Search Results (262)

Introduction: Hip abductor strength is essential for pelvic stability, lower limb alignment, and injury prevention. Weaknesses of the gluteus medius and minimus contribute to various musculoskeletal conditions. Lateral band walks and monster walks are elastic resistance exercises commonly used to target the hip abductors and external rotators in functional, weight-bearing tasks. Therefore, the aim was to summarize the current evidence on the biomechanics, muscle activation, and clinical applications of lateral and monster band walks. Methods: This narrative review was conducted following the SANRA guideline. A comprehensive literature search was performed across PubMed, Scopus, Web of Science, and SPORTDiscus up to April 2025. Studies on the biomechanics, electromyography, and clinical applications of lateral band walks and monster walks were included, alongside relevant evidence on hip abductor strengthening. Results: A total of 13 studies were included in the review, of which 4 specifically investigated lateral band walk and/or monster walk exercises. Lateral and monster walks elicit moderate to high activation of the gluteus medius and maximus, especially when performed with the band at the ankles or forefeet and in a semi-squat posture. This technique minimizes compensation from the tensor fasciae latae and promotes selective gluteal recruitment. Proper execution requires control of the trunk and pelvis, optimal squat depth, and consistent band tension. Anatomical factors (e.g., femoral torsion), sex differences, and postural variations may influence movement quality and necessitate tailored instruction. Full article

Maintaining body symmetry in sports characterized by high lateralization is crucial for optimizing long-term athletic performance and mitigating injury risk. This study aimed to evaluate the extent of morphological asymmetry in anthropometric features among elite professional fencers. Additionally, the presence of functional asymmetry and its associations with morphological asymmetry were assessed. Thirty-two Polish adult female fencers, aged 18–33 yrs, were examined. Data collection involved a questionnaire survey, anthropometric measurements, calculation of anthropological indices, and assessment of functional asymmetry. For the 24 bilateral anthropometric features, small differences were found in seven characteristics: foot length, subscapular skinfold thickness, upper arm circumference, minimum and maximum forearm circumference, upper limb length, and arm circumference in tension. Morphological asymmetry index did not exceed 5%. Left-sided lateralization of either the upper or lower limbs was associated with significantly high asymmetry, specifically indicating larger minimum forearm circumferences in the right limb. Continuous, individualized monitoring of morphological asymmetry and its direction in athletes is essential, demanding concurrent consideration of functional lateralization. This ongoing assessment establishes a critical baseline for evaluating training adaptations, reducing injury susceptibility, and optimizing rehabilitation strategies. Deeper investigation of symmetry within non-dominant limbs is warranted to enhance our understanding. Full article

The paper offers a reinterpretation of Wittgenstein’s 1938 lecture on religious belief and challenges a prominent view that it commits Wittgenstein to a form of non-cognitivism and/or that it reflects a lack of understanding of religious practices. It further argues that the lecture is not in tension with Wittgenstein’s later views on the nature of philosophy. Full article

Background/Objectives: Chronic stress has an undeniable effect in generating emotional disorders and physiological changes. It results in excessive muscle tension throughout the body, also in the masticatory system. A situation of chronic stress was the COVID-19 pandemic. The aim of this paper was to assess the prevalence of specific masticatory pain symptoms, their severity, and the co-occurrence of associated symptoms (otological symptoms and headaches) in patients diagnosed before and during the COVID-19 pandemic. Methods: A total of 202 patients were divided into two groups: Group A (mean age of 36.46; F = 64; and M = 37) and B (mean age of 26.04; F = 70; and M = 31) included patients who presented for the study before and after the COVID-19 pandemic, respectively. The Oral Behaviours Checklist (OBC) questionnaire was used: patients with result ≥2 scores in the OBC were evaluated by DC/TMD. To evaluate the intensity of pain in masticatory structures, the elements of the RDC-TMD questionnaire were used. Otologic symptoms and headaches were assessed as coexisted complaints. Results: A significant increase in pain occurrence was observed in Group B mainly for masseter muscles (p < 0.0001), temporalis (p = 0.0044), and medial pterygoid muscles (p = 0.0153). A significantly more frequent reporting of pain/tenderness was observed among men in most of the evaluated muscles. For the lateral pterygoid muscles, changes in palpation pain did not reach statistical significance. There was a statistically significant difference in the intensity of pain in the temporomandibular joint area between both the entire groups A and B (p = 0.000152), as well as between women in Group A and B (p = 0.006453) and men in the study groups (p = 0.007990). An increase in the incidence of headaches was observed among men in Group B (Group A with 40.6% vs. Group B with 67.3%). The most commonly reported otological symptom in both groups was ear pain and/or discomfort in the preauricular region, with the frequency of otological symptoms being higher in Group B. Conclusions: (1) The COVID-19 pandemic affected the incidence and severity of masticatory muscle pain and associated complaints. (2) A decrease in the age of patients reporting complaints of masticatory mm pain was observed during the COVID-19 pandemic. (3) An increase in the frequency of headaches was observed in the male group during the pan-demic, while in women there was an increase in palpation tenderness of masticatory muscles. Full article

Objectives: This study aimed to compare the involuntary stimulated neuromuscular response of thigh muscles in karate subgroups and non-athletes. We investigated whether karate training creates neuromuscular adaptations and if the synchronization of knee flexor and extensor muscles in karate practitioners is level-dependent. Methods: The study included 7 elite karate athletes (KE), 14 sub-elite karate athletes (KSE), 16 individuals with basic karate training (KB), and 14 non–athletes (NA). Tensiomyographic (TMG) measurements were obtained from the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, and semitendinosus muscles. Indexes of Intermuscular Synchronization (IIS) were calculated for contraction time (Tc), total contraction time (TcT), and rate of muscle tension development (RMTD) as variables for the observed muscles of a given muscle group (extensors of the dominant leg, flexors of the dominant leg, extensors of the non-dominant leg, and flexors of the non-dominant leg). Results: Statistically significant differences were observed in the intermuscular synchronization indexes between karate experience levels and non-athletes. Compared to non-athletes, elite (KE), sub-elite (KSE), and beginner karateka (KB) all demonstrated shorter contraction time indexes in dominant knee extensors (p = 0.042, 0.040, and 0.013, respectively). In the non-dominant flexors, KE exhibited significantly better synchronization than KSE (p = 0.001), KB (p = 0.033), and NA (p = 0.002). For the total contraction time index, both KSE and KB outperformed NA in dominant extensors (p = 0.023 and p = 0.008), while KE showed superiority in non-dominant extensors and flexors compared to all other groups (p-values ranging from 0.002 to 0.038). Significant RMTD differences were found in the dominant leg between KE and KSE (p = 0.036) and KE and KB (p = 0.001), as well as in the non-dominant leg between KE and KB (p = 0.011) and KE and NA (p = 0.025). These findings were accompanied by statistical powers exceeding 0.80 in most cases, underscoring the robustness of the observed differences. Conclusions: These findings highlight that muscle coordination patterns, as revealed through non-invasive TMG-based indexes, are sensitive to training level and laterality in karate practitioners. Importantly, elite athletes demonstrated more synchronized activation in key muscle groups, suggesting a neuromuscular adaptation specific to high-level combat sports. From a biomechanical perspective, improved intermuscular synchronization may reflect optimized neural strategies for stability, speed, and efficiency—key components in competitive karate. Thus, this method holds promise not only for performance diagnostics but also for refining individualized training strategies in combat sports and broader athletic contexts. Full article

Understanding the tensile properties of extraocular muscles (EOMs) is crucial for successful strabismus surgery and accurate predictions of surgical outcomes. Assessments of EOM tensile strength are traditionally highly dependent on the expertise of the ophthalmic surgeon, since they involve manually pulling the EOM in opposite directions. This approach only provides subjective measurements that are not quantifiable. Previous quantitative approaches have utilized various devices such as implanted force transducers or dial tension gauges connected to muscle tendons with nylon sutures, but these methods are complex and so are rarely used outside of research settings. Consequently, the goal of this study was to create a quantitative and clinically applicable device for assessing EOM tensile strength. This developed device uses a strabismus hook connected to a strain gauge load cell that measures the tensile force and includes a tilting sensor to ensure that the hook is pulled at a consistent angle when a force is applied. The performance of the device was tested on 22 EOMs in 11 patients with intermittent exotropia during surgery for resecting the medial rectus (MR) and recessing the lateral rectus (LR) under general anesthesia. The measured tensile strengths of the MR and LR were 284.9 ± 58.3 and 278.3 ± 64.6 g (mean ± SD), respectively. In conclusion, the novel device developed in this study for quantitative measurements of EOM tensile strength in clinical settings will facilitate understanding of the pathophysiology of strabismus, as well as of the mechanical properties of the EOMs, and enhance the precision of surgical interventions. Full article

The human neck is highly vulnerable in motor vehicle crashes, and cervical spine response data are essential to improve injury prediction tools (e.g., crash test dummies, human body models). This feasibility study aimed to implement the use of pressure sensors in whole-body post-mortem human subject (PMHS) cervical spine intervertebral discs (IVDs) to confirm the feasibility and repeatability of cervical IVD pressure response to biomechanic research. Two fresh frozen whole-body PMHSs were instrumented with miniature pressure sensors (Model 060S, Precision Measurement Company, Ann Arbor, MI, USA) at three cervical IVD levels (C3/C4, C5/C6, and C7/T1) using minimally invasive surgical insertion techniques. Each PMHS underwent three quasistatic motion test trials, and each trial included multiple head/neck motions (i.e., gentle traction, flexion/extension, lateral bending, axial rotation, and forced tension/compression). Results showed marked pressure differences between both the cervical level assessed and the motion undertaken as well as successful intra-subject repeatability between the three motion trials. This study demonstrates that changes in cervical IVD pressure are associated with motion events of the cervical spine. Cervical IVD response data could be utilized to assess and supplement the characterization of the head/neck complex motion, and data could facilitate the continued improvement of injury prediction tools. Full article

This study aims to investigate the effectiveness of two machine learning methods for the prediction of the mechanical and fracture properties of Cenosphere-reinforced lightweight thermoset polyurethane composites. To evaluate the effectiveness of the models, datasets from our experimental study of composites made of five different volume fractions (0% to 40%) of Cenospheres (hollow Aluminum Silicate particles) in increments of 10% are fabricated. Experiments are conducted to determine the effect of the volume fraction of Cenospheres on Young’s modulus (both in tension and compression), percentage elongation at break, tensile strength, specific tensile strength, and fracture toughness of the composites. Two machine learning models, shallow artificial neural network (ANN) and the non-linear deep neural network (DNN), are employed to predict the above properties. A parametric study was performed for each model and optimized parameters were identified and later used to predict the properties beyond 40% volume fraction of Cenospheres. The predictions of non-linear DNN demonstrated less slope than shallow ANN and, for mass density, the non-linear DNN had unexpected predictions of increasing mass density with the addition of lighter Cenospheres. Hence, a double-hidden-layer DNN is used to predict the mass density beyond 40%, which provides the expected behavior. Full article

The vibration of the belt drive system in fresh wolfberry sorting machines significantly impacts the sorting efficiency of wolfberries. To analyze the vibration changes induced by the belt drive, a simulation model was developed using multi-body dynamics software, Recur Dyn. The lateral vibration characteristics of the grading device’s belt were examined under varying initial tensions, speeds, and deflection angles. Response surface methodology (RSM) was employed to determine the relative influence of these factors on the belt’s vibration characteristics. The analysis indicated the order of influence, from greatest to least, as initial tension, deflection angle, and speed. Aiming to minimize the vibration amplitude at the belt’s midpoint, the optimal parameter combination was determined. The operating conditions yielding the minimum amplitude were found to be an initial tension of 520 N/mm, a drive speed of 60 rpm, and a belt deflection angle of 5°. Concurrently, a transverse vibration modal analysis was conducted to study the system’s natural frequencies and corresponding mode shapes, aiding in the identification of potential resonance issues. Finally, under optimal operating conditions, guided by the results of the belt simulation test, a 10 mm fillet was introduced at the edge of the pulley, effectively mitigating wear and vibration. Specifically, when the effective length of the transmission mechanism is set to 2200 mm and the total length of the fixed device is configured as 1600 mm, the amplitude attenuation rate achieves its peak value. This study demonstrates that the integration of theoretical analysis with simulation techniques provides a robust approach for optimizing the structural design of the grading device. Full article

Wind-induced vibrations in additional conductors on electrified railway catenary systems pose a risk to operational safety and long-term structural performance. This study investigates the dynamic response of these components under wind excitation through nonlinear finite element analysis. A wind speed spectrum model is developed using wind tunnel tests and field data, and the autoregressive method is used to generate realistic wind fields incorporating longitudinal, lateral, and vertical components. A detailed finite element model of the additional conductors and fittings was constructed using the Absolute Nodal Coordinate Formulation to account for large deformations. Time domain simulations with the Newmark-β method were conducted to analyze vibration responses. The results show that increased wind speeds lead to greater vibration amplitudes, and the stochastic nature of wind histories significantly affects vibration modes. Higher conductor tension effectively reduces vibrations, while longer spans increase flexibility and susceptibility to oscillation. The type of fitting also influences system stability; support-type fittings demonstrate lower stress fluctuations, reducing the likelihood of resonance. This study enhances understanding of wind-induced responses in additional conductor systems and informs strategies for vibration mitigation in high-speed railway infrastructure. Full article

Background: Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease affecting both upper and lower motor neurons, with bulbar dysfunction manifesting in up to 80% of patients. Dysarthria, characterized by impaired speech production, is common in ALS and often correlates with disease severity. Voice analysis has emerged as a promising tool for detecting disease progression and monitoring functional status. Methods: This study investigates acoustic and biomechanical voice alterations in ALS patients and their association with clinical measures of functional independence. A descriptive observational case series study was conducted, involving 43 ALS patients and 43 age and sex matched controls with non-neurological voice disorders. Sustained vowel /a/ recordings were obtained and analyzed using Voice Clinical Systems^® and Praat software (version 6.2.22). Biomechanical and acoustic parameters were correlated with ALS Functional Rating Scale-Revised (ALSFRS-R) and Barthel Index scores. Results: Significant differences were observed between ALS and control groups (elevated muscle force and tension and interedge distance in non-ALS individuals). Between bulbar and spinal ALS subtypes, elevated values were observed in certain parameters in Bulbar ALS patients, indicating irregular vocal fold contact and weakened phonatory control, while spinal ALS exhibited increased values, suggesting higher phonatory muscle tension. Elevated biomechanical parameters were significantly correlated with low ALSFRS-R scores, suggesting a possible relationship between voice measures and functional decline. However, acoustic measurements showed no relationship with performance status. Conclusions: These results highlight the potential of voice analysis as a non-invasive, objective tool for monitoring ALS stage and differentiating between subtypes. Further research is needed to validate these findings and explore their clinical applications. Full article

Background: The Upper Limb Neural Tension Test (ULNTT) is a common assessment for neurodynamic function, yet the relationship between ULNTT findings and specific spinal biomechanical patterns remains poorly understood, particularly in the context of cervicobrachial neuralgia. This study aimed to investigate the association between ULNTT asymmetry and cervicothoracic spine biomechanics using advanced motion capture analysis. Methods: A longitudinal experimental study was conducted on two groups of asymptomatic participants: one with ULNTT asymmetry > 10° (AS group, n = 12) and another with symmetrical ULNTT (S group, n = 11). Neurodynamic testing and 3D motion capture of spinal kinematics during head lateral bending were performed at baseline. The AS group then underwent manual medicine intervention targeting spinal mobility impairments, followed by post-intervention reassessment. Spine biomechanics data, focusing on the C5-T4 region, were analyzed using the least squares approximation method to derive parameters describing upper thoracic (T1-T4_VERT) and lower cervical (C5-T1_CONC) lateral bending, and their interrelationship (ANGLE_TANG). Results: At baseline, the AS group showed significant differences between sides in neurodynamic parameters and T1-T4_VERT, with limited upper thoracic lateral bending contralateral to the side of the restricted ULNTT. Significant intergroup differences were also observed for these parameters. Following intervention in the AS group, significant improvements were noted in neurodynamic parameters and T1-T4_VERT, with no significant between-side differences post-intervention. Conclusions: These are preliminary results and preliminary conclusions based on the first study on a small group of patients. Given the limitations, this study provides evidence for a relationship between ULNTT asymmetry and upper thoracic spine biomechanics, specifically a contralateral limitation in lateral bending. These findings suggest a functional link between brachial plexus neurodynamics and upper thoracic spine mobility, offering potential insights into the pathophysiology of cervicobrachial conditions and highlighting the potential role of manual therapy in addressing both neurodynamic and biomechanical impairments. The developed motion capture analysis method offers a novel approach to quantify fine spinal motion patterns. Full article

Background and Clinical Significance: The occurrence of cerebral venous sinus thrombosis (CVST), both with or without thrombocytopenia, following COVID-19 vaccination, is well documented and more common in recipients of vector vaccines. Cases of CVST following immunization with the COVID-19 messenger RNA (mRNA) vaccine are rare; most of these cases occur within 28 days of the first dose of the vaccine. Case Presentation: We present the case of a 38-year-old male with a history of two episodes of deep vein thrombosis in the lower limbs, but without a specific thrombophilic condition, who developed CVST 13 days after the second dose of the Pfizer/BioNTech BNT162b2 vaccine. He suffered from diffuse tension-type headache of progressively increasing intensity, and his objective neurological findings were normal. Magnetic resonance venography showed thrombosis of the transverse and right sigmoid sinuses, and magnetic resonance imaging (MRI) of the brain revealed no cerebral infarction. Two months later, a follow-up MR venography showed partial recanalization of the affected sinuses, and a brain MRI showed no infarction. Conclusions: Given the temporal sequence and the absence of other possible causes, we speculate that the second dose of the COVID-19 BNT162b2 vaccine may have triggered the development of CVST. Full article

Background: Reverse shoulder arthroplasty (RSA) improves shoulder function in cases of glenohumeral osteoarthritis and rotator cuff arthropathy. The design of the glenosphere influences mobility and scapular impingement. This study evaluates the impact of joint volume on the range of motion (RoM) and identifies design modifications to enhance mobility while reducing the impingement risk. Methods: Thirty-four cadaveric shoulders were implanted with the Aequalis Reversed II^® prosthesis in seven configurations: four with 36 mm spheres (centered, 2 mm eccentric, and lateralized by 5 mm and 7 mm) and three with 42 mm spheres (centered, and lateralized by 7 mm and 10 mm). The joint volumes (inferior, anteroinferior, and posteroinferior) were measured via 3D CT scans. The RoM in adduction and elbow-at-side rotations (IR1 and ER1) was recorded. A statistical analysis identified threshold joint volumes correlating with improved mobility. Results: Larger joint volumes correlated with enhanced mobility. The 42 mm spheres demonstrated better adduction and ER1 compared to those of the 36 mm spheres (p < 0.0001). An inferior volume > 5000 mm³ and anteroinferior/posteroinferior volumes >2500 mm³ were thresholds for significant mobility improvement. Lateralization (≥7 mm) or inferior eccentricity (2 mm) improved the mobility with the 36 mm spheres, with the 36 + 2 configuration offering a practical balance for smaller patients. Conclusions: Increased joint volume enhances mobility, particularly in adduction and elbow-at-side rotations. A sphere with a 2 mm inferior offset or a 42 sphere with 7 mm lateralization optimizes the RoM while minimizing impingement risks. Patient-specific considerations, including anatomy and soft tissue tension, remain essential for optimal prosthesis selection. Full article

This study investigates a novel steel grid shear wall (SGSW) structure with lightweight and discrete lateral-resistance members, focusing on its structural behavior in lateral resistance. By comparing the characteristics of the thin steel plate shear wall, the mechanism of the steel grid components in both the tension zone and compression zone was briefly described. The formulas of lateral-resistant capacity and initial stiffness of the SGSW were derived through the static equilibrium method. Then, the influence laws of the span–height ratio, steel member spacing and section size of the steel members on the lateral-resistant performance of the SGSW were determined through a parametric analysis. In addition, the accuracy of the calculation formula was validated. The results showed that the strains of the steel grid components in different positions were all the same when the bending stiffnesses of the edge members were significantly large. The lateral-resistance capacity of the SGSW increased with the span-to-height ratio, while it decreased as the spacing between the steel components increased. Compared with the effects of web height, web thickness and flange width, increasing the flange thickness exhibited the best effects on improving the lateral capacity. As the flange thickness increased from 7 mm to 13 mm, the lateral-resistant capacity showed an improvement of 35.45%. Additionally, the formula derived in this study demonstrated high accuracy and reliability, with the error not exceeding 8% between the formula calculation and the simulation results. Full article