Effect of Level of Competition and Drill Typology on Internal and External Load in Male Volleyball Players During the Preseason Period.

PURPOSE: This study aimed at evaluating the effect of level of competition and drill typology on loads during the preseason period in male volleyball players. METHODS: Internal (percentage of peak heart rate [HR] and summated HR zone) and external (PlayerLoad per minute, total and high accelerations per minute [tACCmin and hACCmin], decelerations per minute [tDECmin and hDECmin], and jumps per minute [tJUMPmin and hJUMPmin]) loads were monitored across a 5-week preseason period in 12 Division 1 (age: 22.5 [3.9] y; stature: 188 [6.2] cm; body mass: 85 [11.6] kg; training experience: 9.4 [4.2] y) and 12 Division 2 (age: 20.7 [2.9] y; stature: 186 [6.2] cm; body mass: 77.8 [9.6] kg; training experience: 5.6 [2.3] y) male volleyball players. Furthermore, differences in load were assessed for each drill typology (warm-up, conditioning, technical, tactical, and integral). RESULTS: No effects (P > .05) of level of competition on the internal (except for summated HR zone, P = .05) and external loads (except for tJUMPmin, P = .002) were found. Differently, drill typologies showed an effect (P < .001) on all the investigated internal- and external-load measures. The main post hoc results revealed higher (P < .05) percentage of peak HR, summated HR zone, PlayerLoad per minute, and tACCmin in warm-up and conditioning drills, while higher (P < .05) hDECmin and hJUMPmin were found in tactical and integral drills. CONCLUSIONS: These results suggest that volleyball coaches use warm-up and conditioning drills when aiming at increasing the internal loads, PlayerLoad per minute, and tACCmin, while tactical and integral drills should be preferred to enhance the number of hDECmin and hJUMPmin.

Prevalence of Skin Injuries in Beach Volleyball Athletes in Greece.

Background: Skin injuries often affect the sports community. Almost every type of athletic activity is associated with traumatic skin injuries, such as surface wounds, bruising, abrasions, subcutaneous hematomas, blunt trauma, nail injuries, friction burns, and blisters. Methods: The aim of this study was to assess the rates, location sites, and seasons of appearance of skin injuries in beach volleyball athletes in Greece. Seven hundred and eighty-five beach volleyball athletes participated in this study. The average age was 28.4 years. Skin injuries included superficial wounds (erosions, incisions, lacerations), deep wounds, hematomas, nail lacerations, friction burns, and friction blisters. The recorded variables encompassed gender, age, the time of year when athletes might be at higher risk of injuries, and the specific body regions affected. Additionally, data regarding training details such as years of practice, weekly training frequency, and daily training duration were also documented. Results: Incidence rates correlated to gender: (a) superficial wounds (p < 0.001), (b) years of training: hematomas (p < 0.001), and (c) average hours of daily training: superficial wounds (p < 0.001), deep wounds (p < 0.001), and friction blisters (p < 0.001). Conclusions: Although early detection, recognition, and treatment are essential, the prevention of skin injuries can also be linked to health and athletic performance.

Prognostic Power of Foot Mobility in Identifying the Risk of Musculoskeletal Injuries: A Cross-Sectional Study of Male Volleyball Players at Different Competitive Levels.

(1) Background: The arch structure and mobility of the foot are considered injury risk factors in volleyball. However, there are limited studies presenting differences in injury prevalence and the risk of lower limb injuries in relation to the competitive level in male volleyball. Therefore, the main aim of the current study was to evaluate foot mobility (through navicular drop test) as an injury risk factor in volleyball players from different competitive levels. (2) Methods: The reliability and usefulness of navicular drop testing were initially assessed in test-retest procedures (based on a sample of eight participants and 16 feet measurements), with primary analyses conducted using foot measurements of the twelve top-level volleyball players (24 feet) and eighteen academic-level volleyball players (36 feet). The modified navicular drop test was conducted, and the feet were classified based on arch height, and injury prevalence was retrospectively assessed with a previously validated questionnaire. Chi-squared tests, receiver operating curves, and logistic regression were used as statistical methods. The navicular drop test was verified as a reliable tool by intraclass correlation coefficient (ICC) (3.1) analysis. (3) Results: There were no significant differences in injury prevalence between academic- and top-level volleyball players, though there was a significant relationship between pronated foot and injury risk independent of competitive level. Generally, for both groups, thresholds above 10 mm of the navicular drop were predictors of lower limb injuries. The risk of injury if the foot was pronated ranged from 70% (academic level) to over 90% (top-level players). However, no statistically significant effect of competitive level on the chance of injury was observed. (4) Conclusions: Our study found a high prevalence of foot injuries independently of competitive level. There was a relationship between pronation of the foot and the risk of injury. However, the risk of lower limb injury was higher in pronated top-level players. Also, a navicular drop greater than 10 mm was an excellent predictor of injuries at both competitive levels.

Integrative Approach of Conventional Physiotherapy, Mulligan's Mobilisation With Movement, and Plyometric Training in a Young Volleyball Athlete After Anterior Cruciate Ligament (ACL) Reconstruction: A Case Report.

The requirements of volleyball include specialized, strategic, and acrobatic skills. In volleyball, it is thus essential to build maximal power and strength properly. Strengthening has been recommended as an effective means to avoid injuries and build muscle strength. It also enhances one's health in relation to performance in the game. Anterior cruciate ligament (ACL) tears are a common knee injury affecting athletes of all levels. A big problem with injury healing and getting back to sports is that there isn't a tried-and-true protocol or set of steps an athlete should follow following an ACL injury. Plyometric training focuses on the core, hip, and thigh muscles to help with appropriate lower limb alignment and recruiting of muscle. We present a 25-year-old male volleyball athlete who suffered from an ACL tear. This case report emphasises how important sports physiotherapy rehabilitation is for athletes. The case report advances the treatment of ACL injury by a multifaceted approach of Mulligan's mobilisation with movement and plyometric-based interventions.

Combination of narrow and wide bandwidth knowledge of performance in the acquisition of a complex sports motor skill.

OBJECTIVES: This study tested the effects of combining two bandwidth knowledge of performance (KP) on a complex sports motor skill. METHOD: Twenty-two elementary students were divided into combined wide and narrow bandwidth KP (WNG) and control group (CG). The task was the volleyball serve, whose goal was to hit the bull's eye center of a target lying on the floor on the opposite side of the court. The study was composed of a pre-test, acquisition phase and retention test, and had three measures (pre-test, intermediate test, and retention test) with 15 serves recorded each. The acquisition phase consisted of 252 trials. The WNG had a wide bandwidth KP in the first half of the acquisition phase and a narrow one in the second. The CG received KP in all trials. The effects of bandwidth KP were analyzed separately to infer parameters and skill structure learning. RESULTS: Both groups improved the skill structure from the first to the intermediate test, but only WNG also improved on the retention test. The parameters accuracy improved only on retention compared to the pre-test and intermediate test but had no difference between groups. CONCLUSION: Providing information using the bandwidth KP led to an initial engagement and prioritization of skill structure learning.

Applicability of the Cumberland Ankle Instability Tool in Elite Volleyball Athletes: A Cross-Sectional Observational Study.

BACKGROUND: The ease of administration of the Cumberland Ankle Instability Tool (CAIT) could represent a methodology for periodically evaluating athletes, preventing ankle instability injuries. This study aimed to achieve three objectives: (a) to evaluate the applicability of the CAIT scale in volleyball; (b) to explore whether ankle instability presents a greater risk in lower-level volleyball categories and whether elite athletes demonstrate an ability to mitigate this risk; and (c) to identify potential predictors of ankle instability. METHODS: Eighty female volleyball players participated in this cross-sectional observational study. The CAIT was administered to evaluate the athletes belonging to some teams in Series A, B, and C. RESULTS: The Spearman's ranks correlation coefficient showed significant correlations between CAIT items. Additionally, the Cronbach's α showed a high internal consistency. Our results showed a significant difference between athletes who reported pain and those who did not (p < 0.001). The multiple linear regression model analysis showed that pain was a predictor of ankle instability (p < 0.001). CONCLUSIONS: Our findings suggest that the CAIT can be used to evaluate ankle stability in volleyball players. This scale could represent a valuable tool for implementing specific intervention programs to prevent ankle injuries in athletes.

Expert Performance in Action Anticipation: Visual Search Behavior in Volleyball Spiking Defense from Different Viewing Perspectives.

Volleyball spiking requires defenders to possess exceptional anticipatory skills. However, most volleyball defense video eye-tracking studies have used fixed or off-court perspectives, failing to replicate real-world environments. This study explored different visual search behaviors between elite and novice volleyball players from various viewing perspectives using video eye tracking. We examined spiking anticipation in 14 competitive elite, 13 semi-elite, and 11 novice players. We captured spiking videos from three on-court perspectives using GoPro cameras mounted on the defenders' heads, closely replicating real game scenarios. For comparison, we recorded baseline videos using a fixed camera. The present study revealed that competitive and semi-elite players demonstrated higher accuracy than novices. Competitive elite players used fewer fixations, indicating that their superior performance was related to stable visual search patterns. All participant groups, regardless of skill level, showed similar visual allocation among areas of interest (AOIs). However, notable differences in visual search patterns and AOI allocation were observed between baseline and on-court perspective videos. From the baseline perspective, the participants primarily utilized global perception and peripheral vision, focusing more on the setter zone or the spiker's trunk. Conversely, from the on-court perspective, they employed more fixations, focusing more intensely on the spiker's detailed movements.

The effect of flywheel complex training with eccentric-overload on muscular adaptation in elite female volleyball players.

This study aimed to compare the effects of 8 weeks (24 sessions) between flywheel complex training with eccentric overload and traditional complex training of well-trained volleyball players on muscle adaptation, including hypertrophy, strength, and power variables. Fourteen athletes were recruited and randomly divided into the flywheel complex training with an eccentric-overload group (FCTEO, n = 7) and the control group (the traditional complex training group, TCT, n = 7). Participants performed half-squats using a flywheel device or Smith machine and drop jumps, with three sets of eight repetitions and three sets of 12 repetitions, respectively. The variables assessed included the muscle thickness at the proximal, mid, and distal sections of the quadriceps femoris, maximal half-squats strength (1RM-SS), squat jump (SJ), countermovement jump (CMJ), and three-step approach jump (AJ). In addition, a two-way repeated ANOVA analysis was used to find differences between the two groups and between the two testing times (pre-test vs. post-test). The indicators of the FCTEO group showed a significantly better improvement (p < 0.05) in CMJ (height: ES = 0.648, peak power: ES = 0.750), AJ (height: ES = 0.537, peak power: ES = 0.441), 1RM-SS (ES = 0.671) compared to the TCT group and the muscle thicknes at the mid of the quadriceps femoris (ES = 0.504) after FCTEO training. Since volleyball requires lower limb strength and explosive effort during repeated jumps and spiking, these results suggest that FCTEO affects muscular adaptation in a way that improves performance in well-trained female volleyball players.

Does dynamic balance affect cube mental rotation task in badminton vs. volleyball female players?

BACKGROUND: Changing from a static to a dynamic balance condition could affect the performance of a cognitive task such as mental rotation. Thus, the main goal of this study is to investigate aspects of visual-spatial cognition between two non-contact sports (i.e., badminton and volleyball) in different upright conditions (i.e., standing position, frontal balance, and sagittal balance). METHODS: Thirty-five volunteer female sports and physical education students, fourteen specialists in badminton and twenty-one specialists in volleyball agreed to participate in this study. Each of the assessments was a 3D cube mental rotation task with and/or without balance exercises (i.e., frontal and/or sagittal balance) on a wobble board. Five stimuli were used in the mental rotation task (i.e., 45°, 135°, 180°, 225° and 315° for objected-based cube condition with egocentric transformation) which included pairs of standard and comparison images. RESULTS: The findings indicate that there was a notable decrease (p < 0.001; d = 1.745) in response time in both dynamic balance conditions (i.e., frontal and sagittal balance) compared to standing position condition. In addition, results revealed significant interaction between balance conditions (i.e., frontal and/or sagittal balance) and groups (i.e., badminton and volleyball) in the response time at 225° angle and in the error percentage. CONCLUSIONS: In sum, dynamic balance is also an activity that involves mental manipulation of objects in 3D space, which can enhance badminton and volleyball female players' ability to rotate 3D cube stimuli.

Effects of shoe collar height and limb dominance on landing knee biomechanics in female collegiate volleyball players.

Volleyball-specific footwear with higher collar heights (a mid-cut shoe) are worn to restrict ankle motion. Reduced ankle dorsiflexion has been associated with increased frontal plane motion and injury risk at the knee. With the high frequency of unilateral landings in volleyball, the purpose of this study was to determine the effect of volleyball-specific shoes and limb dominance on knee landing mechanics in collegiate volleyball players. It was hypothesized that participants would exhibit smaller sagittal plane and greater frontal plane knee joint mechanics in mid-cut and dominant limb and that vertical and posterior directed ground reaction forces would be greater wearing mid-cut, yet similar between limbs. Seventeen female volleyball players performed unilateral landings on each limb in mid-cut and low-top volleyball shoes. For shoe main effects, smaller peak dorsiflexion angle and internal peak plantarflexion moment and greater peak medial ground reaction force were found in the mid-cut but with no impact on knee mechanics. For limb main effects, the internal peak knee abduction moment was greater in the dominant limb. Greater peak lateral ground reaction force was found in the interaction between the non-dominant limb and low-top. Further research is warranted to better understand shoe and limb impact in volleyball players.

Enhancing Volleyball Athlete Performance: A Comprehensive Review of Training Interventions and Their Impact on Agility, Explosive Power, and Strength.

Volleyball is one of the most globally renowned sports in terms of global popularity. The game is a team sport that both men and women can participate in. The gameplay relies heavily on physical activities such as jumping, landing, and quick movements, often causing strain on the musculoskeletal system and leading to injuries. For this reason, agility training is crucial to improving a player's ability to change direction swiftly as and when required by the gameplay. Although it is relatively safer than other team sports, actions like jumping, blocking, and spiking can lead to potential injuries. Properly monitoring the training loads and injury prevention during training should be the major focus in formulating a holistic training methodology in volleyball training. The main goal of this literature study is to evaluate the impact of various training interventions on agility and other performance parameters specific to volleyball players. The range of research approaches and interventions described in this literature review highlights the significance of agility in volleyball training. In many studies, the use of tailored training programs for volleyball has been shown to have positive effects on agility, strength, and jump performance. Although there are limitations to the study design and sample size, the findings from this review necessitate the need for better scientifically informed training programs to reduce injury risk while enhancing player's overall performance potential. To conclude, the current literature review highlights the importance of agility training in volleyball, providing insights into effective training strategies and highlighting the low quality of evidence, suggesting the need for well-structured research on the topic.

Role of Physiotherapy in Osgood-Schlatter's Disease in Adolescent Volleyball Smasher: A Case Report.

A 14-year-old female presented to the sports physiotherapy with a diagnosis of Osgood-Schlatter's disease (OSD), a condition particularly prevalent in adolescents engaged in sports with repetitive knee motions, such as volleyball. This ailment commonly manifests at the tibia, directly beneath the patella, eliciting discomfort and inflammation. The chronic overuse injuries involve repetitive activities inducing fatigue in specific anatomical structures. Adequate recovery mechanisms allow for tissue adaptation, mitigating the risk of injury. In the absence of proper recovery, microtrauma ensues, instigating inflammation mediated by substances like histamines. The release of inflammatory cells and enzymes inflicts damage on local tissue, and prolonged stress contributes to degenerative changes, resulting in weakness, diminished flexibility, and chronic pain. These manifestations are intimately associated with OSD in chronic or recurrent instances. The primary symptom of OSD is knee pain, often of sufficient severity to induce limping. Patients report discomfort during activities such as kneeling, descending stairs, prolonged stationary positions, prolonged episodes of sitting with the knee rendered immobile, and engagement in sporting activities. This case study specifically underscores the efficacy of tailored physiotherapy in the management of OSD among adolescent volleyball players. The study's findings indicate that the patient successfully alleviated symptoms, facilitating recovery with improved outcomes. Furthermore, the physiotherapy regimen appears instrumental in enhancing the patient's functional mobility, as evidenced by the study's outcomes.

A single session of a beach volleyball exergame did not improve state anxiety level in healthy adult women.

This study evaluated the acute effect of the exergame Kinect Sports® beach volleyball on state anxiety level in adult women. Thirty healthy adult women (age: 21 [4] years, body mass: 54.70 [19.50] kg, height: 1.61 ± 0.05 m, and body mass index: 21.87 [5.76] kg/m2, data are expressed as median [interquartile range] and as the mean ± standard deviation) were assigned to play an exergame of beach volleyball in singleplayer mode session (intervention session) for ~ 30 min using the Xbox 360 Kinect® or remained seated (control session). State anxiety was evaluated before and after the intervention and control sessions through the State-Trait Anxiety Inventory. State anxiety obtained in both sessions (exergame and control) was classified as intermediate before (median: 36.00 [IQR: 4.75] and mean = 38.73 ± 7.23, respectively) and after (mean: 34.86 ± 6.81 and mean: 37.66 ± 8.44, respectively). Friedman test found no time significant effect on state anxiety of the sessions (χ2 [3] = 6.45, p-value = 0.092, Kendall's W = 0.07 "trivial"). In conclusion, the present study showed that there were no significant differences in the state anxiety level after an acute session of the exergame beach volleyball.

KEY POINTS: • Exergame beach volleyball presented high enjoyment and a moderate to strong future engagement possibility. • A session of the volleyball exergame did not improve affectivity and state anxiety level compared with control condition. • A session of the volleyball exergame elicited moderate physical exercise intensity.

Hormonal and psychological influences on performance anxiety in adolescent female volleyball players: a multi-approach study.

Background: The neuroendocrine system has important implications for affiliation behavior among humans and can be used to assess the correlation between social relationships, stress, and health. This can be influenced by social closeness; this aspect is the closeness towards another individual or a group of individuals such as a sports team. Sports performance anxiety is considered an unpleasant emotional reaction composed of physiological, cognitive, affective, and behavioral components. This motivates us to learn about the process that can influence the outcome of competition. Hormones and genetics would seem to influence outcome and performance. In this regard, many studies have focused on the exercise response as a function of ovarian hormones and it has been observed that progesterone is a hormone that plays a key role in reducing anxiety, and thus stress, in humans and other animals. On the other hand, high cortisol concentrations are known to contribute to increased anxiety levels. However, the salivary alpha-amylase (sAA) enzyme has been suggested as marker of acute stress than cortisol. Genetics also seem to influence anxiety and stress management as in the case of brain-derived neurotrophic factor (BDNF) and striatal dopamine transporter (DAT). Therefore, the study aims to investigate social closeness, as a measure of sports team cohesion that can influence athletes' performance results, and its ability to influence the secretion of hormones, such as progesterone and cortisol, that affect the management of sports anxiety while also taking into account genetic background during a volleyball match. Methods: Twenty-six female volleyball players who volunteered participated in this study (mean ± SD: age, 12.07 ± 0.7 years), and played in the final of the provincial volleyball championship in Palermo. All girls were during the ovarian cycle, in detail between the follicular and early ovulatory phases. Results: The results showed a significant decrease in salivary cortisol only in the winning group (p < 0.039). In fact, whilst in the latter the pre-match level was 7.7 ng/ml and then decreased to 4.5 ng/ml after the match, in the losers group change was not statistically significant (7.8 ng/ml vs 6.6 ng/ml pre- and post-match). As to the sAA concentration, the winning team showed a statistically significant variation between pre- and post-match than the losers (166.01 ± 250 U/ml vs 291.59 ± 241 U/ml) (p = 0.01). Conclusion: Analyzing the results of the SAS-2 psychological test it is highlighted that, on average, the loser group was more anxious than the winning group, and this contributed to the final result. In conclusion, there is strong evidence supporting the state of the art that many factors can affect performance anxiety and thus the performance itself.

Damage for gain: The useful damage of the Pitcher's paradox.

Introduction: Sport-specific adaptations of the glenohumeral joint may arise in adolescent overhead athletes who begin high-performance sports early in life. Research mainly addresses overuse injuries, leaving gaps in prevention, with adults studied more than youths. Objective: This study aims to investigate sport-adaptations of the glenohumeral joint in asymptomatic adolescent volleyball players to identify potential shoulder injury risk factors. Design: Observational study. Setting: Clinical screening campaign conducted at the Physical Medicine and Rehabilitation Unit of Policlinic Hospital in Catania, Italy. Participants: Forty asymptomatic under-16 athletes were evaluated. Interventions: Shoulder internal rotation (IR) and external rotation (ER), range of motion (ROM), total-rotation ROM, glenohumeral IR deficit (GIRD), general joint laxity using Beighton score, apprehension, relocation, O'Brian tests, and ultrasound (US) glenohumeral distance were tested bilaterally. Variables such as the player's position, the age they began the sport, limb dominance, weight, and height were also considered. Results: The median US glenohumeral distance was at 0.42 ± 0.26 cm, which is consistent with the range found in non-dislocated shoulders of a healthy non-athletic population. The ER ROM was significantly greater in the dominant shoulder than the contralateral one (P = 0.0001), and there was a significant correlation between the ER ROM of attackers and their US glenohumeral distance (P = 0.0413). Furthermore, shoulder IR ROM and US glenohumeral distance were not significantly different between the dominant and contralateral limbs (P = 0.05). None of the athletes presented GIRD. Other tests, including the Beighton score, apprehension, and relocation tests, yielded no significant differences between the dominant and contralateral limbs. Conclusions: Despite an increased shoulder ER in the dominant limb, the glenohumeral joint remains stable, suggesting that greater ROM in ER does not equate to instability in overhead athletes without hyperlaxity. Nevertheless, increased ER impacts glenohumeral distance in attacker volleyball players. This finding suggests that the shoulder morphological adaptation process starts early in attackers.

Rehabilitation of Supraspinatus Impingement in a Volleyball Athlete: A Case Report.

Volleyball players with supraspinatus tendinopathy commonly present with a spectrum of symptoms, including shoulder pain, especially during the overhead phases of the game. They may experience pain during serves, spikes, or attempting to block at the net. Weakness in the affected shoulder and limited range of motion can impede performance and overall playing experience. Physiotherapy plays a crucial role in managing supraspinatus tendinopathy, focusing on reducing pain, improving shoulder joint range and function, and preventing recurrence. The research question arises as to how the rehabilitation process impacts the recovery and performance outcomes in a volleyball athlete with supraspinatus impingement which is explained as detailed in a case report. The present case is a 21-year-old male volleyball athlete complaining of pain in the anterolateral and posterior aspects of the right shoulder joint and a restricted range of motion while doing abduction and flexion at the shoulder joint for three months. After the orthopedic physical assessment, the patient was diagnosed with supraspinatus tendinopathy. This case report introduces an exact understanding of the rehabilitation tailored specifically to volleyball athletes with supraspinatus impingement.

An insidious rectus abdominis muscle injury in an elite volleyball player: a case report.

BACKGROUND: Structural muscle injuries are characterized by acute and localized onset of pain. Abdominal muscle injuries are an insidious pathology in overhead athletes. However, only a few cases are reported in literature related to volleyball players, where clinical presentation may not have reflected the severity of the lesion. CASE PRESENTATION: An elite volleyball player, a 21-year-old Caucasian female, reported the onset of mild abdominal muscular pain, confirmed on clinical evaluation findings and self-reported symptoms. Abdominal muscle ultrasound was performed following 2 weeks of continuing symptoms. This evidenced a more serious structural muscle injury of the rectus abdominis (type 3b). Having this correct diagnosis allowed a personalized rehabilitation program to be instituted to enable a safe return to play. CONCLUSION: In presence of persistent abdominal muscle pain, even if mild, the possibility of a structural muscle injury must be considered. Clinical evaluation must be complemented by an instrumental evaluation including an ultrasound by an experienced operator for correct diagnosis and the setting of functional recovery related to biological healing.

A sports-related injury prevention program for Dutch youth volleyball players: Process evaluation alongside a quasi-randomized controlled trial.

OBJECTIVE: This process evaluation aimed to gain insight into the implementation of the VolleyVeilig Youth program by Dutch volleyball clubs within the context of an effectiveness trial. METHODS: We applied the UK Medical Research Council framework for process evaluations and assessed the context, implementation and mechanisms of impact. Trainers participating in the effectiveness trial were asked to complete a questionnaire at the end of the study. A subsample of the trainers based on the self-reported adherence score was invited to participate in an interview accordingly. We used a thematic analysis to present the data. RESULTS: Thirty-one trainers (100%) completed the questionnaire, and seven agreed to participate in an interview. Although adherence gradually decreased over the volleyball season, most trainers reported partially adhere with the program until the end of the study. The main themes included factors associated with the (1) VolleyVeilig Youth program, (2) trainer, (3) players, and (4) volleyball club. CONCLUSION: Although (partial) adherence to the VolleyVeilig Youth program was high in this study, implementation strategies must be developed to target the barriers reported by the trainers before the program can be successfully implemented nationwide in the Netherlands.

Is There a Relationship Between Birth Quartile and Vertical Jump Performance Among Young Male Elite Volleyball Athletes?

Vertical jump is an important skill that influences volleyball performance. In this study, we analyzed the relationship between vertical jump performance and birth quartile of Brazilian male youth volleyball players. We calculated chi-square goodness-of-fit tests to compare the athletes' birthdate distributions in quarters of their birth years (Q1, Q2, Q3, and Q4) according to player age categories (U17, U18, U19, and U21). We calculated one-way ANOVAs to compare spike jump and block jump heights of players born in different quarters of the same year. Overall, we found a relative age effect (i.e., more players with birth dates early in the birth year) in U17 (p < .001), U18 (p < .001), U19 (p < .001), and U21 (p = .04). Regarding vertical jump performance, U18 athletes born in Q2 reached higher spike jump heights (p = .006) and block jump heights (p = .002) than athletes born in Q4, and U19 athletes born in Q1 reached higher block jump heights than athletes born in Q3 (p = .049). There were no significant differences in vertical jump performance across birth quartiles among U17 and U21 athletes. Thus, a relative age effect was present in all age categories but not always reflected in vertical jump performance. Volleyball coaches and policymakers are still advised to employ strategies to ensure fairer opportunities for players born later in the year of their eligibility dates, as we found RAE to be sometimes, but not always, related to higher spike or block jump heights even among these older adolescents and young adult athletes.

Post-Activation Performance Enhancement (PAPE) Increases Jumping Power in Elite Female Volleyball Athletes.

This study investigated PAPE effects of two conditioning activities (CA) and recovery times on the peak jumping power (PP) of elite female volleyball athletes. Players performed CA separately: three sets of three repetitions of back squats with 85% of 1RM (BS) or one set of five depth drops (DD). PP was measured with countermovement (CMJ) and squat jumps (SJ) before (pre-test) and two minutes (post-test 1) and six hours (post-test 2) after each CA. BS significantly reduced PP at post-test 1 (CMJ and SJ: p < 0.04, d between -0.36 and -0.28). At post-test 2, following BS, PP for both jump forms was significantly greater than at post-test 1 (p < 0.001, d between 0.54 and 0.55) and at pre-test (p < 0.048, d between 0.21 and 0.30). DD increased PP significantly (CMJ and SJ p < 0.05, d between 0.40 and 0.41) relative to pre-test at post-test 2 (there was no significant difference between pre-test and post-test 1). Comparing BS with DD, there were no significant differences (p > 0.05). The greatest PAPE effects were observed six hours after BS. CA are recommended for female athletes to improve jumping performance, but individual responses should be determined prior to use.