Search Results (300)

Background: Elevated global temperatures increase the risk of heat-stroke among athletes exercising in hot conditions. Japanese high school baseball tournaments occur during peak summer, raising concerns regarding heat-related health issues. We examined whether the color of footwear and legwear affects lower-limb temperature, exploring approaches to prevent heat-related health problems. Methods: Eight mannequin legs were fitted with shoes, socks, and baseball stirrup socks in white or black combinations. Plantar and shin surface temperatures were recorded for 120 min on both dirt and artificial turf at wet-bulb globe temperatures above 30 °C and compared across color combinations. Reflectance spectra of shin legwear were also measured. Results: Plantar and shin surface temperatures increased under all conditions. On the dirt field, mannequins wearing all-black gear (shoe, sock, and baseball stirrup sock) exhibited plantar temperatures exceeding 45 °C and shin temperatures over 50 °C. The highest shin temperature occurred with the white shoe/black baseball stirrup sock combination. Temperature increases were smaller for all-white items compared with all-black items. Reflectance spectra showed that white baseball stirrup socks strongly reflected both visible and infrared light. Conclusions: Footwear and legwear color significantly influence lower-limb temperature increases during baseball games in summer heat, especially when wearing all-black items. White gear may help prevent heat-related health problems and improve performance in baseball and other outdoor sports. Full article

A wheeled–legged robot has the advantage of stable and agile movement on flat ground and an excellent ability to overcome obstacles. However, when faced with a narrow footprint, there is a limit to its ability to move. We developed the control moment gyroscope (CMG) unicycle–legged robot to solve this problem. A scissored pair of CMGs was applied to control the roll balance, and the pitch balance was modeled as a double-inverted pendulum. We performed Linear Quadratic Regulator (LQR) control and model predictive control (MPC) in a system in which the control systems in the roll and pitch directions were separated. We also devised a method for controlling the rotation of the robot in the yaw direction using torque generated by the CMG, and the performance of these controllers was verified in the Gazebo simulator. In addition, forward driving control was performed to verify mobility, which is the main advantage of the wheeled–legged robot; it was confirmed that this control enabled the robot to pass through a narrow space of 0.15 m. Before implementing the verified controllers in the real world, we built a CMG test platform and confirmed that balancing control was maintained within $\pm 1^{\circ }$. Full article

To address the ill-posedness of the Hessian matrix in monocular visual-inertial SLAM (Simultaneous Localization and Mapping) caused by unobservable depth of feature points, which leads to convergence difficulties and reduced robustness, this paper proposes a Pre-Dog-Leg feature optimization method based on an adaptive preconditioner. First, we propose a multi-candidate initialization method with robust characteristics. This method effectively circumvents erroneous depth initialization by introducing multiple depth assumptions and geometric consistency constraints. Second, we address the pathology of the Hessian matrix of the feature points by constructing a hybrid SPAI-Jacobi adaptive preconditioner. This preconditioner is capable of identifying matrix pathology and dynamically enabling preconditioning as a strategy. Finally, we construct a hybrid adaptive preconditioner for the traditional Dog-Leg numerical optimization method. To address the issue of degraded convergence performance when solving pathological problems, we map the pathological optimization problem from the original parameter space to a well-conditioned preconditioned space. The optimization equivalence is maintained by variable recovery. The experiments on the EuRoC dataset show that the method reduces the number of Hessian matrix conditionals by a factor of 7.9, effectively suppresses outliers, and significantly improves the overall convergence time. From the analysis of trajectory error, the absolute trajectory error is reduced by up to 16.48% relative to RVIO2 on the MH_01 sequence, 20.83% relative to VINS-mono on the MH_02 sequence, and up to 14.73% relative to VINS-mono and 34.0% relative to OpenVINS on the highly dynamic MH_05 sequence, indicating that the algorithm achieves higher localization accuracy and stronger system robustness. Full article

In field exploration, disaster rescue, and complex terrain operations, the accuracy of ground type recognition directly affects the walking stability and task execution efficiency of legged robots. To address the problem of terrain recognition in complex ground environments, this paper proposes a high-precision classification method based on single-leg triaxial force signals. The method first employs a one-dimensional convolutional neural network (1D-CNN) module to extract local temporal features, then introduces a long short-term memory (LSTM) network to model long-term and short-term dependencies during ground contact, and incorporates a convolutional block attention module (CBAM) to adaptively enhance the feature responses of critical channels and time steps, thereby improving discriminative capability. In addition, an improved whale optimization algorithm (iBWOA) is adopted to automatically perform global search and optimization of key hyperparameters, including the number of convolution kernels, the number of LSTM units, and the dropout rate, to achieve the optimal training configuration. Experimental results demonstrate that the proposed method achieves excellent classification performance on five typical ground types—grass, cement, gravel, soil, and sand—under varying slope and force conditions, with an overall classification accuracy of 96.94%. Notably, it maintains high recognition accuracy even between ground types with similar contact mechanical properties, such as soil vs. grass and gravel vs. sand. This study provides a reliable perception foundation and technical support for terrain-adaptive control and motion strategy optimization of legged robots in real-world environments. Full article

Background: Foot injuries are common among Umrah pilgrims due to prolonged walking, overcrowded conditions, and inadequate preventive measures, such as inappropriate footwear or walking barefoot. Despite their potential impact on mobility and overall pilgrimage experience, these conditions remain underreported and insufficiently addressed in public health strategies. Objectives: This study aims to assess the prevalence and types of foot problems among Umrah pilgrims, examine their associations with demographic characteristics and comorbidities, analyze the utilization of medical attention for foot pain, and assess the use of preventive measures to reduce foot-related health risks during the pilgrimage. Methods: A cross-sectional study was conducted throughout the 2024 G (1445 H) Umrah season at the Grand Mosque, Makkah. The study recruited 1138 Umrah pilgrims aged 18 and older who performed the pilgrimage. A structured questionnaire was administered to collect data on demographic characteristics, chronic diseases, foot conditions, medical-attention-seeking behavior, and preventive practices. Pilgrims with pre-existing foot conditions were excluded from participation. Results: Foot diseases were reported by 46% of participants. The most common foot injuries included sprains/strains (18.7%) and muscle pain/cramps (4.9%), with the leg and forefoot being the most affected areas. Significant associations were observed between foot diseases and lower education levels (p = 0.03), chronic liver disease (p = 0.04), and cardiovascular disease (p = 0.04). Despite the high prevalence of foot-related conditions, only 9.6% sought medical attention, and 14.9% reported using preventive measures. Conclusions: The study highlights a substantial burden of foot problems among Umrah pilgrims, with limited utilization of healthcare services and preventive strategies. Targeted interventions, including educational campaigns and improved screening for high-risk individuals, are essential for enhancing foot health and ensuring a safer pilgrimage experience. Full article

This paper proposes a cascaded state estimation framework based on proprioception for robots. A generalized-momentum-based Kalman filter (GMKF) estimates the ground reaction forces at the feet through joint torques, which are then input into an error-state Kalman filter (ESKF) to obtain the robot’s prior state estimate. The system’s dynamic equations on the Lie group are parameterized using canonical coordinates of the first kind, and variations in the tangent space are mapped to the Lie algebra via the inverse of the right trivialization. The resulting parameterized system state equations, combined with the prior estimates and a sliding window, are formulated as a moving horizon estimation (MHE) problem, which is ultimately solved using a parallel real-time iteration (Para-RTI) technique. The proposed framework operates on manifolds, providing a tightly coupled estimation with higher accuracy and real-time performance, and is better suited to handle the impact noise during foot–ground contact in legged robots. Experiments were conducted on the BQR3 robot, and comparisons with measurements from a Vicon motion capture system validate the superiority and effectiveness of the proposed method. Full article

In precision livestock farming, synchronous and high-precision instance segmentation of multiple key body parts of sika deer serves as the core visual foundation for achieving automated health monitoring, behavior analysis, and automated antler collection. However, in real-world breeding environments, factors such as lighting changes, severe individual occlusion, pose diversity, and small targets pose severe challenges to the accuracy and robustness of existing segmentation models. To address these challenges, this study proposes an improved model, MPDF-DetSeg, based on YOLO11-seg. The model reconstructs its neck network, and designs the multipath diversion feature fusion pyramid network (MPDFPN). The multipath feature fusion and cross-scale interaction mechanism are used to solve the segmentation ambiguity problem of deer body occlusion and complex illumination. The design depth separable extended residual module (DWEResBlock) improves the ability to express details such as texture in specific parts of sika deer. Moreover, we adopt the MPDIoU loss function based on vertex geometry constraints to optimize the positioning accuracy of tilted targets. In this study, a dataset consisting of 1036 sika deer images was constructed, covering five categories, including antlers, heads (front/side views), and legs (front/rear legs), and used for method validation. Compared with the original YOLO11-seg model, the improved model made significant progress in several indicators: the mAP50 and mAP50-95 under the bounding-box metrics increased by 2.1% and 4.9% respectively; the mAP50 and mAP50-95 under the mask metrics increased by 2.4% and 5.3%, respectively. In addition, in the mIoU index of image segmentation, the model reached 70.1%, showing the superiority of this method in the accurate detection and segmentation of specific parts of sika deer, this provides an effective and robust technical solution for realizing the multidimensional intelligent perception and automated applications of sika deer. Full article

This study aimed to evaluate cow longevity and identify the main culling reasons in dairy herds in Southern Brazil. Two data sets from 26 predominantly confined Holstein herds were analyzed over a 10-year period (2007–2016). The first included 11,150 cows that were culled, died, or sold, and the second comprised 636,739 cows for demographic analysis. The average annual culling rate was 24.2%, mainly due to reproductive disorders (34.0%), mastitis/high somatic cell count (20.4%), and feet and leg problems (17.9%). Involuntary causes represented 89.5% of all culling. The death rate averaged 3.8%, with the most frequent causes being unknown (27.3%), other reasons (25.6%), tick fever (10.2%), and accidents/injuries (10.0%). Larger herds had higher culling rates than smaller ones (26.2% vs. 22.8%; p = 0.04), as did higher-producing herds compared to lower-producing ones (25.7% vs. 22.0%; p = 0.02). Cows with ≥5 calvings were culled more often (p < 0.01) than those in earlier lactations. Culling was lowest (p < 0.02) in spring and highest (p < 0.01) during early (0–60 d) and late (>420 d) lactation. Herds with a higher proportion of older cows had slightly lower milk yields (p < 0.01), indicating longevity does not always enhance productivity. Full article

Most of the developed and studied service robots for vertical locomotion, as visual inspection, are made up by a rigid body with legs, wheels, or both. Thus, the robot can only displace over regular and/or flat surfaces since it is not able to adapt to the irregularities and projections of the wall. Therefore, this paper presents the design and analysis of an adaptable robot for vertical locomotion service tasks, which has a body made up of four wheeled legs that can easily adapt to the different irregularities and projections of building facades. The robot uses an Electric Ducted Fan (EDF) as the vortex adhesion system. Each leg has a rubber cover, which allows a higher mechanical adaptability of the robot over different irregularities of the wall. Theoretical backgrounds and open issues are addressed by considering some challenging problems such as mechanical adaptability modeling as well as kinematic and static analysis. Laser sensors are mounted over the robot to measure the adaptability of the robot, between the legs and body, at each time of the experimental tests for vertical locomotion. Full article

Background/Objectives: Among the various types of masses that can cause compression, hematomas are a relatively common but often overlooked cause. Rheumatoid arthritis (RA) is associated with bleeding problems due to vascular inflammation, platelet dysfunction, impaired production of clotting factors, and medication use. Case Presentation: We report a case of a 76-year-old woman with RA who developed vascular and neurological symptoms in her right lower leg due to compression of the popliteal artery and tibial nerve by an organized hematoma in the popliteal fossa. She experienced swelling, pain, and plantar flexor weakness in the affected leg with no history of trauma. Magnetic resonance imaging revealed a mass measuring 1.2 × 1.0 × 3.0 cm in size in the right popliteal fossa that was in contact with the popliteal artery and tibial nerve on its posterolateral aspect. Electrodiagnostic examination revealed that the right tibial neuropathy developed most probably around the knee level. Surgical excision of the hematoma resulted in almost complete resolution of symptoms, and excisional biopsy disclosed findings of an organized hematoma. We confirmed that the patient’s symptoms were induced by compression of the popliteal artery and tibial nerve due to the organized hematoma in the right popliteal fossa. Conclusions: This case report emphasizes the importance of considering space-occupying lesions, such as organized hematomas, in patients with RA who develop neurological and vascular symptoms. Full article

Legged robots often encounter the problem that the foot-end steps into empty spaces due to terrain collapse in complex environments such as mine tunnels and coal shafts, which in turn causes body instability. Aiming at this problem, this paper takes the hexapod robot as the research object and proposes a multi-segmented electrically driven single-leg compliance control strategy for robots with tripod and quadrupedal gaits, to reduce the impact when the foot-end touches the ground, and thus to improve the stability of the robot. First, this paper analyzes the kinematic and dynamic models of the multi-segmented electrically driven single leg of the hexapod robot. Then, the minimum tipping angle of the fuselage is obtained based on force-angle stability margin (FASM) and used as the index to design the single-leg pit-probing control algorithm based on position impedance control and the single-leg touchdown force adjustment control algorithm based on inverse dynamics control. Finally, this paper designs a finite state machine to switch between different control strategies of the multi-segmented electrically driven single leg of the hexapod robot, and the vertical dynamic impact characteristic index is applied to evaluate the effect of single-leg impedance control. The simulation and prototype test results show that the proposed method significantly reduces the foot-end touchdown force and improves the walking stability of the hexapod robot in complex environments compared with the multi-segmented electrically driven single leg without the compliance control strategy. Full article

Human exploration and rescue in unstructured environments including hill terrain and depression terrain are fraught with danger and difficulty, making autonomous vehicles a promising alternative in these areas. In flat terrain, traditional wheeled vehicles demonstrate excellent maneuverability; however, their passability is limited in unstructured terrains due to the constraints of the chassis and drivetrain. Considering the high passability and exploration efficiency, wheel–leg vehicles have garnered increasing attention in recent years. In the automation process of wheel–leg vehicles, planning and mode decisions are crucial components. However, current path planning and mode decision algorithms are mostly designed for wheeled vehicles and cannot determine when to adopt which mode, thus limiting the full exploitation of the multimodal advantages of wheel–leg vehicles. To address this issue, this paper proposes an integrated path planning and mode decision algorithm (IPP-MD) for wheel–leg vehicles in unstructured environments, modeling the mode decision problem using a Markov Decision Process (MDP). The state space, action space, and reward function are innovatively designed to dynamically determine the most suitable mode of progression, fully utilizing the potential of wheel–leg vehicles in autonomous movement. The simulation results show that the proposed method demonstrates significant advantages in terms of fewer mode-switching occurrences compared to existing methods. Full article

Diabetes mellitus is characterized by a state of hyperglycemia, which can lead to severe complications if left untreated or poorly managed. Diabetic peripheral neuropathy (DPN) is one common complication. This condition is characterized by damage to the nerves that supply the legs and feet as well as problems with blood vessels, the heart, or urinary tract. To alleviate pain for patients, clinicians resort to long-term treatment regimens of nerve pain medications, which are usually either anticonvulsants or antidepressants. However, little is understood about the underlying mechanisms of DPN. Many pathogenic pathways have been proposed, one of which is mitochondrial dysfunction. Mitochondrial dysfunction includes a range of possible deficiencies given the number of functions controlled by or located in mitochondria, including their core function of bioenergetics. This review focuses on mitochondrial bioenergetics, including respiration/ATP synthesis and reactive oxygen species (ROS) production, as well as calcium homeostasis and apoptosis, and their potential as targets for the effective treatment of diabetic peripheral neuropathy. Full article

The normal development and growth of bones are critical for poultry health. With the rapid increase in poultry growth rates achieved over the last few decades, juvenile meat-type poultry exhibit a high incidence of leg weakness and lameness. These issues are significant contributors to poor animal welfare and substantial economic losses. Understanding the potential etiology of bone problems in poultry will aid in developing treatments for bone diseases. The gut microbiota represents the largest micro-ecosystem in animals and is closely related to many metabolic disorders, including bone disease. It achieves this by secreting secondary metabolites and coordinating with various tissues and organs through the circulatory system, which leads to the concept of the gut–X axis. Given its importance, modulating gut microbiota to influence the gut–X axis presents new opportunities for understanding and developing innovative therapeutic approaches for poultry bone diseases. In light of the extensive literature on this topic, this review focuses on the effects of gut microbiota on bone density and strength in poultry, both directly and indirectly, through the regulation of the gut–X axis. Our aim is to provide scientific insights into the bone health problems faced by poultry. Full article

Visual conditions significantly influence fear of movement (FOM), which is a condition that impairs postural control and quality of life (QOL). This study examined how visual conditions influence sway velocity during repeated one-leg standing tasks and explored the potential relationship between postural control, FOM, and QOL in older adults with and without FOM. Thirty-seven older adults with FOM and 37 controls participated in the study. Postural sway velocity was measured across three repeated trials under visual conditions in both anteroposterior (AP) and mediolateral (ML) directions. The groups demonstrated significant interaction under visual conditions (F = 7.43, p = 0.01). In the eyes-closed condition, the FOM group exhibited faster ML sway velocity than the control group, with significant differences across all three trials. There was a significant interaction between sway direction and vision (F = 27.41, p = 0.001). In addition, the FOM demonstrated strong negative correlations with several QOL measures on social functioning (r = −0.69, p = 0.001) and role limitations due to emotional problems (r = −0.58, p = 0.001) in the FOM group. While FOM influenced sway velocity during balance tasks, visual input emerged as a key determinant of postural control. The FOM group demonstrated a heightened reliance on vision, suggesting an increased need for vision-dependent strategies to maintain balance. Full article