraft do not only fly at supersonic speed, but their subsonic flight performance is also important. Aircraft design is an iterative process in which many disciplines work together. The design process is updated by the negotiation of different disciplines. There may be a demand for a body volume increase in the interior design process. The increase in volume can be achieved by the elongation or expansion of the body. A volume increase in the center body causes an increase in drag. The aim of this study is to predict the effect of the elongation or expansion of the center body on drag in a practical way. It is investigated using a structure proposed with MATLAB and DATCOM. The results in both subsonic and supersonic regimes are formalized separately and compared. It is shown that in case of providing the same volume increase in both subsonic and supersonic regimes, the elongation of the aircraft center body causes less drag compared to widening.

Alterations in Thyroid Hormones in Obese Patients are Associated with Body Composition Changes after Bariatric Surgery.

This study investigates how metabolic/bariatric surgery (MBS) affects thyroid hormone (TH) levels and TH resistance in obese euthyroid individuals, focusing on their correlation with changes in body composition. We included 470 obese individuals and 118 controls for baseline assessment, and 125 obese patients receiving MBS for longitudinal study. Data on body composition and thyroid function were collected. Correlations between baseline and changes in thyroid function and body composition were assessed. In the obese group, thyroid stimulating hormone (TSH), free triiodothyronine (fT3) levels, and thyroid feedback quantile-based index (TFQI) were elevated and significantly decreased post-MBS, along with visceral fat area (VFA) and body fat percentages, while skeletal muscle mass (SMM) percentage increased. Preoperative partial correlation analysis adjusted for age and sex revealed that TSH positively correlated with VFA (r=0.109, P=0.019), body fat percentage (r=0.114, P=0.013), and negatively correlated with SMM percentage (r=-0.104, P=0.024). Similar correlations were observed between central TH resistance indices and body composition, but no significant correlations were found in the control group. Post-MBS, decreased TSH positively correlated with decreased VFA (r=0.251, P=0.006) and increased SMM percentage (r=0.233, P=0.011). While reductions in VFA and body fat percentage were linked to improved central thyroid hormone resistance, a decrease in peripheral TH conversion was noted. MBS significantly impacts thyroid function and TH resistance, with notable correlations to changes in body composition.

An overview of the dynamic and complex regulatory landscape of cargo transportation in the United Arab Emirates

This article explores the dynamic and complex regulatory landscape of cargo transportation in the United Arab Emirates (UAE). As a critical hub in global trade, the UAE’s approach to cargo transportation not only impacts its economic landscape but also has broader implications for international logistics and trade. When the authors speak about air cargo, a very prominent characteristic comes to mind, that is, the ‘speed’ at which goods are transported from one point to another in a world which is fueled by time-based competition which connects leading suppliers, smaller businesses to consumers within a complicated global supply chain operating within networks. The authors aim to examine the current regulatory framework governing cargo operations, highlighting key events contributing to the growth of cargo transportation in recent years within the UAE, shedding light on the central regulatory bodies and key players in the UAE which contribute to the chain of transporting cargo and shipments in the UAE. This study will also briefly compare the standards applied in the UAE with international norms. It delves into the implications of existing regulations on various facets of trade and logistics, including compliance challenges faced by businesses. The article identifies specific challenges in the regulatory setting, such as safety, environmental considerations and the integration of emerging technologies. Furthermore, it distinguishes between the flexible and rigid aspects of these regulations, analyzing their impact on the industry. Looking ahead, the article forecasts emerging trends and potential shifts in regulatory policies, emphasizing the need for adaptability and forward-thinking in policymaking. The aim is to provide a comprehensive overview of the UAE’s regulation of the cargo transportation landscape. The present study offers insights into its current status, challenges, and future directions, thereby contributing to policy development in this vital sector. New research examining the UAE’s cargo regulations reveals significant gaps that could stall its ambitions of becoming a leading cargo transportation global hub. The study identifies shortcomings in regulations related to cargo transportation in the UAE and its efficiency. These areas, along with potential inflexibility in the current system, pose challenges to the UAE to compete effectively in the time-sensitive world of cargo shipments.

Radiating particles accelerated by a weakly charged Schwarzschild black hole

It is well known that supermassive black holes in the centers of galaxies are capable of accelerating charged particles to very high energies. In many cases, the particle acceleration by black holes occurs electromagnetically through an electric field induced by the source. In such scenarios, the accelerated particles radiate electromagnetic waves, leading to the appearance of the backreaction force, which can considerably change the dynamics, especially, if the particles are relativistic. The effect of the radiation reaction force due to accelerating electric field of the central body in curved spacetime has not been considered previously. We study the dynamics of radiating charged particles in the field of the Schwarzschild black hole in the presence of an electric field associated with a small central charge of negligible gravitational influence. We use the DeWitt-Brehme equation and discuss the effect of the self-force, also known as the tail term, within the given approach. We also study the pure effect of the self-force to calculate the radiative deceleration of radially moving charged particles. In the case of bounded orbits, we find that the radiation reaction force can stabilize and circularize the orbits of oscillating charged particles by suppressing the oscillations or causing the particles to spiral down into the black hole depending on the sign of the electrostatic interaction. In all cases, we calculate the energy losses and exact trajectories of charged particles for different values and signs of electric charge.

Kinematic Analysis of the Final Release position of elite Archer

The purpose of the study was kinematical analysis of an Elite archers. In present study total sample five Indian International level male Recurve category Archers was selected by Purposive sampling technique from SAI Archery training Center Sonipat. The age of the subjects was between 24 (± 5) years, hight of the subjects 6.0` (± 5 Inch), participation year between 2016-2022, shooting FITA score between 650-720 in archery was selected as a subjects for the study. According to Casio EX-F1 high speed camera was used, which have frequency from 60-300 frames per second (f/s). The data were recorded from Superior view, Lateral view, Anterior view and Medial view. The distance between shooting line and target is 70 meter. Shooting line is passed horizontally through the Center of Gravity box, Center of Gravity box is a square box drown with the measurement of 1×1 m, Center of Gravity box is equally divided into 4 parts. A straight line is passed vertically on it and a horizontal line which is shooting line and is drawn 70 meter apart from the target. The distance between bull eye of the target and the floor surface is 5 feet. Siliconcoach Pro8 update motion analysis software and Tracker motion analysis software was used for kinematical analysis of at the time of final release position in archery. Descriptive statistic was used. To find out multi correlation between dependent variable performance on target 1-10 (bull eye) in points and independent variables (selected linear variables). The significant correlation was found between Height of body Center of Mass, Height of body Center of Gravity, Height of Projectile and obtained value (-.893), (.878), (-.945) is greater than tabulated value of (.878) therefore it shows significant relationship of this independent variable with performance in archery. Whereas, in case of Body force aliment right medial, Body force aliment left medial the obtained values (.360) and (.770) are lower than tabulated value of (.878) therefore it shows insignificant relationship of these independent variable with performance in archery. The significant correlations with height variables suggest that certain aspects of an archer's body positioning, such as the height of the center of mass, center of gravity, and projectile, play a crucial role in archery performance. The negative correlation with the height of the center of mass implies that a lower center of mass is associated with better performance. The insignificant correlations with body forced alignment variables suggest that, at least within the parameters measured, the lateral alignment of the body (right and left medial) does not significantly influence performance in archery. Since the significant relationship was found between Height of body Center of Mass and Height of body Center of Gravity, Height of Projectile and Body force aliment left medial of the subject among independent variables as calculated “r” (-.960), (.887), (-.959) is found greater than the required tabulated value of (.878) at .05 level of significance. In case be seen the significant relationship was found between Height of body Center of Gravity and Body force aliment left medial of the subject among independent variables as calculated “r” (.935), is found greater than the required tabulated value of (.878) at .05 level of significance. The strong correlations among these variables indicate a close relationship between the height-related kinematic variables (center of mass, center of gravity, and projectile) and the lateral alignment of the body (body forced alignment left medial). The negative correlations suggest that as the height of the center of mass decreases, the height of the center of gravity and the height of the projectile tend to decrease, and as the height of the projectile decreases, the body forced alignment left medial tends to increase. The study concludes that there is a statistically significant and positive relationship between the height of the center of gravity and body forced alignment on the left medial side in archery. This finding implies that variations in the height of the center of gravity are associated with corresponding changes in the lateral alignment of the body, specifically towards the left medial side.

Association of combined body mass index and central obesity with cardiovascular disease in middle-aged and older adults: a population-based prospective cohort study

BackgroundCardiovascular diseases (CVDs) pose a significant threat to public health. Evidence indicates that the combination of central obesity and normal body mass index (BMI) is associated with an increased risk of cardiovascular disease and mortality. However, limited evidences exists in middle aged and elderly adults in China.MethodsThis was a prospective cohort study that utilized a nationally representative sample of 6,494 adults aged 45 years and above. These individuals participated in the China Health and Retirement Longitudinal Study spanning from 2011 to 2018. Height, weight and waist circumference (WC) were measured, and BMI was calculated by height and weight. Other variables were obtained through self-reported questionnaires. Association analysis was conducted using Cox proportional hazard regression models.ResultsA total of 10,186 participants were investigated, with 57,185 person-years of follow-up. During this period, 1,571 CVDs occurred, including 1,173 heart diseases and 527 strokes. After adjusting for various factors including age, gender, education, marital status, smoking status, alcohol intake, social activity, hypertension, dyslipidemia, diabetes, cancer, chronic lung diseases, liver disease, kidney disease, digestive disease, ENP(emotional, nervous, or psychiatric problems), memory related disease, arthritis or rheumatism, asthma, self-rated health and depression, the results revealed that compared to those with normal WC normal body mass index (BMI), individuals with central obesity normal BMI had a 27.9% higher risk of CVD incidence (95% confidence interval [CI]:1.074–1.524), and a 33.4% higher risk of heart disease incidence (95% CI:1.095–1.625), while no significant association was found with stroke. Additionally, those with normal WC high BMI showed a 24.6% higher risk of CVD incidence (95% CI:1.046–1.483), and a 29.1% higher risk of heart disease incidence (95% CI:1.045–1.594), again with no significant association with stroke. Finally, individuals with central obesity high BMI exhibited a 49.3% higher risk of CVD incidence (95% CI:1.273–1.751), a 61% higher risk of heart disease incidence (95% CI:1.342–1.931), and a 34.2% higher risk of stroke incidence (95% CI:1.008–1.786). Age- and sex- specific analyses further revealed varying trends in these associations.ConclusionsWe discovered that the combined association of body mass index(BMI) and central obesity with CVD incidence exhibited a significantly enhanced predictive value. Specifically, a high BMI with central obesity was notably linked to an increased risk of CVD incidence. Additionally, central obesity with a normal BMI or a normal WC coupled with a high BMI significantly augmented the risk of heart disease incidence, but not stroke. Notably, male and middle-aged adults demonstrated a greater propensity for heart disease incidence. Our study underscores the importance of maintaining an optimal BMI and preventing abdominal obesity in promoting cardiovascular health.

Walking symmetry is speed and index dependent

Gait symmetry is one of the most informative aspects describing the quality of gait. Many indices have been proposed to quantify gait symmetry. Among them, indices focusing on the comparison of the two body sides (e.g., Symmetry Angle, SA) and indices based on the analysis of the locomotor act as a whole, dealing with the body center of mass (e.g., Symmetry Index, SIBCoM) or lower trunk accelerometry (e.g., improved Harmonic Ratio, iHR) have been proposed. Remarkably, the relationship between these indices has received little attention so far, as well as the influence of gait speed on their values. The aim of this study is to investigate this relationship by comparing the SA, SIBCoM, and iHR, and to explore the effect of walking speed on these indices. Ten healthy adults walked for 60 s on a treadmill at seven different speeds (from 0.28 to 1.95 m s−1) and simulate an asymmetric gait (ASYM) at 0.83 m s−1. Marker-based trajectories were recorded, and the body center of mass 3D trajectory was obtained. Simultaneously, lower trunk 3D linear accelerations were collected using a triaxial accelerometer. SIBCoM, iHR, and SA were calculated for each stride, each anatomical direction, and each condition. Perfect symmetry was never displayed in any axes and any indices. Significant differences existed between SIBCoM, and iHR in all anatomical directions (p < 0.0001). The walking speed significantly affected SIBCoM and iHR values in anteroposterior and craniocaudal directions, but not in mediolateral. Conversely, no walking speed effect was found for SA (p = 0.28). All three indices significantly discriminated between ASYM and the corresponding walking condition (p < 0.05). Gait symmetry may differ significantly according to the data source, mathematical approach, and walking speed. Healthy individuals display an asymmetrical gait and acknowledging this aspect is crucial when establishing rehabilitation objectives and assessing the quality of gait in the clinical setting.

A novel health monitoring system for vital signs using IoT

The current research looked at how to use the Internet of Things (IoT) to create a vital sign health monitoring system. Eight indications are employed to get critical patient information. Therefore, the number of nodes of the IoT embedded in the human body is 8, which have been worked on in different places of the body. Among the 8 nodes, node number 1 is located in the center of the grid (the center of the human body). The number of rounds is 9000 and the nodes are adopted with the initial energy of the nodes of 0.5 J and the radio range of 10 m. MATLAB software was used to simulate the WBAN network, which consists of IoT sensors embedded in the human body. The eight-item health assessment tool takes the following into account: pulse rate, blood pressure (mm Hg), serum cholesterol (mg/dl), temperature (°C), exercise-induced angina, and exercise-induced ST-wave depression, major blood vessels are counted using a medical procedure called endoscopy that involves examining the alveoli, which are small air sacs in the lungs where gas exchange occurs. We compared the number of major vessels at rest with the maximal heart rate during activity. The sensors were responsible for sending this data to the health center (base station). The data collected from the installation of these 8 sensors on 303 patients were collected and evaluated by machine learning method using MLP neural network method. Finally, it can be claimed that the present study has provided an automated method of determining the health of people using the IoT in a way that provides a state of health with an accuracy of over 99% and can be used in medical centers.

Dilution induced variation of microstructure and mechanical properties on Co-Cr-Fe-Ni high entropy alloy coatings prepared by laser cladding

The remarkable properties of some series of high entropy alloys (HEAs) have garnered extensive interest in the development of HEA coatings. In this study, we prepared non-equiatomic Co-Cr-Fe-Ni HEA coatings using laser cladding method with Co-Cr-Fe-Ni cable-type welding wire (CTWW) as the filling material and investigated the effect of dilution rate on the microstructure evolution of coatings. By changing the wire feeding speed, a large dilution rate range was obtained which is from over 80 % to below 20 % and a variation of the coating's microstructure and mechanical properties was discovered within this large dilution rate range. All of the coatings are dense and uniform, with good metallurgical bonding. A pivotal discovery was made when the dilution rate decreased from approximately 35 %–40 % to below this threshold. The coating transitions from face centered cubic (FCC) and body centered cubic (BCC) dual-phase to FCC single-phase, accompanied by a precipitous drop in hardness from approximately 425 HV to below 175 HV. The interlaced distribution and dislocation pile-up of the layered BCC eutectic structure within the FCC phase are the main reasons for this dramatic change. Therefore, controlling the dilution rate is an effective way to regulate the performance of Co-Cr-Fe-Ni HEA coatings.

Quantitative Measurements in the Exhaust Flow of a Rotating Detonation Combustor Using Rainbow Schlieren Deflectometry

Abstract This study employs Rainbow Schlieren Deflectometry (RSD) to characterize the unsteady, supersonic/subsonic exhaust plume of a Rotating Detonation Combustor (RDC). Firstly, RSD images are analyzed to quantify the frequency and strength of flow oscillations and their relationship to the detonation wave. Secondly, a 3D tomographic algorithm is used to obtain the local 3D density field across the whole region of interest (ROI). The tomographic analysis relies upon wave rotation to infer projection data of the 3D exhaust plume at multiple view angles using a single RSD/camera system and was previously validated using phantom data from computational fluid dynamics analysis of an RDC. The annular RDC operated on methane and 2/3 O2 - 1/3 N2 oxidizer mixture is equipped with a converging nozzle to pressurize the combustion chamber. The product flow exiting the nozzle throat expands across an unoptimized conical aerospike attached to the center body of the RDC. RSD images provide a temporal resolution of 369 ns and spatial resolution of 100 ?m in a 6.4 high and 25.6 mm wide ROI of the exhaust plume. A rainbow filter is calibrated to convert hue in color schlieren images into deflection angle data. This data is used to characterize the unsteady flow oscillations that show excellent agreement with PCB pressure probe measurements acquired inside the combustion chamber. Tomographic analysis yields a 3D local density field that shows distinct features, consistent with published numerical simulations of the RDC exhaust plume.

Some new minimax inequalities for centered convex bodies

AbstractThe purpose of this manuscript is to derive some new minimax inequalities for centered convex bodies in $${\mathbb {R}}^{d}$$ R d . As consequences, new characterizations of ellipsoids will be established as well. Some open problems related to the Busemann-Petty list of problems will also be discussed.

Swirling flow and heat transfer in a pipe: Decay and transition to axial flow

This paper describes an experimental study of heat transfer, local and total swirl flow parameters in the pipe 80 mm in a diameter and 150 diameters long. The pipe consists of 12 separate pipes of different length, connected to each other using 20 mm ring spacers. These spacers were also used to provide the flow and heat transfer measurements. Overall, eight blade-type swirl generators with central body and profiled according to the power low, are installed at the pipe inlet. The actual swirl intensity S of swirl generators is ranged from 0.38 to 1.29. The profiles of mean axial and tangential velocity, surface heat flux, swirl flow angle, static and total pressure, flow and surface temperature are measured. A few novel scientific results and equations are obtained, including the axial and tangential speed maximum, axial and tangential momentum flux, swirl number decay and energy loss transformation. The common link between the local and total swirl parameters, one-valued correlation between tangential and axial velocity were obtained. The results, presented in the paper led to the conclusion that transition from swirling to axial flow occurs at S ≈ 0.19 in terms of the heat transfer decrease, but at S ≈ 0.10 – in terms of the energy loss reduction.

Nonlinear dynamic modeling and vibration analysis for flexible tethered satellite systems under large deformations

The escalating threat posed by space debris necessitates innovative approaches for its removal. This article presents a comprehensive mathematical modeling and dynamic analysis of a flexible tethered satellite system (FTSS) in the post-capture phase, taking into account nonlinear strain effects for the flexible appendages. The FTSS consists of a rigid central body satellite, two identical flexible panels, and a towing mass that manipulates the satellite through a tether. We develop a detailed dynamic model that accurately represents the system’s three-dimensional motion, incorporating the rigid body’s 6 degrees of freedom (DOF), the tether’s 3 DOF motion, and two modal generalized coordinates for each panel. The extended Hamilton method is employed to derive this model, enabling us to investigate the conditions under which nonlinear strain considerations become critical. The findings of this article reveal that nonlinear strain effects can profoundly impact the system’s dynamics under certain geometric and forcing conditions, often overlooked in previous studies. In these scenarios, the panel strains exceed the linear regime, necessitating the use of nonlinear models for accurate representation. This work emphasizes the importance of incorporating nonlinear strain terms in the dynamic analysis of FTSSs, particularly when dealing with large deformations and high-amplitude vibrations encountered in debris removal applications.

ESTABLISHMENT OF THE CONCEPT OF PUBLIC DIPLOMACY IN MODERN SCIENTIFIC DISCOURSE: THE ROLE OF PARADIPLOMACY

The article reveals the essence of the concept of public diplomacy and a retrospective of its formation in the current scientific discourse. It is noted that the field of US public diplomacy is quite actively researched by modern scientists. It is shown that the term “public diplomacy” should be understood as the activity of various actors, both governmental and non-governmental, which is intended to explain to the foreign public the foreign policy pursued by the country and to encourage this or that state to make its foreign policy decisions in the direction that is beneficial to the given actor . It has been established that the concept of “cultural diplomacy” is narrower than the concept of “public diplomacy”, which should be understood as a set of activities carried out by both central and foreign bodies of external relations of the state with the aim of researching the attitude and informing the foreign public. as well as establishing contacts abroad, with the aim of improving the state’s image and achieving national interests. So, in the United States of America, there is no separation of “cultural diplomacy” from “public diplomacy”. The concept of paradiplomacy is also considered as a tool of activity of subnational actors in the international arena and components of diplomatic communication processes taking place in the modern world. It has been proven that paradiplomacy is an integral part of modern international relations along with public diplomacy and cultural diplomacy.

An overactuated aerial robot based on cooperative quadrotors attached through passive universal joints: Modeling, control and 6-DoF trajectory tracking

This article discusses a novel aerial robot architecture that overcomes the underactuation of conventional multirotor systems without adding dedicated rotor tilting actuators. The proposed system is based on four quadrotors cooperatively carrying a central body to which they are attached through passive universal joints. While conventional parallel axis multirotors are underactuated, the proposed mechanism makes the system overactuated, enabling independent position and orientation control of the main body. This implies that the payload can be carried in the minimum drag orientation, it enables take-off and landing on inclined surfaces and it provides thrust-vectoring capabilities to the system, leading to high control authority. A detailed dynamic model is derived making use of Lagrangian formalism and a hierarchical control law based on such model is proposed to stabilize the system. This control law is designed to ensure good tracking while minimizing power consumption. The proposed control law and the capabilities of the architecture are evaluated in simulation and in outdoor experimental flights, where the aerial robot shows autonomous tracking of the six degrees of freedom (DoF) of the main body, an inherently unfeasible maneuver for conventional underactuated multirotors.

Smartphone Usage and Postural Stability in Individuals With Forward Head Posture: A Nintendo Wii Balance Board Analysis.

To assess postural stability, specifically center of body sway during single-leg standing balance, among individuals with and without forward head posture (FHP) during smartphone use. The research recruited 53 healthy smartphone users, aged 18-25, and categorized them into FHP group comprising 26 subjects and the normal (control) group with 27 subjects. Participants were assigned the task of maintaining balance while engaged in smartphone typing during single-leg standing. The experiment involved four specific conditions according to neck posture and stable of surface. The study meticulously quantified body center of pressure (COP) sway amplitudes using the Nintendo Wii Balance Board. The research revealed that individuals with FHP exhibited significantly greater body sway compared to the control group when using smartphones. Notably, distinct variations were observed in path length sway, anteroposterior (AP), and mediolateral (ML) sway amplitude, particularly evident when maintaining flexed neck positions on a soft surface while engaged with smartphones. These findings strongly suggest that individuals with FHP encounter deteriorated postural stability during smartphone use, particularly in challenging head positions.

Solid‐State Bonding of Iron or Steel with Stainless Steels by Spark Plasma Sintering Bonding

In this study, pure iron, S45C carbon steel (Fe–0.45mass%C), carburized iron, and nitrided iron are bonded with two types of stainless steels, i.e., SUS304 austenitic stainless steel (Fe–18mass%Cr–8mass%Ni) with face center cubic structure or SUS430 ferritic stainless steel (Fe–18mass%Cr) with body center cubic structure by a spark plasma sintering (SPS) machine. Bonding experiments are carried out by SPS bonding. It is found that the bonding temperature of the S45C/SUS samples is lower than that of Fe/SUS samples, and carbon atoms in the S45C play important role on the bonding performance. The bonding temperature for SUS304/SUS430 sample is more than 30 °C higher than those for the Fe/SUS and S45C/SUS samples. The presence of thin chromium oxides on both stainless steels reduces the bonding performance of SUS304/SUS430 sample. Better bonding performance is found for the carburized and nitrided iron for bonding with stainless steels. However, continuous single‐phase layer on the surface leads to reduce the bonding performance. It is concluded that not only the concentration of carbon and nitrogen but also the phase configuration in the iron at interface strongly influences the bonding performance between iron alloys and stainless steels by SPS bonding.

Influence of tactile and verbal guidance on lateral weight-shifting in double-leg standing after total hip arthroplasty

IntroductionAnomalous gait after total hip arthroplasty (THA), marked by increased trunk lateral flexion during weight-bearing, is a noteworthy aspect to consider for enhancing ambulatory capacity. One potential training modality that is feasible in the early post-THA period is lateral weight shifting during double-leg standing. However, the influence of physical therapists’ instructional guidance on trunk lateral flexion and hip abductor muscle activity in this context remains unclear. PurposeTo investigate the influence of physical therapist's guidance directed towards reducing the trunk lateral flexion angle during lateral weight-shifting in double-leg standing post-THA. MethodsTwenty THA patients, assessed at 2 weeks postoperatively, performed lateral weight-shifting under two conditions: the normal condition and the instructed condition, for comparison. The latter involved tactile and verbal guidance guidance to minimize trunk lateral flexion. Patients were categorized based on trunk flexion direction for comparison, exploring the correlations between hip abductor muscle activity and kinematic parameters. ResultsIn the instructed condition, a significant reduction in trunk lateral flexion and increased hip lever arm length were observed compared to those in the normal condition. Patients with trunk flexion towards the operated side exhibited a notable reduction, while those on the non-operated side showed no significant changes. Gluteus medius muscle activity correlated with trunk lateral flexion, and tensor fasciae latae muscle activity correlated with body's center of mass lateral displacement and hip adduction angle. ConclusionsPhysical therapist's guidance influenced lateral weight-shifting in double-leg standing post-THA. Differences in the trunk lateral flexion direction may lead to different effects from the guidance.