Search Results (139)

Accurate gait-phase detection is essential for rehabilitation monitoring, prosthetic control, and human–robot interaction. Artificial intelligence supports continuous, personalized mobility assessment by extracting clinically meaningful patterns from wearable sensors. A richer view of gait dynamics can be achieved by integrating additional signals, including inertial, plantar flex, footswitch, and EMG data, leading to more accurate and informative gait analysis. Motivated by these needs, this study investigates discrete gait-phase recognition for the right leg using a multi-subject IMU dataset collected from lower-limb sensors. IMU recordings were segmented into 128-sample windows across 23 channels, and each window was flattened into a 2944-dimensional feature vector. To ensure reliable ground-truth labels, we developed an automatic relabeling pipeline incorporating heel-strike and toe-off detection, adaptive threshold tuning, and sensor fusion across sensor modalities. These windowed vectors were then used to train a comprehensive suite of machine learning models, including Random Forests, Extra Trees, k-Nearest Neighbors, XGBoost, and LightGBM. All models underwent systematic hyperparameter tuning, and their performance was assessed through k-fold cross-validation. The results demonstrate that tree-based ensemble models provide accurate and stable gait-phase classification with accuracy exceeding 97% across both test sets, underscoring their potential for future real-time gait analysis and lower-limb assistive technologies. Full article

To address the low efficiency and stress-inducing nature of traditional manual weighing for dairy cows, this study proposes a semantically guided 3D reconstruction and body weight estimation method for dairy cows. First, a dual-viewpoint Kinect V2 camera synchronous acquisition system captures top-view and side-view point cloud data from 150 calves and 150 lactating cows. Subsequently, the CSS-PointNet++ network model was designed. Building upon PointNet++, it incorporates Convolutional Block Attention Module (CBAM) and Attention-Weighted Hybrid Pooling Module (AHPM) to achieve precise semantic segmentation of the torso and limbs in the side-view point cloud. Based on this, point cloud registration algorithms were applied to align the dual-view point clouds. Missing parts were mirrored and completed using semantic information to achieve 3D reconstruction. Finally, a body weight estimation model was established based on volume and surface area through surface reconstruction. Experiments demonstrate that CSS-PointNet++ achieves an Overall Accuracy (OA) of 98.35% and a mean Intersection over Union (mIoU) of 95.61% in semantic segmentation tasks, representing improvements of 2.2% and 4.65% over PointNet++, respectively. In the weight estimation phase, the BP neural network (BPNN) delivers optimal performance: For the calf group, the Mean Absolute Error (MAE) was 1.8409 kg, Root Mean Square Error (RMSE) was 2.4895 kg, Mean Relative Error (MRE) was 1.49%, and Coefficient of Determination (R²) was 0.9204; for the lactating cows group, MAE was 12.5784 kg, RMSE was 14.4537 kg, MRE was 1.75%, and R² was 0.8628. This method enables 3D reconstruction and body weight estimation of cows during walking, providing an efficient and precise body weight monitoring solution for precision farming. Full article

Background: The relationship between sagittal malocclusion, temporomandibular disorders (TMD), and musculoskeletal pain remains uncertain. Methods: Cross-sectional study (April 2020–August 2021) in Małopolska, Poland. Ninety participants (ages 19–35) were classified into Angle Classes I–III (n = 30 each) and examined using RDC/TMD (Axis I/II). A proprietary, nonvalidated, piloted whole-body pain-map questionnaire, presented in anterior and posterior views and subdividing the body into predefined craniofacial, spinal, and limb regions, was used to capture pain presence, Numerical Rating Scale (NRS, 0–10) scores by region, and the total number of painful sites. Group differences were analyzed using χ² and Kruskal–Wallis tests with corresponding effect sizes (measures of association strength). For NRS outcomes, a minimal clinically important difference (MCID)—defined as the smallest difference in NRS considered clinically relevant—was prespecified as approximately 1 point. Results: Occlusal class was not associated with TMD Axis I prevalence. However, sagittal malocclusion—particularly Class III—was linked to a less favorable pain profile. Left temporal pain was more frequent in Class III than in Classes I–II (p = 0.024, Cramér’s V = 0.31, medium effect), and cervical spine pain occurred more often in malocclusion groups than in Class I (p = 0.043, Cramér’s V = 0.26, small effect), indicating statistically significant associations. Cervical pain intensity was higher in Classes II–III than in Class I, with a pooled mean difference—defined as the difference in mean NRS between the combined Classes II–III and Class I—of 1.23 NRS points (95% CI 0.38–2.08), exceeding the ≈1-point MCID and suggesting a clinically important burden. The total number of painful sites was also greater in Class III than in Class I (p = 0.023, η² = 0.09; Δ = 1.40 sites, 95% CI 0.39–2.41), which indicates a statistically significant association with a medium effect size and a higher overall pain burden. Conclusions: Sagittal occlusal class was not associated with TMD diagnosis, but malocclusion—especially Class III—was associated with a more unfavorable craniofacial pain pattern and higher cervical pain burden (p ≤ 0.05), with effects of potential clinical relevance. Full article

The acquisition, processing, and monitoring of biomechanical variables in dynamic environments require sensor network architectures capable of handling high concurrency and large data volumes. This study aims to develop, validate, and deploy a robust asynchronous network architecture of Inertial Measurement Units (IMUs) utilizing Bluetooth Low Energy (BLE) 5.0 for real-time biomechanical signal acquisition, overcoming the range, speed, and stability limitations of prior implementations. A network of six IMUs was implemented, with communication managed by a hybrid Python 3.10–LabVIEW 2022 Q3 framework. This architecture ensures concurrent, asynchronous data acquisition while maintaining stable sensor interconnection through virtual port emulation. System evaluation demonstrated superior technical performance, exhibiting high acquisition efficiency (close to 100%) and data loss below ±2% across 75 assessments per sensor. These assessments were obtained by evaluating the posture of 25 participants during three postural experiments, with a maximum indoor range of 40 m and an outdoor range of 105 m, validating the system’s scalability and robustness for motion capture. The approach was applied in a case study using a Fuzzy Inference System (FIS) to assess the upper limb via the Rapid Upper Limb Assessment (RULA) method. The system successfully quantified the temporal distribution of injury risk bilaterally, overcoming the limitations of observational methods and providing objective metrics crucial for occupational health in seated tasks. Full article

Background/Objectives: Stroke often results in lasting upper limb deficits. Mirror visual feedback (MVF) supports motor recovery, and electromyography-triggered electrical stimulation (ES) could enhance engagement. However, the effects in healthy older adults, age-matched to typical patient cohorts, remain insufficiently understood. We tested MVF and MVF + ES using functional near-infrared spectroscopy. Methods: Seventeen right-handed older adults performed left-wrist flexion under three visual conditions: circle fixation, viewing the right hand at rest, and mirror viewing, with/without electrical stimulation to the right-wrist flexors time-locked to left-forearm electromyography. Oxygenated hemoglobin (oxy-Hb) was recorded over the bilateral inferior frontal gyrus (IFG), precentral gyrus (PrG), postcentral gyrus (PoG), supramarginal gyrus (SMG), superior parietal lobule (SPL), and supplementary motor area. Effects were assessed with linear mixed-effects models (stimulation × visual condition); pairwise comparisons of estimated marginal means used Fisher’s least significant difference. Left-forearm electromyography verified comparable effort across conditions. Results: Linear mixed-effects models revealed left-lateralized increases in oxy-Hb, most prominently under mirror viewing with stimulation. Post hoc tests showed high oxy-Hb in the left IFG, PrG, PoG, SMG, and SMA. The left EMG did not differ. Conclusions: In healthy older adults, MVF paired with EMG-triggered ES enhances frontoparietal–motor engagement beyond MVF alone, with recruitment shaped by visuo–proprioceptive congruence. These findings support mechanistic plausibility and motivate dose–response optimization and patient-focused trials testing behavioral transfer in stroke. Full article

The astragalus is a key biomechanical link between the autopodium and limb in mammals, modulating stability and mobility during stance. Its morphology provides reliable proxies for inferring posture, body mass, and locomotor behavior in extinct taxa. Mesotheriids (Notoungulata, Mesotheriidae) have traditionally been regarded as fossorial generalists, yet their functional diversity remains poorly tested. The astragali of Caraguatypotherium munozi (Miocene, Chile) and Trachytherus spegazzinianus (early Miocene, Argentina) were analyzed, integrating osteological measurements and functional indices to explore their locomotor ecology. Principal component analyses were performed to compare their morphofunctional spaces with those of 38 extant terrestrial mammals grouped by posture, body mass, top speed, and locomotor habit. Total Angular Excursion (TAE) and Angular Efficiency Index (AEI) were estimated using a comparative dataset of 182 terrestrial mammals spanning 15 taxonomic orders, focused on stance-phase mechanics during comfortable locomotion. C. munozi shows a deeper trochlea and moderately expanded navicular facets, whereas T. spegazzinianus presents a shallower trochlea and narrower articular proportions. Despite these morphological differences, both species share broadly overlapping stance-phase kinematic ranges, reflecting a conserved plantigrade locomotor module optimized for stability and energy-efficient weight support. These findings challenge the view of mesotheriids as functionally uniform and highlight ecological diversification through subtle morphological adjustments within a constrained locomotor framework. Full article

This study presents a comprehensive analysis of Speed Climbing athletes by examining motion parameters critical to elite performance. As such, several key values are extracted from about 900 competition recordings in order to generate a dataset for the identification of patterns in athletes’ technique and efficiency. A CNN-based framework is used to automate the detection of human keypoints and features, enabling a large-scale evaluation of climbing dynamics. The results revealed significant variations in performance for single sections of the wall, particularly in relation to start reaction times (with differences of up to 0.27 s) and increased split times the closer the athletes are to the end of the Speed Climbing wall (from 0.39 s to 0.45 s). In addition, a more detailed examination of the movement sequences was carried out by analyzing the velocity trajectories of hands and feet. The results showed that coordinated and harmonic movements, especially of the lower limbs, correlate strongly with the performance outcome. To ensure an individualized view of the data points, a comparison was made between multiple athletes, revealing insights into the influence of individual biomechanics on the efficiency of movements. The findings provide both trainers and athletes with interesting insights in relation to tailoring training methods by including split time benchmarks and limb coordination. Full article

Hyaluronan, a key component of the extracellular matrix, plays a crucial role in joint development and maintenance. In order to determine the role of hyaluronan function in joint development and homeostasis, conditional loss-of-function experiments of Hyaluronan Synthase 2 (Has2) were carried out in mice. Has2 depletion in limb mesenchymal cells led to severely shortened limbs with appendicular joints that are deformed, decreased proteoglycan content as characterized by Safranin-O staining, and severely pitted epiphyseal ends of long bones and deformed joints as viewed by micro-CT reconstructions. The embryonic deletion of Has2 in mesoderm mesenchyme of limbs by Prx1-Cre confirmed its involvement in joint development, while in situ hybridization and hyaluronan staining confirmed Has2 expression and abundant accumulation of hyaluronan in the onset of joint formation, the joint interzone. These findings position Has2 as the main hyaluronan-making enzyme in articular cartilage and highlight its essential function in joint formation and retention of proteoglycans of the extracellular matrix of the cartilage. Full article

Adequate exercise prescription requires a deep understanding of the body’s response to exercise. This study explored the responses of heart rate (HR), muscle oxygen saturation (SmO₂), and perceived exertion (RPE) during six body-weight squat exercise variations. A total of 15 recreationally active participants (age: 28.2 ± 8.0 years; body mass: 71.1 ± 11.2 kg; height: 1.73 ± 0.08 m) were recruited. Six body-weight squat variations (deep, jumping, single-leg, uneven, unstable, and wall-sit) were randomly performed for 90 s. Results revealed that the jumping squat promoted a higher average and peak HR (165.3 ± 14.5 and 146.1 ± 14.8 bpm, respectively), and a lower average SmO₂ and higher deoxygenation SmO₂ in the soleus muscle (40.3 ± 15.4 and 46.0 ± 11.4%, accordingly). No differences were observed in recovery time or in the same SmO₂ derived-parameters in the vastus lateralis muscle. The jumping variation promoted a greater response at a physiological level, both centrally, related to cardiovascular response, and peripherally, related to soleus SmO₂. It was also the more demanding variation at both the overall and lower limb muscular level of RPE. This holistic view allows a precise identification of the response patterns in body-weight squat exercise variations to an acute session, with a training intervention providing additional information. Full article

Background: Ankle fractures are among the most common injuries requiring surgical intervention. Standard radiographs are typically used for postoperative assessment; however, some patients continue to experience residual symptoms despite satisfactory radiographic outcomes. Weight-bearing computed tomography (WBCT), though not yet widely integrated into clinical practice, offers potential advantages in evaluating lower-limb deformities, injuries, and arthritis. This study explores the utility of WBCT for the midterm assessment following ankle fracture fixation and compares its findings with those obtained from standard radiographs. Methods: In this retrospective case study, we analyzed the correlations between the functional outcome scores approximately one year post-surgery and parameters assessed using WBCT. Pearson’s correlation coefficient was used to evaluate these correlations, and a t-test was performed to assess their statistical significance, with a threshold p-value of 0.05. Additionally, Spearman’s rank correlation coefficient was calculated as a supplementary descriptive measure, without significance testing. These correlations were then compared with those obtained from standard ankle radiographic views (anteroposterior, lateral, and mortise). Results: Several correlations were identified between WBCT parameters and functional scales, with certain parameters demonstrating high statistical significance (p < 0.05). Overall, the correlations observed for WBCT were stronger than those for standard radiographs. Conclusions: Although the study cohort was limited, the findings suggest that WBCT may provide additional insights beyond conventional radiography. Further research with larger patient groups is needed to establish its clinical relevance. Full article

This paper presents a space-based limb-imaging spectrometer (LIS) for detecting atmospheric O₂ airglow; it scans the atmosphere with a vertical range of 10–100 km and has a vertical resolution of 2 km. The LIS’s detection performance needs to be examined before launch. A forward radiative transfer model (RTM) of airglow is studied to determine the airglow emission intensity. Spectral and radiation calibration is conducted to obtain the response parameters. Based on the airglow emission intensity, calibration results, and airglow spectral lines, the LIS’s simulated spectra are obtained, and then an optimal estimation inversion method for the LIS is studied. The results show that the LIS’s spectral range is 498.1 nm–802.3 nm, with a spectral resolution of 1.38 nm. Simulation results show that the LIS can detect airglow emission spectral lines, which characterize their dependence on temperature. The digital number response value is 20% to 50% of the saturation value. An inversion error analysis shows that, when the signal-to-noise ratio (SNR) of the LIS is 1000 and the prior temperature error is 10%, the inversion errors are 6.2 and 3 K at 63 and 77 km, respectively. This study shows that the LIS can achieve good SNR detection for airglow. Full article

This paper aims to review researchers’ concerns over time (from the 1980s to the present) regarding the transmission of mechanical vibrations in the workplace to the limbs, with a preponderant focus on the hand–arm system and some of the effects over time. These concerns are strictly approached from the point of view of their effects on different races, types of jobs, and forms of tools handled in the workplace. In this regard, when we refer to unwanted vibrations (harmful to a person) in the industrial environment, these are vibrations that can produce harmful effects on an individual’s health, leading to occupational diseases such as white finger syndrome. Some of the terms specific to the studies reviewed, such as vibration perception and biodynamic force, among others, are explained in this paper as needed. Studies in the field have shown that vibrations are transmitted differently when the arm is bent at the elbow joint compared to when it is outstretched; also, the transmission of vibrations is influenced by other factors, such as the temperature of the working environment, the gender and age of the person who is using the vibrating devices, and last but not least, the time of their use and the frequency. The conclusions presented by the specialized literature often refer to existing standards, in particular SR EN ISO 5349/2003. Finally, in this paper, conclusions are drawn regarding how to analyze the transmission of vibrations over time, and some recommendations are given for avoiding or minimizing them, which can be added to the already-existing standards. Full article

Background: This paper aims to complement the latest contribution in the literature that provides estimates of physiological parameters of a dynamic model for the elbow time profile during walking while linking them to a neurodegenerative disorder (Parkinsons’s disease) characterized by motor symptoms. An upper limb model is here proposed in which an active contractile element is included within a model, viewing the arm as a double pendulum system and muscles as represented by a Kelvin–Voight system. All model parameters characterizing both the shoulder and the elbow of each subject are estimated via a gradient-like identifier whose exponential convergence properties are determined by a non-anticipative Lyapunov function, ensuring robustness features. Methods: Joint angle data from different walking subjects (healthy subjects and patients with Parkinson’s disease) have been recorded using an IMU sensor system and compared with the joint angles obtained by means of the proposed model, which was adapted to each subject using available anthropometric knowledge and relying on the estimated parameters. Results: Experiments show that the reconstruction of shoulder and elbow time profiles can be definitely achieved through the proposed procedure with the estimated stiffness parameters turning out to constitute objective and quantitative indices of muscle stiffness (as a pivotal symptom of the pathology), which are able to track changes due to the therapy. Conclusions: The same dynamic model is actually able to capture the main features of the upper limb movement of both (healthy and pathological) walking subjects, with its parameters, in turn, characterizing the nature and progress of the pathology. Full article

The Microwave Temperature Sounder-3 (MWTS-3) onboard the Chinese FengYun-3E (FY-3E) satellite is the third generation of Chinese microwave temperature sounder. Based on MWTS-2, the number of MWTS-3 channels has been increased from 13 to 17, which can observe the atmospheric temperature and water vapor profiles from the surface to the lower stratosphere. In this study, two generations of MWTSs onboard FY-3D/3E were inter-calibrated by the Double Difference (DD) method to eliminate bias. The results showed that the biases of tropospheric channels were stable (within 1 K) and the biases of stratospheric channels were relatively large (over 2 K). In addition, the weighting functions of all MWTS channels varied with fields of view (FOVs) due to different optical paths, causing the brightness temperature (TB) observations to display strong scan-dependent features, i.e., the limb effect. This work used a limb correction method to remove scan-dependent patterns so that the underlying weather signals could be uncovered. After inter-calibration and limb correction, this work converted the TB observations from MWTS-2/3 onto a global gridded dataset at 0.5° × 0.5° latitudinal and longitudinal resolutions using a method of nested interpolation. Based on this research, more long-term FengYun series satellite climate datasets can be established in the future. Full article

Background: Lymphedema represents a frequent cause of disability for patients undergoing oncological treatments and, being a chronic, non-reversible pathology, requires targeted and continuous rehabilitation treatments. To date, the studies available on the use of ultrasound in patients with lymphedema mainly report descriptive data; therefore, with this study, we wanted to describe in a more objective way the typical ultrasound alterations found in these patients, measuring the thickness of the different superficial structures, and defining subcutis echogenicity. Methods: 14 patients affected by secondary lymphedema of the upper limbs were enrolled in this cross-sectional observational study (12 had breast cancer and 2 with melanoma as their primary diagnosis). All patients were classified as stage II according to the ISL classification. Patients were examined between March and July 2023 with a clinical and an ultrasound evaluation. Ultrasound evaluation was performed following a protocol and took into consideration thickness of the cutis, subcutis, superficial and deep fascia, and subcutis echogenicity. Results: The cutis of the affected limbs was thicker in the distal anterior region of the arm and throughout the anterior region of the forearm. The subcutaneous tissue was thicker in the posterior region of the distal arm and throughout the forearm, including the dorsum of the hand and excluding only the proximal posterior region of the forearm. Fascial structures did not demonstrate statistically significant differences in thickness between pathological and healthy limbs, despite undergoing significant changes from a qualitative point of view (loss of the trilaminar skin appearance and the development of anechoic areas due to fluid accumulation around the hyperechoic adipose lobule). A statistically significant difference in the echogenicity of subcutaneous tissue was found at the distal anterior region of the arm and at the entire anterior forearm. Conclusions: High-resolution ultrasound has been confirmed to be a tool capable of supporting the diagnosis of lymphedema and identifying the most compromised regions of the limb. A tailored rehabilitation plan can be developed based on the non-uniform alterations in subcutaneous tissue, where some areas are affected earlier than others. This compartmentalization should be considered in lymphedema staging and management. Ultrasound may provide early detection of these changes, guiding a more precise therapeutic approach. Full article