Search Results (826)

Background: Traditional functional mobility assessments often fail to detect subclinical postural decline in active aging populations. This study introduces the Head–Sternum Dissociation Index as a novel digital biomarker to identify latent sensorimotor deficits before macroscopic balance failure occurs. Methods: Ninety-four participants (Young, Middle-Aged Civil, Middle-Aged Dancers, and Older Adults) performed instrumented limits of stability tasks, specifically functional and lateral reach tests, utilizing a three-sensor inertial measurement unit configuration. Postural strategies were quantified via the Head–Sternum Dissociation Index and the peak ratio of corrective micro-movements, validating the sensor output against a gold-standard force platform. Results: A significant kinematic breakpoint in postural control was identified at age 55 (p < 0.001). However, Middle-Aged Civilians exhibited early kinematic divergence despite maintaining normal Timed Up and Go test performance. Receiver operating characteristic analysis revealed distinct, sex-specific physiological limits: aging males predominantly adopted a rigid “Stiffness” strategy (peak ratio ≤ 1.15, head–sternum dissociation threshold > 0.63°), while females utilized a broader, more permissive “Continuous” strategy (head–sternum dissociation threshold > 0.31°). Notably, recreational rhythmic training (dance) completely neutralized this age-related decay, with middle-aged dancers maintaining highly efficient, youthful stabilization profiles (Cohen’s d = 2.20). Conclusions: The Head–Sternum Dissociation Index, combined with relative corrective frequency, successfully phenotypes early sensorimotor erosion. These findings advocate for the integration of sex-specific kinematic screening into primary care, allowing clinicians to prescribe targeted interventions well before clinical fall risk manifests. Full article

Background: Joubert syndrome (JS) is a rare ciliopathy characterized by cerebellar and brainstem malformations and the molar tooth sign on magnetic resonance imaging. Motor impairment is primarily driven by axial hypotonia, impaired postural control, and disrupted respiratory-postural integration. Longitudinal reports describing structured neurorehabilitation with standardized functional outcomes remain limited. Case presentation: We report a female child with prenatally suspected vermian hypoplasia and postnatally MRI-confirmed Joubert syndrome. Subsequent molecular testing performed at the age of 3 years and 11 months identified heterozygous variants in the B9D2 gene associated with Joubert syndrome. Early development was marked by axial hypotonia, global motor delay, impaired trunk stabilization, sleep-disordered breathing, and early hip migration. At 2.5 years of age, following motor plateau under conventional therapy, a structured 12-month rehabilitation programme was introduced, combining Vojta-based reflex locomotion, respiratory therapy targeting thoraco-diaphragmatic synchronization, daily home-based practice, and supported standing. Results: After 12 months, gross motor function improved substantially, with GMFM-88 increasing from 12% to 52% (+40 percentage points). PEDI scaled scores improved across all domains, with mobility increasing from 8 to 40, self-care from 15 to 45, and social function from 25 to 50. Ataxia severity decreased from 22 to 15 on the modified Brief Ataxia Rating Scale, consistent with improved trunk stability and coordination. Postural and respiratory organization improved, reflected by a reduction in the subcostal angle from 137° to 90°, an increase in sacral slope from 5° to 10°, and increased expiratory pressure from 10 to 25 mmHg. Caregiver-reported assessment combined with structured clinical observation indicated improved functional visual performance, including enhanced visual attention, visuomotor coordination, and environmental visual interaction. Conclusions: Structured neurorehabilitation was associated with substantial functional improvement across motor, postural, and respiratory domains. These findings support the clinical relevance of mechanism-oriented neurorehabilitation and standardized longitudinal outcome assessment in Joubert syndrome. Full article

Background: Intrinsic foot muscle strengthening and orthotic devices such as toe spacers are commonly used to improve foot alignment and function. However, evidence regarding the combined effects of strengthening exercises and interdigital spacers remains limited. Objective: To examine whether adding a silicone toe spacer to a foot strengthening exercise program provides additional benefits compared with exercise alone. Design: Randomized controlled trial. Setting: University biomechanics laboratory. Participants: Twenty-five healthy adults (mean age 23.8 ± 1.3 years) without lower limb injury or neurological disorders were randomly allocated to one of two intervention groups. Interventions: Participants performed a six-week foot strengthening program (22 sessions). One group performed exercises alone, while the second group performed the same exercises while wearing a silicone interdigital toe spacer. Main outcome measures: The primary outcome was hallux valgus angle. Secondary outcomes included active and passive hallux range of motion (ROM), ankle dorsiflexion ROM (weight-bearing lunge test), navicular drop, and postural stability during single-leg stance assessed using center-of-pressure (CoP) measures. Results: Both groups demonstrated improvements over time in hallux valgus angle (p = 0.001, η² = 0.361), active hallux range of motion (p < 0.001, η² = 0.545), and ankle dorsiflexion (p < 0.001). However, no significant between-group differences were observed for the primary outcome or most secondary outcomes. A significant time × group interaction was observed only for passive hallux range of motion (p = 0.040, η² = 0.170), indicating greater improvement in the exercise-only group. Navicular drop and postural stability variables did not change significantly. Conclusions: A six-week foot strengthening program improved hallux alignment, hallux mobility, and ankle dorsiflexion in healthy adults. The addition of a silicone toe spacer did not provide additional short-term benefits compared with exercise alone. Full article

Continuous monitoring of pathological motor features is vital for post-stroke rehabilitation but remains challenged by power reliance and low sensitivity of wearable sensors. Here, we develop a high-sensitivity, self-powered breathable nanogenerator (BN-TENG) utilizing fish-scale-derived biological hydroxyapatite/carbon (Bio-HAp/C) fillers within electrospun polyvinylidene fluoride (PVDF) nanofibers. The Bio-HAp/C enhances electron-trapping capability, while a high-resilience ethylene-vinyl acetate (EVA) spacer optimizes contact-separation dynamics. The BN-TENG achieves a superior sensitivity of 16.28 V·N⁻¹ and remarkable stability over 10,000 cycles. By implementing a multi-node sensing strategy, the sensor successfully captures complex hemiplegic patterns, including compensatory shoulder hiking, distal muscle spasticity, and postural asymmetry. By resolving subtle micro-vibrations missed by traditional electronics, this work provides a sustainable, autonomous interface for characterizing pathological motor features and assessing rehabilitation progress in hemiplegic patients. Full article

Generative AI systems increasingly mediate how students retrieve literature and generate citations, shifting methodological rigor toward the maintenance of an auditable evidence trail. This study audits the search stage of AI-assisted literature review work, focusing on retrieval performance and citation traceability rather than downstream screening or synthesis. Four widely accessible tools were compared across two retrieval postures, and Boolean queries were executed against Scopus and evaluated against a DOI-verified librarian baseline built from Scopus, Web of Science, and Google Scholar. Using a canonical prompt and a bounded top-k capture rule (k = 20), each bibliographic record was evaluated for DOI traceability, DOI resolution integrity, metadata accuracy, and run-to-run drift. Records were screened through staged title/abstract and full-text eligibility review, and the final set included 37 studies after quality appraisal was 37 studies. Across sixteen audit runs, natural-language prompting frequently produced under-target yields, recurrent integrity failures, and low overlap with the librarian benchmark. Boolean translation improved run completion and increased the proportion of auditable records, but reproducibility remained unstable across repeated runs. These findings show that correctness at the record level does not ensure stability at the evidence-set level. Limitations include the bounded tool set, the search-stage focus, and the absence of downstream screening or synthesis evaluation. Retrieval posture, therefore, emerges as a practical governance lever for AI-assisted literature review workflows and supports the use of a student-facing verification checklist anchored in DOI verification and transparent protocol capture. This research received no external funding. OSF registration: Open Science Framework, 10.17605/OSF.IO/U8NHT. The manuscript reports the final included set as n = 37, states no external funding, and lists the OSF registration DOI. Full article

Background: Sensorimotor differences have frequently been reported in children with developmental dyslexia, but are often considered secondary or comorbid to phonological deficits. Within an embodied cognition perspective, reading acquisition emerges from dynamic interactions between bodily regulation, multisensory integration, and learning-related neural plasticity. Proprioception contributes to spatial orientation, motor coordination, and perceptual stabilization, while sleep-dependent processes play a critical role in the consolidation and automatization of cognitive and motor skills. Objectives: Building on early clinical observations, including the hypothesis proposed by Martins da Cunha, this review explores whether variations in proprioceptive processing and sensorimotor regulation may influence multisensory stability and the conditions under which reading skills develop in some individuals with dyslexia. Methods: This narrative synthesis integrates clinical observations and experimental paradigms examining proprioceptive function in children with dyslexia, including studies conducted in our laboratory over the past two decades. These investigations address postural regulation under varying attentional demands, laboratory measures of proprioceptive acuity, visuospatial localization tasks, multisensory interactions, and exploratory observations concerning sleep–wake regulation. Results: Across studies, children with dyslexia often show differences in proprioceptive processing associated with variations in postural regulation, visuospatial stability, and multisensory tasks. Laboratory measurements suggest reduced proprioceptive acuity in some individuals, with moderate correlations observed between proprioceptive sensitivity and reading-related measures. Additional observations suggest that nocturnal physiological regulation—including respiratory dynamics and sleep architecture—may interact with daytime sensorimotor stability and attentional functioning. Conclusions: Taken together, these findings support the hypothesis that variations in sensorimotor regulation across the sleep–wake cycle may influence the stability of multisensory processing and attentional conditions relevant for reading acquisition. Within this perspective, proprioception is not proposed as an alternative explanation for dyslexia but as a complementary dimension that may contribute to the heterogeneity of dyslexic profiles. Further longitudinal and controlled studies are required to clarify the relationships between sensorimotor regulation, sleep-dependent plasticity, and learning processes. Full article

Enhancement of postural stability in standing is essential for fall prevention in the context of demographic aging. Against such a background, this study proposes a personalized training system based on individual limits of stability (LOS) for a human standing state. The system evaluates LOS in eight directions using center-of-mass (COM) and center-of-pressure (COP) measurement devices and provides game-based feedback, then promotes balance within the relevant LOS parameters. Loading is individualized by applying greater force to virtual objects as the COP approaches the LOS determined for each subject. Experiments with 32 younger and 19 mature subjects produced evaluations for postural stability index (IPS), LOS area, and COP sway. The results revealed two distinct response patterns: LOS expansion and sway reduction, both observed across younger and mature cohorts. These findings suggest that individualized LOS-based training can be applied to improve standing stability with two distinct strategies. These preliminary findings suggest that individualized LOS-based training is associated with changes in standing stability through two distinct response patterns. Full article

Background: Motor decline associated with ageing compromises mobility, postural control and the ability, thereby increasing risk among older adults. Biomechanical characterization of movement, particularly using non-linear methods, offers a process-oriented approach capable of detecting subtle changes in motor coordination. The MIND&GAIT programme has previously demonstrated benefits in physical function in frail older individuals; however, its potential to improve motor coordination parameters that underpin fall risk remains insufficiently explored. Objectives: To analyse the impact of the MIND&GAIT program on motor coordination during sit-to-stand (STS) and walking tasks, two daily activities strongly associated with fall risk, using advanced non-linear and biomechanical metrics in institutionalized older adults. Methods: Fourteen institutionalized older adults (82.21 ± 7.14 years) participated. Three-dimensional acceleration and angular velocity were recorded using inertial sensors. Motor variability and predictability were quantified using the multivariate Lyapunov exponent (LyEM) and multivariate incremental entropy (MIE). STS (30 s) and walking-in-place (2 min) tasks were assessed pre- and post-intervention following a three-month, thrice-weekly programme. Results: Although no statistically significant differences emerged (ps > 0.05), trends were observed suggesting increases in LyEM during STS and in both MIE and LyEM during walking were found post-intervention. These exploratory findings may indicate enhanced motor complexity, stability and adaptability, features associated with reduced fall vulnerability. Conclusions: Despite the absence of statistical significance, the biomechanical trends observed suggest improvements in motor coordination patterns relevant to fall risk reduction in institutionalized older adults following the MIND&GAIT programme. These findings highlight the potential of structured exercise-based interventions for promoting safer movement behaviors in frail populations. Full article

Background: Spinal cord injury (SCI) is a leading cause of chronic disability. Loss of upper extremity (U.E.) function is central to limitations, in mobility, postural control, transfers, and self-care. The aim of this exploratory pilot study was to investigate whether self-reported UE function is associated with independence in activities of daily living (ADLs) in people with motor-incomplete tetraplegia. Methods: Eleven (n = 11) individuals with motor-incomplete tetraplegia (AIS C–D; neurological levels C4–T1; injury duration ≥ 1 year), recruited through convenience sampling from five specialist rehabilitation centres, participated in an exploratory cross-sectional pilot study designed to generate hypotheses rather than test them. U.E. function was assessed using the Patient-Rated Tennis Elbow Evaluation (PRTEE) questionnaire, selected for its ability to capture pain and task-related functional difficulty in the elbow, wrist, and hand; its application in this neurological population is considered exploratory. Independence in ADLs was evaluated using the Spinal Cord Independence Measure III (SCIM III). Given the small sample, all analyses were primarily descriptive and along with bivariate associations (Spearman correlations). Regression findings are reported strictly for exploratory purposes. Results: The median age was 50 years (interquartile range [IQR] 43–55). A strong negative correlation was observed between PRTEE total score and SCIM III (r_s = −0.76). In an exploratory univariate analysis, each 1-point increase in PRTEE total score was associated with a 1.3-point lower SCIM III score (β = −1.3, 95% CI −2.34 to −0.26, p = 0.02). Age also showed a positive association (β = 1.31, 95% CI 0.04 to 2.58, p = 0.05) with SCIM III; however, this finding is highly likely to reflect a statistical artefact of the small and unrepresentative sample. Multivariable regression was not conducted as a primary analysis due to insufficient statistical power. All findings should be treated as strictly exploratory and hypothesis-generating. Conclusions: Self-reported U.E. function appears to be associated with ADL independence in motor-incomplete tetraplegia. U.E. capacity may contribute to functional tasks requiring postural stability and mobility-related activities, but no predictive inferences can be made from this underpowered, convenience sample. Future studies with larger cohorts and performance-based measures are needed to confirm these preliminary observations and clarify the role of U.E. function in rehabilitation planning. Full article

Total hip arthroplasty (THA) reliably restores function, yet instability remains a clinically relevant complication. Increasing evidence indicates that postoperative stability is strongly influenced by the dynamic spine–pelvis–hip interaction, which modulates functional acetabular orientation across postures. This narrative review summarizes current evidence on postoperative spinopelvic alignment changes after THA with emphasis on temporal patterns, underlying mechanisms, and predictive factors. Early after THA, restoration of hip motion can partially normalize hip-driven compensatory patterns, however substantial interindividual variability persists. Mid- to long-term follow-up shows that pelvic orientation continues to evolve, particularly progressive posterior pelvic tilt in standing, largely driven by aging and spinal degeneration, with acceleration in older patients and those with spinal pathology. Prediction of postoperative pelvic behavior requires integrated assessment of pelvic orientation, spinal alignment and mobility, contralateral hip status, and whether imbalance is hip-driven versus spine-driven. Although classification- and model-based approaches can estimate postoperative pelvic tilt, clinically meaningful prediction uncertainty remains, supporting a strategy focused on risk stratification and adaptive preoperative planning. Full article

Achieving stable bipedal locomotion for humanoid robots remains a central challenge in reinforcement learning (RL), in which the design of reward functions is pivotal but non-trivial. This paper proposes a three-tier statistical reward shaping framework to optimize bipedal gait learning. First, training outcomes are diagnostically monitored using forward distance, fall rate, and posture score. Pearson correlation and regression analyses are then employed to identify trade-offs and isolate the direct effects of reward components. Finally, targeted parameter sweeps enable directionally guided optimization, substantially reducing heuristic parameter tuning while refining a reward function for the H1 robot in Isaac Lab. Experimental results demonstrate clear improvements over the baseline. The optimized policy reduces convergence time by 14% and increases forward distance by 186%. Stability is markedly enhanced, with fall rate decreasing from 75% to 2% and active locomotion efficiency nearly doubling (0.339 to 0.678). These results validate a reproducible, data-driven framework for reward design, highlighting the importance of principled statistical analysis in complex RL-based humanoid locomotion. Full article

Background: Pumping in Laser-class sailing is a dynamic propulsion technique used in marginal wind conditions and characterized by repetitive, coordinated oscillations of the sailor–sail system. Despite its practical relevance, its biomechanical and ergonomic demands remain insufficiently characterized. Methods: A mixed-methods framework was applied combining questionnaire data, kinematic analysis, ergonomic assessment, and musculoskeletal modelling. Thirty-six competitive Laser sailors completed a Borg CR-10-based questionnaire on perceived discomfort/fatigue across body regions at predefined time points (during pumping, immediately after training, and the following day). A controlled land-based multi-angle video acquisition was used to reconstruct a standardized pumping posture and parameterize a digital human model in DELMIA^® for postural/kinematic analysis. Ergonomic risk was assessed using REBA, and muscle activity was estimated using the AnyBody^® Modeling System (simulation-derived normalized muscle activity across 129 muscles). Results: the simulation identified high neuromuscular demand in the trunk and shoulder complex, with several deep trunk stabilizers and the left latissimus dorsi reaching 100% modeled normalized muscle activity. Marked lateral asymmetry was observed, with right-sided trunk dominance and left-sided shoulder dominance. Kinematic analysis showed substantial joint excursions, with large lumbar motion amplitudes, while REBA yielded a score of 11 (Very-High Risk). Questionnaire data indicated a high prevalence of pumping-related musculoskeletal discomfort (72.2%), most frequently involving the lower back, shoulders, and knees. A dissociation was observed between modeled muscle activity and perceived fatigue, with the lower limbs rated as most fatigued despite lower modeled activation than the trunk. Conclusions: Findings identify the deep trunk stabilizers, latissimus dorsi, and lower extremities as key regions involved in pumping, with marked lateral asymmetry and high ergonomic risk. They support targeted training, injury-prevention, and ergonomic strategies to improve performance and reduce injury risk in competitive sailing. Full article

Background: Existing evidence suggests an association between temporomandibular disorders (TMDs) and alterations in body posture and balance; however, the mechanism underlying this relationship remains unknown. The present study aimed to investigate the associations between specific TMD subtypes, indices of bioelectrical activity of the masticatory muscles, and parameters of body posture and balance. Methods: The study followed a case–control study design. A total of 81 participants were enrolled, including 33 controls and 48 individuals with TMD, classified into myofascial (n = 14), articular (n = 17), and mixed (n = 17) subtypes. Diagnosis of temporomandibular disorders was carried out by prosthodontic specialists using the Polish adaptation of the Diagnostic Criteria for Temporomandibular Disorders. Masticatory muscle bioelectrical activity was assessed by surface electromyography. For statistical analysis, the Asymmetry Index and Functional Clenching Activity Indices were used. Static balance was evaluated with a pedobarographic platform. The sway area, velocity, and length of the Center of Pressure, as well as the foot contact area, were recorded and automatically calculated by the system. Measurements were performed under different mandibular conditions, with both eyes open and eyes closed. Correlation analyses were performed using Spearman Rank Order Correlation. Pearson’s Chi-squared test was used for the analysis of categorical variables. Results: Weak to moderate negative correlations were primarily observed, indicating that higher indices of masticatory muscle bioelectrical activity were associated with better postural balance, with distinct correlation patterns identified across different TMD subtypes. Conclusions: This exploratory study identified multiple correlations between masticatory muscle activity and postural or balance parameters, suggesting possible subtype-specific patterns in TMDs. However, the evidence remains preliminary and should be interpreted with caution, warranting further confirmatory and longitudinal research. Full article

Background: Balance impairment and falls are a major health concern in older adults. Beyond vestibular and visual factors, growing evidence indicates that age-related hearing loss contributes to postural instability through altered multisensory integration. However, interventions addressing the interaction between auditory input and postural control remain limited. This study examined whether integrating Taopatch^® nanotechnology, based on localized photobiomodulation, into conventional hearing aids could influence postural control in individuals with hearing loss. Methods: Forty experienced hearing aid users (mean age 77.3 ± 15.6 years) completed five postural assessments using a SensorMedica^® baropodometric platform. Four sessions employed a placebo patch identical in appearance to the active device, and the fifth used Taopatch^®. Static and stabilometric parameters were analyzed under open- and closed-eye conditions. Results: Significant improvements were observed with the Taopatch^®-integrated device. Sway path length (−8%, p = 0.002), mean velocity (−8%, p = 0.002), and low-frequency sway (−30%, p = 0.04) decreased, indicating smoother and more efficient postural control. A lateral redistribution of plantar load and an increase in contact surface area (up to +15%) were also found. These effects were less evident without visual input. Conclusions: Preliminary findings suggest that localized photobiomodulation integrated into hearing aids may positively influence postural stability in older adults with hearing impairment, possibly by supporting sensory integration processes. Further controlled studies are needed to confirm these effects and clarify the underlying mechanisms. Full article

Objectives: This study investigated the effects of trunk extension-based inspiratory muscle strengthening on respiratory function, balance, and gait in patients with stroke. Methods: Thirty stroke patients were randomly assigned to the study group (n = 15) or control group (n = 15). The study group performed inspiratory muscle strengthening exercises in a trunk extension posture, while the control group received conventional inspiratory muscle training. Both groups trained five times per week for six weeks. Outcome measures included maximal inspiratory pressure (MIP), maximal inspiratory flow rate (MIFR), maximal inspiratory volume (MIV), peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV₁), Berg Balance Scale (BBS), weight distribution ratio (WDR), limits of stability (LOSs), Timed Up and Go (TUG), gait velocity, cadence, and stride length. Results: The study group showed significantly greater improvements in respiratory parameters (MIP, MIFR, MIV, PEF, FEV₁) and functional outcomes (WDR, LOS, BBS, TUG, gait velocity, cadence, stride length) compared to the control group. Conclusions: Trunk extension-based inspiratory muscle strengthening effectively improves respiratory function, balance, and gait in stroke patients, and may serve as a valuable addition to stroke rehabilitation programs. Full article