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.

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 ​± ​2.1] years) and 18 women (age: [24.5 ​± ​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 ​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 ​< ​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 ​> ​0.4, p ​< ​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 ​> ​0.4, p ​< ​0.05). We have concluded that biological maturation has a significant impact on cardiac autonomic recovery.

UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: 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.
UNASSIGNED: 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.

Purpose: The objective of this research was to develop a sensor device to control and evaluate the jumping ability of elite volleyball athletes and to test its efficacy in a pedagogical experiment. Methods: The study involved determining the pulsometric and respiratory parameters during test loads, indicative of the endurance and speed-strength aspects essential for volleyball performance. Additionally, the necessity for post-training and post-competition jump performance restoration via short-term relaxation exercises was identified. Results: Through the developed computer program, a method for storing maximal vertical jumps in computer memory was established. Furthermore, a technique was developed to determine the functional significance of maximum vertical jump performance among elite volleyball players. Notably, participants in the experimental group, who performed specialized exercises developed within the experimental framework, exhibited discernible progressive improvements compared to the control group participants. Before the experiment, the maximum number of jumps in the experimental group was 29.2 ± 2.73, with a jump time of 31.7 ± 3.08. Conclusions: The equipment developed for monitoring and assessing volleyball players\' jumping ability has proven effective, warranting its incorporation into training regimens.

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.

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.
OBJECTIVE: 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).
CONCLUSIONS: 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.

BACKGROUND: There is a well-established increased risk of lower-extremity (LE) musculoskeletal (MSK) injury following a sport-related concussion (SRC). Neuromuscular training programs improve biomechanics associated with LE MSK injury and reduce LE MSK injury incidence, but their relative effectiveness in athletes with history of SRC is unknown. The purpose of this study was to evaluate LE MSK injury incidence in female adolescent athletes with history of SRC following a neuromuscular training intervention.
METHODS: Prospective case-control.
METHODS: Seventy-seven adolescent female athletes aged 12-18 years who participated in soccer, volleyball, or basketball were recruited from a single institutional sports medicine research and performance center to complete a 6-week neuromuscular training program prior to competitive athletic season. Group (Control, History of SRC) comparisons of athlete exposure and relative LE MSK injury risk and rates during the competitive athletic season were assessed.
RESULTS: Ten injuries were recorded by 9 athletes. Female athletes who reported history of SRC had increased injury risk (Risk Ratio 3.9, 95% CI, 1.1-13.8, P = .01) and increased injury rate (rate ratio 4.1, 95% CI, 1.1-15.8, P = .03) compared with female athletes without history of SRC.
CONCLUSIONS: Female adolescent athletes with history of SRC showed a greater risk of LE MSK injury compared with athletes with no history of SRC. Future work is still needed to understand the underlying mechanisms associated with future LE MSK injury following SRC and interventions that ameliorate elevated injury risk.

暂无摘要。

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.
OBJECTIVE: 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.
CONCLUSIONS: 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.
CONCLUSIONS: 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.

BACKGROUND: Girls\' high school volleyball is a popular sport with a high rate of overuse injuries and sport specialization. Health professionals perceive that high school athletes are reluctant to follow treatment plans involving sport activity reduction. This study\'s purpose was to describe high school girls\' volleyball athletes\' self-reported shoulder and knee pain, the likelihood of adhering to medical advice, and the association of factors that influence the likelihood of reporting overuse injuries and sport specialization.
METHODS: Cross-sectional.
METHODS: Participants completed an online survey (demographics, sport participation measures, shoulder and knee pain information, medical adherence likelihood [4-point Likert: not at all likely to extremely likely], and factors influencing overuse injury reporting intentions). A 2 × 2 chi-square analysis compared factors that influence athletes\' intentions to \"not report an overuse injury\" (eg, I thought my coach would get mad; yes/no) and sport specialization (nonhighly specialized/highly specialized athletes).
RESULTS: There were 150 participants (highly specialized = 56%, grade: ninth = 33%, 10th = 28%, 11th = 22%, 12th = 17%). At least 60% reported shoulder and knee pain related to an overuse mechanism. Most reportedly did not seek rehabilitation led by a medical provider (shoulder pain = 66%, knee pain = 60%). Only 11% of athletes reported they were \"extremely likely\" to rest from sporting activity during the regular season if advised by a medical professional. Highly specialized athletes were more likely to report the pursuit of a college scholarship as a factor that influences their intention to report an overuse injury compared to nonhighly specialized athletes (13% vs 3%, respectively, P = .04).
CONCLUSIONS: Most girls\' volleyball athletes did not treat their pain with guided rehabilitation, which may increase their risk of a worse overuse injury or even acute injury. Clinicians, athletes, parents, and coaches need to work together to create a sport culture that empowers athletes to discuss their pain and overuse injuries with medical professionals.