Temporal Parameters Research Articles

Using a video-based eye tracker to analyse the binocular near-reflex dynamics response.

This study presents a novel video-based eye-tracking system for analysing the dynamics of the binocular near-reflex response. The system enables the simultaneous measurement of convergence, divergence and pupillary size during accommodation and disaccommodation to aid the comprehensive understanding of the three-component near-reflex. A high-speed (90 Hz) video-based eye tracker was used to capture changes in eye gaze and pupil radius in 15 participants in response to altering stimulus conditions. An offline analysis involved separating the gaze vector components and pupil radius, which were fitted to a hyperbolic tangent function to characterise the dynamics of the near-reflex process. Significant differences in the temporal parameters of the pupil radius were observed between the near-to-far and far-to-near vision changes, with faster miosis compared with mydriasis. Additionally, differences in response times were found between gaze angle components, with longer convergence times compared to changes in the vertical direction (saccades). The steady-state values of the gaze components and pupil radius were in line with theoretical expectations and previous reports. The proposed system provides a non-invasive, portable and cost-effective method for evaluating near-reflex dynamics under natural viewing conditions using a video-based eye tracker. The sampling rate ensures the accurate assessment of vergence eye movements and pupillary dynamics. By simultaneously measuring eye convergence, divergence and pupil size, the system offers a more comprehensive assessment of the near-reflex response. This makes it a valuable tool for clinical diagnosis, research studies and investigating the effects of near work on the visual system.

Automated Gait Analysis Based on a Marker-Free Pose Estimation Model.

Gait analysis is an essential tool for detecting biomechanical irregularities, designing personalized rehabilitation plans, and enhancing athletic performance. Currently, gait assessment depends on either visual observation, which lacks consistency between raters and requires clinical expertise, or instrumented evaluation, which is costly, invasive, time-consuming, and requires specialized equipment and trained personnel. Markerless gait analysis using 2D pose estimation techniques has emerged as a potential solution, but it still requires significant computational resources and human involvement, making it challenging to use. This research proposes an automated method for temporal gait analysis that employs the MediaPipe Pose, a low-computational-resource pose estimation model. The study validated this approach against the Vicon motion capture system to evaluate its reliability. The findings reveal that this approach demonstrates good (ICC(2,1) > 0.75) to excellent (ICC(2,1) > 0.90) agreement in all temporal gait parameters except for double support time (right leg switched to left leg) and swing time (right), which only exhibit a moderate (ICC(2,1) > 0.50) agreement. Additionally, this approach produces temporal gait parameters with low mean absolute error. It will be useful in monitoring changes in gait and evaluating the effectiveness of interventions such as rehabilitation or training programs in the community.

Vocalizations of wild West Indian manatee vary across subspecies and geographic location

Geographic variation in the vocal behavior of manatees has been reported but is largely unexplored. Vocalizations of wild West Indian manatees (Trichechus manatus) were recorded with hydrophones in Florida from Florida manatees (Trichechus manatus latirostris), and in Belize and Panama from Antillean manatees (Trichechus manatus manatus) to determine if calls varied between subspecies and geographic regions. Calls were visually classified into five categories: squeaks, high squeaks, squeals, squeak-squeals, and chirps. From these five categories, only three call types (squeaks, high squeaks and squeals) were observed in all three populations. Six parameters from the temporal and frequency domains were measured from the fundamental frequency of 2878 manatee vocalizations. A repeated measures PERMANOVA found significant differences for squeaks and high squeaks between each geographic location and for squeals between Belize and Florida. Almost all measured frequency and temporal parameters of manatee vocalizations differed between and within subspecies. Variables that may have influenced the variation observed may be related to sex, body size, habitat and/or other factors. Our findings provide critical information of manatee calls for wildlife monitoring and highlight the need for further study of the vocal behavior of manatees throughout their range.

AdaBoost-driven multi-parameter real-time warning of rock burst risk in coal mines

The stope dynamic disaster, which occurs around the mining space and is represented by stress-type rock burst and fracture-type rock burst, seriously affects the safety production of coal mine. How to effectively forewarn rock burst risk to reduce the disaster caused by rock burst is an urgent problem to be solved in stope. In this paper, the spatiotemporal parameters that affect the occurrence of stope dynamic disaster are collected, and the big data of stope state is established. Due to the complex temporal and spatial parameters of rock bursts with different intensities occurrence and their varying degrees, it is difficult for some machine learning methods to excavate their internal relationships and make accurate warning. In this paper, (1) a big data platform is used to record and integrate the multiple parameters of stope dynamic disaster, and data preprocessing technology is used to de-noise and standardize them. (2) Based on the fused historical data, a strong classifier is iteratively found by the classification algorithm AdaBoost to identify the existence of the rock burst risk, so as to achieve the purpose of accurately and timely warning of rock burst risk. The research of this paper uses big data mining technology and machine learning method to carry out intelligent perception warning of the rock burst risk in real time. The experimental results show that the proposed method has a good effect and is of great significance to the prevention and control of rock burst disaster in stope.

Multilevel analysis of acoustic variation in a Scinax fuscomarginatus population (Anura, Hylidae) of Central Brazil

The vocalisations of anurans are one of their principal forms of communication and are mainly used for specific recognition involving the attraction of reproductive mates and territorial defense. In this study, we analysed the advertisement calls of 101 individuals from a population of Scinax fuscomarginatus sampled in the type locality of S. pusillus (currently under the synonymy of S. fuscomarginatus). Specifically, we investigated acoustic variation at several levels: intraindividual, interindividual, throughout the night, and across six breeding seasons by analysing temporal and spectral parameters. We identified that all parameters of the advertisement call can be used for individual recognition, with the maximum frequency having the greatest potential. We then observed that all other acoustic parameters were influenced by the predictor variables, with the exception of maximum frequency. The air temperature negatively influenced call duration, number of pulses, dominant frequency and minimum frequency; while it positively influenced pulse rate and call rate during the breeding season. Furthermore, with the exception of call duration and pulse rate, the other acoustic parameters varied significantly across the different nocturnal periods. This study provides data on the variation in S. fuscomarginatus acoustic features. Besides, we also discuss the implications of individual recognition. Studies that consider different sources of variation for the same population of a given species are uncommon, but of paramount importance for understanding the behavioural dynamics of the population. Keywords: advertisement call, behaviour, individual recognition, sexual-selection

The First AGILE Solar Flare Catalog

We report the Astro-rivelatore Gamma a Immagini LEggero (AGILE) observations of solar flares, detected by the onboard anticoincidence system in the 80–200 keV energy range, from 2007 May 1 to 2022 August 31. In more than 15 yr, AGILE detected 5003 X-ray, minute-lasting transients, compatible with a solar origin. A cross-correlation of these transients with the Geostationary Operational Environmental Satellites (GOES) official solar flare database allowed us to associate an intensity class (i.e., B, C, M, or X) to 3572 of them, for which we investigated the main temporal and intensity parameters. The AGILE data clearly revealed the solar activity covering the last stages of the 23rd cycle, the whole 24th cycle, and the beginning of the current 25th cycle. In order to compare our results with other space missions operating in the high-energy range, we also analyzed the public lists of solar flares reported by RHESSI and Fermi Gamma-ray Burst Monitor. This catalog reports 1424 events not contained in the GOES official data set, which, after statistical comparisons, are compatible with low-intensity, short-duration solar flares. Besides providing a further data set of solar flares detected in the hard X-ray range, this study allowed to point out two main features: a longer persistence of the decay phase in the high-energy regime, with respect to the soft X-rays, and a tendency of the flare maximum to be reached earlier in the soft X-rays with respect to the hard X-rays. Both these aspects support a two-phase acceleration mechanism of electrons in the solar atmosphere.

Selection of the bandwidth of the «raised cosine» shaping filter for navigation meander signals

Problem statement. One of the ways to reduce the level of out-of-band radiation when generating navigation signals is to use a "raised cosine" type filter. However, the issues of the formation of meander navigation signals using the "raised cosine" filter have not been fully investigated. In particular, the question of choosing the frequency band of the "raised cosine" type filter remains open. Purpose. Evaluation of the influence of the bandwidth of the "raised cosine" forming filter on the spectral and temporal characteristics, the energy efficiency of the transmitter, as well as the integrity of the structural and temporal parameters of navigation meander signals. Results. Analytical expressions for the pulse characteristic of the "raised cosine" type filter are obtained, taking into account the parameters of meander signals. The influence of the frequency band of the "raised cosine" filter on the distortion of meander signals in the frequency and time domain is estimated by mathematical modeling. It is shown that for the formation of meander signals in the "raised cosine" filters, it is advisable to choose the maximum frequency band, which ensures minimal distortion in the frequency and time domains, the minimum value of the peak factor and the best characteristics of the integrity of the structural and temporal parameters of the signals. Practical significance. The results can be used by specialists in the field of satellite radio navigation in the modernization of global navigation satellite systems.

Color Categorization and its Electroencephalography Correlates: A Review of Neuro-Linguistic Oddball Paradigm Research

This paper presents a review of neuro-linguistic studies on color categorization, developed using the oddball paradigm. The selection of research sources was conducted through Russian National Corpus, Google Scholar, Scopus, Web of Science. This study undertook a comprehensive analysis of all relevant articles published within the last 15 years (with the earliest dating back to 2007). Through this analysis, traditional methodologies were identified and five thematic groups of research were established, all of which employed the oddball paradigm. The focus of neuro-linguistic research has been shown to be directed towards (1) studying the neurophysiological mechanisms of color categorization and their temporal parameters; (2) investigating the mechanisms of color categorization in preverbal infants; (3) examining the effect of lateralization; (4) analyzing inter- and intra-linguistic differences in color categorization; and (5) determining the neurophysiological correlates of artificial color categories. Paying particular attention to experimental design, principles of stimulus chromatic characteristics selection, and the results obtained by the authors will enable specialists in the field of theoretical, applied, and comparative linguistics to use the review presented in this article as a basis for planning and developing new experimental research in this area.

All-optical spatiotemporal phase-matching of high harmonic generation using a traveling-grating pump field

We demonstrate spatiotemporal phase-matching of high harmonic generation both theoretically and experimentally utilizing a pump field in the form of a traveling intensity grating. Such an arrangement has the potential to enable selective enhancement of specific harmonic orders while fine-tuning their frequency by controlling the spatial and temporal parameters of the pump.

Walking ability of individuals fitted with transfemoral bone-anchored prostheses: A comparative study of gait parameters.

This study presents the walking abilities of participants fitted with transfemoral bone-anchored prostheses using a total of 14 gait parameters. Two-centre retrospective cross-sectional comparative study. Research facilities equipped with tridimensional motion capture systems. Two control arms included eight able-bodied participants arm (54 ± 9 years, 1.75 ± 0.07 m, 76 ± 7 kg) and nine participants fitted with transfemoral socket-suspended prostheses arm (59 ± 9 years, 1.73 ± 0.07 m, 80 ± 16 kg). The intervention arm included nine participants fitted with transfemoral bone-anchored prostheses arm (51 ± 13 years, 1.78 ± 0.09 m, 87.3 ± 16.1 kg). Fitting of transfemoral bone-anchored prostheses. Comparisons were performed for two spatio-temporal, three spatial and nine temporal gait parameters. The cadence and speed of walking were 107 ± 6 steps/min and 1.23 ± 0.19 m/s for the able-bodied participants arm, 88 ± 7 steps/min and 0.87 ± 0.17 m/s for the socket-suspended prosthesis arm, and 96 ± 6 steps/min and 1.03 ± 0.17 m/s for bone-anchored prosthesis arm, respectively. Able-bodied participants and bone-anchored prosthesis arms were comparable in age, height, and body mass index as well as cadence and speed of walking, but the able-bodied participant arm showed a swing phase 31% shorter. Bone-anchored and socket-suspended prostheses arms were comparable for age, height, mass, and body mass index as well as cadence and speed of walking, but the bone-anchored prosthesis arm showed a step width and duration of double support in seconds 65% and 41% shorter, respectively. Bone-anchored and socket-suspended prostheses restored equally well the gait parameters at a self-selected speed. This benchmark data provides new insights into the walking ability of individuals using transfemoral bionics bone-anchored prostheses.

A unified science of matter, life and evolution.

We are accustomed to looking at matter, life and evolution from different viewpoints. In this article, we present a simple but unified theoretical framework inspired by classical mechanics and thermodynamics. Our framework generalizes Newton's third law of matter to encompass life and evolution. The generalized action-reaction relationship includes scale and temporal parameters. This generalization helps explain why life is a system out of equilibrium. Life can go beyond the action-reaction symmetry law of matter. We define life as an open system that is self-aware of the time trajectory of energy state and environment. The theoretical framework we propose for studying life in terms of power reduces to the science of matter as a limiting case. This article is part of the theme issue 'Thermodynamics 2.0: Bridging the natural and social sciences (Part 1)'.

Synergising single-cell resolution and 4sU labelling boosts inference of transcriptional bursting

Despite the recent rise of RNA-seq datasets combining single-cell (sc) resolution with 4-thiouridine (4sU) labelling, analytical methods exploiting their power to dissect transcriptional bursting are lacking. Here, we present a mathematical model and Bayesian inference implementation to facilitate genome-wide joint parameter estimation and confidence quantification (R package: burstMCMC). We demonstrate that, unlike conventional scRNA-seq, 4sU scRNA-seq resolves temporal parameters and furthermore boosts inference of dimensionless parameters via a synergy between single-cell resolution and 4sU labelling. We apply our method to published 4sU scRNA-seq data and linked with ChIP-seq data, we uncover previously obscured associations between different parameters and histone modifications.

Human Gait Symmetry Analysis Based on Human Electrostatic Fields

Gait symmetry is a clinically relevant indicator that distinguishes between normal gait and pathological gait, and it can provide a strong basis for mobility assessment and rehabilitation interventions. This paper proposes a comprehensive quantitative assessment method for gait symmetry based on human electrostatic gait signals (EGSs). This study is the first application of EGSs to examine gait symmetry in terms of trend symmetry, amplitude symmetry, and time symmetry in 30 subjects, including healthy subjects (HSs), hemiplegic patients (HPs), and Parkinson’s disease patients (PDs). The trend symmetry index ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SI _trend</i> )compares the two sides of the continuous waveform of the gait waveforms using the eigenvector; the amplitude symmetry indexes( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SI_{A_IC}, SI_{A_SE}</i> )compare the amplitude of EGSs at the moment of initial contact (IC) with the ground and separation (SE) from the ground; the time symmetry indexes( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SI_TSP, SI_TSW</i> ) compare the durations of the support phase and the swing phase. The results showed that the HPs and PDs showed significant asymmetry in gait trends, gait signal amplitude, and gait temporal parameters on both sides compared to the HSs. In addition, the HPs showed greater asymmetry than the PDs. The Kruskal–Wallis test was used to verify that the distributions of the 5 symmetry indexes differed significantly among the three different groups (p<0.05); trend symmetry was the most effective feature for distinguishing among the three groups. This paper provides a comprehensive and effective EGSs-based analysis of gait symmetry in terms of continuous gait waveforms and discrete gait parameters.

Contending Temporalities: Stretching the Temporal Reach of Lustration in Central and Eastern Europe

As part of de-Communization, states in central and eastern Europe and the former Soviet Union used lustration measures to remove Communist officials and secret police collaborators from positions of power and to bring to light Communist-era abuses. As a form of transitional justice, lustration is unusually temporally tethered to the Communist past. However, in practice some states stretched lustration’s temporal parameters, reaching back up to eighty years to pre-Soviet and Nazi World War II (WWII) abuses, and extending forward decades into the post-Communist present. This temporal stretching expanded lustration’s goals beyond vetting mechanism to corruption fighter, historical memory marker, and nation-state (re)builder. Lustration’s temporal stretching conflicts with Venice Commission, Council of Europe, and European Court of Human Rights guidelines and legal rulings on lustration. This article presents three temporal approaches to the window of time covered by lustration in eleven post-Communist states between 1990 and 2018: lustration focused on a single, elongated Communist past, lustration covering multiple pasts, and lustration spanning both Communist and post-Communist abuses. Comparative cases in these three temporal categories illustrate significant variation within states surrounding the temporal purview of lustration. This regional variation is juxtaposed with Council of Europe guidelines, related court rulings, and Venice Commission amicus briefs to illustrate contending temporalities surrounding the use of lustration as an “extraordinary” justice measure in consolidated democracies. This study highlights the importance of time as a variable and invites more empirical work on the conditional effects of time on transitional justice.

Spatiotemporal parameters for energy efficient kilohertz-frequency nerve block with low onset response

BackgroundElectrical nerve conduction block has great potential for treatment of disease through reversible and local inactivation of somatic and autonomic nerves. However, the relatively high energy requirements and the presence of undesired excitation at the onset of the kilohertz-frequency (KHF) signals used for block pose obstacles to effective translation. Frequency, electrode geometry, and waveform shape are known to influence block threshold and onset response, but available data provide a limited understanding of how to select these parameters to optimize nerve block.MethodsWe evaluated KHF nerve block in rat tibial nerve across frequencies (5–60 kHz), electrode geometries (monopolar, bipolar, and tripolar), and waveform shapes. We present a novel Fourier-based method for constructing composite signals that systematically sample the KHF waveform design space.ResultsThe lowest frequencies capable of blocking (5–16 kHz) were not the most energy-efficient among the tested frequencies. Further, bipolar cuffs required the largest current and power to block, monopolar cuffs required the lowest current, and both tripolar and monopolar cuffs required the lowest power. Tripolar cuffs produced the smallest onset response across frequencies. Composite signals comprised of a first harmonic sinusoid at fundamental frequency (f0) superposed on a second harmonic sinusoid at 2f0 could block at lower threshold and lower onset response compared to the constituent sinusoids alone. This effect was strongly dependent on the phase of the second harmonic and on the relative amplitudes of the first and second harmonics. This effect was also dependent on electrode geometry: monopolar and tripolar cuffs showed clear composite signal effects in most experiments; bipolar cuffs showed no clear effects in most experiments.ConclusionsOur data provide novel information about block threshold and onset response at the boundary of frequencies that can block. Our results also show an interaction between spatial (cuff geometry) and temporal (frequency and waveform shape) parameters. Finally, while previous studies suggested that temporal parameters could reduce onset response only in exchange for increased block threshold (or vice versa), our results show that waveform shape influences KHF response in ways that can be exploited to reduce both energy and onset responses.

Gait Stability Characteristics in Able-Bodied Individuals During Self-paced Inclined Treadmill Walking: Within-Subject Repeated-Measures Study.

Inclined walking is a challenging task that requires active neuromuscular control to maintain stability. However, the adaptive strategies that preserve stability during inclined walking are not well understood. Investigating the effects of self-paced inclined treadmill walking on gait stability characteristics and the activation patterns of key lower limb muscles can provide insights into these strategies. The aim of this study was to investigate the effects of self-paced inclined treadmill walking on gait stability characteristics and the activation of key lower limb muscles. Twenty-eight able-bodied individuals (mean age 25.02, SD 2.06 years) walked on an augmented instrumented treadmill for 3 minutes at 3 inclination angles (-8°, 0°, and 8°) at their preferred walking speed. Changes in gait characteristics (ie, stability, walking speed, spatial-temporal, kinematic, and muscle forces) across inclination angles were assessed using a repeated measures ANOVA and the Friedman test. The study revealed that inclined treadmill walking has a significant impact on gait characteristics (P<.001). Changes were observed in spatial-temporal parameters, joint angles, and muscle activations depending on the treadmill inclination. Specifically, stability and walking speed decreased significantly during uphill walking, indicating that it was the most challenging walking condition. Uphill walking also led to a decrease in spatial parameters by at least 13.53% and a 5.26% to 10.96% increase in temporal parameters. Furthermore, joint kinematics and peak activation of several muscles, including the hamstrings (biceps femoris, long head=109.5%, biceps femoris, short head=53.3%, semimembranosus=98.9%, semitendinosus=90.9%), gastrocnemius (medial gastrocnemius=40.6%, lateral gastrocnemius=35.3%), and vastii muscles (vastus intermedius=12.8%, vastus lateralis=16.7%) increased significantly during uphill walking. In contrast, downhill walking resulted in bilateral reductions in spatial-temporal gait parameters, with knee flexion increasing and hip flexion and ankle dorsiflexion decreasing. The peak activation of antagonist muscles, such as the quadriceps, tibialis anterior, and tibialis posterior, significantly increased during downhill walking (rectus femoris=97.7%, vastus lateralis =70.6%, vastus intermedius=68.7%, tibialis anterior=72%, tibialis posterior=107.1%). Our findings demonstrate that able-bodied individuals adopt specific walking patterns during inclined treadmill walking to maintain a comfortable and safe walking performance. The results suggest that inclined treadmill walking has the potential to serve as a functional assessment and rehabilitation tool for gait stability by targeting muscle training. Future research should investigate the effects of inclined treadmill walking on individuals with gait impairments and the potential benefits of targeted muscle training. A better understanding of the adaptive strategies used during inclined walking may lead to the development of more effective rehabilitation interventions for individuals with lower limb injuries.

Vertical and Leg stiffness modeling during running: effect of speed and incline.

A spring mass model is often used to describe human running, allowing to understand the concept of elastic energy storage and restitution. The stiffness of the spring is a key parameter and different methods have been developed to estimate both the vertical and the leg stiffness components. Nevertheless, the validity and the range of application of these models are still debated. The aim of the present study was to compare three methods (i.e., Temporal, Kinetic and Kinematic-Kinetic) of stiffness determination. Twenty-nine healthy participants equipped with reflective markers performed 5-min running bouts at four running speeds and eight inclines on an instrumented treadmill surrounded by a tri-dimensional motion camera system. The three methods provided valid results among the different speeds, but the reference method (i.e., Kinematic-Kinetic) provided higher vertical stiffness and lower leg stiffness than the two other methods (both p<0.001). On inclined terrain, the method using temporal parameters provided non valid outcomes and should not be used. Finally, this study highlights that both the assumption of symmetry between compression and decompression phases or the estimation of the vertical displacement and changes in leg length are the major sources of errors when comparing different speeds or different slopes.

Inertial Sensor-Based Estimation of Temporal Events in Skating Sub-Techniques While In-Field Roller Skiing.

The aim of this study was to test and adapt a treadmill-developed method for determination of inner-cycle parameters and sub-technique in cross-country roller ski skating for a field application. The method is based on detecting initial and final ground contact of poles and skis during cyclic movements. Eleven athletes skied 4 laps of 2.5km at low- and high-endurance intensities, using 2 types of skis with different rolling coefficients. Participants were equipped with inertial measurement units attached to their wrists and skis, and insoles with pressure sensors and poles with force measurements were used as reference systems. The method based on inertial measurement units was able to detect >97% of the temporal events detected with the reference system. The inner-cycle temporal parameters had a precision ranging from 49 to 59milliseconds, corresponding to 3.9% to 13.7% of the corresponding inner-cycle duration. Overall, this study showed good reliability of using inertial measurement units on athletes' wrists and skis to determine temporal events, inner-cycle parameters, and the performed sub-techniques in cross-country roller ski skating in field conditions.

Spatial and Temporal Gait Characteristics in Patients Admitted to a Neuro-Rehabilitation Department with Age-Related White Matter Changes: A Gait Analysis and Clinical Study.

Patients with age-related white matter changes (ARWMC) frequently present a gait disorder, depression and cognitive impairment. Our aims are to define which alterations in the gait parameters are associated with motor or neuro-psychological impairment and to assess the role of motor, mood or cognitive dysfunction in explaining the variance of the gait parameters. Patients with gait disorders admitted to a Neuro-rehabilitation Department, affected by vascular leukoencephalopathy who had ARWMC confirmed by a brain MRI, were consecutively enrolled, classified by a neuroradiological scale (Fazekas 1987) and compared to healthy controls. We excluded subjects unable to walk independently, subjects with hydrocephalus or severe aphasia, with orthopaedic and other neurological pathologies conditioning the walking pattern. Patients and controls were assessed by clinical and functional scales (Mini Mental State Examination, Geriatric Depression Scale, Nevitt Motor Performance Scale, Berg Balance Scale, Functional Independence Measure), and computerised gait analysis was performed to assess the spatial and temporal gait parameters in a cross-sectional study. We recruited 76 patients (48 males, aged 78.3 ± 6.2 years) and 14 controls (6 males, aged 75.8 ± 5 years). In the multiple regression analysis, the gait parameter with overall best model summary values, associated with the ARWMC severity, was the stride length even after correction for age, sex, weight and height (R2 = 0.327). The motor performances justified at least in part of the gait disorder (R2 change = 0.220), but the mood state accounted independently for gait alterations (R2 change = 0.039). The increase in ARWMC severity, the reduction of motor performance and a depressed mood state were associated with a reduction of stride length (R = 0.766, R2 = 0.587), reduction of gait speed (R2 = 0.573) and an increase in double support time (R2 = 0.421). The gait disorders in patients with ARWMC are related to motor impairment, but the presence of depression is an independent factor for determining gait alterations and functional status. These data pave the way for longitudinal studies, including gait parameters, to quantitatively assess gait changes after treatment or to monitor the natural progression of the gait disorders.

The Hyoid Bone Kinematics in Dysphagic Stroke Patients: Instantaneous Velocity, Acceleration and Temporal Sequence Matters.

Hyoid bone excursion (HBE) is one of the most critical events in the pharyngeal phase of swallowing. Most previous studies focused on the total displacement and average velocity of HBE. However, HBE during swallowing is not one-dimensional, and the change of velocity and acceleration is not linear. This study aims to elucidate the relationship between the instantaneous kinematics parameters of HBE and the severity of penetration/aspiration and pharyngeal residue in patients with stroke. A total of 132 sets of video-fluoroscopic swallowing study images collected from 72 dysphagic stroke patients were analyzed. The maximal instantaneous velocity, acceleration, displacement, and the time required to reach these values in the horizontal and vertical axes were measured. Patients were grouped according to the severity of the Penetration-Aspiration Scale and the Modified Barium Swallow Impairment Profile- Pharyngeal Residue. The outcome was then stratified according to the consistencies of swallowing materials. Stroke patients with aspiration were associated with a lower maximal horizontal instantaneous velocity and acceleration of HBE, a shorter horizontal displacement, and prolonged time to maximal vertical instantaneous velocity compared to the non-aspirators. In patients with pharyngeal residue, the maximal horizontal displacement of HBE was decreased. After stratification according to bolus consistencies, the temporal parameters of HBE were more significantly associated with aspiration severity when swallowing thin bolus. Meanwhile spatial parameters such as displacement had a bigger influence on aspiration severity when swallowing viscous bolus. These novel kinematic parameters of HBE could provide important reference for estimating swallowing function and outcomes in dysphagic stroke patients.