Cikkek

• Graph-Based Quantification of Basketball Spacing Using Spatial and Network Metrics

  Tsiakalos Apostolos

  Tsiakalos Anastasios

  Megtekintések száma:

  29

  In modern basketball, effective player spacing is critical for optimizing offensive efficiency and shot quality. This paper proposes a novel approach to quantifying spacing using graph theory. Each player is represented as a node, and the pairwise Euclidean distances between them form the weighted edges of a complete graph. We compute several spatial and structural metrics, including total spacing, convex hull area, minimum spanning tree weight, and centrality measures. Our method allows for a frame-by-frame quantitative analysis of spacing, revealing key patterns associated with successful possessions. Results demonstrate that certain geometric and network-derived properties are strong indicators of tactical efficiency.

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• Differences Between Standard and Sport-Specific Countermovement Jumps in High-Performance U18 Male Water Polo Players: A Cross-Sectional Study

  Băltean Alexandru Ioan

  de Hillerin Pierre Joseph

  Geantă Vlad Adrian

  Megtekintések száma:

  19

  Introduction: Vertical jump capacity is essential for evaluating lower-limb performance in water polo, especially under dryland testing conditions. While power or force is often implied, jumping height remains the primary measurable outcome in these protocols. Aim: This study aimed to compare vertical jump performance in U18 male water polo players using two jump types: the standard Counter-movement Jump (CMJ) and a modified "Frog Style" CMJ (CMJ-Frog), hypothesizing that the latter better reflects sport-specific lower-limb mechanics. Materials & Methods: A cross-sectional, within-subjects design was employed on a sample of 39 male water polo players from the Under-18 category (mean height: 183.02 ± 5.43 cm; mean weight: 75.20 ± 10.41 kg). Each athlete performed three maximal trials of two jump protocols: the standard Counter-movement Jump (CMJ) and the modified sport-specific CMJ-Frog. Jump height was measured using the OptoJump Next system. Data analysis comprised descriptive statistics and normality assessment using the Kolmogorov–Smirnov test. Inferential statistics were conducted via paired-samples t-tests to compare protocols within subjects, with effect sizes calculated using Cohen's d. Results: CMJ-Frog jumps yielded significantly higher values (37.43 ± 4.59 cm) than standard CMJs (34.17 ± 4.49 cm), t (38) = -7.46, p < .001, with a large effect size (d = 1.19). Conclusions: The CMJ-Frog style may serve as a more functionally relevant assessment for evaluating vertical jump capacity in Under-18 male water polo players, as it better reflects the mechanics of aquatic elevation during gameplay. It may offer a more specific alternative for performance testing and monitoring in aquatic athletes. Future studies should validate the CMJ-Frog protocol in senior players and investigate its relationship with in-water performance metrics.

   

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• Antagonist Muscle Activation During Isometric Elbow Flexion at Varied Joint Angles: A Comparative Neuromuscular Analysis Between Volleyball Players and Sedentary Adults

  Roy Dipika

  Pal Manisha

  Chatterjee Priyam

  Bandyopadhyay Anupam

  Megtekintések száma:

  18

  Neuromuscular coordination enhances athletic performance and prevents injuries. Antagonist muscle activation during isometric movements, such as elbow flexion, is crucial for joint stability and efficiency. Volleyball-specific training may lead to distinct neuromuscular adaptations that differ from those of sedentary individuals. This study aims to investigate differences in antagonist activation patterns during isometric elbow flexion between volleyball players and sedentary adults, with a focus on neuromuscular control and the effects of co-contraction. Twenty-eight males (14 volleyball players and 14 sedentary individuals; ages 18–25) participated in the study. Surface electromyography (EMG) recorded biceps and triceps activity at 45°, 90°, and 120° elbow angles. Muscle activity, co-contraction indices (CCI), and perceived exertion (RPE) were statistically analyzed using descriptive statistics and two-way repeated measures Analysis of Variance. Bonferroni corrections assessed angle-specific effects. Significance levels (α) were set to 0.05 for all analyses. Athletes exhibited significantly higher biceps activation (mean EMG_max = 0.63 vs. 0.48) and lower triceps activation (mean EMG_max = 0.25 vs. 0.35, p < 0.001). Co-contraction (CCI) was lower among athletes (mean = 0.55 vs. 0.89). RPE scores were consistently lower in athletes (mean = 12.8 ± 1.6) compared to non-athletes (15.7 ± 1.5), indicating superior neuromuscular efficiency. Volleyball players demonstrated enhanced neuromuscular control, as evidenced by higher agonist activation, reduced antagonist activation, and lower co-contraction. The enhanced neuromuscular adaptations of volleyball players, likely resulting from consistent training, suggest improved movement mechanics and a reduced risk of injury. Future longitudinal studies are advised to explore causality and sport-specific neuromuscular changes.

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• Examining the Correlation Between Speed and Change of Direction Running Speed (CODS) in Football

  Horváth Tamás

  Müller Anetta

  Karap Bálint

  Bíró Melinda

  Megtekintések száma:

  13

  The correlation between speed and change-of-direction running speed (CODS) remains unclear, as indicated by the results of previous research. One reason may be that researchers have used different tests to investigate the speed of running with a change of direction (CODS), where the number of direction changes, the angle, the total length of the running test, and the time required to complete the test vary. The researchers agree that agility is not the same as straight-line running speed, but suggest that further studies are needed to determine the relationship. Regarding the relationship between speed and agility, the results showed a consistent trend that faster players tend to perform better on the agility test. Still, we could only statistically confirm this at 20 and 30 metres. Only for the agility test in the right direction was there a significant correlation between 20 and 30 meters alone. Our results indicate that both agility and and CODS require different developmental stages.

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• High Performance Management (HPM) a Sportban a Nemzetközi és Magyar Szakirodalomban

  Gyermán Istvan

  Laczkó Tamás

  Megtekintések száma:

  18

  A High Performance Management (HPM) a sportban egy olyan integrált eszközkészlet és megözelítés, amely a sportolók, sportszervezetek és a sportágak teljesítményének optimalizálását célozza többdimenziós szinten (makro, mezo, mikro). A nemzetközi szakirodalom – például Sotiridau - De Bosscher (2013), O’Boyle (2015), Molan et al.(2019) és Turner et al. (2019) munkái az olvasóknak és kutatóknak hollisztikus modelleket kínálnak, amelyek a HPM rendszerbe integrálják a gazdasági, pszichológiai és az emberi fejlődési tényezőket egyaránt. Ezzel szemben a magyar szakirodalom (András, 2014; Géczi, 2012; Győri 2020) elsősorban, gazdasági, jogi és szervezeti keretekre fókuszál, kiemelve a hazai sportfinanszírozás és intézményi struktúrák meghatározó szerepét. A két irányzat összevetése és az irodalmi anyaghalmaz értékelése egyértelműen rávilagít a tényre, hogy Magyarországon a HPM rendszer széttöredezett és a legtöbb esetben ad hoc módon valósul meg, míg nemzetközi szinten az átfogó, emberközpontú és mérőszámokra épülő moellek dominálnak. Tanulmányom következtetése szerint, a magyar sportban a HPM fejlesztéséhez szükség van a holisztikus megközelítések adaptálására, elfogadására, ehhez a kellő személyzeti anyag biztosítása, továbbá a teljesítménymutatók egységesítésére és a sportolók hosszútávú jólétének integrálásra a sportszervezeteket és egyesületek menedzsmentfolyamataiba. 

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