Search Results (36)

Hexapod robots that use external sensors to sense the environment are susceptible to factors such as light intensity or foggy weather. This effect leads to a drastic decrease in the motility of the hexapod robot. This paper proposes a motion control strategy for a blind hexapod robot. The hexapod robot is symmetrical and its environmental sensing capability is obtained by collecting proprioceptive signals from internal sensors, allowing it to pass through rugged terrain without the need for external sensors. The motion gait of the hexapod robot is generated by a central pattern generator (CPG) network constructed by Hopf oscillators. This gait is a periodic gait controlled by specific parameters given in advance. A policy network is trained in the target terrain using deep reinforcement learning (DRL). The trained policy network is able to fine-tune specific parameters by acquiring information about the current terrain. Thus, an adaptive gait is obtained. The experimental results show that the adaptive gait enables the hexapod robot to stably traverse various complex terrains. Full article

Quadruped robots have shown significant potential in disaster relief applications, where they have to navigate complex terrains for search and rescue or reconnaissance operations. However, their deployment is hindered by limited adaptability in highly uncertain environments, especially when relying solely on vision-based sensors like cameras or LiDAR, which are susceptible to occlusions, poor lighting, and environmental interference. To address these limitations, this paper proposes a novel sensor-enhanced hierarchical switching model predictive control (MPC) framework that integrates proprioceptive sensing with a bi-level hybrid dynamic model. Unlike existing methods that either rely on handcrafted controllers or deep learning-based control pipelines, our approach introduces three core innovations: (1) a situation-aware, bi-level hybrid dynamic modeling strategy that hierarchically combines single-body rigid dynamics with distributed multi-body dynamics for modeling agility and scalability; (2) a three-layer hybrid control framework, including a terrain-aware switching MPC layer, a distributed torque controller, and a fast PD control loop for enhanced robustness during contact transitions; and (3) a multi-IMU-based proprioceptive feedback mechanism for terrain classification and adaptive gait control under sensor-occluded or GPS-denied environments. Together, these components form a unified and computationally efficient control scheme that addresses practical challenges such as limited onboard processing, unstructured terrain, and environmental uncertainty. A series of experimental results demonstrate that the proposed method outperforms existing vision- and learning-based controllers in terms of stability, adaptability, and control efficiency during high-speed locomotion over irregular terrain. Full article

Background/Objectives: Soccer players, particularly females, exhibit an increased risk of both concussions and Anterior Cruciate Ligament (ACL) injuries. Emerging evidence suggests that neurcognitive deficits following concussions may impair neuromuscular control, increasing ACL injury susceptibility. This study aims to explore the interplay between concussions, neuromuscular deficits, and ACL injury risk, while proposing targeted prevention strategies. Methods: A comprehensive review of current literature was conducted to analyze the biomechanical and neurophysiological impact of concussions on ACL injury risk. Key areas investigated include the effect of sub-concussive impacts on proprioception, reaction time, and postural stability, as well as sex-based differences in injury susceptibility. Results: Findings indicate that post-concussion neuromuscular impairments—such as altered proprioception, delayed reaction times, and compromised joint stability—heighten ACL injury risk. Female athletes, due to biomechanical and hormonal factors, are particularly vulnerable. Preventive measures, including neuromuscular training, cervical spine strengthening, and optimized return-to-play protocols, are essential to mitigate these risks. Conclusions: Longitudinal research is needed to further elucidate the connection between head trauma and ACL injuries. Implementing evidence-based interventions and policy changes, such as modifying heading exposure in youth athletes, may enhance player safety and reduce long-term injury burden in female soccer players. Full article

Arthrogenic muscle inhibition (AMI) is a neuromuscular impairment commonly observed following anterior cruciate ligament reconstruction (ACLR). This condition, characterized by persistent quadricep inhibition due to altered afferent feedback, significantly impacts neuromuscular recovery, delaying return to running and sport. Despite advancements in rehabilitation strategies, AMI may persist for months or even years after ACLR, leading to muscle strength asymmetries, altered biomechanics, and an increased risk of reinjury. The mechanisms underlying AMI involve both peripheral (joint effusion, mechanoreceptor dysfunction) and central (corticospinal inhibition, neuroplasticity alterations) components, which collectively hinder voluntary muscle activation and movement control. AMI alters gait mechanics, reduces knee stability, and promotes compensatory patterns that increase injury risk. Current return-to-sport protocols emphasize strength symmetry and functional performance but often neglect neuromuscular deficits. A comprehensive assessment integrating neuromuscular, biomechanical, and proprioceptive evaluations is needed at specific stages to optimize rehabilitation and minimize reinjury risk. Future research should explore targeted interventions such as neuromuscular stimulation, cognitive–motor training, and advanced gait analysis to mitigate AMI’s impact and facilitate a safer, more effective return to sport. Full article

This narrative review explores the significant evolution of sports rehabilitation, tracing its trajectory from basic exercise therapies of the early 20th century to the advanced, neuroplasticity-driven approaches of the 21st century, with a specific focus on anterior cruciate ligament reconstruction (ACLR). The primary aim is to understand how neuroplasticity, motor control, and sensorimotor retraining can optimize recovery, reduce reinjury risk, and enhance long-term athletic performance, and to synthesize current rehabilitation strategies that integrate innovative technologies, such as robotics, virtual reality (VR), and biofeedback systems, to address the neurocognitive deficits that contribute to the alarmingly high reinjury rates (9–29%) observed in young athletes post-ACLR. These deficits include impaired proprioception, motor control, and psychological factors like fear of reinjury. The methodology employed involves a narrative review of peer-reviewed literature from databases including PubMed, Scopus, and Web of Science. The synthesis of findings underscores the importance of holistic rehabilitation approaches, including targeted proprioceptive exercises, dual-task drills, and immersive VR training, in enhancing sensorimotor integration, decision-making, and athlete confidence. Furthermore, this review highlights the critical need for long-term monitoring and interdisciplinary collaboration between neuroscientists, physiotherapists, and engineers to refine rehabilitation protocols and ensure sustained recovery. By leveraging neuroplasticity and advanced technologies, the field can shift from a focus on purely physical restoration to comprehensive recovery models that significantly reduce reinjury risks and optimize athletic performance. Full article

The work presented in this paper is to be read within the context of a connected autonomous vehicle (CAV). This context makes it possible to consider dividing the overall operational domain (operational design domain: ODD) of the vehicle into three sub-domains, relating to the areas of comfort (ODD1), road-holding (ODD2), and emergency situations (ODD3). Thus, based on information from the CAV’s proprioceptive and exteroceptive sensors, in addition to information from the infrastructure and other vehicles, supervision makes it possible, at any time, to identify the ODD in which the vehicle is located and to propose the most appropriate strategy, particularly for suspension control. Work already carried out by the authors made it possible to determine a crone sky hook (CSH) strategy for suspension control, 100% comfort-oriented for ODD1, a mixed crone sky hook—crone ground hook (CSH-CGH) strategy, oriented towards road-holding for ODD2, and a CGH strategy oriented towards safety for ODD3. In this paper, a comparative study focusing on security (ODD3) is presented. It concerns two versions of the CGH strategy (nominal CGHN and generalized CGHG). More precisely, for the comparative study to be meaningful, the control loops of the two versions have the same speed (iso-speed constraint), and the performance indices are normalized with respect to the values obtained in fault mode when the actuator is faulty. Notably, the CGHG version is part of the dynamics of fractional systems. Full article

Objective: Mental fatigue (MF) induced by prolonged cognitive tasks poses significant risks to postural stability, yet its effects on multi-sensory integration remain poorly understood. Method: This study investigated how MF alters sensory reweighting and postural control in 27 healthy young males. A 45 min incongruent Stroop task was employed to induce MF, validated via subjective Visual Analog Scale (VAS) scores and psychomotor vigilance tests. Postural stability was assessed under four sensory perturbation conditions (O-H: no interference; C-H: visual occlusion; O-S: proprioceptive perturbation; C-S: combined perturbations) using a Kistler force platform. Center of pressure (COP) signals were analyzed through time-domain metrics, sample entropy (SampEn), and Discrete Wavelet Transform (DWT) to quantify energy distributions across sensory-related frequency bands (visual: 0–0.1 Hz; vestibular: 0.1–0.39 Hz; cerebellar: 0.39–1.56 Hz; proprioceptive: 1.56–6.25 Hz). Results: MF significantly reduced proprioceptive energy contributions (p < 0.05) while increasing vestibular reliance under O-S conditions (p < 0.05). Time-domain metrics showed no significant changes in COP velocity or displacement, but SampEn decreased under closed-eye conditions (p < 0.001), indicating reduced postural adaptability. DWT analysis highlighted MF’s interaction with visual occlusion, altering cerebellar and proprioceptive energy dynamics (p < 0.01). Conclusion: These findings demonstrate that MF disrupts proprioceptive integration, prompting compensatory shifts toward vestibular and cerebellar inputs. The integration of nonlinear entropy and frequency-domain analyses advances methodological frameworks for fatigue research, offering insights into real-time sensor-based fatigue monitoring and balance rehabilitation strategies. This study underscores the hierarchical interplay of sensory systems under cognitive load and provides empirical evidence for optimizing interventions in high-risk occupational and clinical settings. Full article

Background/Objectives: Chronic low back pain (CLBP) after middle age is a complex multifactorial condition, and subgrouping is recommended to determine effective treatment strategies. Multidimensional data help create new groupings to increase the effectiveness of interventions in middle-aged and older adults with CLBP. This study aimed to investigate the relationship between the factors associated with CLBP after middle age and to create and characterize a new subgroup based on these factors. Methods: A cross-sectional observational study was conducted and included 46 women aged ≥40 years with CLBP who participated in health events. Trunk muscle mass, lumbar movement control ability, autonomic balance, lumbar tenderness threshold, lumbar proprioception, and severity of central sensitization were assessed. Results: Partial correlation analysis revealed a significant negative correlation between lumbar movement control ability and autonomic balance. A significant positive correlation was observed between trunk muscle mass and the lumbar tenderness threshold. Hierarchical clustering analysis identified three subgroups. The cluster 1 participants had low trunk muscle mass, low tenderness threshold, and low severity of central sensitization. The cluster 2 participants had low trunk muscle mass and tenderness threshold and high severity of central sensitization. The cluster 3 participants had high trunk muscle mass and tenderness threshold and were sympathetically predominant. Trunk muscle mass, pressure pain threshold, severity of central sensitization, and autonomic balance were significantly different between the clusters. Conclusions: Three characteristic subgroups were identified. The results contribute to treatment and prevention strategies for middle-aged and older adults with CLBP based on the characteristics of the subgroups rather than a uniform approach. Full article

The performance of unmanned ground vehicle (UGV) formation is crucial for large-scale material transport. In a non-communicative environment, visual perception plays a central role in formation control. However, due to unstable lighting conditions, dust, fog, and visual occlusions, developing a high-precision visual formation control technology that does not rely on external markers remains a significant challenge in UGVs. This study developed a new UGV formation controller that relies solely on onboard visual sensors and proposed a teacher–student training method, TSTMIPI, combining the PPO algorithm with imitation learning, which significantly improves the control precision and convergence speed of the vision-based reinforcement learning formation controller. To further enhance formation control stability, we constructed a belief state encoder (BSE) based on convolutional neural networks, which effectively integrates visual perception and proprioceptive information. Simulation results show that the control strategy combining TSTMIPI and BSE not only eliminates the reliance on external markers but also significantly improves control precision under different noise levels and visual occlusion conditions, surpassing existing visual formation control methods in maintaining the desired distance and angular precision. Full article

Background/Objectives: Ocular proprioception is implicated in balance control and heterophoria is associated with abnormal posture, though previous research focused mainly on the role of vertical phoria and the use of vertical prisms. This study aims to evaluate whether ocular misalignment and prismatic correction of horizontal phoria affect posture. Methods: Sixty-nine (N = 69) young healthy subjects were included and equally divided by horizontal distance phoria: orthophoria (n = 23), esophoria (n = 23) and exophoria (n = 23). A prism of low power (two-diopter) was placed base out on the non-dominant eye, reducing misalignment in esophorics and increasing it in exophorics more than in orthophorics. Dynamic computerized posturography was performed with the sensory organization test protocol (SOT) of the EquiTest^® NeuroCom^® version 8 platform both without and with prism, always maintaining subjects unaware of prism use. A mixed model for repeated measures analysis of variance was run to evaluate the main effect of prism and the interaction effect of prism with baseline phoria. Results: Composite movement strategy score without prism was 88.1 ± 2.8% (ankle-dominant strategy) and slightly increased to 89.0 ± 3.1% with prism insertion (p = 0.004), further shifting toward ankle strategy. Composite equilibrium score without prism was 80.3 ± 6.5% and remained stable with prism insertion (81.3 ± 8.2%, p = 0.117), medio-lateral and antero-posterior projection of center of gravity did not displace significantly under prism insertion (p = 0.652 and p = 0.270, respectively). At baseline, posturographic parameters were statistically independent of individual phoria, and no significant interaction between prism insertion and individual phoria was documented for any parameters (p > 0.05 for all). Secondary analysis and pairwise comparisons confirmed that the effect of prism was strongly selective on condition SOT 5 (eyes-closed, platform sway-referenced) with improvement of equilibrium (70.4 ± 9.7% with prism vs. 65.7 ± 11.6% without) and more use of ankle strategy (81.6 ± 5.3% with prism vs. 78.2 ± 6.0% without), without any interaction of phoria and ocular dominance, while the other conditions were comparable with and without prism. Conclusions: A two-diopter prism base out on the non-dominant eye induces the body to use the ankle joint more independently of individual phoria, suggesting a small improvement in postural control, while maintaining oscillations of the center of gravity unaltered. Prism seems to enhance the function of vestibular system selectively. Phoria adjustments with prismatic correction enable intervention in postural behavior. Extraocular muscles could act as proprioceptors influencing postural stability. Full article

Background/Objectives: This study investigated the impacts of a 12-week training program on kinetic parameters during landings in non-professional recreational athletes. Methods: Fifty-seven non-elite recreational athletes performed three unilateral-landing trials from a 30 cm high structure on a force platform. The following outcome measures were analyzed: the ground reaction forces at initial ground contact (PF1) and the highest value (PF2), impulse (change in the moment of force during landing), stabilization time, and ankle and knee accelerations. The ground reaction forces, momentum, and accelerations were evaluated in the vertical, medio-lateral, and anteroposterior axes. Participants were randomly assigned to two groups. The experimental group (EG) underwent a 12-week intervention, three times per week, consisting of various exercises, such as strength, eccentric, proprioceptive, whole-body vibration (WBV), and neuromuscular exercises. After 12 weeks, the same outcome measures were analyzed. Results: The effects of the training program on vertical ground reaction forces were not clear (0.3% and 0.9%, respectively). Medio-lateral (64.8%, d = 0.51) and anteroposterior (43.9%, d = 1.34) forces were probably reduced due to the training program. The stabilization time was also reduced in the experimental group (44.2%). The training program most likely decreased the vertical impulse (47.3%, d = −1.56), whereas the total ankle acceleration increased (18.4%, d = 0.79). Conclusions: The findings reveal significant improvements in neuromuscular control and stability during landings, specifically demonstrating reduced medio-lateral forces, vertical momentum, and acceleration during monopodal landings. This study focuses on the importance of proper landing techniques in minimizing the risk of knee injuries, emphasizing the falling strategy’s role in injury prevention. Full article

Reactive postural control (RPC), essential for maintaining balance during daily activities, relies on a complex sensory system integrating visual, vestibular, and proprioceptive inputs. Deficits in RPC can lead to falls, especially in unpredictable environments where sensory inputs are challenged. Traditional rehabilitation often fails to prepare patients adequately for real-world conditions. This study aims to explore the effects of varying instability levels (ILs) and sensory integration strategies (SIS) on RPC by evaluating balance disturbances without applying additional external force. Twenty-five healthy participants (12 men, 13 women, 24.5 ± 6.1 years) performed balance tasks on Abili^® platforms with adjustable ILs (0, 1, 2, 3) while altering sensory strategies (Basic, Visual, Proprioception, Vestibular) using the Modified Clinical Test of Sensory Integration and Balance (mCTSIB). RPC efficiency was measured using the 95th percentile confidence interval for chest movement’s ellipsoid volume and average velocity, analyzed with Wilcoxon signed-rank tests and Cliff’s delta effect size. Results showed significant increases in chest movement velocity and volume, particularly with the Vestibular strategy at higher ILs, with a 7176% increase in chest volume from Basic strategy at 0IL to Vestibular strategy at 3IL. Additionally, removing visual input (Visual and Vestibular strategies) had a greater impact on chest movement than increasing instability levels. These findings underscore the significant role of combined platform instability and reduced sensory input on postural control. This study presents a novel method for challenging balance and suggests that sensory integration with variable instability could be valuable in training and rehabilitation, even for healthy individuals. Full article

Soft pneumatic actuators/robotics have received significant interest in the medical and health fields, due to their intrinsic elasticity and simple control strategies for enabling desired interactions. However, current soft hand pneumatic exoskeletons often exhibit uniform deformation, mismatch the profile of the interacting objects, and seldom quantify the assistive effects during activities of daily life (ADL), such as extension angle and predicted joint stiffness. The lack of quantification poses challenges to the effective and sustainable advancement of rehabilitation technology. This paper introduces the design, modeling, and testing of pneumatic bioinspired segmented composite proprioceptive bending actuators (SCPBAs) for hand rehabilitation in ADL tasks. Inspired by human finger anatomy, the actuator’s soft-joint–rigid-bone segmented structure provides a superior fit compared to continuous structures in traditional fiber-reinforced actuators (FRAs). A quasi-static model is established to predict the bending angles based on geometric parameters. Quantitative evaluations of predicted joint stiffness and extension angle utilizing proprioceptive bending are performed. Additionally, a soft under-actuated hand exoskeleton equipped with SCPBAs demonstrates their potential in ADL rehabilitation scenarios. Full article

This paper presents the anatomical and biomechanical aspects of chronic instability of the craniocervical junction (CCJ) with a discussion on clinical diagnostics based on mobility tests and provocative tests related to ligamentous system injuries, as well as radiological criteria for CCJ instability. In addition to the structural instability of the CCJ, the hypothesis of its functional form resulting from cervical proprioceptive system (CPS) damage is discussed. Clinical and neurophysiological studies have shown that functional disorders or organic changes in the CPS cause symptoms similar to those of vestibular system diseases: dizziness, nystagmus, and balance disorders. The underlying cause of the functional form of CCJ instability may be the increased activity of mechanoreceptors, leading to “informational noise” which causes vestibular system disorientation. Due to the disharmony of mutual stimulation and the inhibition of impulses between the centers controlling eye movements, the cerebellum, spinal motoneurons, and the vestibular system, inadequate vestibulospinal and vestibulo-ocular reactions occur, manifesting as postural instability, dizziness, and nystagmus. The hyperactivity of craniocervical mechanoreceptors also leads to disturbances in the reflex regulation of postural muscle tone, manifesting as “general instability”. Understanding this form of CCJ instability as a distinct clinical entity is important both diagnostically and therapeutically as it requires different management strategies compared to true instability. Chronic CCJ instability significantly impacts the quality of life (QOL) of affected patients, contributing to chronic pain, psychological distress, and functional impairments. Addressing both structural and functional instability is essential for improving patient outcomes and enhancing their overall QOL. Full article

Background and Objectives: It has been seen that jaw opening is associated with neck extension and jaw closing is associated with neck flexion. This natural association between the jaw and neck can be used as a novel approach to treat chronic non-specific neck pain, although the effects of this concept have never been previously evaluated as a treatment strategy. This article intends to study the effects of integrating jaw opening and closing movements along with active neck exercises versus active neck exercises alone in the management of chronic non-specific neck pain. Materials and Methods: A total of 80 patients, aged 20 to 50, with chronic non-specific neck pain were included in a double-blind randomized controlled trial, conducted at the Sindh Institute of Physical Medicine and Rehabilitation, Karachi, Pakistan from 2018 to 2022. The patients were divided into two groups: Group A patients were assigned jaw movements with active neck exercises, while Group B patients were assigned only active neck exercises. Both groups were assigned isometric strengthening exercises and self-resisted strengthening exercises for cervical spine muscles as a home plan. The study used various outcome measures, including the numerical pain rating scale (NPRS), neck disability index (NDI), neck flexion endurance (NFE), neck extension endurance (NEE), the neck proprioception error (NPE): neck flexion proprioception error (NFPE), neck extension proprioception error (NEPE), neck right rotation proprioception error (NRRPE), and neck left rotation proprioception error (NLRPE), with measurements taken at week 1 and week 6, respectively; the mean differences between the groups were measured using a two-way repeated ANOVA. Results: The experimental group showed better improvements compared to the control group, NPRS (73%), NDI (57%), NFE (152%), NEE (83%), NFPE (58%), NEPE (65%), NRRPE (65%), and NLRPE (62%), with a significant difference (p < 0.05). Conclusions: Active neck extension and flexion movements combined with jaw opening and closing are more effective in reducing pain and disability, improving neck muscles endurance and normalizing neck proprioception in patients with chronic neck pain. Full article