Search Results (81)

Facial neuromodulation with botulinum toxin has traditionally been approached from the perspective of wrinkle correction. However, facial expressions primarily arise from coordinated muscular interactions that convey both positive and negative emotional valence. A conceptual framework focused on muscular equilibrium rather than wrinkle severity may therefore offer a more comprehensive, reproducible, and clinically meaningful approach. In this article, we propose the Index of Muscular Equilibrium (IME) Framework, a conceptual model for aesthetic neuromodulation that integrates functional muscle mapping, validated severity scales, and a composite IME score to support personalized treatment planning and outcome assessment. The framework is derived from a narrative review of PubMed-indexed literature on facial muscle activity, emotional expression, and validated clinical assessment tools. It combines a Valence Map to classify positive- and negative-valence muscle groups, a standardized evaluation of static and dynamic hypertonus, a conceptual Plan Score to guide selective neuromodulation, and a feedback-based longitudinal workflow (the IME Loop). Together, these components enable structured assessment of muscular imbalance, integration of established wrinkle severity scales, and translation into individualized, function-oriented treatment strategies, with intended benefits including improved objectivity, reproducibility, and patient communication. By reframing treatment success from the duration of muscle blockade to the duration of expressive harmony, the IME Framework introduces testable constructs for future validation and offers a functional perspective on facial neuromodulation aligned with contemporary affective science. Full article

Background: Physical inactivity remains a major public health challenge, particularly for underserved populations lacking exercise facility access. AI-powered smartphone applications with real-time human pose estimation offer scalable solutions, but they lack rigorous clinical validation. Objective: This study validates the clinical efficacy of a 16-week on-device AI-driven resistance training program using MediaPipe pose estimation technology in young adults with limited facility access. Primary outcomes included muscular strength (1RM squat), body composition, functional movement (FMS), and cardiorespiratory fitness (VO₂max). Methods: A single-group pre–post study enrolled 216 participants (mean age 23.77 ± 4.02 years; 69.2% male), with 146 (67.6%) completing the protocol. Participants performed three 30 min weekly sessions of seven compound exercises delivered via a smartphone app providing real-time pose analysis (97.2% key point accuracy, 28.6 ms inference), multimodal feedback, and personalized progression using self-selected equipment. Results: Significant improvements across all domains: muscular strength (+4.39 kg 1RM squat, p < 0.001, d = 1.148), body fat (−2.92%, p < 0.001, d = −1.373), skeletal muscle mass (+2.19 kg, p < 0.001, d = 1.433), FMS (+0.29 points, p = 0.001, d = 0.285), and VO₂max (+1.82 mL/kg/min, p < 0.001, d = 0.917). Pose classification accuracy reached 95.8% vs. physiotherapist assessment (ICC = 0.94). Conclusions: This study provides the first clinical evidence that on-device AI pose estimation enables facility-independent resistance training with outcomes comparable to traditional programs. Unlike cloud-based systems, our lightweight model (28.6 ms inference) supports real-time mobile deployment, advancing accessible precision exercise medicine. Limitations include a single-arm design and gender imbalance, warranting future RCTs with diverse cohorts. Full article

Lactylation serves as a vital link between cellular metabolism and epigenetic regulation and plays a pivotal role in muscle biology. Muscle tissue is the primary site of lactate production; its unique metabolic environment confers dynamism, specificity and functional diversity for lactylation. Under physiological conditions, lactylation regulates myocyte energy metabolism, proliferation, differentiation, and exercise adaptation through a dynamic “writer–eraser–reader” mechanism. In pathological states, lactate imbalance directly contributes to the progression of various muscular disorders. For instance, diminished histone lactylation during muscle aging suppresses the expression of genes critical for DNA repair and protein homeostasis. Aberrant lactylation is involved in the development of insulin resistance and diabetic cardiomyopathy. Furthermore, lactylation exerts dual effects in cardiovascular diseases; it provides protection by enhancing the transcription of repair genes and simultaneously aggravates injury by promoting processes such as fibrosis and ferroptosis. Collectively, these findings underscore the importance of lactylation in muscular pathologies and provide a theoretical foundation for the development of therapies that target this modification process. As the regulatory mechanisms of lactylation have become clearer, precise interventions targeting specific modification sites are expected to open new therapeutic avenues for muscular diseases. Full article

Obesity is a multidimensional condition characterized by autonomic imbalance, metabolic inflexibility, impaired physical resilience, and ectopic adiposity, pathophysiological alterations that arise long before overt cardiometabolic disease becomes clinically detectable. Despite this, current cardiometabolic risk scores continue to rely predominantly on biochemical and anthropometric variables, such as BMI, waist circumference, glucose, and lipid levels. While these markers are practical, inexpensive, and validated across large population cohorts, growing evidence shows that they offer limited incremental predictive value and fail to capture early functional and structural abnormalities. The recent literature highlights the prognostic importance of autonomic dysfunction, reduced metabolic flexibility, diminished cardiorespiratory fitness, impaired muscular strength, and ectopic fat depots including visceral and epicardial adiposity, independently of the traditional anthropometric indices. The domains remain absent from traditional algorithms such as the Metabolic Syndrome criteria, the Framingham Risk Score, and SCORE2. As a result, cardiometabolic risk is frequently underestimated in key subgroups, including young adults with obesity, individuals with high visceral adiposity but normal BMI, those with subclinical myocardial dysfunction, and metabolically unhealthy normal-weight phenotypes. This narrative review synthesizes current evidence on obesity-related cardiometabolic impairment, highlights major gaps in established risk scores, and supports the conceptual development of the C.O.R.E. (Cardio-Obesity Risk Evaluation) Indicator Model—a hypothesis-generating, non-validated multidomain framework integrating autonomic, metabolic, functional, and structural markers to enable earlier risk phenotyping in future studies. Full article

Bilateral morphological asymmetry of the upper limbs may influence grip strength even in semi-active young adults. Understanding this relationship is important for identifying early neuromuscular imbalances with implications for ergonomics and rehabilitation. This study aimed to examine associations between upper limb anthropometric characteristics and grip strength in non-athlete students, considering gender and manual dominance. The sample included 192 healthy university students (110 females, 82 males; mean age 19.92 ± 1.4 years) without prior sports training. Thirteen bilateral anthropometric parameters of the upper limbs were assessed, including hand and palm dimensions, segmental lengths, and arm and forearm circumferences, along with grip strength measured by dynamometry in two positions: arm extended and arm flexed at 90°. Statistical analysis revealed significant differences in forearm length, arm and forearm circumferences, and grip strength (p < 0.001). The dominant limb consistently demonstrated higher grip strength, with mean differences of approximately 2 kg. Male participants showed higher absolute values for all morphological and functional variables, whereas stronger correlations between distal upper-limb morphology and grip strength were observed in females. These findings indicate that, despite largely symmetric skeletal dimensions, moderate functional asymmetries exist and grip strength is influenced primarily by local muscular development rather than overall limb size. Full article

Hamstrings–quadriceps (H–Q) imbalance represents a biomechanical marker of knee instability and injury risk in running. This in silico (simulation-based) study introduces a digital machine learning framework designed to estimate H–Q imbalance using biomechanical features derived entirely from synthetic running trials and conceptually mappable to inertial-sensor domains. Key biomechanical predictors included the dynamic hamstrings-to-quadriceps ratio (H:Qdyn), the knee moment limb symmetry index (LSI), and the early-stance co-contraction index (CCI), all standard indicators of muscular balance and coordination in sports medicine. A reduced musculoskeletal framework emulating flexor–extensor balance, limb symmetry, and co-contraction patterns generated 573 synthetic running trials for 160 virtual subjects across three speeds. These interpretable features trained a calibrated gradient-boosting classifier evaluated via ROC-AUC, PR-AUC, balanced accuracy, F1, and Brier score. Across all conditions, the model achieved ROC-AUC 0.933 (95% CI 0.908–0.958), balanced accuracy 0.943 (95% CI 0.924–0.962), PR-AUC 0.918 (95% CI 0.892–0.943), F1 0.940 (95% CI 0.919–0.958), and Brier 0.056 (95% CI 0.041–0.072), outperforming the logistic baseline. Dynamic H:Q ratio and knee moment symmetry were the dominant predictors, while co-contraction provided complementary biomechanical nuance. These results demonstrate that simulation-derived frameworks can reproduce IMU-relevant biomechanical variability, enabling interpretable machine learning for transparent assessment of muscular balance in sports medicine. Full article

Muscle imbalance due to reduced muscular endurance is a significant risk factor. Thus, for the lower limb, muscle imbalance is one of the most common causes of traumatic injury. A number of studies on isoinertial technology have demonstrated that it allows the development of forces similar to or greater than those generated in the same exercise but performed with traditional weights. Our research aimed to analyze the morpho-functional changes at the muscle level using ultrasound, and the evolution of muscle power output express of maximal muscle strength at the level of the knee extensors, specifically the rectus femoris muscle, following an isoinertial training program. The study included 11 female soccer-practicing sportswomen with average age (15.18 ± 1.08). The assessment included an ultrasound assessment of the rectus femoris muscle, before and after isoiniertial training (post acute moment); a muscle force assessment using dynamometry; and an evaluation of isoinertial parameters as concentric and excentric power, in terms of coefficients that represent report between the left and right sides. The isoinertial protocols training included three weekly sessions of isoinertial exercises. The results show an increase in the values of the ultrasound dimensions, approximately at the same level for both measured dimensions, which is significant for demonstrating the existence of an increase in muscle volume. An important progress is observed in the mean maximum strength and maximum force, but especially in the duration of maintenance of the maximum loading force. There is no statistically significant symmetry at the level of the rectus femoris muscle for concentric power and no statistically significant symmetry tendency for eccentric power, although there is a favorable evolution in terms of values. Full article

Background: Relative Energy Deficiency in Sport (REDs) results from an imbalance between energy intake and expenditure, leading to low energy availability (LEA) and impairments of physiological and/or psychological functions in female and male athletes. While physical determinants of REDs are well documented, psychological factors such as body image (BI) have received comparatively little attention. The aim of this scoping review was to synthesize the current scientific evidence on the relationship between BI and REDs. Methods: A scoping review examined the current literature, including quantitative and qualitative studies. The scoping review was conducted in April 2025 in PubMed, Web of Science, MEDLINE, SPORTDiscus, APA PsycArticles, APA PsycInfo, CINAHL and OpenDissertations. Studies were included if they examined BI aspects in relation to LEA or REDs in a sporting context, regardless of participants’ gender, age, level or sport. Inclusion criteria were based on the Population—Context—Concept (PPC) framework. Results: Seven studies met the inclusion criteria, covering athletes from various ages, genders, sports, and performance levels. Findings indicate that BI dissatisfaction—manifesting, for example, as a drive for thinness or muscularity, exercise dependence, and disordered eating—represents a relevant psychological factor associated with LEA in both female and male athletes. Conclusions: The relationship between BI and REDs is complex and insufficiently explored. Future research should address this link systematically across sports, performance levels, genders, and age groups. In sports medicine practice, screening tools should systematically incorporate psychological risk factors such as BI disturbances to enable early detection, targeted intervention, and prevention of long-term health consequences. Full article

Aim: The study developed and validated AppER, an mHealth tool for informal caregivers of children with Duchenne Muscular Dystrophy, and examined differences between app users and non-users. Methods: Four phases were followed: (1) focus groups with experts and caregivers to identify care-related domains; (2) prototype development and validity testing (CVR, I-CVI, I-FVI) using the MARS scale; (3) implementation of the final app; and (4) psychosocial profiling of 88 caregivers (42 users and 46 non-users) measuring quality of life, dependency, somatic symptoms, and coping strategies. Results: AppER showed high content and face validity, surpassing reference thresholds. In the psychosocial analysis, users reported lower perceived quality of life than non-users, despite no significant differences in dependency, somatic symptoms, or coping strategies. Conclusions: Employment patterns differed: more users were dedicated to household tasks, while more non-users were self-employed, suggesting economic factors may affect app uptake and quality of life perceptions. Findings indicate AppER is a valid, well-rated support tool, and that caregivers with lower perceived quality of life may be more inclined to adopt digital health solutions, potentially to address complex care demands. Designing targeted digital interventions may be particularly valuable for those in less favorable socioeconomic contexts. Because of the small sample and between-group imbalances, results are exploratory and warrant confirmation in larger, balanced samples. Full article

Background/Objectives: Dental professionals engage in a variety of dental procedures within a confined workspace that is often challenging to access and navigate. This environment frequently results in static, asymmetrical, and inappropriate postures, which can lead to muscular imbalances and cause pain or damage to the musculoskeletal system. Such issues can adversely affect the dental workforce, resulting in increased absenteeism, reduced productivity, disability, and premature retirement from the profession. Therefore, the objective of this study was to develop and evaluate the performance of an Artificial Intelligence (AI)-based deep learning model designed to assess dental ergonomics. Methods: An AI-based Dental Ergonomic Posture Assessment Model [SBK-DentErgo] was developed through the strategic integration of YOLOv11 and MediaPipe. Model training and validation were conducted using 500 photographs of dental professionals performing procedures on patients, captured from both frontal and sagittal planes. In the initial phase of the study, two calibrated evaluators assessed 50 photographs, demonstrating excellent agreement. In the subsequent phase, five dental specialists, along with the AI model, evaluated the same set of photographs, and the results were recorded. Results: AI-based model demonstrated excellent agreement with that of calibrated evaluators (Kappa = 0.922, p = 0.000). The reliability of AI-based scores was also consistent (ICC = 1.000, p = 0.000). Human evaluation of ergonomic posture exhibited very low sensitivity (20.5%) compared to AI, which showed very high sensitivity (97%). The specificity of human evaluation was also extremely low (9.1%) in contrast to AI (85.7%). The AI model (AUC = 0.917, 95% CI 0.762–1.000) could serve as the ‘gold standard’ in evaluating dental operator ergonomics. Conclusions: This AI model demonstrated exceptional performance in evaluating the working postures of dental professionals, surpassing experienced specialists in both sensitivity and specificity. The model provides real-time feedback, enabling dentists to conduct self-assessments and correct their posture immediately, thereby preventing postural issues. Full article

Symmetry and asymmetry significantly influence running biomechanics, performance, and injury risk. Given the practical, ethical, and methodological constraints inherent in human-subject studies, computational modeling emerges as a valuable alternative for exploring biomechanical asymmetries in detail. This study systematically evaluated the mechanical effects of lower limb imbalance during running using a simulation-based musculoskeletal framework in OpenSim. A total of 130 simulations were performed, incorporating controlled asymmetries in limb strength, stride length, and ground reaction forces (±5% and ±10%), to quantify alterations in joint moments, ground reaction forces (GRF), and muscular activation patterns. Results demonstrated clear biomechanical deviations under asymmetric conditions. Vertical ground reaction forces (GRF) decreased on the weaker limb and increased on the stronger limb, with peak knee joint moments rising by up to 20% under pronounced asymmetry. Muscle activation in major lower limb muscles, including the gastrocnemius and quadriceps, increased substantially on the stronger side, reflecting compensatory mechanical loading. These findings highlight the negative consequences of uneven limb loading and support the use of computational modeling to guide personalized training, rehabilitation, and injury prevention strategies. Full article

The treatment of shoulder dysplasia resulting from brachial plexus birth injury (BPBI) remains a matter of debate within pediatric orthopedic and neurosurgical communities. Various approaches have been proposed to address the muscular imbalance and joint incongruity that develop in affected children, with special attention paid to the roles of humeral head reduction and tendon transfers. Background/Objectives: These procedures aim to correct the disproportionate strength between internal and external rotators of the shoulder. However, the specific contribution of skeletal procedures such as glenoid osteotomy to restoring shoulder mechanics remains controversial. Glenoid osteotomy, a technique that involves surgically reorienting the glenoid cavity, is hypothesized to promote better containment of the humeral head and allow more physiological joint development. On one hand, altering the glenoid axis could enhance joint congruency and facilitate remodeling during growth. On the other hand, there is limited evidence supporting its efficacy and safety. Methods: This review aims to assess the available literature to determine whether glenoid osteotomy represents a safe and effective procedure for patients with BPBI-associated shoulder dysplasia. A comprehensive literature search yielded 1380 titles. After excluding studies focused on adults and those failing to meet inclusion criteria, only three studies were selected for final analysis. Due to the limited data and variability in study design, no statistical meta-analysis could be performed. Results: Findings suggest that glenoid osteotomy, particularly when combined with tendon transfers, may lead to improvements in shoulder abduction and external rotation. However, outcomes are often difficult to interpret in isolation, and the specific benefits attributable to the osteotomy remain unclear. The lack of standardized imaging, follow-up, and scoring systems limits the strength of current conclusions. Conclusions: Further multicenter, prospective studies are needed to evaluate the long-term efficacy of glenoid osteotomy, its role in skeletal remodeling, and its contribution to overall shoulder stability and function. Such studies would help clarify the true potential of this surgical technique in the broader context of BPBI treatment. Full article

The fine regulation of antioxidant systems and intracellular production of reactive oxygen species (ROS) is responsible for cellular redox balance. The main organelles responsible for ROS production are mitochondria, and they complete this process through the electron transport chain. These potentially harmful molecules are buffered by enzymatic and non-enzymatic antioxidant systems. Oxidative stress is determined by an imbalance between the production and clearance of ROS in favor of the accumulation of these detrimental species, which generate cellular damage by interacting with macromolecules. In neurodegenerative diseases, oxidative stress has been demonstrated to be a crucial component, both causal and consequential to the disease itself. On the other hand, neurodegeneration disrupts neuromuscular junctions, leading to reduced muscle use and subsequent atrophy. Additionally, systemic inflammation and metabolic dysfunction associated with neurodegenerative diseases exacerbate muscle degeneration. Thus, sarcopenia and atrophy are common consequences of neurodegeneration and play a significant role in these disorders. Regarding this, ROS have been defined as promoting sarcopenia, stimulating the expression of genes typical of this condition. Overall, this review aims to contribute to filling the gap in the literature regarding the consequences at the muscular level of the relationship between oxidative stress and neurodegenerative diseases. Full article

In the context of global population aging, identifying reliable, objective tools to assess physical function and postural stability in older adults is increasingly important to mitigate fall risk. This study presents a non-contact platform that uses a Microsoft Azure Kinect depth camera to evaluate functional performance related to lower-limb muscular capacity and static balance through self-selected depth squats and four progressively challenging stances (feet apart, feet together, semitandem, and tandem). By applying markerless motion capture algorithms, the system provides key biomechanical parameters such as center of mass displacement, knee angles, and sway trajectories. A comparison of older and younger individuals showed that the older group tended to perform shallower squats and exhibit greater mediolateral and anteroposterior sway, aligning with age-related declines in strength and postural control. Longitudinal tracking also illustrated how performance varied following a fall, indicating potential for ongoing risk assessment. Notably, in 30 s balance trials, the first 10 s often captured meaningful differences in stability, suggesting that short-duration stance tests can reliably detect early signs of imbalance. These findings highlight the feasibility of low-cost, user-friendly depth-camera technologies to complement traditional clinical measures and guide targeted fall-prevention strategies in older populations. Full article

Sarcopenic obesity (SO), characterized by an excess of fat and a decrease in muscle strength or mass, is a global public health concern and is linked to metabolic conditions such as metabolic syndrome (MetS). Different mechanisms contribute to SO, such as inflammation, fatty acid infiltration, and insulin resistance (IR). Recently, myostatin (MYOST), an inhibitory factor for skeletal muscle tissue, was proposed as an aimed compound for the treatment of conditions of muscular metabolic imbalance mass and MetS. On the other hand, a therapy with natural compounds such as resveratrol (R) and quercetin (Q) is effective for the treatment of MetS, but its effect on the MYOST pathway has been poorly explored. The control group received water, and the MetS group received 30% commercial sugar in the drinking water for 6 months. Polyphenol mix (R at a dose of 50 mg/kg/day and Q at 0.95 mg/kg/day) was administered for 1 month. MetS rats present SO linked to an increase in the expression of MYOST/ActRIIA and ActRIIB (p < 0.0001). R+Q treatment prevented SO by lowering the expression of MYOST and its receptors and increased the expression of Smad 7 in MetS rats (p < 0.0001). Moreover, the polyphenol treatment reverted IR by increasing Akt phosphorylation, leading to an increase in muscle mass. It decreased lipid stores, restored glycogen accumulation, and increased myosin expression (p < 0.0001). The results of this work indicate that R+Q supplementation could be a promising therapeutic agent to prevent SO and sarcopenia derived from other metabolic alterations. Full article