Search Results (983)

Background: Marker-based motion capture systems are commonly used for three-dimensional movement analysis in sports. Novel, markerless motion capture systems enable the collection of comparable data under more time-efficient conditions with higher flexibility and fewer restrictions for the athletes during movement execution. Studies show comparable results between markerless and marker-based systems for kinematics of the lower extremities, especially for walking gait. For more complex movements, such as throwing, limited data on the agreement of markerless and marker-based systems is available. The aim of this study is to compare the outcome of a video-based markerless motion capture system with a marker-based approach during an artificial basketball-throwing task. Methods: Thirteen subjects performed five simulated basketball throws under laboratory conditions, and were recorded simultaneously with the marker-based measurement system, as well as two versions of a markerless measurement system (differing in their release date). Knee, hip, shoulder, elbow and wrist joint angles were acquired and root mean square distance (RMSD) was calculated for all subjects, parameters and attempts. Results: The RMSD of all joint angles of the marker-based and markerless systems ranged from 7.17° ± 3.88° to 26.66° ± 14.77° depended on the joint. The newest version of the markerless system showed lower RMSD values compared to the older version, with an RMSD of 16.68 ± 5.03° for elbow flexion, capturing 93.84% of the data’s RMSD of 22.22 ± 5.52, accounting for 87.69% of the data. While both versions showed similar results for right knee flexion, lower differences were observed in the new version for right hip flexion, with an RMSD of 8.17 ± 3.75 compared to the older version’s 13.24 ± 5.78. Additionally, the new version demonstrated lower RMSD values for right hand flexion. Conclusions: Overall, the new version of the markerless system showed lower RMSD values across various joint angles during throwing movement analysis compared to the older version. However, the differences between markerless and marker-based systems are especially large for the upper extremities. In conclusion, it is not clearly explainable if the detected inter-system differences are due to inaccuracies of one system or the other, or a combination of both, as both methodologies possess special limitations (soft tissue vibration or joint center position accuracy). Further investigations are needed to clarify the accordance between markerless and marker-based motion capture systems during complex movements. Full article

This paper interrogates two important but obscured admission policy developments at leading American universities in the post-World War II era. First, we critically examine the University of California’s “special admissions,” later formalized as the “Admission by Exception” policy adopted at two flagship campuses (Berkeley and UCLA) to open opportunities for veterans returning from the War under the GI Bill. The scale of this Admission by Exception policy was orders of magnitude larger than any comparable admissions policy in recent decades, including both the eras with and without legally permissible affirmative action. Second, we excavate archival evidence from the immediate aftermath of the 1954 Brown v. Board of Education decision, where leaders at the flagship University of Texas at Austin campus hastily adopted a new standardized exam requirement because their enrollment modeling indicated this was the most efficient way to not face further losses in federal court while excluding the largest number of African Americans (and thereby resisting Brown) and maintaining the same overall size of the freshmen class. These two post-war admission policy changes, one arising in de facto segregated California and the other in de jure segregated Texas, operated as racialized institutional mechanisms analogous to “redlining” racially restrictive housing policies that are a more familiar feature of the post-War era. We draw on historical data about earnings and wealth accumulation of the overwhelmingly white graduates of UC and UT in the 1950s–70s and connect these findings to the theoretical frameworks of Cheryl Harris’s “whiteness as property” and George Lipsitz’s racialized state investment. We show how these admission policies contributed to the intergenerational transfer of advantage. We then turn to the contemporary admissions landscape at highly selective American universities after the Supreme Court’s SFFA v. Harvard ruling. We link current trends at some elite institutions toward a return to standardized testing requirements, maintaining considerations of athletic ability mostly in “country club” sports as manifestations of bias in university admissions, which tend to favor white applicants (Jayakumar and Page 2021; Jayakumar et al. 2023b). The paper connects historical racialization of admissions to ongoing inequities in access and outcomes, showing how both historical and contemporary admissions policies reward inherited forms of cultural capital aligned with whiteness. Full article

As an emerging sports tourism event, Guizhou’s “Village Super League” injects new vitality into the optimization of human–land relationships and the development of household livelihoods in traditional villages of ethnic mountainous regions. Studying five affected traditional tourism villages from an “event–actor–capital” perspective using mixed methods, this research finds the following: (1) The composite average score of household livelihood capital is 0.3177, indicating a medium–low level, which suggests that households’ livelihood structure still requires significant enhancement despite the tourism boost from the “Village Super League”. (2) There is an imbalance in development among the villages. The livelihoods of households under the influence of the “Village Super League” exhibit distinct characteristics, being “driven by external flows, led by social capital, supported by the material foundation, and coordinated with other forms of capital.” (3) The evolution of household livelihoods follows a pathway of “event-driven supplementation, endogenous renewal of actors, capital integration and synergy.” By constructing shared event memory markers, the livelihoods of villages at different stages of tourism development demonstrate differentiated dynamic mechanisms. The findings deepen the theoretical understanding of livelihoods in traditional villages under event-driven development. Consequently, this study recommends that policymakers and community stewards channel transient social capital and external flows into durable physical and financial assets to ensure livelihood sustainability beyond the initial event boom. Full article

This study examines the integration of artificial intelligence (AI)-based strategies within the framework of landscape sustainability science and urban ecology, focusing on urban sports and recreation areas in Turkey and Lithuania. In the era of sustainable urban transformation, AI technologies offer new opportunities for maintaining ecological integrity, enhancing green infrastructure connectivity, and supporting adaptive management of urban ecosystems. The research aims to comparatively analyze the role and effectiveness of AI applications—such as intelligent waste management, predictive maintenance, and spatial planning tools—in promoting clean, safe, and ecologically resilient environments. A qualitative design was employed, and data were collected through semi-structured interviews with 30 experts, including local administrators, facility managers, environmental professionals, AI specialists, and academics from both countries. Thematic analysis using NVivo revealed key themes linking AI functions to ecological outcomes, including improved resource efficiency, habitat connectivity, and data-informed governance. Results show that Lithuania’s institutionalized green infrastructure facilitates multi-scale AI adoption, while Turkey’s evolving policy framework presents significant potential for system integration. The study emphasizes the necessity of embedding AI-driven ecological indicators into landscape-scale planning and developing an interdisciplinary governance model to achieve sustainable, resilient, and inclusive urban ecosystems. Full article

The definition of the recycling and recyclability rates used today relies too heavily on the mass of the recycled materials, to the disadvantage of less dense materials such as polymers. In order to help with this issue, two indices have been created to, respectively, evaluate the retrievability of materials in their end-of-life stage and their reintegrability in new equipment once they have been recycled. These two indices comprise four indicators each, which are themselves divided into 23 sub-indicators. The six formal mathematical principles of the construction of these entities are presented, along with the formulas used for their calculation. Then, a case study is presented: the data of an equipment from a French EEE and sports and leisure distributor have been collected, and all sub-indicators, indicators and indices have been calculated for this equipment, hence assessing the retrievability and reintegrability of its constitutive materials. In conclusion, the precise nature of the indicators and sub-indicators has allowed us to give eco-design recommendations on different aspects of the design process, such as the choice of materials, the mechanical connections and modularity of the product, and its insertion into the waste treatment chain. Full article

A series of articles has tested von Neumann’s minimax theory against behavioral evidence based on field data from professional sports. The evidence has been viewed and collectively cited as positive evidence that elite athletes in their familiar sports contexts mix well and behave in line with minimax. In this paper, based on open state-of-the-art tennis data and analytics, we shall uncover new and significant evidence against minimax at the very top of the game, where previously, such results had not been obtained. The kinds of behavioral deviations from minimax that we find become apparent, because we enrich the test strategy to take into account whether or not players face ‘pressure’ situations like break points and other decisive points. Our paper highlights that the prior literature’s failure to reject minimax does not constitute positive behavioral evidence, as some of that literature argued, because it is not robust to data aggregations and separations that are psychologically natural given the relevant real-world context. In this case, this means separating serves into the serve types that players actually consider and separating situations by pressure levels, which leads to clear and sound rejection of minimax. Full article

As so many drugs have failed in ALS a new approach is needed. The author proposes that recent human genetic variants may play major roles in the disease, changing metabolism. Evolution of hominins was accelerated 3–2.5 Mya, by cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH) becoming a unitary pseudogene after a pathogenic infection, changing the sialome, and hence metabolism, brain development and neuromuscular junctions (NMJs). This was when hominins evolved to run in Africa and develop bigger brains. Deletion of CMAH in mice allows them to run for longer (~50%). The enzyme CMAH is critical for the sialome, particularly the neurotrophin GM1, a critical hub for viral infection and for NMJ stability, but which is lost from NMJs at the beginning of denervation, probably due a 10-fold increase in spinal cord glucosylceramidases (non-lysosomal GBA2). A GBA2 inhibitor, ambroxol, is currently in phase II for ALS. Human-specific GM1 may be critical for human evolution, lactate metabolism and ALS. Lipid/lactate metabolism changed to support these evolutionary changes and lactate is a major body/brain fuel, but compromised in ALS patients and a marker of disease progression. Recent progress in sports science involving lactate metabolism and human performance may also be relevant to ALS therapies, and incidence. Full article

This article presents the accumulated technical and scientific knowledge from energy performance upgrade work in emblematic and essential municipal and public buildings in Crete and the Greek islands, such as the Venetian historical building Loggia, which is used as the Heraklion City Hall, the Natural History Museum of Crete, Pancretan Stadium, the municipal swimming pool of the municipality of Minoa Pediadas, the indoor sports hall in Leros, primary schools, high schools and a cultural center. Each one of the aforementioned buildings has a distinct use, thus covering almost all different categories of municipal or public buildings and facilities. The applied energy performance upgrade process in general terms is: (1) Mapping of the current situation, regarding the existing infrastructure and final energy consumption. (2) Formulation and sizing of the proposed passive measures and calculation of the new indoor heating and cooling loads. (3) Selection, sizing and siting of the proposed active measures and calculation of the new expecting energy sources consumption. (4) Sizing and siting of power and heat production systems from renewable energy sources (RES). Through the work accomplished and presented in this article, practically all the most technically and economically feasible passive and active measures were studied: insulation of opaque surfaces, opening overhangs, natural ventilation, replacement of openings, daylighting solar tubes, open-loop geo-exchange plants, refrigerant or water distribution networks, air-to-water heat pumps, solar thermal collectors, lighting systems, automation systems, photovoltaics etc. The main results of the research showed energy savings through passive and active systems that can exceed 70%, depending mainly on the existing energy performance of the facility. By introducing photovoltaic plants operating under the net-metering mode, energy performance upgrades up to zero-energy facilities can be achieved. The payback periods range from 12 to 45 years. The setup budgets of the presented projects range from a few hundred thousand euros to 7 million euros. Full article

The convergence of Internet of Things (IoT) and Artificial Intelligence (AI) has enabled personalized sports coaching, yet a significant gap remains: translating low-level sensor data into high-level, contextualized feedback. Large Language Models (LLMs) excel at reasoning and instruction but lack a native understanding of physical kinematics. This paper introduces BoxingPro, a novel framework that bridges this semantic gap by fusing wearable sensor data with LLMs for automated boxing coaching. Our core contribution is a dedicated translation methodology that converts multi-modal time-series data (IMU) and visual data (video) into structured linguistic prompts, enabling off-the-shelf LLMs to perform sophisticated biomechanical reasoning without extensive retraining. Our evaluation with professional boxers showed that the generated feedback achieved an average expert rating of over 4.0/5.0 on key criteria like biomechanical correctness and actionability. This work establishes a new paradigm for integrating sensor-based systems with LLMs, with potential applications extending far beyond boxing to any domain requiring physical skill assessment. Full article

Ensemble techniques are crucial for preprocessing near-infrared (NIR) data, yet effectively integrating information from multiple preprocessing methods remains challenging. While multi-block approaches have been introduced to optimize preprocessing selection, they face issues such as block order dependency, slow optimization, and limited interpretability. This study proposes PFCOVSC—a fast, order-independent, and interpretable ensemble preprocessing strategy integrating multi-block fusion and variable selection. The method combines diverse preprocessed data into a unified matrix and employs the efficient fCovsel technique to select informative variables and construct an ensemble model. Evaluated against SPORT and PROSAC on three public datasets, PFCOVSC substantially reduced prediction root mean squared error (RMSE) on wheat and meat datasets by 17%, 13% and 49%, 20%, respectively, while performing comparably on tablet data. The method also demonstrated advantages in computational speed and model interpretability, offering a promising new direction for preprocessing ensemble strategies. Full article

Fatigue is not only a widespread subjective experience but also a complex physiological and pathological state involving multiple organs and systems. Currently, there is no consensus on the definition and classification of fatigue. Based on its causes, this paper categorizes fatigue into sports fatigue, occupational fatigue, and pathological fatigue. It elaborates on the specific manifestations and underlying mechanisms of fatigue in the motor, nervous, cardiovascular, digestive, urinary, endocrine, and reproductive systems, aiming to uncover the intrinsic connections of fatigue phenotypes across different systems. These findings may provide key targets for gene-assisted therapy of fatigue-related complications, thereby establishing a new theoretical foundation for the clinical management of fatigue and related research. Full article

This paper contains an analysis of methods for person classification based on signals from wearable IMU sensors during sports. While this problem has been investigated in prior work, existing approaches have not addressed it within the context of few-shot or minimal-data scenarios. A few-shot scenario is especially useful as the main use case for person identification in sports systems is to be integrated into personalised biofeedback systems in sports. Such systems should provide personalised feedback that helps athletes learn faster. When introducing a new user, it is impractical to expect them to first collect many recordings. We demonstrate that the problem can be solved with over 90% accuracy in both open-set and closed-set scenarios using established methods. However, the challenge arises when applying few-shot methods, which do not require retraining the model to recognise new people. Most few-shot methods perform poorly due to feature extractors that learn dataset-specific representations, limiting their generalizability. To overcome this, we propose a combination of an unsupervised feature extractor and a prototypical network. This approach achieves 91.8% accuracy in the five-shot closed-set setting and 81.5% accuracy in the open-set setting, with a 99.6% rejection rate for unknown athletes. Full article

The advancement of sports science has heightened demands for precise monitoring of athletes’ technical movements, physiological status, and performance. Optical fiber sensing (OFS) technology, with its unique advantages including high sensitivity, immunity to electromagnetic interference, capability for distributed sensing, and strong biocompatibility, demonstrates significant application potential in sports science. This review systematically examines the technical principles, innovative breakthroughs, and practical application cases of optical fiber sensors in various domains: monitoring key human physiological parameters such as respiration, heart rate, and body temperature; capturing motion and analyzing movement covering muscle activity, joint angles, and gait; integrating within smart sports equipment and protective gear; and monitoring sports apparatus and environments. The value of OFS technology is further analyzed in areas including sports biomechanics analysis, training load monitoring, injury prevention, and rehabilitation optimization. Concurrently, current technical bottlenecks such as the need for enhanced sensitivity, advancements in flexible packaging technologies, cost control, system integration, and miniaturization are discussed. Future development trends involving the integration of OFS with artificial intelligence, the Internet of Things, and new materials are explored, aiming to provide a theoretical foundation for sports medicine and training optimization. Full article

(1) Background: This study aimed to develop and validate a new instrument to measure relational reflexivity in management settings. Relational reflexivity—defined as the integration of self-awareness, perspective-taking, and interpersonal responsibility—has been discussed conceptually, but it lacks a standardized, psychometrically sound measurement tool. (2) Methods: A 25-item scale was developed based on a literature review and administered to 524 sport management students. Exploratory factor analysis (EFA) was used to identify the underlying structure. A 15-item version, based on item performance and theoretical fit, was then tested using confirmatory factor analysis (CFA) on a randomly selected subsample (n = 400). Model fit was assessed using RMSEA, CFI, TLI, and χ²/df. (3) Results: EFA revealed a five-factor structure consistent with theoretical expectations: self-awareness, perspective-taking, communication and conflict resolution, respect and mediation, and intrapersonal reflexivity, explaining 53.5% of the total variance. CFA confirmed the model with excellent fit indices (RMSEA = 0.0605; CFI = 0.955; TLI = 0.941). Factor loadings were high (0.89–1.13), and all were statistically significant. (4) Conclusions: The result (RRMQ) is a valid and reliable tool for assessing multidimensional relational reflexivity in leadership and team contexts. Its structure reflects both theoretical foundations and psychometric rigor, providing a foundation for future research and practical applications in leadership development. Full article

Congenital agenesis of the tensor fascia lata (TFL) muscle is an extremely rare anomaly, with very few reports in the literature and unclear clinical significance. We report the incidental finding of unilateral TFL agenesis in a 25-year-old male physician who had been enrolled as a healthy control in a muscle MRI study on genetic myopathies. Imaging demonstrated a complete absence of the right TFL with mild compensatory hypertrophy of the ipsilateral rectus femoris, while the contralateral side and all other muscles appeared normal. The subject had no history of neuromuscular disease, exhibited only a subtle waddling gait, and had previously completed the New York Marathon in 4 h and 16 min without symptoms. Laboratory tests, including creatine kinase, were within normal limits. Thirteen years later, he remains in good health, continues regular sports activities, and has not developed pain or functional impairment. This case emphasizes that TFL agenesis may remain clinically silent and compatible with high levels of physical activity. Nevertheless, awareness of such anomalies is important, as compensatory mechanisms might predispose to long-term biomechanical imbalance, and recognition on imaging can prevent misinterpretation or unnecessary investigations Full article