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The risk of thrombosis increases after SARS-CoV-2 infection. This study aimed to assess associations between pre-infection anticoagulant exposure and SARS-CoV-2 infection-related outcomes in a population-based cohort. Members of the "Meuhedet" health maintenance organization aged >45 years who tested positive for SARS-CoV-2 infection (03/2020–04/2022) were followed. Pre-infection anticoagulant exposure (PAE) was defined as any anticoagulant therapy prescribed ≥1 month prior to SARS-CoV-2 testing. Univariate analyses, multivariable models adjusting for confounders, propensity-score matching, and an age-stratified analysis were performed to assess associations between PAE and hospitalization, intensive care unit (ICU) admission, 30-day and one-year mortality. Of the 127,801 patients included, 2951(2.3 %) had PAE. Comorbidities including ischemic heart disease, diabetes mellitus, hypertension, heart failure, and atrial fibrillation were more common among anticoagulant-exposed than unexposed individuals (p < 0.001). Patients with PAE experienced higher hospitalization (22.7 % vs 5.6 %), ICU admissions (1.9 % vs 0.5 %), 30-day and 1-year mortality rates (4.8 % vs. 0.6, and 8.8 % vs. 1.1 %, respectively), than unexposed individuals, but similar lengths-of-stay. In the multivariable analysis, PAE was independently associated only with hospitalizations (adjusted odds ratio (aOR) = 1.29 [95 % confidence interval (CI): 1.13–1.47]), whereas in the propensity-matched analysis, none of the outcomes differed significantly between the groups. However, in the stratum aged >75 years, 30-day and one-year mortality were significantly reduced in those with PAE (aOR = 0.68 [CI:0.48–0.97], and aOR = 0.73 [CI:0.55–0.97], respectively). SARS-CoV-2-infected individuals with prior exposure to anticoagulants have more comorbidities and experienced a higher incidence of hospitalization but not mortality compared to unexposed patients. Paradoxically, mortality risks decreased in the oldest stratum of anticoagulant-exposed individuals. Further research is required to assess mechanisms for this apparent protective effect. • SARS-CoV2-infected individuals with prior exposure to anticoagulant therapy experienced higher hospitalization rate but not mortality rates. • Mortality risks decreased in older individuals who were exposed to pre-infection anticoagulant therapy. • These results might suggest protective effect of pre-infection anticoagulant therapy in the elderly. [ABSTRACT FROM AUTHOR]

• A single training session with "Just Walk" device didn't improve gait a-symmetry. • The diagonal angle of the resistance cord resulted in insufficient horizontal force. • An improvement was found in the preparation phase of voluntary stepping. Patients with stroke (PwS) demonstrate impaired gait and balance, and asymmetric gait, placing them at high risk of falls. We aimed to investigate the effects of a single training session that included mechanical external perturbation which resists forward movement of the paretic leg during its swing phase of walking on gait and balance in PwS. In a pre-post pilot study, gait asymmetry and balance function were assessed in 22 first-event chronic PwS (i.e., unilateral hemiparesis). PwS underwent tests during baseline and one week later, after participating in a single training session that resisted forward stepping during the swing phase of walking with a device secured around the patient's waist and connected diagonally to the patient's foot by a tension cord. Ground reaction forces and center of pressure were sampled during treadmill gait to assess step length asymmetry. Performance-oriented mobility assessment (POMA), a two-minute walk test (2MWT), and the voluntary step execution test were also measured. We found no significant improvement in step length asymmetry. However, POMA scores, as well as voluntary step execution tests improved with a moderate effect size. It seems that applying diagonal resistance force to the swinging leg resulted in insufficient horizontal force. However, the improvement in the preparation phase, i.e., better weight-bearing abilities during the voluntary stepping, may be due to the compression force applied to the lower limb joints thus providing proprioceptive training. This suggests that proprioceptive training may improve gait performance in stroke patients in a very short training period. [ABSTRACT FROM AUTHOR]

• People with stroke demonstrated significantly greater postural sway than healthy adults. • People with stroke demonstrated larger distance of sway until closed-loop control took place. • People with stroke have a significantly greater reliance on visual input compared with healthy subjects. Many people with stroke (PwS) demonstrate reduced balance and increased postural sway afterwards, which may ultimately lead to falls and injury. In this study, we aimed to better understand postural sway behavior and the mechanisms of balance control by examining balance in upright standing among PwS using methods from statistical mechanics i.e., the Stabilogram diffusion analysis (SDA). Center-of-pressure displacements while standing still were measured in 25 PwS and 11 healthy subjects. The traditional postural sway parameters were measured, and the SDA was used to characterize balance control in eyes-open and eyes-closed conditions. We found that PwS demonstrated significantly greater postural sway in the mediolateral and anterior–posterior directions and significantly higher SDA short-term diffusion coefficients and critical displacement in both eyes-open and eyes-closed conditions. There was also a significant group-by-condition interaction, whereas PwS demonstrated more sway in the eyes-closed condition. The SDA analysis revealed unstable behavior during short-term intervals, interpreted as larger distance of sway until closed-loop control took place. This significant group-by-condition interaction suggests that PwS have a significantly greater reliance on visual input compared with healthy subjects. [ABSTRACT FROM AUTHOR]

Summary Background Obesity is one of the most significant epidemiological trends of the last decades. Recently it was found that obese individuals show postural instability. Balance control mechanisms in obese older adults were less studied. Therefore we aimed to investigate the effect of obesity on balance control mechanisms in older adults. Methods Parameters from Stabilogram-Diffusion Analysis (SDA) and measures from summary statistics of foot centre-of-pressure (COP) displacements along the anterior-posterior (AP) and mediolateral (ML) directions in eyes open and eyes closed conditions were used to characterize postural control in 22 obese (30–<35 kg/m 2 ), 26 overweight (25–<30 kg/m 2 ), and 18 normal weight subjects (18.5–<25 kg/m 2 ). Results Obese group subjects demonstrated significantly greater transition displacement, transition time interval, and short-term scaling exponent in the ML-direction compared with the normal weight group (eyes open and closed). In the AP-direction the obese group showed greater transition displacement (eyes open) and short-term scaling exponent (eyes open and closed). Average AP-COP and ML-COP ranges of COP sway were higher in the obese group compared with the normal weight group (eyes open and closed). Conclusions This work indicates an altered postural control process in obese older adults. A greater sway displacement before closed-loop feedback mechanisms are called into play was seen in the ML direction that may lead to a higher risk of instability and fall events. [ABSTRACT FROM AUTHOR]

Abstract: Background: In order to evaluate the effect of an auditory–memory attention-demanding task on balance control, nine blind adults were compared to nine age–gender-matched sighted controls. This issue is particularly relevant for the blind population in which functional assessment of postural control has to be revealed through “real life” motor and cognitive function. The study aimed to explore whether an auditory–memory attention-demanding cognitive task would influence postural control in blind persons and compare this with blindfolded sighted persons. Methods: Subjects were instructed to minimize body sway during narrow base upright standing on a single force platform under two conditions: 1) standing still (single task); 2) as in 1) while performing an auditory–memory attention-demanding cognitive task (dual task). Subjects in both groups were required to stand blindfolded with their eyes closed. Center of Pressure displacement data were collected and analyzed using summary statistics and stabilogram-diffusion analysis. Findings: Blind and sighted subjects had similar postural sway in eyes closed condition. However, for dual compared to single task, sighted subjects show significant decrease in postural sway while blind subjects did not. Interpretation: The auditory–memory attention-demanding cognitive task had no interference effect on balance control on blind subjects. It seems that sighted individuals used auditory cues to compensate for momentary loss of vision, whereas blind subjects did not. This may suggest that blind and sighted people use different sensorimotor strategies to achieve stability. [ABSTRACT FROM AUTHOR]

Background: A cross-sectional retrospective study of parameters reflecting balance function in elderly fallers and non-fallers was conducted to better understand postural control mechanisms in individuals prone to falls. Methods: Ninety-nine old adults (65–91years, mean age 78.4 (SD 5.7)) from two self-care residential facilities participated in the study. Foot center-of-pressure (CoP) displacement data were collected during narrow base upright stance eyes closed conditions and analyzed using summary statistics and Stabilogram-Diffusion Analysis (SDA) for mediolateral (ML) and anteroposterior (AP) directions. Subjects were instructed to minimize body sway. Findings: Twenty-nine of the subjects reported at least one fall and 69 subjects reported no falls in the past six months. The SDA showed significantly higher short-term diffusion coefficients and critical displacements in fallers in the ML but not the AP direction. Mean sway area and ML-CoP sway range were also larger in fallers. Interpretation: The greater ML critical displacement seen in fallers suggests that balance corrections on average occurred at higher sway amplitudes in this population. This is consistent with an ML decrease in the sensitivity of their postural control system. A higher short-term diffusion coefficient is consistent with increased muscle stiffness, a possible compensation for lost control sensitivity. Testing balance function under narrow stance conditions provides a modest increase in task difficulty that may help reveal pre-conditions of the balance control system that could increase the risk of falls. [Copyright &y& Elsevier]

Abstract: Objective: If balance is lost, quick step execution can prevent falls. Research has shown that speed of voluntary stepping was able to predict future falls in old adults. The aim of the study was to investigate voluntary stepping behavior, as well as to compare timing and leg push-off force–time relation parameters of involved and uninvolved legs in stroke survivors during single- and dual-task conditions. We also aimed to compare timing and leg push-off force–time relation parameters between stroke survivors and healthy individuals in both task conditions. Methods: Ten stroke survivors performed a voluntary step execution test with their involved and uninvolved legs under two conditions: while focusing only on the stepping task and while a separate attention-demanding task was performed simultaneously. Temporal parameters related to the step time were measured including the duration of the step initiation phase, the preparatory phase, the swing phase, and the total step time. In addition, force–time parameters representing the push-off power during stepping were calculated from ground reaction data and compared with 10 healthy controls. Results: The involved legs of stroke survivors had a significantly slower stepping time than uninvolved legs due to increased swing phase duration during both single- and dual-task conditions. For dual compared to single task, the stepping time increased significantly due to a significant increase in the duration of step initiation. In general, the force time parameters were significantly different in both legs of stroke survivors as compared to healthy controls, with no significant effect of dual compared with single-task conditions in both groups. Conclusions: The inability of stroke survivors to swing the involved leg quickly may be the most significant factor contributing to the large number of falls to the paretic side. The results suggest that stroke survivors were unable to rapidly produce muscle force in fast actions. This may be the mechanism of delayed execution of a fast step when balance is lost, thus increasing the likelihood of falls in stroke survivors. [Copyright &y& Elsevier]

Abstract: Melzer I, Tzedek I, Or M, Shvarth G, Nizri O, Ben-Shitrit K, Oddsson LE. Speed of voluntary stepping in chronic stroke survivors under single- and dual-task conditions: a case-control study. Objective: To investigate voluntary step behavior of chronic stroke survivors during single- and dual-task conditions and compare the results to healthy age- and sex-matched controls. Design: Case-control. Setting: Laboratory-based study. Participants: Chronic stroke survivors (n=16) and healthy controls (n=16). Interventions: Not applicable. Main Outcome Measures: Forward and backward rapid voluntary stepping were performed as a reaction time task under 2 conditions: (1) awaiting a cutaneous cue (single task), and (2) awaiting a cutaneous cue while performing an attention-demanding task. Step initiation, preparatory and swing phases, foot-off time, and foot-contact time were extracted from center of pressure and ground reaction forceplate data. Results: Chronic stroke survivors were significantly slower than healthy controls in all step parameters under single- and dual-task conditions. For dual compared with single task, the foot-contact time increased from 1295ms to 1445ms (12%) in chronic stroke survivors and from 876ms to 1006ms (15%) in controls. Conclusions: The significant increase in step phase''s duration during single- and dual-task conditions may be a factor contributing to the large number of falls seen in stroke patients. The interference effects of attention-demanding task were similar between groups, suggesting that both groups used similar strategies. Future research should determine whether step training can improve step decrements in chronic stroke survivors. [Copyright &y& Elsevier]

Highlights: [•] VOR and static balance control were tested in young adults with IDD. [•] Vestibular-ocular response (VOR) function was clinically impaired in 62% of the study group. [•] Balance standing on foam with eyes closed is impaired in young adults with IDD and VOR deficits. [•] VOR function should be screened in IDD to enable early detection. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the inter-observer reliability and agreement of balance recovery responses, step and multiple-steps thresholds, and kinematic parameters of stepping responses. Older and younger adults were exposed to 36 progressively challenging right and left unannounced surface translations during quiet standing. Subjects were instructed to "react naturally". Step threshold and multiple-step threshold were defined as the minimum disturbance magnitude that consistently elicited one and more than one recovery step, respectively. Fall threshold is defined as the minimum disturbance magnitude from which a fall resulted (i.e., fall into harness system or grasped one of the anchor straps of the harness, or grasped the research assistant to maintain balance). The inter-observer reliability of balance recovery responses for older adults were excellent, especially for step and multiple-step thresholds (ICC2,1 = 0.978 and ICC2,1 = 0.971, respectively; p < 0.001). Also kinematic parameters of stepping responses such as step recovery duration and step length were excellent (ICC2,1 > 0.975 and ICC2,1 = 0.978, respectively; p < 0.001), substantial reliability was found for swing phase duration (ICC2,1 = 0.693, p < 0.001). Younger adults showed similar ICCs. The Bland-Altman plots demonstrated excellent limits of agreement (LOA > 90%) for most kinematic step parameters and stepping thresholds. These results suggest that balance recovery responses and kinematic parameters of stepping including step threshold and multiple-step threshold are extremely reliable parameters. The measure of balance recovery responses from unexpected loss of balance is feasible and can be used in clinical setting and research-related assessments of fall risk. [ABSTRACT FROM AUTHOR]

Speaker Change Detection (SCD) is the problem of splitting an audio-recording by its speaker-turns. Many real-world problems, such as the Speaker Diarization (SD) or automatic speech transcription, are influenced by the quality of the speaker-turns estimation. Previous works have already shown that auxiliary textual information (for mono-lingual systems) can be of great use for detection of speaker-turns and the diarization systems' performance. In this paper, we suggest a framework for speaker-turn estimation, as well as the determination of clustered speaker identities to the SD system, and examine our approach over a multi-lingual dataset that consists of three mono-lingual datasets—in English, French, and Hebrew. As such, we propose a generic and language-independent framework for the SCD problem that is learned through textual information using state-of-the-art transformer-based techniques and speech-embedding modules. Comprehensive experimental evaluation shows that (i) our multi-lingual SCD framework is competitive enough when compared to a framework over mono-lingual datasets, and that (ii) textual information improves the solution's quality compared to the speech signal-based approach. In addition, we show that our multi-lingual SCD approach does not harm the performance of SD systems. • Improvement of speaker change detection & diarization system by textual data. • Multilingual training framework to compute speaker-turns in multiple languages. • Competitive strategy transformers and speech embedding for speaker labeling. • Additive approach for multilingual domain adaptation in NLP. [ABSTRACT FROM AUTHOR]

Introduction Falling during walking is a common problem among the older population. Hence, the challenge facing clinicians is identifying who is at risk of falling during walking, for providing an effective intervention to reduce that risk. We aimed to assess whether the clinical version of the narrow path walking test (NPWT) could identify older adults who are reported falls. Materials and methods A total of 160 older adults were recruited and asked to recall fall events during the past year. Subjects were instructed to walk in the laboratory at a comfortable pace within a 6 meter long narrow path, 3 trials under single task (ST) and 3 trials dual task (DT) conditions without stepping outside the path (i.e., step errors). The average trial time , number of steps, trial velocity , number of step errors, and number of cognitive task errors were calculated for ST and DT. Fear of falling, performance oriented mobility assessment (POMA) and mini-metal state examination (MMSE) were measured as well. Results Sixty-one subjects reported that they had fallen during the past year and 99 did not. Fallers performed more steps, and were slower than non-fallers. There were no significant differences, however, in the number of steps errors, the cognitive task errors in ST and DT in POMA and MMSE. Conclusion Our data demonstrates slower gait speed and more steps during the NPWT in ST and DT in fallers. There is no added value of DT over the ST for identification of faller’s older adults. [ABSTRACT FROM AUTHOR]

This study aimed at investigating age-related changes in gait kinematics and in kinematic adaptations over a wide range of walking velocities. Thirty-four older adults and 14 younger adults walked on a treadmill; the treadmill velocity was gradually increased in increments of 0.2 miles/hour (mph) (1.1–1.9 mph) and then decreased in the same increments. Pelvic, trunk, upper limbs and lower limbs angular total ranges of motion (tROM), stride time, stride length, and step width were measured. The older adults had lower pelvic, trunk tROM and shorter strides and stride time compared with the younger adults. As the treadmill speed was gradually increased, the older adults showed an inability to change the pelvic list angular motions (3.1 ± 1.3° to 3.2 ± 1.4°) between different walking velocities, while the younger adults showed changes (5.1 ± 1.8° to 6.3 ± 1.7°) as a function of the walking velocity. As the walking velocity increased, the older adults increased their stride length (from 57.0 ± 10 cm to 90.2 ± 0.1 cm) yet stride times remained constant (from 1.17 ± 0.3 sec to 1.08 ± 0.1 sec), while the younger adults increased stride length and reduced stride times (from 71.4 ± 10 cm to 103.0 ± 7.9 m and from 1.45 ± 0.2 sec to 1.22 ± 0.1 sec, respectively). In conclusion, the older adults were unable to make adaptations in pelvic and trunk kinematics between different walking speeds (rigid behavior), while the younger adults showed more flexible behavior. Pelvic and trunk kinematics in different walking speeds can be used as variables in the assessment of gait in older adults. [ABSTRACT FROM AUTHOR]

Abstract: Decline in gait stability has been associated with increased fall risk in older adults. Reliable and clinically feasible methods of gait instability assessment are needed. This study evaluated the relative and absolute reliability and concurrent validity of the testing procedure of the clinical version of the Narrow Path Walking Test (NPWT) under single task (ST) and dual task (DT) conditions. Thirty independent community-dwelling older adults (65–87 years) were tested twice. Participants were instructed to walk within the 6-m narrow path without stepping out. Trial time, number of steps, trial velocity, number of step errors, and number of cognitive task errors were determined. Intraclass correlation coefficients (ICCs) were calculated as indices of agreement, and a graphic approach called “mountain plot” was applied to help interpret the direction and magnitude of disagreements between testing procedures. Smallest detectable change and smallest real difference (SRD) were computed to determine clinically relevant improvement at group and individual levels, respectively. Concurrent validity was assessed using Performance Oriented Mobility Assessment Tool (POMA) and the Short Physical Performance Battery (SPPB). Test–retest agreement (ICC1,2) varied from 0.77 to 0.92 in ST and from 0.78 to 0.92 in DT conditions, with no apparent systematic differences between testing procedures demonstrated by the mountain plot graphs. Smallest detectable change and smallest real change were small for motor task performance and larger for cognitive errors. Significant correlations were observed for trial velocity and trial time with POMA and SPPB. The present results indicate that the NPWT testing procedure is highly reliable and reproducible. [Copyright &y& Elsevier]

Abstract: This study evaluated the effects of a water exercise training program that includes perturbation exercises (WEP) to improve the speed of voluntary stepping reaction in older adults. Speed of voluntary stepping considered as an important skill to prevent a fall when balance is lost. In a single-blinded randomized controlled trial with a crossover design thirty-six independent old adults (64–88 years old) were divided into two groups. Group A received WEP for the first 12 weeks, followed by no intervention for the second 12 weeks. Group B did not receive intervention for the first 12 weeks and received WEP for the second 12 weeks. Voluntary Step Execution Test and postural stability in upright standing (eyes open and closed conditions) were measured at baseline, 12 weeks, and 24 weeks. A significant interaction effect between group and time was found for the step execution, due to improvement in initiation phase and swing phase durations in the WEP group. Also significant improvement in postural stability parameters in eyes open and closed conditions is noted. The present results indicate that the primary benefit of WEP that include perturbations to induce stepping, was a reduction in voluntary stepping times. The WEP generalized to a better control of balance in up-right standing. [Copyright &y& Elsevier]

Abstract: Objective: Previous studies have demonstrated that ankle muscle fatigue alters postural sway. Our aim was to better understand postural control mechanisms during upright stance following plantar flexor fatigue. Method: Ten healthy young volunteers, 25.7±2.2years old, were recruited. Foot center-of-pressure (CoP) displacement data were collected during narrow base upright stance and eyes closed (i.e. blindfolded) conditions. Subjects were instructed to stand upright and as still as possible on a force platform under five test conditions: (1) non-fatigue standing on firm surface; (2) non-fatigue standing on foam; (3) ankle plantar flexor fatigue, standing on firm surface; (4) ankle plantar flexor fatigue, standing on foam; and (5) upper limb fatigue, standing on firm surface. An average of the ten 30-s trials in each of five test conditions was calculated to assess the mean differences between the trials. Traditional measures of postural stability and stabilogram-diffusion analysis (SDA) parameters were analyzed. Results: Traditional center of pressure parameters were affected by plantar flexor fatigue, especially in the AP direction. For the SDA parameters, plantar flexor fatigue caused significantly higher short-term diffusion coefficients, and critical displacement in both mediolateral (ML) and anteroposterior (AP) directions. Long-term postural sway was different only in the AP direction. Conclusions: Localized plantar flexor fatigue caused impairment to postural control mainly in the Sagittal plane. The findings indicate that postural corrections, on average, occurred at a higher threshold of sway during plantar flexor fatigue compared to non-fatigue conditions. [Copyright &y& Elsevier]

Abstract: We propose a variational method for model based segmentation of gray-scale images of highly degraded historical documents. Given a training set of characters (of a certain letter), we construct a small set of shape models that cover most of the training set''s shape variance. For each gray-scale image of a respective degraded character, we construct a custom made shape prior using those fragments of the shape models that best fit the character''s boundary. Therefore, we are not limited to any particular shape in the shape model set. In addition, we demonstrate the application of our shape prior to degraded character recognition. Experiments show that our method achieves very accurate results both in segmentation of highly degraded characters and both in recognition. When compared with manual segmentation, the average distance between the boundaries of respective segmented characters was 0.8 pixels (the average size of the characters was pixels). [Copyright &y& Elsevier]

Upper-extremity reactions are part of a whole-body response to counterweight the falling center of mass after unexpected balance loss. Impairments in upper-extremity reactions due to unilateral hemiparesis may contribute to stroke survivors propensity for falling. We aimed to characterize upper-extremity (paretic and non-paretic sides) reactive movements in response to lateral balance perturbations in Persons with Stroke vs. healthy controls. Twenty-six subacute persons with stroke and 15 healthy controls were exposed to multidirectional sudden unannounced surface translations in stance. Spatiotemporal parameters of upper- and lower-extremity balance responses to lateral perturbations were analyzed. In both groups reactive upper-extremity movement initiation preceded reactive step initiation. In response to a loss of balance toward the paretic side, persons with stroke demonstrated delayed movement initiation of both upper- and lower-extremity compared with healthy controls (In persons with stroke: 234.7 ± 60.0 msec and 227.1 ± 39.6 msec for upper extremities vs. 272.1 ± 59.1 msec for lower-extremity; and in controls: 180.1 ± 39.9 msec and 197.8 ± 61.3 msec for upper-extremities vs. 219.3 ± 40.8 msec for lower-extremity; p = 0.001, Cohen's d's: 0.59–1.03) and a greater abduction excursion in the ipsilateral upper-extremity compared with the contralateral upper-extremity (In persons with stroke: 39.3 ± 23.6 cm vs. 24.9 ± 10.1 cm, respectively; In Controls: 42.6 ± 21.8 cm vs. 29.3 ± 17.3 cm, respectively). The faster upper-extremity reactive movement reactions compared to reactive step initiation in both persons with stroke and healthy controls suggests that balance recovery is an automatic "reflex-like" response. Delayed upper-extremity reactive reactions in conditions of surface translation toward the non-paretic side in persons with stroke may increase the risk of falls in the direction of the paretic side. • Persons with stroke demonstrated similar reactive response patterns to healthy persons. • Persons with stroke demonstrated a delayed movement onset when balance is lost to the paretic side. • Healthy people and persons with stroke have faster upper- vs. lower-limb movement initiation. [ABSTRACT FROM AUTHOR]