Phase Of Movement Research Articles

Neuromuscular synergy characteristics of Tai Chi leg stirrup movements: optimal coordination patterns throughout various phases

ObjectiveTo investigate the neuromuscular activity characteristics of Tai Chi athletes and identify optimal muscle synergy patterns.MethodData were collected from 12 elite Tai Chi athletes using a Vicon motion capture system, a Kistler 3D force plate, and a Noraxon surface electromyography system. Muscle synergy patterns were extracted using Non-negative Matrix Factorization.ResultsFour muscle synergy patterns were identified in each of the three phases of the leg stirrup movement, with the optimal synergy pattern for each phase determined as follows: knee lift phase: rectus femoris and vastus lateralis of the right leg; extension phase: rectus femoris, vastus lateralis, biceps femoris, and medial gastrocnemius of the right leg; recovery phase: rectus femoris, vastus lateralis, and medial gastrocnemius of the right leg. These patterns explain the muscle coordination activities for each phase.ConclusionThis study identified the optimal muscle synergy patterns for each phase, supporting the fluidity and force generation of the leg stirrup movement. This provides Tai Chi athletes with a more efficient way to exert strength and maintain balance.

Directional enhancement of underwater impact and bubble loads in neighbor two-phase fluid domains charge

The loading characteristics of underwater explosions and the dynamic behavior of bubbles are directly related to the charge structure. This study proposes a unique charge structure in a gas–liquid two-phase fluid domain. Numerical methods are used to investigate the effects of fluid layer thickness and gas–liquid ratio on underwater explosion shock wave load, bubble dynamics, and bubble pulsation load. The results show that the two-phase fluid layer significantly enhances the directional release of shock wave energy and bubble pulsation load. During the shock wave phase, a lagging wave effect appears in the liquid layer direction, causing a secondary high-energy shock, significantly increasing the specific impulse. The gas layer direction may form a pressure relief channel effect, enhancing the shock wave peak pressure. For the bubble motion phase, differences in the physical properties of the fluid layer medium lead to irregular bubble boundary movements, promoting bubble tearing and rupture. The gaseous medium converts the accumulated shock wave energy into the internal energy of the bubble, increasing its volume potential. Although this characteristic reduces the pulsation frequency, it significantly increases the specific impulse. Altering the fluid layer medium can control explosion loads and bubble movement, offering new insights for ocean engineering applications.

Cybernic robot hand-arm that realizes cooperative work as a new hand-arm for people with a single upper-limb dysfunction

A robot hand-arm that can perform various tasks with the unaffected arm could ease the daily lives of patients with a single upper-limb dysfunction. A smooth interaction between robot and patient is desirable since their other arm functions normally. If the robot can move in response to the user’s intentions and cooperate with the unaffected arm, even without detailed operation, it can effectively assist with daily tasks. This study aims to propose and develop a cybernic robot hand-arm with the following features: 1) input of user intention via bioelectrical signals from the paralyzed arm, the unaffected arm’s motion, and voice; 2) autonomous control of support movements; 3) a control system that integrates voluntary and autonomous control by combining 1) and 2) to thus allow smooth work support in cooperation with the unaffected arm, reflecting intention as a part of the body; and 4) a learning function to provide work support across various tasks in daily use. We confirmed the feasibility and usefulness of the proposed system through a pilot study involving three patients. The system learned to support new tasks by working with the user through an operating function that does not require the involvement of the unaffected arm. The system divides the support actions into movement phases and learns the phase-shift conditions from the sensor information about the user’s intention. After learning, the system autonomously performs learned support actions through voluntary phase shifts based on input about the user’s intention via bioelectrical signals, the unaffected arm’s motion, and by voice, enabling smooth collaborative movement with the unaffected arm. Experiments with patients demonstrated that the system could learn and provide smooth work support in cooperation with the unaffected arm to successfully complete tasks they find difficult. Additionally, the questionnaire subjectively confirmed that cooperative work according to the user’s intention was achieved and that work time was within a feasible range for daily life. Furthermore, it was observed that participants who used bioelectrical signals from their paralyzed arm perceived the system as part of their body. We thus confirmed the feasibility and usefulness of various cooperative task supports using the proposed method.

An experimental and numerical investigation into the influence of wind effects on wind turbines with tubular towers

This study delves into investigating the profound impact of wind loads on the structural integrity of wind turbines. To comprehensively assess the influence of wind loads, a two-pronged approach was adopted: first, a meticulously crafted 1/100 scale model was employed within a wind tunnel, and second, advanced numerical simulations based on computational fluid dynamics (CFD) were conducted. Moreover, the study takes into account the intricate factor of turbine proximity in the wind tunnel setup. The design of the tower structure takes into consideration an array of loads, including lateral and gravitational forces. Notably, a substantial load arises from the rotational force generated by blade motion, which exerts its effects on the structure. Calculations of this force were executed using ABAQUS software. This multifaceted analysis involves the application of angular velocity to the blades, subsequently enabling the computation of time-dependent support reactions via dynamic numerical analysis employing the Newmark method. Furthermore, the study encompasses the determination of static equivalent forces. It is noteworthy that the maximum displacement experienced by the structure coincides with the initial phase of blade movement.

Effects of inter- and intraindividual compensation-sensitive shot styles on performance in Olympic air rifle shooting

Background: Aiming point analysis systems (APAS) are commonly used in sports shooting but face four main challenges: they do not account for intra-session variations, they overlook inter-individual shooter preferences, they ignore compensation mechanisms of technical features, and they do not respect the real shot location at the target. Methods: To address the first three challenges, we developed and validated an automated approach detector algorithm (ADA) for movement phase detection. When compared to three independent expert ratings, the ADA demonstrated a high correlation (r = .811). Building on the ADA and addressing challenge 3 and 4, this study applied cluster-analysis and ANOVA to determine the performance relevance of compensation-sensitive shot styles using datasets from a single athlete and 26 advanced to elite level athletes. Results: Significant performance differences in shot styles for both datasets, with each shot style distinctively differing from the others could be found. Conclusions: Shot styles which allow for compensation and intra-individual movement phase differences exhibit performance variations. Coaches and athletes should emphasize holistic training, focusing on combinations of features that allow for compensation.

Revealing the different levels of action monitoring in visuomotor transformation task: Evidence from decomposition of cortical potentials.

This study investigates the cortical correlates of motor response control and monitoring, using the Theory of Event Coding (TEC)as a framework to investigate signals related to low-level sensory processing of motor reafference and high-level response monitoring, including verification of response outcomes with the internal model. We used a visuomotor paradigm with two targets at different distances from the participant. For the recorded movement-related cortical potentials (MRCPs), we analyzed their different components and assessed the movement phases during which they are active. Residual iteration decomposition (RIDE) and multivariate pattern analysis (MVPA) were used for this analysis. Using RIDE, we separated MRCPs into signals related to different parallel processes of visuomotor transformation: stimulus processing (S-cluster), motor response preparation and execution (R-cluster), and intermediate processes (C-cluster). We revealed sequential activation in the R-cluster, with execution-related negative components and positive contralateral peaks reflecting reafference processing. We also identified the motor post-imperative negative variation within the R-cluster, highlighting the response outcome evaluation process included in the action file. Our findings extend the understanding of C-cluster signals, typically associated with stimulus-response mapping, by demonstrating C-activation from the preparatory stages through to response termination, highlighting its participation in action monitoring. In addition, we highlighted the ability of MVPA to identify movement-related attribute encoding: where statistical analysis showed independence of stimulus processing activity from movement distance, MVPA revealed distance-related differences in the S-cluster within a time window aligned with the lateralized readiness potential (LRP). This highlights the importance of integrating RIDE and MVPA to uncover the intricate neural dynamics of motor control, sensory integration, and response monitoring.

Vimseltinib versus a placebo in patients with tenosynovial giant cell tumor: a plain language summary of the MOTION phase 3 trial.

This article presents a patient-friendly summary of the MOTION phase 3 clinical trial results, which were published in The Lancet in June 2024.The primary goal of the MOTION trial was to understand if treatment with a drug called vimseltinib shrank tumors more than a placebo in participants with symptomatic tenosynovial giant cell tumor, also known as TGCT, for which surgery was unlikely to provide benefit. A placebo is something that looks like the treatment being studied but does not contain any medicine.The MOTION trial compared the effects of vimseltinib versus a placebo using several different outcomes associated with TGCT. These outcomes included tumor size, active range of motion of the affected joint, and several patient-reported quality-of-life measures including physical function, stiffness, overall health, and pain. The trial showed that more participants treated with vimseltinib experienced significant tumor shrinkage, as defined by a 30% or greater reduction in tumor size, compared with those receiving a placebo. Participants receiving vimseltinib had improved active range of motion, and they reported improved physical function, stiffness, overall health, and pain, regardless of the amount of tumor shrinkage, compared with participants receiving a placebo. Most side effects in participants treated with vimseltinib were not severe and were manageable. Vimseltinib was better at shrinking tumors and improving active range of motion, stiffness, pain, and other health measures than the placebo for participants with TGCT. Vimseltinib has the potential to become a new treatment option for patients with TGCT for whom surgery may not provide benefit.

Gender Differences in Performing an Overhead Drilling Task Using an Exoskeleton-A Cross-Sectional Study.

(1) Exoskeletons offer potential benefits for overhead working tasks, but gender effects or differences are unclear. This study aimed to compare the performance as well as subjective body strain and comfort of men and women using an upper-body exoskeleton. (2) n = 20 female and n = 16 male participants performed an overhead drilling task with and without a passive upper-body exoskeleton in a randomized cross-over study. The task performance of different movement phases, perceived exertion, and ease of use were measured to compare gender differences. One- and two-way analyses were used to compare genders in the different conditions. The body mass index (BMI) was included as a covariate. (3) Gender differences in task performance were found for error integrals (p < 0.001) with higher values in male participants. Moreover, there was a significant interaction effect for gender x exoskeleton use. While females showed performance decrements in aiming with exoskeleton use, the males' performance increased (p = 0.025). No other gender differences were observed. (4) Gender differences in task performance using an upper-body industrial exoskeleton were less detectable than expected, indicating that body composition and anthropometrics might be valuable indicators for performance including assisting devices. Moreover, future studies should also integrate the examination of muscle activity to gain more insights into potential gender movement control patterns.

Standing on Elevated Platform Changes Postural Reactive Responses during Arm Movement.

Background/Objectives: This study investigated the behavior of postural adjustments throughout the entire action: from the preparatory phase (anticipatory postural adjustment, APA), the focal movement phase (online postural adjustments, OPA), to the compensatory phase (compensatory postural adjustment, CPA) while raising the arms in a standing position, both with eyes opened and closed. The goal was to analyze the effects of reduced sensorial information and different heights on postural muscle activity during these three phases. Methods: Eight young women performed rapid shoulder flexion while standing on the ground and on a 1-m elevated platform. The EMG activity of the trunk and lower limb muscles was recorded during all three phases. Results: Although average muscle activity was similar on the ground and the elevated platform, the pattern of postural muscle activation varied across the motor action. During OPA, all postural muscle activity was the highest, while it was the lowest during APA. On the elevated platform postural muscles have increased their activation during APA. In the most stable condition (standing on the ground with eyes opened), muscle activity showed a negative correlation between APA and OPA, but there was no correlation between OPA and CPA. Conclusions: Our results suggest postural control adapts to sensory, motor, and cognitive conditions. Therefore, the increased demand for postural control due to the height of the support base demands greater flexibility in postural synergies and alters muscle activity.

Numerical analysis of the Thermal EHL line contact problem under intermittent motion

Abstract A mathematical model of time-varying thermal elastohydrodynamic lubrication (EHL) is developed using a sleeve chain as the object of study. The effects of thermal effect, load, speed, rest time and equivalent radius of curvature on its EHL are investigated using theoretical simulations. The results show that during intermittent motion, a portion of oil is entrapped in the contact zone at the end of the deceleration phase, after which this entrapped oil gradually moves out of the contact zone with the onset of speed, and a lower film of oil at the lubrication inlet passes through the center of the contact zone. In simple sliding intermittent motion, the temperature rise plays a crucial role in the variation of the oil film, particularly during the motion phases, and is an unavoidable factor. An increase in stop time reduces the film thickness and increases the following friction coefficient in the acceleration stage. An increase in the equivalent radius of curvature increases the film thickness and thermal rise in the contact zone as well as decreases the friction coefficient. Since the sleeve chain is one of the most commonly used mechanism in industry, high priority should be given to the lubrication design of this structure.

Visual Deprivation's Impact on Dynamic Posture Control of Trunk: A Comprehensive Sensing Information Analysis of Neurophysiological Mechanisms.

Visual information affects static postural control, but how it affects dynamic postural control still needs to be fully understood. This study investigated the effect of proprioception weighting, influenced by the presence or absence of visual information, on dynamic posture control during voluntary trunk movements. We recorded trunk movement angle and angular velocity, center of pressure (COP), electromyographic, and electroencephalography signals from 35 healthy young adults performing a standing trunk flexion-extension task under two conditions (Vision and No-Vision). A random forest analysis identified the 10 most important variables for classifying the conditions, followed by a Wilcoxon signed-rank test. The results showed lower maximum forward COP displacement and trunk flexion angle, and faster maximum flexion angular velocity in the No-Vision condition. Additionally, the alpha/beta ratio of the POz during the switch phase was higher in the No-Vision condition. These findings suggest that visual deprivation affects cognitive- and sensory-integration-related brain regions during movement phases, indicating that sensory re-weighting due to visual deprivation impacts motor control. The effects of visual deprivation on motor control may be used for evaluation and therapeutic interventions in the future.

A semi-analytical time-domain model with explicit fluid force expressions for streamwise fluidelastic instability of a single and multiple flexible tube array

Fluidelastic instability (FEI) within steam generator tube arrays poses a significant safety concern for nuclear power plants. Traditionally assumed to manifest in the transverse direction, recent failures at the San Onofre Nuclear Generating Station have underscored the importance of understanding streamwise FEI (SFEI). These incidents have spurred analytical investigations into SFEI, but progress has been hindered by the lack of explicit fluid force formulations, particularly in semi-analytical SFEI models. This paper presents a novel semi-analytical time-domain SFEI model featuring an ideal geometry-based decay function and meticulously derived explicit fluid elastic force expressions. The proposed model supports both frequency-domain stability analysis and true time-domain response analysis, and it is applicable to configurations featuring either a single elastic tube in a rigid array or multiple flexible tubes in an array. Additionally, the tube motion phases are obtained by comparing time-domain responses and employing modified multi-tube frequency-domain SFEI analyses. The stability thresholds predicted for a parallel triangular array using our theoretical model closely align with reported experimental data, thereby validating its accuracy. Our work supplements and advances semi-analytical modeling, alleviating implementation challenges for analyzing SFEI phenomena.

LBA78 Updated efficacy and safety of vimseltinib in patients (pts) with tenosynovial giant cell tumor (TGCT): One-year follow-up from the MOTION phase III trial

LBA78 Updated efficacy and safety of vimseltinib in patients (pts) with tenosynovial giant cell tumor (TGCT): One-year follow-up from the MOTION phase III trial

Analytically controlling the laser-induced electron phase in sub-cycle motion

We develop an approach to directly control the phase of an electron's sub-cycle motion in an intense laser field. The method is established by tuning a low-frequency electric field applied on a centrosymmetric gaseous target during its interaction with a few-cycle infrared laser pulse. We find a universal analytical relation between the low-frequency electric field and its induced harmonic frequency shift, derived by the strong-field approximation. This simple relation and its universality are confirmed numerically by directly solving the time-dependent Schrödinger equation. Moreover, we demonstrate the benefits of the discovered relation in applications, including continuously and precisely tuning XUV waves and developing a method of comprehensively sampling the THz pulse. Published by the American Physical Society 2024

Coupled analysis of floating offshore wind turbines with new mooring systems by CFD method

This paper presents a fully coupled aero-hydro-mooring numerical model of the National Renewable Energy Laboratory's (NREL) 5 MW OC4 semi-submersible Floating Offshore Wind Turbine (FOWT). The model's accuracy was validated through comparisons with existing experimental and numerical data, utilizing OpenFOAM, a Computational Fluid Dynamics (CFD) software. The key contributions of this study include demonstrating the model's precision in predicting aerodynamic performance, motion responses, and mooring system dynamics under wind and wave conditions. Additionally, a comparative analysis is conducted between a Conventional mooring system (CMS) and a New mooring system (NMS). The results show that the NMS offers improved stability in surge and heave motions, crucial for operational effectiveness and resilience. Furthermore, the NMS demonstrates a more efficient stress distribution and also reduced tensions in the mooring lines, contributing to the long-term durability and safety of the structure. In terms of aerodynamic performance, the differences between the two mooring systems are limited due to the combined surge and pitch motion phase difference. Future research will focus on optimizing these phase differences to enhance performance and refine the cost-efficiency of the mooring system.

Analysis of Rhodamin B in Lipstick Preparations in Padangsidimpuan City by Thin Layer Chromatography (TLC) Method

Rhodamin B is a synthetic dye in the form of a crystalline powder, green or reddish-purple, odorless, and in solution will be bright red with fluorescence or fluorescence. Rhodamin B is commonly used as a dye in the textile and papermaking industries. Rhodamin B can cause irritation in short-term exposure and has carcinogenic effects. This study aims to find out whether there is Rhodamin B in lipsticks circulating in the Padangsidimpuan City market. Samples were taken by purposive sampling and 5 red samples were obtained. To identify the presence of Rhodamin B, a thin-layer chromatography method was used using eluene as the phase of motion, namely methanol, ethyl acetate, ammonia (50:20:25) and a 254 nm UV lamp The results of the study showed that out of 5 lipstick samples identified, there was one lipstick sample that was identified as containing Rhodamin B.

CD3-engaging bispecific antibodies trigger a paracrine regulated wave of T-cell recruitment for effective tumor killing

The mechanism of action of bispecific antibodies (bsAbs) directing T-cell immunity to solid tumors is incompletely understood. Here, we screened a series of CD3xHER2 bsAbs using extracellular matrix (ECM) embedded breast cancer tumoroid arrays exposed to healthy donor-derived T-cells. An initial phase of random T-cell movement throughout the ECM (day 1–2), was followed by a bsAb-dependent phase of active T-cell recruitment to tumoroids (day 2–4), and tumoroid killing (day 4–6). Low affinity HER2 or CD3 arms were compensated for by increasing bsAb concentrations. Instead, a bsAb binding a membrane proximal HER2 epitope supported tumor killing whereas a bsAb binding a membrane distal epitope did not, despite similar affinities and intra-tumoroid localization of the bsAbs, and efficacy in 2D co-cultures. Initial T-cell-tumor contact through effective bsAbs triggered a wave of subsequent T-cell recruitment. This critical surge of T-cell recruitment was explained by paracrine signaling and preceded a full-scale T-cell tumor attack.

The effects of core muscle fatigue on lower limbs and trunk during single-leg drop landing: A comparison between recreational runners with and without dynamic knee valgus

BackgroundA deficit in neuromuscular trunk control can impact the lower limb motion, predisposing runners to injuries. This deficit may show a greater impact on runners with dynamic knee valgus. This study aimed to compare the effect of core fatigue on kinetic, kinematic, and electromyographic parameters of the trunk and lower limbs during single-leg drop landing between runners with and without dynamic knee valgus. MethodsTwenty-seven recreational runners were allocated to the valgus (n = 14) and non-valgus groups (n = 13). They performed the test before and after a fatigue protocol, taking a step forward and landing on the force platform while maintaining balance. The fatigue protocol included isometric and dynamic exercises performed consecutively until voluntary exhaustion. The vertical ground reaction force, the sagittal and frontal plane angles, and the electromyographic activity were evaluated. The integral of electromyographic activity was calculated into three movement phases. ANOVA with repeated measures was used to verify the group, time, and interaction effects. ResultsAfter fatigue, both groups showed a significant reduction in the minimum (p = 0.01) and maximum (p = 0.02) knee angles in the frontal plane (more dynamic knee valgus) and greater gluteus medius activity (p = 0.05) from the peak of knee flexion to the end of the movement. The valgus group had a greater hip excursion (p = 0.01) and vertical linear shoulder displacement (p = 0.02) than the non-valgus. ConclusionOur results suggest that core fatigue can impact the local muscle and the distal joint and that the groups presented different strategies to deal with the demand during landing.

Increased force and elastic energy storage are not the mechanisms that improve jump performance with accentuated eccentric loading during a constrained vertical jump.

Accentuated eccentric loading (AEL) involves higher load applied during the eccentric phase of a stretch-shortening cycle movement, followed by a sudden removal of load before the concentric phase. Previous studies suggest that AEL enhances human countermovement jump performance, however the mechanism is not fully understood. Here we explore whether isolating additional load during the countermovement is sufficient to increase ground reaction force, and hence elastic energy stored, at the start of the upward movement and whether this leads to increased jump height or power generation. We conducted a trunk-constrained vertical jump test on a custom-built device to isolate the effect of additional load while controlling for effects of squat depth, arm swing, and coordination. Twelve healthy, recreationally active adults (7 males, 5 females) performed maximal jumps without AEL, followed by randomised AEL conditions prescribed as a percentage of body mass (10%, 20%, and 30%), before repeating jumps without AEL. No significant changes in vertical ground reaction force at the turning point were observed. High load AEL conditions (20% and 30% body weight) led to slight reductions in jump height, primarily due to decreased hip joint and centre of mass work. AEL conditions did not alter peak or integrated activation levels of the knee extensor muscles. The constrained movement task used here, which excluded potential contributions of trunk motion, arm swing, rate of descent, squat depth, and point of load application, allows the conclusion that increased elastic energy return is not the primary mechanism for potentiating effects of AEL on jump performance.

Antibacterial Activity and Thin-Layer Chromatography (KLT) Ethanol Extract of Dragon Scale Leaves (Drymoglossum piloselloides (L.) C. Presl) Against Bacteria Staphylococcus epidermidis

The dragon scale plant is a plant containing flavonoid compounds, tannins, alkaloids, saponins. Flavanoid compounds, alkaloids, and tannins are found in dragon scales that are thought to provide antibacterial effects. Thin Layer Chromatography Test (KLT). On quarstin there is a stain distance spot of 1 cm and an 8 cm motion phase with an Rf value of 0.129 and in the extract there is a stain spot of 7.3 cm with an 8 cm motion phase with an Rf value of 0.9. In Staphylococcus epidermidis bacteria from the average of the largest inhibitory zones are applied to the extract with a concentration of 20%. The diameter of the average inhibitory zone formed around the disc paper at each concentration is: 5% 10.5 mm ± 0.20 at a concentration of 10% 11.26 mm ± 0.20 and a concentration of 20% 12.2 mm ± 0.30 each concentration has a strongly categorized response. Ethanol extract of dragon scale leaves (Drymoglossum piloselloides (L.) C. Presl) has antibacterial activity against Staphylococcus epidermidis. The diameter of the inhibitory zone that is best formed in the treatment of dragon scale leaf ethanol extract against Staphylococcus epidermidis bacteria with a concentration of 20%12.2 mm±0.30 is 12.2 mm with a strong category.