Search Results (339)

Objectives: The purpose of the present study was to investigate the acute effects of cold-water immersion (CWI), cryotherapy (CRT), and intermittent pneumatic compression (IPC) on lower-body neuromuscular performance in female basketball players. Methods: Eighteen athletes volunteered to participate (body mass = 63.0 ± 7.2 kg; height = 171.4 ± 6.5 cm; age = 16.4 ± 1.2 years), completing testing at three time points: (i) pre-practice, (ii) post-practice, and (iii) 45–60 min following a randomly assigned recovery intervention. At each time point, athletes performed three countermovement vertical jumps on a dual force plate system sampling at 1000 Hz (VALD Performance). To standardize external load across groups, all players wore inertial measurement units (Kinexon). Results: The two-way repeated measures ANOVA showed no statistically significant interaction (p > 0.05) between the three testing time points and recovery modalities for any of the analyzed variables. However, a significant main effect of time was observed, with 13 of 20 force-time metrics (65%), including jump height, reactive strength index-modified, contraction time, and concentric peak and mean force, declining post-recovery compared with pre-practice values, regardless of the recovery intervention applied. External load measures (e.g., total distance, number of jumps) remained consistent across groups. Conclusions: Overall, these findings suggest that CWI, CRT, and IPC were no more effective than passive recovery (i.e., control group) in mitigating post-practice declines in lower-body force and power-producing capacities. Full article

Basketball is an intermittent sport with high neuromuscular and metabolic demands. To optimize specificity, training tasks should replicate competitive loads, but little is known about how drills compare to official matches. This study compared the physiological and biomechanical load of training tasks with official competition in elite U18 basketball players. Twelve male players (16.9 ± 0.8 years) were monitored across two seasons (179 training sessions, 21 matches). A total of 3136 individual records were collected using Catapult Vector S7 LPS units. Training drills were classified by specificity (0–5). Physiological (distance and intensity zones) and biomechanical variables (accelerations, decelerations, jumps, explosive efforts, PlayerLoad™) were analyzed using cluster analysis and linear mixed models. Competition imposed the highest physiological and biomechanical loads. Non-opposition drills (1v0–5v0) showed limited transfer, though 1v0–2v0 accumulated higher jump density. Among opposition formats, 3v3 full-court was the best at replicating match demands. Continuous opposition tasks (3v3v3, 4v4v4, 5v5v5) elicited lower physiological but comparable biomechanical load. Small-sided formats, particularly 3v3 and 4v4, are the most effective training tools for reproducing competition demands, while non-opposition drills are better suited for technical or rehabilitation purposes. Full article

This study systematically investigated the influence of approach kinematics on the subsequent kinetics and power production strategies during the approach to running jumps with a single leg (ARJSL). Twenty-five physically active male university students performed ARJSL trials under two prescribed approach speeds (fast and slow) and three approach distances (3, 6, and 9 m) in a 2 × 3 within-subjects design. Three-dimensional motion capture synchronized with force platform data was used to quantify jump height (JH), vertical touchdown velocity (TDv), reactive strength index (RSI), peak joint power (hip, knee, and ankle), and joint stiffness. Significant approach speed × distance interactions were observed for JH (p = 0.006), TDv (p < 0.001), RSI (p = 0.014), ankle stiffness (p = 0.006), and peak power generation at all lower-limb joints (all p < 0.034). The results demonstrate that changes in approach strategy systematically alter the distribution of mechanical power among the hip, knee, and ankle joints, thereby influencing the effectiveness of horizontal-to-vertical momentum conversion during take-off. Notably, RSI and ankle stiffness were particularly sensitive to combined manipulations of speed and distance, highlighting their value as neuromechanical indicators of stretch–shortening cycle intensity and joint loading demands. In conclusion, ARJSL performance depends on finely tuned, speed- and distance-specific biomechanical adaptations within the lower extremity. These findings provide a constrained, joint-level mechanical characterization of how approach speed and distance interact to influence power redistribution and stiffness behavior during ARJSL, without implying optimal or performance-maximizing strategies. Full article

Background and Objectives: Evidence on motor performance in children with autism spectrum disorder (ASD) is scarce and inconsistent. The association of motor impairments with autism severity and intelligence remains insufficiently studied. We aimed to examine motor performance parameters in children with ASD compared with typically developing (TD) peers. Materials and Methods: In this cross-sectional study, a convenience sample of 26 children with ASD, aged 4–10 years, was recruited from specialized centers in KSA, alongside 27 age- and sex-matched TD children. For the ASD group, severity (Childhood Autism Rating Scale, CARS-2) and intelligence quotient (Stanford–Binet Intelligence Scale, SB5) were extracted from medical records. CARS-2 score was utilized to categorize children with ASD into two groups (mild-to-moderate and severe groups). All study children were assessed for gross and fine motor skills using the Movement Assessment Battery for Children-2 (MABC-2), balance, muscle strength, endurance, and flexibility. Results: ASD groups recorded significantly lower scores in all MABC-2 component areas when compared to the TD group (p < 0.001). Aiming and catching percentile was significantly lower in the severe ASD group compared to the mild-to-moderate group (p = 0.05). Furthermore, children with ASD exhibited increased hypermobility, predominantly at the elbow joints, reduced grip strength, shorter distance in the modified 6 min walk test, and lower standing long-jump performance (p < 0.001) when compared to TD group; however, no significant difference was recorded between the ASD groups. Spearman correlation revealed that aiming and catching was negatively correlated with autism severity (CARS-2) (r = −0.38, p = 0.05) and positively with IQ (r = 0.51, p = 0.03). Aiming and catching was positively correlated with grip strength (r = 0.55, p = 0.003), endurance (r = 0.58, p = 0.002), and jump distance (r = 0.44, p = 0.03), while balance was positively correlated with grip strength (r = 0.44, p = 0.02). Conclusions: Children with ASD exhibit significant impairments in gross and fine motor performance compared with TD peers, accompanied by hypermobility, reduced strength, and diminished endurance. Notably, aiming and catching ability correlated with both IQ and autism severity as well as specific motor parameters, suggesting its potential as a clinical marker of motor–cognitive interaction in ASD. Full article

Background and Objectives: Lower-extremity injuries are common among female athletes; however, their multifactorial predictors remain insufficiently understood. Given the interplay between physiological and psychological readiness in athletic performance, identifying the factors that influence lower limb performance is crucial for effective injury prevention. This study aimed to evaluate the predictive effects of physiological (VO₂peak, anaerobic power, agility, and isokinetic strength) and psychological (resilience and self-efficacy) variables on functional performance related to risk of injury. Materials and Methods: This cross-sectional study included 60 athletes with a mean age of 24.5 ± 6.90 years and mean body mass index of 23.12 ± 3.6 kg/m² (range: 16–30 kg/m²). The testing protocol included anthropometric measurements, the Lower Extremity Functional Test (LEFT), Wingate anaerobic cycling test, assessments of aerobic capacity, isokinetic muscle strength, and jumping performance (Single-Leg Hop [SLH] and Standing Long Jump [SLJ] tests). Psychological assessments included the General Self-Efficacy Scale (GSES) and a resilience questionnaire. A hierarchical regression analysis was performed. Results: The participants trained 5 ± 2 days per week and had 42 ± 39 months of sports experience. The mean VO_2peak was 40.82 ± 5.8 mL·kg⁻¹·min⁻¹, relative anaerobic peak power was 7.53 ± 1.92 W/kg, and fatigue index was 60.63 ± 15.41%. The mean isokinetic knee extension and flexion torque were 184.55 ± 44.60 N·m and 95.08 ± 21.44 N·m, respectively, with a flexion-to-extension ratio of 53.5%. The mean LEFT completion time was 160 ± 22 s. The participants demonstrated moderate resilience (BRS = 21 ± 4) and good self-efficacy (GSES = 33 ± 7.5). Among the psychological variables, GSES exhibited a modest negative correlation with LEFT (r = −0.28, p = 0.02). No significant associations were found between LEFT and psychological resilience. Longer LEFT completion times were associated with lower VO_2peak, mean power, and jump distance (p < 0.01). In the final model (R² = 0.58, p = 0.02), SLH (β = −0.54), VO_2peak (β = −10.32), and GSES (β = −0.70) were the strongest independent predictors of LEFT performance. Conclusions: SLH distance, VO_2peak, and general self-efficacy are key predictors of functional performance on the LEFT among female athletes. These factors may serve as practical indicators for identifying athletes who could benefit from targeted injury prevention programs. Full article

Purpose: This study assessed the adaptations resulting from implementing an experimental, integrated training program tailored to sex-specific traits. The aim was to enhance motor abilities, aerobic capacity, and metabolic variables in female and male rugby sevens athletes. Methods: Employing a combined observational and experimental design, initial and post-intervention assessments were conducted over three months (March–June 2023) with 24 elite professional players, divided equally by sex (12 females, 12 males). The protocol consisted of 12 micro-cycles, each lasting 7 days and comprising 12 training sessions. The evaluations included sprint and jumping tests, as well as functional assessments such as resting metabolic rate and cardiopulmonary exercise testing. Results: Using one-way repeated measures ANOVA, significant improvements were noted across all performance parameters (p < 0.001), with effect sizes ranging from small to very large. Sex-specific differences were evident, with females demonstrating consistent improvements in aerobic capacity and jumping ability, while males excelled in explosive power and longer sprints. Despite initial performance disparities, both sexes improved in short-distance sprints (10 m and 40 m). Cardiovascular efficiency improved as indicated by reduced maximum heart rates and lower respiratory quotients. Conclusions: Males showed superior progress in strength and explosive power tests, reflecting distinct physiological traits. These findings underscore the need for individualized and sex-specific training programs to optimize performance in high-intensity sports, such as rugby sevens. Full article

Solar irradiance is one of the main factors affecting the output of photovoltaic power stations. The cloud distribution above the photovoltaic power station can determine the strength of the absorbed solar irradiance. Cloud estimation is another important factor affecting the output of photovoltaic power stations. Ground-based cloud automation observation is an important means to achieve cloud estimation and cloud distribution. Ground-based cloud image segmentation is an important component of ground-based cloud image automation observation. Most of the previous ground-based cloud image segmentation methods rely on convolutional neural networks (CNNs) and lack modeling of long-distance dependencies. In view of the rich fine-grained attributes in ground-based cloud images, this paper proposes a new Transformer architecture for ground-based cloud image fine-grained segmentation based on deep learning technology. The model consists of an encoder–decoder. In order to further mine the fine-grained features of the image, the BiFormer Block is used to replace the original Transformer; in order to reduce the model parameters, the MLP is used to replace the original bottleneck layer; and for the local features of the ground-based cloud, a multi-scale dual-attention (MSDA) block is used to integrate in the jump connection, so that the model can further extract local features and global features. The model is analyzed from both quantitative and qualitative aspects. Our model achieves the best segmentation accuracy, with mIoU reaching 65.18%. The ablation experiment results prove the contribution of key components to segmentation accuracy. Full article

This study aimed to compare the effects on post-activation performance enhancement (PAPE) of an axial load exercise, the deadlift (DL), and a hip joint-dominant exercise, the hip thrust (HT). Fifteen resistance-trained male rugby players with ≥5 years of experience (age: 22.7 ± 1.6 years; body mass index: 27.2 ± 2.3 kg/m²) participated in this study. They performed two repetitions at 90% of their one-repetition maximum with 8 min of recovery between the HT and the DL exercises. The order of the exercises was randomized, and then a standing broad jump (BJ) was performed. There were significant changes in BJ distance after DL (Δ = 7.1 cm; 95% confidence interval [CI] 4.5–9.7; p < 0.001; d = 0.29 [0.16–0.53]) and after HT (Δ = 5.1 cm; 95% CI 2.1–7.8; p = 0.003; d = 0.23 [0.08–0.43]); no difference was found between protocols. In a two-way repeated-measures model, a main effect of Time was observed (p < 0.001; η²_p = 0.707), with no effects for Protocol (p = 0.122; η²_p = 0.162) or for the Time × Protocol interaction (p = 0.326; η²_p = 0.069). DL and HT elicited significant but small PAPE effects as expressed through BJ outcomes, with no between-protocol differences. Full article

In contrast to a relatively simple whole structure of the African Large Low Velocity Province (LLVP), the Mid-Pacific LLVP appears to be much more complex and likely interacts more with the down-going slab debris from the circum-Pacific subduction zones. Tomographic models show an apparent hole in the Mid-Pacific LLVP, coinciding with observed anomalous SPdKS arrivals. Previous studies have linked these anomalies to a large-scale mega ultra-low velocity zone (ULVZ) exhibiting up to a 45% S-wave velocity reduction. To further investigate this anomaly, we analyzed SKS waveforms from Fiji–Tonga earthquakes recorded by the USArray. Many events display pronounced travel time jumps and waveform distortions near epicentral distances of 100°, consistent with strong multipathing effects. Notably, such complexities are absent in S and SKKS phases, indicating that only the down-going SKS leg is affected. Using waveform modeling, we find that a northeast-dipping high-velocity anomaly approximately 300 km wide, 800 km long, and with a shear velocity increase of ~2% provides a good fit to the observed SKS data. This apparent LLVP hole may represent a localized downwelling within the LLVP or a remnant slab fragment interacting with the deep mantle. Full article

Purpose: This study investigated how variations in approach speed and distance influence lower-limb muscle activation, joint co-contraction ratios (CCRs), and mechanical joint stiffness during single-leg approach run jump landings (ARJSL), to clarify adaptive neuromuscular strategies for joint stiffness regulation. Methods: Twenty-five physically active male university students performed ARJSLs under six randomized conditions combining two approach speeds (fast > 4.0 m/s; slow < 4.0 m/s) and three approach distances (3, 6, and 9 m). Surface electromyography (sEMG) from five dominant-limb muscles—rectus femoris, biceps femoris, tibialis anterior, gastrocnemius, and soleus—was analyzed across three movement phases: pre-activation, downward (braking), and push-off. Knee and ankle CCRs were computed, while kinematic and kinetic data were used to calculate mechanical joint stiffness via inverse dynamics. A two-way repeated-measures ANOVA evaluated the main and interaction effects of approach speed and distance. Results: Significant speed × distance interactions were observed for tibialis anterior activation, several CCRs, and eccentric ankle stiffness (p < 0.05). Pre-activation knee CCR increased with longer, faster approaches, indicating anticipatory joint pre-stiffening. During braking, greater ankle co-contraction under fast–9 m conditions coincided with reduced mechanical ankle stiffness, suggesting a compensatory yielding strategy under high kinetic loads. In the push-off phase, faster approaches elicited higher concentric stiffness at the hip and ankle, supporting efficient energy transfer. Rectus femoris and gastrocnemius activation scaled with both approach speed and distance. Conclusions: Athletes adapt neuromuscular co-contraction and mechanical stiffness in a coordinated, phase-dependent manner to balance protection and performance. These insights may inform targeted training strategies for enhancing jump efficiency and mitigating ACL injury risk. Full article

Whether an unmanned aerial vehicle (UAV) can complete its mission successfully is determined by trajectory planning. Reasonable and efficient UAV trajectory planning in 3D environments is a complex global optimization problem, in which numerous constraints need to be considered carefully, including mountainous terrain, obstacles, no-fly zones, safety altitude, smoothness, flight distance, and so on. Generally speaking, symmetry characteristics from the starting point to the endpoint can be concluded from the potential spatial multiple trajectories. Aiming at the deficiencies of the Sparrow Search Algorithm (SSA) in 3D symmetric trajectory planning such as population diversity and local optimization, the sine–cosine function and the Lévy flight strategy are combined, and the Improved Sparrow Search Algorithm (ISSA) is proposed, which can find a better solution in a shorter time by dynamically adjusting the search step size and increasing the occasional large step jumps so as to increase the symmetry balance of the global search and the local development. In order to verify the effectiveness of the improved algorithm, ISSA is simulated and compared with the Sparrow Search Algorithm (SSA), Particle Swarm Algorithm (PSO), Gray Wolf Algorithm (GWO) and Whale Optimization Algorithm (WOA) in the same environment. The results show that the ISSA algorithm outperforms the comparison algorithms in key indexes such as convergence speed, path cost, obstacle avoidance safety, and path smoothness, and can meet the requirement of obtaining a higher-quality flight path in a shorter number of iterations. Full article

With the expansion of unmanned aerial vehicles (UAVs) into complex three-dimensional (3D) terrains for reconnaissance, rescue, and related missions, traditional path planning methods struggle to meet multi-constraint and multi-objective requirements. Existing swarm intelligence algorithms, limited by the “no free lunch” theorem, also face challenges when the standard Information Acquisition Optimizer (IAO) is applied to such tasks, including low exploration efficiency in high-dimensional search spaces, rapid loss of population diversity, and improper boundary handling. To address these issues, this study proposes a Multi-Strategy Enhanced Information Acquisition Optimizer (MEIAO). First, a Levy Flight-based information collection strategy is introduced to leverage its combination of short-range local searches and long-distance jumps, thereby broadening global exploration. Second, an adaptive differential evolution operator is designed to dynamically balance exploration and exploitation via a variable mutation factor, while crossover and greedy selection mechanisms help maintain population diversity. Third, a globally guided boundary handling strategy adjusts out-of-bound dimensions to feasible regions, preventing the generation of low-quality paths. Performance was evaluated on the CEC2017 (dim = 30/50/100) and CEC2022 (dim = 10/20) benchmark suites by comparing MEIAO with eight algorithms, including VPPSO and IAO. Based on the mean, standard deviation, Friedman mean rank, and Wilcoxon rank-sum tests, MEIAO demonstrated superior performance in local exploitation of unimodal functions, global exploration of multimodal functions, and complex adaptation on composite functions while exhibiting stronger robustness. Finally, MEIAO was applied to 3D mountainous UAV path planning, where a cost model considering path length, altitude standard deviation, and turning smoothness was established. The experimental results show that MEIAO achieved an average path cost of 253.9190, a 25.7% reduction compared to IAO (341.9324), with the lowest standard deviation (60.6960) among all algorithms. The generated paths were smoother, collision-free, and achieved faster convergence, offering an efficient and reliable solution for UAV operations in complex environments. Full article

Background: Plyometric training (PT) and resistance training (RT) can improve jumping and sprinting performance, although their comparative effectiveness in elite female basketball players remain unknown. Objectives: To compare the effects of PT and RT on jumping and sprinting performance in elite female basketball players. Methods: Thirty elite female basketball players were randomly assigned to PT (n = 10), RT (n = 10) or control groups (n = 10, standard basketball training). Performance assessments before and after the interventions (8 weeks, 16 training sessions) included countermovement jump (CMJ) height and peak power, drop jump (DJ) height and reactive strength index (RSI), standing long jump distance (LJ), CMJ with arm swing (CMJA) height, running CMJA height, and 22.2 m linear sprint time. Performance changes were analyzed using linear and Bayesian mixed-effects models. Results: Compared to controls, RT and PT improved the RSI. Additionally, PT improved (p < 0.05; posterior probability >0: 99.4–99.9%) CMJ height, CMJ peak power, DJ height and RSI, LJ, CMJA, Running CMJA and sprint time when compared to both controls and RT. Conclusions: Compared to RT, PT induced greater jumping and sprinting performance improvements in elite female basketball players. Full article

This paper introduces a versatile approach to achieve specific surface functionality with-out the need for detailed knowledge of surface topography. This is accomplished for applications targeting wettability properties by integrating contact angle measurement into a micromachining setup with a nanosecond pulsed UV laser, allowing for fully automated programs to find optimal functionalization without requiring knowledge on the topography or on possible laser-induced chemical changes itself. This study investigates the impact of various processing parameters, including laser pulse energy, scanning speed, hatching distance, jump speed, and laser repetition rate, on the wetting properties of two widely used polymers: polyethylene (PE) and ethylene propylene diene monomer (EPDM). A design of experiment (DOE) approach is used for experimental design and subsequent modeling. Finally, the effectiveness of this new approach is evaluated and compared with conventional methods. Full article

(1) Soccer is the world’s most popular sport, with over 265 million players worldwide. The core muscles play a crucial role in supporting the body’s upper and lower limbs, and training to strengthen these muscles has been shown to improve athletic performance. In 11- to 15-year-old soccer players, core training can be effectively integrated into exercises that resist body weight, improving stability and agility. (2) Our study examines the impact of core muscle training on stability and agility in this age group. (3) 22 male soccer players in an amateur league at the age of 13 ± 1.01 years, height 1.47 ± 0.06 m, weight 60.06 ± 7.44 kg were enrolled. Participants were divided into two groups: experiment (core and ball movement training) and control (ball movement training). The intervention period lasted 12 weeks and included two 15–20 min-long training sessions weekly. Pre- and post-intervention tests were conducted, including tests for agility, stability, ball kick accuracy, speed, and distance jumping. (4) Core training significantly and clearly improved agility, accuracy in ball kicking, and balance with both legs towards the back. Based on these results, and considering that no special equipment is required, we recommend the inclusion of core training in young footballers’ training routine. Full article