Search Results (3,953)

Pedestrian-induced vibration is a critical serviceability concern for flexible structures such as footbridges and long-span floors. Existing human–structure interaction models commonly rely on single-degree-of-freedom simplifications and time-domain simulations, making them less suitable for frequency-domain analysis. This paper proposes a spectral analysis model for crowd-structure interaction vibration under unrestricted pedestrian traffic. The structure was formulated as a multi-degree-of-freedom modal system, whereas each pedestrian is represented by an independent spring–mass–damper system. To address the time-varying nature of moving crowds, a piecewise stationary assumption was introduced: the continuous walking path was discretized into fixed position groups, within each of which a time-invariant coupled equation of motion was established. The response spectra obtained for different position groups were combined using residence-time weighting, thereby allowing nonuniform walking speeds to be considered. The corresponding frequency response function was derived using the state–space method, and the structural acceleration power spectral density and root mean square responses were obtained by incorporating an unrestricted crowd walking load spectral model. Comparisons with field measurements from two footbridges demonstrated reasonable agreement. The resulting framework offers an efficient frequency-domain approach for vibration serviceability assessment under unrestricted pedestrian traffic. Full article

Background/Objectives: Exercise medicine is gaining significant importance in adult oncology to improve physical activity and quality of life (QoL). However, few studies have investigated the effects of adapted physical activities in the pediatric population. The aim of this secondary analysis is to compare the movement quality of a hematological/oncological pediatric population before and after an individualized exercise program (IEP). Methods: Participants who met the inclusion criteria (aged 5–18 years, oncological/hematological diagnosis, consent) underwent an IEP delivered both in the hospital and via telemedicine at home. The subject’s movement quality was assessed before and after six months of the IEP using instrumented functional tests (i.e., 6 min walking test, Timed Up and Go, T25-FW, and turning test). To reduce the number of variables obtained, principal component analysis (PCA) was performed, and the resulting scores were then compared. Results: A total of 18 subjects (median age 12 years; eight females) were included in the analysis. Through the PCA, four dimensions were identified: Gait Efficiency, Gait Quality, Dynamic Balance, and Functional Abilities. The pre–post comparison showed significant improvements (p = 0.002) in Dynamic Balance and a trend (p = 0.05) in Gait Efficiency. Conclusions: The presented results indicate the crucial Principal Components (PCs) of movement in children treated for cancer. Moreover, in our setting, under the IEP we observed a significant improvement in Dynamic Balance. The results are consistent with those observed in previous studies. However, the limited number of subjects and the study design preclude definitive conclusions. Full article

Background and Objectives: Sarcopenia and frailty are associated with falls, disability, and functional decline in older adults. This review evaluated traditional Chinese mind–body exercise (TCMBE), including Tai Chi and Health Qigong, in adults aged 60 years or older with clinically defined sarcopenia or frailty. Materials and Methods: Randomized controlled trials identified through December 2024 from six English- and Chinese-language databases were synthesized. The analyses included physical performance and secondary outcomes and explored sarcopenia and frailty as study-level subgroups. Results: Twenty-two trials involving 1660 participants were included. TCMBE was associated with a shorter Timed Up and Go Test time (mean difference [MD], −1.17 s; 95% CI, −1.80 to −0.54; p < 0.01; I² = 74%), a higher Short Physical Performance Battery score (MD, 0.99 points; 95% CI, 0.58 to 1.40; p < 0.01; I² = 24%), and greater grip strength (MD, 2.02 kg; 95% CI, 0.58 to 3.47; p = 0.006; I² = 89%). The 6 min walk test estimate was borderline and imprecise (MD, 11.76 m; 95% CI, 0.10 to 23.43; p = 0.05; I² = 0%), and no clear overall effects were observed for gait speed, the 30 s chair stand test, sit-to-stand time, Berg Balance Scale score, muscle mass, depressive symptoms, or quality of life. Several analyses showed substantial heterogeneity, and some subgroup estimates were based on only one or two studies. Conclusions: Low-certainty evidence suggests that TCMBE may produce small improvements in TUGT performance, SPPB scores, and grip strength. Very-low-certainty evidence leaves its effects on gait speed and quality of life uncertain. Risk-of-bias concerns, heterogeneity, imprecision, and uncertain clinical significance limit confidence in the current estimates. The available evidence is insufficient to support routine implementation, and larger, rigorously conducted randomized controlled trials are needed. Full article

Background/Objectives: Patients with prolonged disorder of consciousness (PDOC) who regained consciousness in intensive care for consciousness rehabilitation (ICCR) were referred to further brain rehabilitation (FBR). The current retrospective cohort study evaluated the functional and cognitive outcomes of FBR. Methods: We assessed outcomes in 258 PDOC patients during FBR and used multivariate regression analyses to examine the influence of demographic and clinical characteristics on outcomes. Results: During FBR, Functional Independence Measure (FIM) motor, cognitive, and total scores improved from 21 ± 11, 11 ± 10, and 32 ± 15 to 43 ± 26, 18 ± 7, and 61 ± 32, respectively (p < 0.001). Dynamic Lowenstein Occupational Therapy Cognitive Assessment (DLOTCA) total scores increased from 57 ± 29 to 82 ± 36, and the average 6-min-walk (6MW) distances improved from 295 to 374 m (p < 0.001). Higher discharge FIM and DLOTCA scores were associated with younger age, traumatic etiology of the brain injury, shorter time to regaining consciousness, and higher FIM and DLOTCA scores at admission to FBR (p < 0.05). Conclusions: We observed functional and cognitive improvement in the examined patients. The improvement was associated with factors that may mainly reflect the severity of brain damage. The findings support continuing rehabilitation before and after emerging from PDOC. Full article

Portable electromyography biofeedback (EMG-BFB) may support gait rehabilitation, but whole-gait responses across increasing portable auditory feedback goals are unclear. Twenty-four adults completed baseline treadmill walking and four counterbalanced right medial gastrocnemius activation-goal conditions set at 20%, 40%, 60%, and 80% above baseline; 23 contributed primary biomechanical data. Treadmill speed was adjusted within each condition to support achievement of the activation goal. Outcomes included walking speed, ground-reaction forces, force-time metrics, step length, temporal measures, and asymmetry. Repeated-measures MANOVA, outcome-specific repeated-measures ANOVAs, dose-response coefficients, bootstrap intervals, and leave-one-participant-out analyses were used. The combined gait-biomechanics outcomes differed significantly across activation-goal conditions (p < 0.001), with large condition effects for walking speed, propulsion, braking magnitude, and step length. From baseline to the highest goal, treadmill speed increased from 1.07 to 1.44 m/s, mean propulsion by 0.086 N/BW, braking magnitude by 0.109 N/BW, and mean step length by 0.150 m. Exploratory speed-adjusted models retained anterior–posterior and vertical loading-response associations but not peak propulsion; activation goal and achieved speed were strongly collinear. Unilateral feedback was not associated with systematic step-length or step-time asymmetry. Portable auditory EMG-BFB at increasing activation goals was accompanied by coordinated changes across gait mechanics. Full article

This study proposes MSATE-Net for next-day stock index forecasting. The model combines parallel one-dimensional convolutions with receptive fields of 3, 7, and 15 trading days, a bidirectional LSTM operating entirely inside a historical lookback window, sample-dependent temporal attention, and a residual regularized prediction head. Here, “bidirectional” denotes paired processing of the same observed window; it does not assert time-reversal invariance of financial prices or access to observations after the forecast origin. The globally learned attention temperature controls overall selectivity and is not described as a regime-specific adaptive parameter. Experiments use S&P 500, CSI 300, and Nikkei 225 data; persistence and drift benchmarks; recent forecasting architectures; five-seed uncertainty estimates; expanding-window tests; return and directional metrics; and Diebold–Mariano comparisons. The revised evidence supports lower price-level errors, while directional and significance results are mixed across markets. Because a separate model is fitted in each market, the findings establish cross-market consistency rather than transfer learning. Full article

Background/Objectives: Phase angle (PhA), derived from bioelectrical impedance analysis (BIA), has been proposed as an indicator of cellular health, nutritional status, and physical function. This study aimed to investigate the association between PhA, physical function, and sarcopenia defined according to the Asian Working Group for Sarcopenia (AWGS) 2025 criteria in community-dwelling older adults. In addition, we explored a preliminary PhA cutoff for discriminating women with prevalent sarcopenia. Methods: This cross-sectional study included 317 participants (81 men, 236 women) aged ≥65 years who participated in functional assessments conducted in three locations of Fukushima Prefecture, Japan, in 2024. PhA at 50 kHz was measured using BIA. Assessments included body composition, grip strength, knee extension strength, maximum walking speed, Timed Up and Go (TUG), the Montreal Cognitive Assessment, Japanese version (MoCA-J), and the Kihon Checklist (KCL). Sarcopenia was defined according to the AWGS 2025 criteria. Group differences were examined using the Mann–Whitney U test, and associations were assessed using Spearman’s rank correlation coefficients. Age-adjusted logistic regression analysis was performed in women to examine the association between PhA and sarcopenia. Receiver operating characteristic (ROC) analysis was performed in women to explore a preliminary PhA cutoff because the limited number of men with sarcopenia precluded a stable sex-specific analysis. Results: Sex-specific Spearman’s rank correlation analyses showed that lower PhA values were associated with lower muscle strength (grip strength and knee extension strength) and poorer physical function (maximum walking speed and Timed Up and Go [TUG] performance) in both men and women. Lower PhA values were independently associated with prevalent sarcopenia in women after adjustment for age (odds ratio, 0.26; 95% CI, 0.09–0.80). ROC analysis identified an exploratory PhA cutoff of 4.48° for discriminating women with prevalent sarcopenia (AUC = 0.67; sensitivity = 0.65; specificity = 0.71), indicating modest discriminative performance. Conclusions: Lower PhA values were cross-sectionally associated with poorer physical function and prevalent sarcopenia among community-dwelling older women. An exploratory PhA cutoff of 4.48° was identified to discriminate prevalent sarcopenia in women. However, this cutoff should be considered hypothesis-generating rather than an established clinical threshold and requires validation in larger, independent cohorts and prospective longitudinal studies before clinical application. Full article

The Timed Up and Go (TUG) test is widely used to assess functional mobility in Parkinson’s disease (PD), although total test duration may overlook phase-specific biomechanical alterations. This cross-sectional study investigated whether phase-specific analysis of the instrumented TUG (iTUG) could identify candidate biomechanical markers characterizing differences among early-stage PD subgroups and healthy controls. Seventy-nine participants (38 PD, 41 controls) performed four iTUG trials in the OFF-medication state. Movement data were collected using synchronized inertial measurement units and optoelectronic motion capture systems. The iTUG was segmented into six phases, and temporal, spatiotemporal, variability, and multisegmental kinematic parameters were analyzed. Participants with PD at modified Hoehn and Yahr (mH&Y) stage 2 performed the iTUG more slowly than controls (p < 0.001), mainly due to impairments during walking (p = 0.012) and turning. Turning was the only phase that distinguished controls from individuals with PD at mH&Y stages 1–1.5 (p = 0.015), who also showed increased elbow asymmetry (p = 0.009). Participants with PD at mH&Y stage 2 exhibited broader differences, including increased double-support time, shorter stride length, lower walking speed, reduced frontal-plane control, and reduced trunk, elbow, hip, and ankle motion, whereas gait variability did not differ significantly between groups. Sagittal trunk ROM on the less affected side was the only variable that significantly differed between the two PD subgroups. These findings suggest that phase-specific iTUG analysis may reveal candidate biomechanical markers associated with mH&Y stage and functional mobility impairment and support sensor-based assessment for objective characterization of functional mobility in PD. Full article

Accurate continuous prediction of lower-limb joint angles from surface electromyography (sEMG) remains challenging because of the nonlinear, non-stationary, and subject-specific nature of sEMG signals, which can reduce robustness and lead to degraded prediction accuracy during highly dynamic gait phases. In this study, we propose RTGNet, a dual-branch deep learning framework for lower-limb joint-angle prediction from multichannel sEMG. The method constructs two feature views from the same sEMG stream: recurrence-plot (RP)-based representations for nonlinear texture characterization and time-series sequences for long-term temporal dependency modeling. These views are processed by a convolutional neural network (CNN) with a convolutional block attention module (CBAM) and a bidirectional long short-term memory network (BiLSTM), respectively, and integrated through an adaptive gated fusion mechanism. An enhanced Huber-TopK loss is further employed to emphasize samples with large prediction errors. Experiments on the SIAT-LLMD dataset under an offline cross-subject evaluation setting show that RTGNet achieves a mean absolute error (MAE) of 3.87°, a root mean square error (RMSE) of 5.25°, and an $R^2$ of 0.81 during walking, as well as an MAE of 4.53°, an RMSE of 6.47°, and an $R^2$ of 0.84 during stair ascent. The proposed framework outperforms temporal-only and RP-based baselines, and ablation results further support the effectiveness of the gated fusion strategy and CBAM attention. Overall, these results suggest that integrating recurrence texture and temporal dynamics is a promising strategy for sEMG-driven joint-angle prediction and provides a useful basis for future exoskeleton control-oriented studies. Full article

Flexible strain sensors require both a responsive conductive network and a mechanically compliant supporting structure. In this study, a sandwich-structured carbon nanotube (CNT)/graphene–thermoplastic polyurethane (TPU) nanofiber strain sensor was fabricated by electrospinning, spray-coating, pre-stretching, and hot-pressing. Field-emission scanning electron microscopy was used to examine the nanofiber and coated-fiber morphology, while energy-dispersive X-ray spectroscopy was used only to describe elemental distribution. The electrical response was quantitatively evaluated under tensile deformation. The sensor exhibited piecewise gauge factors of approximately 47.3, 269.6, and 613.8 over strain ranges of 0–20%, 20–45%, and 45–60%, respectively. The response and recovery times were approximately 120 and 180 ms, and the electrical response remained observable over 5000 loading–unloading cycles at 20% strain. Qualitative demonstrations involving finger-bending, elbow-bending, pulse, grasping, walking, and repeated pressing produced distinguishable resistance-time patterns. These results indicate the potential of the CNT/graphene–TPU device for wearable deformation monitoring. Full article

Objective: Genetic factors contribute to physical activity (PA) and sedentary behavior (SB), two complex behavioral traits. They may be associated with musculoskeletal and inflammatory diseases. However, the relationships of domain-specific PA and SB traits with osteoporosis (OS), psoriatic arthritis (PsA), and rheumatoid arthritis (RA) remain unclear. A two-sample Mendelian randomization (MR) analysis assessed potential bidirectional associations between these behavioral traits and the three diseases. Methods: GWAS summary statistics were used to examine five domain-specific PA traits, three SB traits, and OS, RA, and PsA. Primary causal estimates were obtained using the inverse-variance weighted (IVW) method. Complementary analyses used MR-Egger regression, the weighted median method, and the weighted mode method. Sensitivity analyses were performed using Cochran’s Q test, the MR-Egger intercept test, MR-PRESSO, and leave-one-out analysis. Multiple testing was addressed using false discovery rate (FDR) correction. Results: In the forward MR analyses, genetically predicted liability to Light DIY was associated with lower odds of PsA after FDR correction (OR = 0.006, 95% CI = 0.0002–0.236, FDR-adjusted p = 0.018). Genetically predicted longer television viewing was linked to increased odds of PsA (OR = 2.205, 95% CI = 1.089–4.463, FDR-adjusted p = 0.028) and RA (OR = 1.006, 95% CI = 1.002–1.010, FDR-adjusted p = 0.004). Walking for pleasure showed a nominal inverse association with PsA, and computer use showed a nominal inverse association with RA. Neither association remained significant after FDR correction. No evidence of associations with the broad self-reported OS diagnosis was observed. Reverse MR analyses showed lower odds of Walking for pleasure (OR = 0.662, 95% CI = 0.484–0.906, FDR-adjusted p = 0.013) and Other exercises (OR = 0.651, 95% CI = 0.490–0.864, FDR-adjusted p = 0.006) for genetic liability to RA. RA liability was also associated with longer television viewing time (β = 0.708, 95% CI = 0.251–1.165, FDR-adjusted p = 0.006). No reverse associations were observed for PsA. Conclusions: This bidirectional MR study identified several potential genetically predicted associations of domain-specific PA and SB traits with PsA and RA. The findings for television viewing and RA may suggest a potential bidirectional association. However, the results should be considered hypothesis-generating. These findings require independent replication and further validation before causal or clinical conclusions can be drawn. Full article

Objective: To investigate the effects of parathyroidectomy (PTX) on muscle mass, muscle strength, and motor function at different postoperative stages in uremic patients with secondary hyperparathyroidism (SHPT). Methods: A total of 47 uremic patients with SHPT who underwent PTX were enrolled in this study. General clinical data, including age and blood biochemical parameters, were collected. Pre- and postoperative measurements of lean body mass, the appendicular skeletal muscle index (ASMI), skinfold thickness, grip strength, and 6-m walk time were recorded. Patients were divided into three groups—short-term, mid-term, and long-term—based on the timing of postoperative follow-up, and the patterns of change in muscle mass, strength, and function at different time points following PTX were analyzed. Results: In the short-term postoperative period, patients’ grip strength increased significantly, and their 6-m walk time decreased significantly (p < 0.05), whilst lean body mass, the ASMI and skinfold thickness showed no significant changes compared with preoperative levels (p > 0.05). In the mid-term postoperative period, lean body mass, the ASMI and grip strength all increased significantly, whilst the 6-m walk time decreased significantly (p < 0.05); there was no significant change in skinfold thickness (p > 0.05). In the long-term postoperative period, skinfold thickness and grip strength increased significantly, and the 6-m walk time was significantly reduced (p < 0.05), whilst lean body mass and the ASMI showed no statistically significant difference compared to preoperative levels (p > 0.05). Conclusions: PTX can effectively improve muscle strength and lower limb motor function in uremic patients with SHPT, and these improvements persist during long-term postoperative follow-up; improvements in muscle mass-related indicators exhibit a phased pattern, with significant increases observed in the mid-postoperative period, suggesting that the improvement in muscle mass following PTX is subject to a certain time-dependent effect. Full article

Background: Achilles tendon contracture is a prevalent issue in pediatric populations, often leading to complications such as toe walking and limited ankle dorsiflexion. This study aims to compare the clinical outcomes of two surgical techniques for Achilles tendon lengthening—conventional percutaneous lengthening and Z-plasty—in children with idiopathic Achilles tendon contracture, while assessing the adequacy of a six-week postoperative immobilization period. Methods: A retrospective analysis was conducted on 60 pediatric patients (ages 5–17) who underwent Achilles tendon lengthening at our institution between 2021 and 2025. Patients were divided into two groups: 25 receiving percutaneous lengthening and 35 undergoing Z-plasty. Inclusion criteria encompassed idiopathic contracture with a follow-up of over 12 months. Outcomes measured included ankle dorsiflexion, time to resume normal activities, length of hospital stay, duration of cast immobilization, complications, the likelihood of choosing the same treatment method again, taking analgesics, AOFAS score, and patient/guardian satisfaction. Results: Both surgical methods resulted in significant improvements in ankle dorsiflexion and functional outcomes. The percutaneous group demonstrated a mean increase of 30° in dorsiflexion, while the Z-plasty group showed a mean increase of 32.5°. The time from surgery to resuming normal activities in the Z-plasty group ranged from 6 to 11 weeks, which was significantly higher than the range of 6 to 7 weeks in the percutaneous lengthening group, p = 0.024. Guardian and patient satisfaction was high in both groups, with 94.3% of patients from the Z-plasty group and 100% of patients from the percutaneous group expressing willingness to choose the same treatment again. Four patients (11.4%) from the Z-plasty group and one patient (4%) from the percutaneous lengthening group developed complications. Conclusions: The period of cast immobilization of six weeks helped achieve good outcomes and caused few complications in children from both study groups. The conventional percutaneous approach to Achilles tendon lengthening in children helps achieve substantial correction of ankle dorsiflexion with a low risk of complications. Due to the risk of selection bias, the results should be interpreted with caution. Full article

Micro-Electro-Mechanical System (MEMS) gyroscopes serve as core components for attitude-sensing systems in low-speed unmanned vehicles and mobile robots. The long-term dynamic stability of MEMS gyroscopes under actual continuous low-speed vehicle operation is significantly inferior to the nominal performance derived from laboratory-based static calibration. This paper adopts a navigation-grade fiber optic gyroscope as the high-precision angular velocity reference. Angular velocity error sequences between the MEMS gyroscope and fiber optic gyroscope are established using field test data collected from a low-speed vehicle experiment lasting approximately 3.3 h. Three analytical approaches are applied to systematically characterize noise evolution features of the MEMS gyroscope under static and dynamic conditions from multiple dimensions. These approaches include time-domain drift analysis, angle random walk evaluation via Allan Variance, and frequency-domain interpretation based on Welch power spectral density. The test results reveal that vehicle motion significantly degrades the 10 s averaged bias stability of the MEMS gyroscope. The bias stability values under dynamic conditions increase by 2.1, 2.7 and 7.7 times compared with static states respectively. Root mean square analysis through band segmentation integration of Welch power spectral density indicates that vehicle motion induces the most obvious rise in noise energy in the middle frequency band. The amplification factor of noise along the Y axis reaches 24.7 times. The joint analytical framework proposed in this paper takes fiber optic gyroscope measurements as the reference and integrates time-domain analysis, Allan Variance and frequency-domain methods. It can provide sufficient experimental evidence and technical support for dynamic error compensation of MEMS gyroscopes deployed on low-speed mobile platforms. Full article

In this short perspective, we analyze the different linear response functions relevant to surface diffusion as studied by helium atom scattering, organizing them around a single object: the intermediate scattering function (ISF), which is also a characteristic function (CF) in the sense of probability theory. This organizing role of the CF is, to our knowledge, not made explicit elsewhere in the surface-diffusion literature. The exponential time dependence of the ISF observed in the diffusive regime (times much greater than the inverse of the friction coefficient) is a special case of the classical continuous-time random walk (CTRW) theory. Special emphasis is placed on this regime where quantum features of the diffusion process are washed out. We show how the entire hierarchy of response functions—the after-effect function, the generalized susceptibility, the relaxation function, and the Green function—can be written directly in terms of the time moments of the ISF at $t=0$. Moreover, the standard Pauli master equation and the Chudley–Elliott (CE) jump model follow as particular lattice realizations of a general compound-Poisson process. The extension to finite surface coverage is discussed within the interacting single adsorbate (ISA) model. Full article