Prevalence and associated factors of non-traumatic shoulder pain during spike and serve movements in male high school volleyball players: a cross-sectional study.

BACKGROUND: Nontraumatic shoulder pain is a prevalent issue among male high school volleyball players, but its comprehensive assessment has been lacking in prior research, which often isolated specific aspects of shoulder function. This study aimed to identify contributing factors to shoulder pain in this population. HYPOTHESIS: The hypothesis posited that limited shoulder internal rotation (IR) range of motion (ROM), imbalance in rotator cuff muscle strength, intrinsic sensory disturbance, and joint stability are associated with shoulder pain in male high school volleyball players. Additionally, there was an anticipation that a substantial proportion of players would experience shoulder pain but refrain from reporting it to coaches. METHODS: Forty-nine male volleyball players aged 15-17 years were evaluated between February and June 2023. Questionnaires assessed the prevalence of shoulder pain during spiking and/or serving, as well as the frequency of reporting this pain to coaches. Various factors, including acromio-humeral distance, shoulder ROM, isometric strength, proprioception, joint stability (Upper Quarter Y-Balance Test), joint position sense, and upper extremity power (Seated Medicine Ball Throw Test; SMBT), were quantified. Logistic regression analyses was conducted to explore potential connections between these variables and shoulder pain. RESULTS: Shoulder pain was reported by 39% of participants, but it was rarely communicated to coaches (95%). Jump serves (odds ratio 1.84, p=0.02) and reduced shoulder IR ROM (odds ratio 0.94, p=0.03) were associated with shoulder pain. CONCLUSION: This study provides crucial insights into the prevalence, severity, and associated factors of shoulder pain among male high school volleyball players. The findings underscore the importance of improving athlete-coach communication to facilitate early intervention and preventive measures. Significant associations were observed between the use of jump serves, reduced shoulder internal rotation range of motion, and shoulder pain, highlighting the relevance of specific volleyball techniques in injury prevention. These findings offer valuable guidance to coaches and trainers in developing interventions aimed at mitigating the risk of shoulder pain and enhancing player performance.

Influence of biological maturation on cardiac autonomic recovery in female volleyball players during & after repeated sprints training: An experimental trial.

Previously, it was suggested that biological maturation (BM) could be linked to cardiac autonomic recovery (CAR) in the pediatric population. However, this influence hasn't been confirmed yet. Our aim was to investigate the impact of BM on CAR in female volleyball players. Experimental study with a sample of 38 volleyball players, comprising 20 girls (age: [11.6 â€‹± â€‹2.1] years) and 18 women (age: [24.5 â€‹± â€‹5.5] years), we analyzed BM, comparing maturing subjects (girls) with mature subjects (women). Additionally, we assessed peak height velocity (PHV) in girls. We conducted a training session involving repeated sprints (3 rounds of 6 sprints interspersed by 5 â€‹min [min] of passive rest). Using short-range radio telemetry, we analyzed CAR during (at the end of the 1st and 2nd rounds) and after (following the 3rd round) the training session of repeated sprints by applying the 60-s to 300-s heart rate recovery index (HRR-Index). Girls exhibited superior CAR compared to women (round 2: 60-s, 120-s, 240-s, and 300-s, p â€‹< â€‹0.005). Subgroup analyses of BM indicated that individuals in the Late-PHV stage demonstrated superior CAR compared to those in the Early-PHV and During-PHV groups. (60-s to 300-s, η 2 p â€‹> â€‹0.4, p â€‹< â€‹0.05). Subjects in the During-PHV stage were superior to those in the Early-PHV stage (240-s á 300-s, η 2 p â€‹> â€‹0.4, p â€‹< â€‹0.05). We have concluded that biological maturation has a significant impact on cardiac autonomic recovery.

Evaluation of hop tests based on Y-Balance test and FMS test outcomes in volleyball and basketball players to identify those prone to injury: a potential predictor of injury.

BACKGROUND: The quest for a reliable and effective method to identify athletes at risk of injury holds the promise of significantly reducing injury rates and improving overall athletic performance. This research delved into the relationship between the Functional Movement Screen (FMS), Y-Balance Test (YBT), and Hop tests (Side hop, Medial triple hop, and Lateral step-down hop), aiming to determine the potential in predicting injuries of hop tests among division 1 volleyball and basketball players. METHODS: This research was conducted with fifty-two participants from the Division 1 league, encompassing both volleyball and basketball players. The study rigorously employed the Functional Movement Screen (FMS), the Y-Balance Test (YBT), and various hop tests (side hop test, medial triple hop test, lateral step-down hop) to measure relevant variables. The data analysis used logistic regression, ensuring a comprehensive approach to the study. RESULTS: Results showed no significant relationship between FMS and Hop test for predicting injuries, but there was a relationship between ΔY and side hop that shows side hop test can predict injury, but there was no relationship between Lateral step down, Medial triple hop, and ΔY. CONCLUSIONS: Based on our findings, side hop, despite the medial triple hop and lateral step-down test, can be used as a sports injury predictor.

Quantifying and analysing the angular momentum in volleyball jump serve during the aerial phase: relationship to arm swing speed.

Background: In volleyball, the jump serve is a crucial and commonly used serving technique. Nonetheless, the angular momentum developed during the jump serve remains unexplored. The objectives of the current study were to determine the angular momentum manifesting during the airborne phase of the jump serve and to analyse the correlations between the angular momentum variables and arm swing speed. Methods: Three-dimensional coordinate data were obtained during the jump serves of 17 professional male volleyball players. Correlation and linear regression analyses were used to identify the angular momentum variables linked to the arm swing speed at ball impact (BI). Results: The arm swing speed at BI exhibited significant correlations with the peak angular momentum of the attack arm (r = 0.551, p = 0.024), non-attack arm (r = 0.608, p = 0.011), non-attack leg (r = -0.516, p = 0.034), forearm (r = 0.527, p = 0.032), and hand (r = 0.824, p < 0.001). A stepwise regression model (R2 = 0.35, p = 0.043) predicted arm swing speed based on the peak angular momentum of the non-attack leg, forearm, and hand. Conclusions: The study results suggest that during the arm-acceleration phase, (1) increasing angular momentum with the non-attack leg helps maintain aerial body balance, thereby enhancing arm swing execution, and (2) controlling the magnitude and timing of the force exerted by the elbow and wrist is crucial for effectively transmitting angular momentum, contributing to an increase in arm swing speed.

Effect of Physical Activity Behaviors, Team Sports, and Sitting Time on Body Image and Exercise Dependence.

This study aimed to evaluate whether the type and degree of physical activity commitment (i.e., team sport athletes, highly active individuals, sedentary behavior) influence body image and exercise behavior. A total of 96 participants (46 women and 50 men; age: 22.7 ± 2.7 years; height: 170 ± 8.6 cm; weight: 67.6 ± 10.8 kg) were divided in six groups: female volleyball and male football players (student athletes classified as Tier 2), highly physically active women and men, with high sitting time completed the Body Image Dimensional Assessment and the 21-item Exercise Dependence Scale to evaluate body dissatisfaction and level of dependency on exercise. The Body Image Dimensional Assessment is a silhouette-based scale, where three direct indices are derived from the participants' responses: body dissatisfaction, sexual body dissatisfaction, and comparative body dissatisfaction. The Exercise Dependence Scale is a six-point Likert scale that evaluates seven dimensions of exercise dependence (tolerance, withdrawal, intention effects, lack of control, time, reductions in other activities, and continuance) and provides an overall score. A multivariate analysis of variance was used to examine the effects of different levels of physical activity, team sport participation (volleyball and football), and sedentary behavior (i.e., high sitting time) on participants' body image indices and dimensions of exercise dependence according to sex. Volleyball players showed significantly higher body dissatisfaction than football players (d = 0.99) and the physically active men group (d = 2.31), who had lower values than sedentary women group (d = 1.68). Football players had lower comparative body dissatisfaction values than volleyball players (d = 1.70) and sedentary women (d = 1.69), who had higher values than sedentary men (d = 1.04). Sedentary women had a significantly lower exercise dependence scale score than volleyball players (d = 1.71), football players (d = 1.12), and physically active men (d = 1.21). The findings highlight the impact of regular physical activity on body dissatisfaction and the variance in body image perceptions between the sexes. Moreover, the high exercise dependence values found in volleyball and football players and physically active men suggest an effect of intense training and maladaptive exercise behaviors, underlining the need for comprehensive strategies to address exercise dependence.

The Impact of Perception-Action Training Devices on Quickness and Reaction Time in Female Volleyball Players.

The objective of this study was to examine the effect of a training program utilizing action perception technology (PAD) tools on improving the motor reaction times and neuromuscular capabilities of the upper and lower limbs compared to a traditional training program. Twenty-four female volleyball players competing in the Italian national championship were randomized into two groups of 12 athletes each: an experimental group (EG) and a control group (CG). A preliminary analysis confirmed the absence of significant differences in age and anthropometric characteristics between the groups. All the players underwent an initial battery of tests (pre-test), including Reaction Time simple Upper and Lower Limb (RTsUL and RTsLL) and Tapping Upper and Lower Limb (TUL and TLL). During a 6-week training program, the experimental group used exercises with a technological system of illuminated disks, while the control group followed the traditional training methods without advanced technology. At the end of the program, both groups were subjected to final tests (post-test). The main results show that after 6 weeks, both groups improved their performance compared to the initial tests. However, EG achieved significantly better results than CG in every test, with significant reductions in average times (ip%) of -14.9% in RTsUL (DX = -0.072 s, t = 23.2, p < 0.05, d = 6.7), -14.9% in RTsLL (DX = -0.091 s, t = 44.0, p < 0.05, d = 12.7), -10.6% in TUL (DX = -0.622 s, t = 42.0, p < 0.05, d = 12.1), and -10.7% in TLL (DX = -0.983 s, t = 43.1, p < 0.05, d = 12.4). The use of light-based perception-action technology devices in volleyball training has shown potential for significantly improving movement speed and reaction time. However, further research is needed to determine whether these improvements actually translate into enhanced overall performance in competitive contexts compared to the traditional training methods.

Serious leisure and successful aging among elderly air volleyball players: examining the mediating role of social support and flow experience.

Introduction: Previous literature has demonstrated that engagement in serious leisure (SL) is associated with subjective well-being among older adults, while the relationship between successful aging (SA) and SL remains unexplored. This study aims to investigated the association between SL, social support (SS), flow experience (FE), and SA. Methods: A total of 435 older adults participating in air volleyball events were included in this study. Results: The findings revealed that: (i) SL directly and positively influences on SS, FE, and SA; (ii) SS is positively related to FE, and FE is positively associated with older adults'SA; (iii) Both SS and FE fully mediate the relationship between SL and SA, with SS partially explaining this mediation through FE. Discussion: This study builds upon prior research in this field and highlights the significance of SL for the SA among older adults. Future studies should further explore the underlying mechanisms linking serious sport experiences to successful elderly life.

Effect of ball positions on trunk, hip, knee, and ankle joint kinematics and kinetics during a spike jump in volleyball.

BACKGROUND: Anterior cruciate ligament injuries are serious conditions encountered in volleyball players and occur frequently during spike jump landings. During spike jumps, the lower limb kinematics and kinetics during landing may be altered in relation to the ball position. RESEARCH QUESTION: Does the ball position have an effect on lower-limb kinematics and kinetics during spike jumps? METHODS: We measured the lower limb kinematics and kinetics of 20 healthy female college volleyball athletes during a spike jump using a three-dimensional motion analysis system. The ball positions were set to normal, dominant, and non-dominant positions. A repeated analysis of variance was used to compare the lower limb kinematics and kinetics at the initial contact and the maximum knee flexion during jump landing. Additionally, statistical parametric mapping analysis was used to analyze changes over time during the spike jumps. RESULTS: At the initial contact of the spike jump landing, the knee valgus angle, trunk lateral bending angle, and maximum knee valgus moment when the ball was set at the non-dominant position increased compared to those at the dominant position. Statistical parametric mapping analysis showed no significant change in knee valgus angle and moment of jump landing. CONCLUSION: Knee valgus angle, trunk lateral bending angle, and maximum knee valgus moment increased with the non-dominant position; furthermore, the risk of ACL injury may also be increased. SIGNIFICANCE: The posture at ball impact may influence the landing kinematics and kinetics. Therefore, it is necessary to pay close attention to movements during and prior to landing.

The effects of fatigue on the relationship between ankle angle at initial contact and the knee and hip joints in landing: Assessing the risk of ACL injury.

BACKGROUND: Anterior cruciate ligament (ACL) injuries may correlate with lower limb angles and biomechanical factors in both dominant and non-dominant legs at initial contact (IC) post-landing. This study aims to investigate the correlation between ankle angles in three axes at IC and knee and hip joint angles during post-spike landings in professional volleyball players, both pre- and post-fatigue induction. RESEARCH QUESTION: To what extent does fatigue influence lower limb joint angles, and what is the relationship between ankle joint angles and hip and knee angles at IC during the landing phase following a volleyball spike? METHODS: Under conditions involving the peripheral fatiguing protocol, the lower limb joint angles at IC following post-spike landings were measured in 28 professional male volleyball players aged between 19 and 28 years, who executed the Bosco fatigue protocol both before and after inducing fatigue. A paired t-test was utilized to compare the joint angles pre- and post-fatigue in both dominant and non-dominant legs. Furthermore, Pearson's correlation test was conducted to explore the relationship between ankle angles at IC and the corresponding knee and hip joint angles. RESULTS: The findings of the study revealed that fatigue significantly increased hip external rotation and decreased knee joint flexion and external rotation in both the dominant and non-dominant legs (p < 0.05). Additionally, correlation analysis demonstrated that the ankle joint's positioning in the frontal and horizontal planes was significantly associated with hip flexion and external rotation at the IC, as well as with knee flexion and rotation (0.40 < r < 0.80). CONCLUSION: Fatigue increased hip external rotation and ankle internal rotation, weakening the correlation between these joints while strengthening the ankle-knee relationship, indicating a reduced hip control in jumps. This suggests a heightened ACL injury risk in the dominant leg due to the weakened ankle-hip connection, contrasting with the non-dominant leg.

Volleyball training video classification description using the BiLSTM fusion attention mechanism.

This study aims to explore methods for classifying and describing volleyball training videos using deep learning techniques. By developing an innovative model that integrates Bi-directional Long Short-Term Memory (BiLSTM) and attention mechanisms, referred to BiLSTM-Multimodal Attention Fusion Temporal Classification (BiLSTM-MAFTC), the study enhances the accuracy and efficiency of volleyball video content analysis. Initially, the model encodes features from various modalities into feature vectors, capturing different types of information such as positional and modal data. The BiLSTM network is then used to model multi-modal temporal information, while spatial and channel attention mechanisms are incorporated to form a dual-attention module. This module establishes correlations between different modality features, extracting valuable information from each modality and uncovering complementary information across modalities. Extensive experiments validate the method's effectiveness and state-of-the-art performance. Compared to conventional recurrent neural network algorithms, the model achieves recognition accuracies exceeding 95 % under Top-1 and Top-5 metrics for action recognition, with a recognition speed of 0.04 s per video. The study demonstrates that the model can effectively process and analyze multimodal temporal information, including athlete movements, positional relationships on the court, and ball trajectories. Consequently, precise classification and description of volleyball training videos are achieved. This advancement significantly enhances the efficiency of coaches and athletes in volleyball training and provides valuable insights for broader sports video analysis research.

Social jetlag affects jump skills in sub-elite volleyball players.

Social jetlag (SJL), resulting from misalignment between biological rhythms and social schedules, has emerged as a prevalent phenomenon in modern society, particularly among young athletes. However, the effect of SJL on performance is poorly studied. Jump and dynamic balance are two key skills in volleyball, as the first allows the player to perform better both during the offense and defense phase, and the second is fundamental in landing and in injury prevention. Therefore, our aim was to investigate the effect of SJL on jump skill performance and balance in female volleyball players. Thirty female volleyball players (mean age: 17.3 ± 0.88 years) participated in the study. SJL was assessed using the Munich ChronoType Questionnaire (MCTQ), integrated with Jankowsky's sleep-corrected formula. Jump skill performance was evaluated using a standardized jump test, the Vertec Jump Test, while balance was assessed with the Y Balance Test. The tests were performed at 09:00 a.m. and at 06:00 p.m. The results revealed that players with greater SJL exhibited decreased jump performance, characterized by lower vertical jump height (p = 0.02). Furthermore, players with lower SJL showed the typical difference between morning and afternoon performance (p = 0.001), demonstrating their synchronization between biological rhythms and social commitments, while no statistically significant difference between the two sessions was shown in players with higher SJL. Regarding balance, no significant association with SJL was found, but the morning session yielded lower results than the afternoon one (p = 0.01). These findings highlight the detrimental impact of SJL on jump skill performance, underscoring the importance of optimizing sleep-wake schedules and circadian alignment to enhance athletic performance. Future research should explore targeted interventions, such as sleep hygiene education, to minimize social jetlag and promote optimal performance in adolescent athletes.

Menstrual cycle tracking in professional volleyball athletes.

Introduction: The menstrual cycle may affect well-being and physical performance of elite female athletes by interfering with the function of multiple physiological systems. The aim of this study was to characterize the symptoms of the menstrual cycle and their frequency in elite female volleyball players. Methods: Twenty professional female volleyball players were instructed to track their menstrual symptoms over the course of the first German national league season using the FitrWoman® tracking app. The app recorded the cycle length, duration, and intensity of the period as well as the occurrence and frequency of frequent cycle symptoms. The reported symptoms were then categorized into four categories (frequently, sometimes, rare, never) in order to create an individual Menstrual Symptom index (MSi) for each athlete. Results: The most frequently occurring symptoms among all players without hormonal contraception (non-HC; n = 15) were "stomach cramps" (n = 15), "sleep disturbances" (n = 11), and "tiredness" (n = 11). The average number of symptoms counted per cycle was 11.8 (±17.7) and the average calculated MSi within the team was 12.9 (±10.7) points for non-HC users. The HC players (n = 4) also regularly experienced symptoms such as "sleep disturbances" or "tendered breasts". The most common symptoms "stomach cramps" and "disturbed sleep" occurred more frequently during menstruation, while symptoms such as "bloating", "cravings" or "tendered breasts" did also peak before menstruation. Discussion: Menstrual cycle symptoms can be highly individual within a professional sports team. The calculation of the MSi seems to be a simple and accessible method to describe and overview the intensity and prevalence of symptoms in top female athletes in sports games.

Does In-The-Moment Strategic Self-Talk Affect Volleyball Officials' Refereeing Efficacy?

Self-talk in sport is a valuable self-help tool for regulating one's emotions, thoughts, and actions. This study aimed to examine whether the use of in-the-moment, strategic self-talk enhances volleyball officials' efficacy beliefs about their refereeing decisions in match-play scenarios. The relationship between officials' general self-talk tendencies and commonly perceived refereeing efficacy in recent matches was also investigated. A between-subjects design powered by an online Qualtrics survey was employed to recruit 62 skilled volleyball officials (Mage = 54.69, SD = 13.15 years) who were randomly assigned to strategic self-talk (experimental) or unrelated pangram statements (control) groups. Before assessing two disputed match-play situations presented as video clips, the officials were instructed to verbally reaffirm three assigned statements. Officials were then asked to rate their confidence in the accuracy and fairness of their decisions in each scenario. They also completed the Automatic Self-Talk Questionnaire for Sports and the Referee Self-Efficacy Scales. The Mann-Whitney-U test found no significant variations in decision-making beliefs to the match-play scenarios between the groups. Further analyses revealed significant associations between the study variables with organic self-talk tendencies employed to "psych up" and convey "worry" to exert significant and opposing influences on various aspects of officials' refereeing self-efficacy. Despite these influences, it is recommended that experienced officials may already have a reservoir of experiential acumen and metacognitive skills, which may necessitate a more protracted engagement with self-talk methods under social evaluative conditions to perceive confidence shifts in volleyball decision-making.

Impacts of Kinematic Information on Action Anticipation and the Related Neurophysiological Associations in Volleyball Experts.

In this study, we investigated the cognitive mechanisms underlying action anticipation in volleyball players, especially concerned with the differences between experts and amateurs. Participants included both expert (male, N = 26) and amateur (male, N = 23) volleyball players, who were asked to predict spiking movements containing high, medium, and low levels of kinematic information while their electrophysiological activities were recorded. The high-information stimuli included the whole spiking action, the medium-information stimuli ended at 120 ms, and the low-information stimuli ended at 160 ms before hand-ball contact. The results showed that experts significantly outperformed amateurs in both prediction accuracy (68% in experts vs. 55% in amateurs) and reaction time (475.09 ms in experts vs. 725.81 ms in amateurs) under the medium-information condition. Analysis of alpha rhythm activity revealed that experts exhibited the strongest desynchronization under the low-information condition, suggesting increased attentional engagement. In contrast, amateurs showed the weakest desynchronization under the medium-information condition. Furthermore, mu rhythm activity analysis showed greater desynchronization in the duration of 100-300 ms before hand-ball contact for experts, correlating with their higher anticipation accuracy. These findings highlight the significant kinematic information-processing abilities of volleyball experts and elucidate the neural mechanisms underlying efficient attentional engagement and mirroring. Therefore, this study provides valuable insights for the development of targeted training programs through which to enhance athletic performance.

Ultrasonographic Evaluation of the Patellar Tendon in Cyclists, Volleyball Players, and Non-Practitioners of Sports-The Influence of Gender, Age, Height, Dominant Limb, and Level of Physical Activity.

This study was based on the ultrasound evaluation of the patellar tendon dimensions in the anteroposterior and transversal approaches in sports practitioners (cyclists and volleyball players) and non-sports practitioners. Relationships between the patellar tendon length, width, and thickness with gender, age, height, the dominant limb, and level of physical activity were evaluated. The samples included cyclists, volleyball players, and non-sports practitioners between 15 and 25 years old. Individuals were positioned supine with 30 degrees of knee flexion for bilateral measurements. Sports practitioners presented with an increased patellar tendon length and thickness. There were significant differences bilaterally between sports and non-sports practitioners (p < 0.003). The three dimensions of the patellar tendon of both limbs presented correlations with the male gender (0.336 < r < 0.601), and values of moderate-to-strong intensity in the length of the patellar tendon was directly proportional to height (0.520 < r < 0.601). There was a significant difference between the patellar tendon width and age (p < 0.025). Regarding the level of physical activity, significant differences were found between low and high levels in the three dimensions bilaterally (p < 0.004). The study results indicate that gender, age, height, and level of physical activity impact patellar tendon dimensions. However, there are no associations with the dominant limb.

Rehabilitation With Eccentric Training Using Kettlebell and Kinesio Taping in a Young Volleyball Player With Proximal Biceps Tendinopathy: A Case Report.

A prevalent overuse injury among athletes, especially to those participating in sports like volleyball that demand repeated overhead motions, is biceps tendinopathy. The painful condition known as biceps brachii tendinopathy is characterized by changes in the structure of the tendon together with chronic degeneration. Furthermore, the biceps aid in the acceleration and deceleration of the arm in numerous overhead sports. The biceps may experience excessive strain as a result of poor training or exhaustion. It is commonly known that the long head of the biceps tendon plays a significant role in producing pain, particularly when it comes to anterior shoulder discomfort and dysfunction in athletes and working people. Athletes' biceps tendon conditions fall into three broad categories: degeneration, instability, and abnormalities that are of source. This case details the use of kettlebell eccentric exercise and kinesio taping in the rehabilitation of a young volleyball player with biceps tendinopathy. The four primary aspects of the rehabilitation regimen were kinesio taping, pain management and rest, eccentric training with kettlebells, and initial assessment and patient education. Kettlebell eccentric training was used to enhance eccentric strength and encourage tendon remodeling, and kinesio taping was used to give pain relief and structural stability. This case study emphasizes the value of an all-encompassing rehabilitation strategy catered to the unique requirements of every athlete by demonstrating the effectiveness of kinesio taping and eccentric exercise with kettlebells in the treatment of biceps tendinopathy.

Motion extrapolation in sport expertise: Representational momentum and representational gravity in volleyball athletes.

When people indicate the vanishing location of a moving target that suddenly disappears, systematic errors forward (in the direction of motion) and downward (in the direction of gravity) emerge. These spatial displacements were coined, respectively, Representational Momentum and Representational Gravity, and are believed to reflect internalized ecologically relevant physical invariants useful for the anticipation of future states of an event. Previous research has shown that sports athletes exhibit increased Representational Momentum, indicating enhanced motion extrapolation and anticipation, albeit it is still not clear up to what degree this effect is specific for the expertise context or if it generalizes to other dynamic events. Furthermore, the influence of expertise on Representational Gravity, particularly in contexts where anticipation of vertically moving objects is crucial, remains understudied. This study aimed to address these gaps by focusing on Volleyball as a context of expertise due to the prevalence of fast vertically moving balls. Volleyball athletes and non-athletes indicated the perceived offset location of a smoothly moving target, which moved at a constant speed or was subjected to acceleration/deceleration, embedded either in a Volleyball or neutral context. Outcomes revealed that for the Volleyball context, athletes, but not non-athletes, revealed a significant trend to misperceive targets moving along the left diagonal to be further displaced forward beyond what would be expected due to Representational Momentum alone. This finding is discussed in relation to the natural statistics of Volleyball games, where crossed ball trajectories, particularly by the outside hitter, are more prevalent, fast, and offensive, requiring better anticipation to be efficiently dealt with.

Vitamin D levels and bone mineral density of middle-aged premenopausal female football and volleyball players in Japan: a cross-sectional study.

BACKGROUND: The number of football teams in senior categories has increased. As outdoor sports entail players being exposed to sunlight, playing football may contribute to maintaining vitamin D stores and body mineral density while preventing osteoporosis. This study aimed to determine the bone mineral density and vitamin D levels in middle-aged premenopausal female football players. METHODS: Participants were premenopausal females in their 40s. We evaluated bone mineral density of the second to the fourth lumbar vertebrae and femoral neck, serum 25-hydroxy vitamin D (25-OHD) levels, which is an indicator of vitamin D stores, and body composition. In addition, we administered a questionnaire survey on exercise habits and lifestyle. Ninety-two participants were categorised into three groups: the football group (n = 27), volleyball group (n = 40), and non-exercise group (n = 25). RESULTS: Bone mineral density was higher in the football and volleyball groups than in the non-exercise group (P < 0.01). The volleyball group had a significantly higher bone mineral density of the lumbar spine and femoral neck than the non-exercise group (P < 0.01). The football group had a significantly higher bone mineral density of the femoral neck than the non-exercise group (P < 0.01). Although the football group had played fewer years than the volleyball group (P < 0.01), serum 25-OHD levels were the highest in the football group and were significantly higher than those in the volleyball and non-exercise groups (P < 0.01). CONCLUSIONS: Middle-aged premenopausal football players had higher body vitamin D levels and bone mineral densities than non-active females. These results suggest that playing football may contribute to the prevention of osteoporosis. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000054235. 2024/04/23. Retrospectively registered.

A multifunctional triboelectric nanogenerator based on PDMS/MXene for bio-mechanical energy harvesting and volleyball training monitoring.

Within the domain of wearable devices that are self-powered and sensory, triboelectric nanogenerators (TENGs) have surfaced as a notable solution to meet the growing needs for energy harvesting. This study unveils an innovative wearable and stretchable multifunctional double-layered TENG, based on PDMS/MXene, known as PM-TENG. Furthermore, PM-TENG can also be used as a joint sensor to monitor the movement of athletes' joints during volleyball training. By augmenting the matrix with PDMS/MXene, which possesses dual capabilities-namely, charge capture and charge movement-the intermediary layer is integrated. This leads to a two fold increase in the ability to trap charges and the overall triboelectric performance. With a power density reaching 11.27 mW, it notably exceeds the performance of its counterparts that solely utilize PDMS, by nearly 11 times. This academic effort elucidates the important role of PM-TENG in biomechanical energy capture and autonomous wearable sports motion sensing.

Volleyball training improves working memory in children aged 7 to 12 years old: an fNIRS study.

This study aimed to investigate the effect of a 12-wk extracurricular volleyball training on working memory from both behavioral and cerebral aspects. A total of 80 children were randomized assigned to (i) the experimental group, who engaged in extracurricular volleyball training for 60 min, thrice a week for 12 wk, and (ii) the control group, who maintained their regular daily routine. Working memory was evaluated in both groups using the N-back task before and after the intervention. Furthermore, functional near-infrared spectroscopy was employed to monitor the level of oxygenated hemoglobin in the prefrontal cortex. The experimental group performed better in the behavioral task than the control group, as evidenced by a shorter response time and a higher correct rate. The functional near-infrared spectroscopy results suggested that the activation of the left dorsolateral prefrontal cortex was significantly higher in the experimental group than in the control group. In addition, correlation analyses showed that the enhancement of left dorsolateral prefrontal cortex activation was significantly correlated with decreasing response time and improving response accuracy in the N-back task. These findings suggest that the left dorsolateral prefrontal cortex is likely the neural substrate for improved working memory performance elicited by 12-wk open skill exercise.