Prevalence and associated factors of non-traumatic knee pain in high school volleyball players: a cross-sectional study

OBJECTIVES

This study aimed to determine the prevalence of knee pain among high school volleyball attackers, identify associated factors, and explore the relationship between knee pain and lower back pain (LBP).

METHODS

A cross-sectional study involving 82 high school volleyball attackers (15-17 years) used questionnaires, interviews, and field-based assessments to collect data on demographics, volleyball-specific factors, flexibility, and jumping ability. Logistic regression analysis was used to identify factors associated with knee pain.

RESULTS

The prevalence of knee pain was 19.5%. Factors significantly associated with knee pain were a history of LBP (OR, 4.64; 95% CI, 1.28 to 16.8; p = 0.019) and flexibility determined by the absolute difference in heel-buttock distance (OR, 1.37; 95% CI, 1.02 to 1.83; p = 0.037). Participants with knee pain had more volleyball experience and a higher proportion of players who competed as starters in the previous year. Both groups reported approximately 18 hours of practice per week during the school year and around 27 hours during school holidays, with no significant difference observed.

CONCLUSION

Factors associated with knee pain include a history of LBP and reduced flexibility on the heel-buttock distance test. The study highlights the need for a comprehensive approach, considering the coexistence of LBP and focusing on improving anterior thigh flexibility.

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.

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.

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.

Rotation sequences for the calculation of shoulder kinematics of the volleyball attack

Calculating upper extremity kinematics during overhead movements presents with problems typically not seen for the lower extremity due to the large range of motion. Due to these unique issues, different rotation sequences have been suggested to circumvent challenges due to gimbal lock (GL) and angle coherence (AC). The purpose of this study is to determine the most appropriate rotation sequence for shoulder angle calculation during a volleyball attack.

METHODS

15 healthy experienced volleyball players (women = 8) performed 5 attacks off a stationary ball. A 12-camera 3D motion capture system was utilized to record trunk and arm kinematics to compare joint angles calculated using the YXY, ZXY, XZY, YXZ, ZYX, and XYZ rotation sequences. Instances of GL and AC inconsistences were marked for each trial. The last 3 trials were used for analysis.

RESULTS

The YXY and XYZ sequences presented with the least total number of errors (12 and 5, respectively). 5 instances of GL were present in the XYZ sequence while none were recorded for the YXY sequence. All other sequences returned incoherent angles that greatly exceeded known ranges of motion.

CONCLUSION

When performing kinematic analyses during a volleyball attack, researchers should adhere to ISB recommendations and employ the Eulerian YXY sequence for calculations. If greater anatomical understanding is desired, the XYZ sequence may be utilized for most subjects.

Prevention of shoulder injuries in volleyball players: The usefulness and efficiency of a warm-up routine

OBJECTIVES

The objective of this study was to assess the efficiency of a warm-up routine focused on shoulder injury prevention in volleyball players.

DESIGN

Prospective study.

SETTING

University.

PARTICIPANTS

Eight recreational volleyball teams (44 males, 49 females) were included in the study and assigned to two different groups (prevention or control) in a blinded way. In the prevention group, the players had to perform specific exercises at the beginning of each training session twice a week.

MAIN OUTCOME MEASURES

Injuries were recorded monthly in both groups with an online questionnaire.

RESULTS

A significant decrease in the total number of injuries as well as in the severity of the injuries was observed in the prevention group in comparison to the control group (p = 0.0001-0.013). For the shoulder, a decrease in injury incidence was also observed in the prevention group. This decrease reached significance in male players (p = 0.045).

CONCLUSIONS

The program appears to be efficient to reduce the risk of shoulder injuries in recreational volleyball players. Adjustments in the duration and in the contents of the program will have to be made to further improve compliance and better meet the requirements of both players and trainers.

Epidemiology of injuries in young volleyball athletes: a systematic review

BACKGROUND

Volleyball is among the five most popular sports in the world. Regardless of level and age, volleyball athletes perform fast high-impact movements such as jumps, landings, and changes in direction, demanding motor and sensory skills to avoid injuries. The available scientific literature provides information regarding the incidence of injuries in volleyball, but the evidence of injuries in young volleyball athletes (12-18 years old) is not well defined. Therefore, a systematic review was conducted to investigate the incidence and prevalence of injuries in young volleyball players.

METHODS

This systematic review was conducted according to the PRISMA recommendations and prospectively registered in PROSPERO (ID: CRD42022344623). An electronic search was conducted in the following databases: Web of Science, PubMed, and SportDiscuss via EBSCO in August 2022 and March 2023. Inclusion criteria followed the PICOS acronym: (P) youth volleyball players; (I) volleyball; (C) none; (O) incidence and/or prevalence of injury; and (S) cohort studies. The risk of bias was analysed using the adapted STROBE instrument.

RESULTS

Five studies were included in the qualitative analysis. They had a mean methodological quality of 6 (range 4-8) on the modified STROBE scale. Injury incidence was presented in varying ways, ranging from 1.51 injuries/1000 player hours to 12.4 injuries/10,000 athlete exposures (AEs). The prevalence was 1.6 ± 1.7 per 100 AEs. A total sample of 3698 youth volleyball athletes predominantly females was found. The body sites with the highest rate of injuries were the ankle, the distal portion of the upper limbs (wrist/hand/fingers) and the knee, respectively.

CONCLUSION

There was remarkable variability in the rate of injuries and the form of presentation between the studies. In addition, junior volleyball athletes had lower injury rates compared to other sports practised in high school, and older athletes had higher injury rates.

Timecourse of two-dimensional decision-making to offensive actions

Decision-making is an important component in the perception-action coupling required for athletes to achieve fine performance. Signal detection theory (SDT) provides a means of quantifying athletes' decision-making processes, based on their ability to discriminate between different types of stimuli (sensitivity) and the locations of their response criteria along a decision axis in a given situation. Studies have shown differences in these two indices between athletes and less-experienced counterparts, although these studies were limited to unidimensional decision-making problems. In the present study, SDT analysis was applied to two-dimensional decision-making by volleyball players regarding their opponents' attacks, using a four-alternative forced-choice task combining judgments of the type (spike or tip) and direction (cross-court or down-the-line) of attacks. Furthermore, a temporal occlusion task was used to reveal the timecourses of changes in sensitivity and the location of response criteria relating to judgments of attack type and direction. There were three groups of participants, eight top-league players, ten collegiate players, and ten novices. The results showed clear effects of expertise and distinct timecourses for the two types of judgment. For the attack type judgments, the sensitivities of the top-league players were relatively low at the early occlusion points, and their response criteria were biased toward judging attacking actions as spikes. At the late occlusion points, their sensitivity peaked, and there was no bias in their response criteria. For the directional judgments, the sensitivity of the three groups improved as the occlusion point advanced, while their response criteria tended to become more similar, which was not the case for the attack type judgments. These results are discussed together with previous studies of volleyball players' decision-making and judgments regarding deceptive actions in sports.

Posterior circumflex humeral artery pathological lesions with digital ischemia in an elite volleyball player: A case report and literature review

The posterior circumflex humeral artery, a branch of the axillary artery, is compressed by the humeral head during repeated abduction and external rotation of the shoulder joint owing to its anatomical structure. This damages the vascular endothelium, resulting in thrombi, arterial dissection, and aneurysms, a condition known as posterior, circumflex humeral artery pathological lesions. A thrombus may form at the site and becomes a peripheral embolus, resulting in peripheral arterial occlusion.A 21-year-old right-handed elite man college volleyball player noticed coldness and pain in his right hand during a game. Cyanosis was present except in the middle finger, and the beating radial artery was palpable; however, the ulnar artery was not. Doppler ultrasound examination revealed thrombus occlusion of the ulnar artery and common palmar artery of the index finger. Peripheral arterial occlusion was diagnosed due to embolization of a thrombus from this site. The patient stopped practicing volleyball immediately after the onset of symptoms and was started on cilostazol 200 mg and rivaroxaban 15 mg. Subjective coldness of the fingers improved one week after the start of treatment. The patient resumed practice four weeks after the start of treatment and participated in a game by the seventh week.Posterior circumflex humeral artery pathological lesions are caused by overhead motions such as pitching. They are most commonly reported in athletes playing volleyball, although rare, and many cases of aneurysm formation have been reported.Observing a cold sensation in the periphery after practice is necessary for screening.

Preseason shoulder screening in volleyball players: is there any change during season?

Background

Volleyball players sollicit their shoulder with high velocity and high ranges of motion. Musculoskeletal adaptations have been described after some years of practice but have not been explored after some months of practice. The objective of this study was to analyze the short-term evolution of shoulder clinical measures and functional performance in youth competitive volleyball players.

Methods

Sixty-one volleyball players were assessed twice, at preseason and at midseason. Shoulder internal and external rotation range of motion as well as forward shoulder posture and scapular upward rotation were measured in all players. Two functional tests were also performed: the upper quarter Y-balance test and the Single-arm medicine ball throw. The results obtained at midseason were compared to those measured at preseason.

Results

Compared to preseason, an increase in absolute value of shoulder external rotation, total rotation range of motion and forward shoulder posture were observed at midseason (P < .001). An increase in side-to-side difference for shoulder internal rotation range of motion was also observed during the season. As for scapular kinematics, scapular upward rotation was significantly decreased at 45° and increased at 120° of abduction at midseason. Concerning functional tests, an increase in throwing distance in the single-arm medicine ball throw was observed at midseason while no change was noted for the upper quarter Y-balance test.

Conclusion

Significant changes in clinical measures and functional performance were observed after some months of practice. Since some variables have been suggested to be correlated to a higher risk of shoulder injuries, the current study emphasizes the importance of regular screening in order to highlight injury risk profiles throughout the season.

The effect of a course of selected corrective exercises on posture, scapula-humeral rhythm and performance of adolescent volleyball players with upper cross syndrome

BACKGROUND

This study aims to investigate the effect of a course of selected corrective exercises on posture, scapula-humeral rhythm and performance of adolescent volleyball players.

METHODS

30 adolescent volleyball players with upper cross syndrome were purposefully selected and assigned into 2 control and training groups. The degree of back curvature was evaluated using a flexible ruler, forward head and forward shoulder size by photographic method, scapula-humeral rhythm by Lateral Scapular Slide Test (LSST), and performance by closed kinetic chain test. The training group performed the exercises for 10 weeks. After the exercises, the post-test was administered. To analyze the data, analysis of co-variance tests and paired t-test at the level of 0.05 were employed.

RESULTS

The research results showed that corrective exercises have a significant effect on abnormalities of forward head, forward shoulder, kyphosis, scapula-humeral rhythm and performance.

CONCLUSIONS

Corrective exercises can be effective in reducing shoulder girdle and spine abnormalities and improving scapula- humeral rhythm and performance of volleyball players.

High frequencies (HF) repetitive transcranial magnetic stimulation (rTMS) increase motor coordination performances in volleyball players

INTRODUCTION

It is widely demonstrated that high frequency (HF) repetitive transcranial magnetic stimulation (rTMS) has facilitative effects and is therefore capable to inducing changes in motor responses. One of the most investigated areas is the dorsolateral prefrontal cortex (DLPFC) as it plays a special executive attention role in actively preserving access to stimulus representations and objectives in environments with plenty of distraction such as those of team sports. Volleyball is a team sport in which the attention and coordination components are essential for achieving performance. Thus, the aim of this study was to investigate if HF rTMS at DLPFC in volleyball players can improve homolateral motor coordination and cortical excitability.

RESULTS

This study was a double-blinded (participant and evaluator) matched-pair experimental design. Twenty right-handed female volleyball players were recruited for the study and were randomly assigned either the active rTMS (n = 10) or the sham stimulation group (n = 10). The stimulation was performed in one session with 10 Hz, 80% of the resting motor threshold (RMT) of the right first dorsal interosseous muscle, 5 s of stimulation, and 15 s of rest, for a total of 1500 pulses. Before and after stimulation, the coordination and the cortical excitability were evaluated. The significant finding of this paper was that HF-rTMS of the DLPFC improved performance in terms of the homolateral interlimb coordination, with a significantly decreased in resting motor threshold and MEP latency of the ipsilateral motor cortex. It seem that HF-rTMS could increase coordination performances when the velocity of the execution is higher (120 bpm and 180 bpm).

CONCLUSION

Moreover, in active rTMS group significant differences emerged after stimulation in RMT and in MEP latency, while no differences emerged after stimulation in MEP amplitude. In conclusion we believe that these results may be of great interest to the scientific community and may also have practical implications in the future.

Epidemiology of Common Injuries in the Volleyball Athlete

PURPOSE OF REVIEW

To review the recent literature regarding the epidemiology of injuries in the volleyball athlete across all levels of play and to discuss areas where further studies are needed.

RECENT FINDINGS

Injury epidemiology for volleyball at the collegiate and high school level has been supported by a longitudinal injury surveillance program through the NCAA Injury Surveillance System (NCAA ISS) and High School Reporting Information Online (HS RIO) for the past 30 years. The creation of the FIVB Injury Surveillance System (FIVB ISS) in 2010 shows promise in advancing the literature on the injury at the professional level, and further studies on beach volleyball injuries are needed. Overall, injury patterns in volleyball in the past decade showed similar distribution to prior studies, but the rate of injury may be decreasing. Common injuries in volleyball include ankle sprains, patellar tendinopathy, finger and thumb sprains, overuse injuries of the shoulder, and concussions. Injury surveillance from the NCAA has demonstrated injury trends at the collegiate level, but further longitudinal studies are needed to evaluate injury at the professional level and for beach volleyball to help develop injury prevention strategy.

Effectiveness of a warm-up programme to reduce injuries in youth volleyball players: a quasi-experiment

OBJECTIVES

To establish the effectiveness of the 'VolleyVeilig' programme on reducing injury rate, injury burden and injury severity in youth volleyball players.

METHODS

We conducted a quasi-experimental prospective study over one season of youth volleyball. After randomisation by competition region, we instructed 31 control teams (236 children, average age 12.58±1.66) to use their usual warm-up routine. The 'VolleyVeilig' programme was provided to 35 intervention teams (282 children, average age 12.90±1.59). This programme had to be used during each warm-up before training sessions and matches. We sent a weekly survey to all coaches, collecting data on each player's volleyball exposure and injuries sustained. Multilevel analyses estimated differences in injury rates and burden between both groups, and we used non-parametric bootstrapping to compare the differences in injury numbers and injury severity.

RESULTS

We found an overall reduction in injury rates of 30% for intervention teams (HR 0.72; 95% CI 0.39 to 1.33). Detailed analyses revealed differences for acute (HR 0.58; 95% CI 0.34 to 0.97) and upper extremity injuries (HR 0.41; 95% CI 0.20 to 0.83). Compared with control teams, the intervention teams had a relative injury burden of 0.39 (95% CI 0.30 to 0.52) and a relative injury severity of 0.49 (95% CI 0.03 to 0.95). Only 44% of teams fully adhered to the intervention.

CONCLUSION

We established that the 'VolleyVeilig' programme was associated with reduced acute and upper extremity injury rates and lower injury burden and severity in youth volleyball players. While we advise implementation of the programme, programme updates to improve adherence are needed.

regular games in youth volleyball players

The aim of the present study was to evaluate the effects of two different formats of small-sided games (SSGs; 2 vs. 2 and 3 vs. 3) on physiological parameters in youth volleyball players. Twelve youth volleyball players (17.2 ± 7.44 years, 1.89 ± 0.6 m, 72.83 ± 8.57 kg) completed three different games formats (regular game (RG): 6 vs. 6, SSG3: 3 vs. 3 and SSG2: 2 vs. 2). associated with two pitch dimensions (i.e., 2 vs. 2 and 3 vs. 3 on 18 × 4.5 m; 6 vs. 6 on 18 × 9 m). Each player performed 4 × 5 min SSG with a recovery period of 1 min between bouts. All players were members of the same youth team and played in a professional league. They had at least 6 years of volleyball training and no current injuries. This study was carried out during the competitive period. Heart rate (HR), blood lactate ([La^-]), and rating of perceived exertion (RPE) were measured. Compared to RG, physiological (i.e., HR and [La^-]) and RPE responses were significantly higher during SSG3 and SSG2 (all p < 0.05; ƞ_p ² = 0.77, ƞ_p ² = 0.65, ƞ_p ² = 0.30, respectively). Moreover, HR and RPE were significantly higher in SSG2 compared to SSG3. In contrast, no significant differences were observed in [La^-] between SSG2 and SSG3. These results suggest that the number of players influences the exercise intensity in small-sided volleyball games in youth players. Therefore, coaches could benefit from incorporating SSGs to manipulate the exercise intensity in youth volleyball players.

Bone Mineral Density and Content among Iranian Elite Male Athletes in Different Sports

Objectives

Sport is one of the best ways to prevent osteoporosis; however, not all sports have the same impact on bones, for instance, swimming (SW) may have no effect or be harmful. Elite athletes are the best choice to detect the effects of any sport. Thus, this study was conducted firstly to compare the bone mineral density (BMD) and bone mineral content (BMC) of elite athletes in volleyball (VB), basketball (BB), and long-distance running (LR) together, and secondly to compare those corresponding values in SW athletes with those of non-athletes (NA).

Methods

The subjects (n=58) of this cross-sectional study included elite male athletes (members of Iran's national teams, with a minimum of 12-15 hours of training per week) and NA (control; C) who were divided into BB, VB, LR, SW (n=12 for each), and C (n=10) groups. The DEXA scan measured the amount of BMD and BMC values in the lumbar spine (LS; L2-L4) and proximal femur (PF; neck, trochanter, and Ward's triangle) areas.

Results

In the LS areas, LR had significantly higher BMD than the BB, VB, SW, and C groups (P<0.001), while for BMC, both LR and VB were significantly superior to other groups (P<0.001). Moreover, the BMD and BMC of the PF areas of VB and BB were significantly higher than those of the LR, SW, and C groups (P<0.001). Finally, in all areas, SW showed significantly higher BMD and BMC, compared to the C group (except for trochanter and femur neck BMC) (P<0.05).

Conclusion

LR athletes showed the most bone acquisition in the LS areas and VB players in the PF areas, while BB players ranked third in osteoporosis prevention in the mentioned regions. Unexpectedly, SW athletes also had better BMD and BMC than NA; therefore, after weight-bearing sports, this type of sport can be effective in bone acquisition.

Reliability levels of motor competence in youth athletes

This study aimed to analyze the reliability of the tests included in the motor competence assessment (MCA) battery and compare the effects of the number of trials per test. Thirty female volleyball players (14.6 ± 1.3 years of age) were tested. The participants performed two or three trials of each test. Intra-class correlation (ICC) was calculated, and a paired sample t-test analyzed the variations between trials (1st vs. 2nd vs. 3rd). Results revealed a significant difference between the first and the second trials for jumping sideways [t(29) = -4.108, p < 0.01], standing long jump [t(29) = -3.643, p < 0.01], and shuttle run [t(29) = -3.139, p < 0.01]. No significant result was registered in the shifting platforms, ball throwing and kicking between the first and second trials. Hence, any difference was recorded between the second and third trial. High ICC values were registered in lateral jumps, among the three repetitions of ball kicking and ball throwing, and between the last two repetitions of shuttle run. Almost perfect values were recorded for the shifting platforms and standing long jump. Nevertheless, there seems to be a learning effect between the first and the second repetition-no differences were registered only considering the two manipulative tests. In conclusion, except for jumping sideways, the MCA tests are reliable and only need to be performed two times instead of three.

Center of pressure-based postural sway differences on parallel and single leg stance in Olympic deaf basketball and volleyball players

In sports such as basketball and volleyball, loss of balance due to the inability to maintain body stability and lack of postural control adversely affect athletic performance. Deaf athletes appear to struggle with balance and postural stability problems. The purpose of this study was to examine postural sway values in parallel and single leg stance of Olympic deaf basketball and volleyball players and reveal differences between the branches. Twenty-three male athletes from the Turkish national deaf basketball (n=11) and volleyball (n=12) teams participated in the study. After anthropometric measurements, the subjects completed postural sway (PS) tests in parallel/single leg stances with open eyes and closed eyes on a force plate. PS parameters (sway path, velocity, and area) obtained from the device software were used for the statistical analysis. The Mann-Whitney U-test was used to compare differences in PS parameters between basketball and volleyball players, and the alpha value was accepted as 0.05. Volleyball players had significantly better results in parallel stance and dominant leg PS values than basketball players (P<0.05). There was no significant difference between the groups in nondominant leg PS values (P>0.05). We think that proprioceptive and vestibular system enhancing training practices to be performed with stability exercises will be beneficial in terms of both promoting functional stability and interlimb coordination. Trainers and strength coaches should be aware of differences in the postural control mechanism of deaf athletes.

Large-scale international volleyball competition in "bubble" under the COVID-19 pandemic

Objective

To verify whether a large-scale international volleyball competition could be conducted safely using the bubble method, both for our participating team and as a whole.

Methods

All 32 men’s and women’s teams were gathered in one place and a large-scale international volleyball competition was held for over a month without spectators using the bubble method. More than 1,000 people participated in the event, and 572 volleyball players played a total of 248 matches during the competition. There were 54 participants from Japan, including 27 male and female staff and players each. There was one team doctor for both men and women. A total of 2,250 PCR tests and 7,920 antigen tests were performed over 38 days. We investigated the incidence of infection in our team and in all participating teams.

Results

There were 9 fever cases from our men’s team, but all of them tested negative for COVID-19. Overall, a total of 10,170 tests were performed and only one was positive.

Conclusion

In order to ensure the health and well-being of all participants, the indoor competition was concluded safely without the occurrence of COIVD-19 clusters in the bubble system with strict adherence to various strict protocols of COVID-19.

Rare brachial artery injury caused by blunt trauma; a case of the brachial artery laceration in an amateur volleyball player

Low-energy blunt brachial artery injury is very rare and can be easily missed. Moreover, brachial artery injury in an amateur volleyball player is extremely rare. A 33-year-old woman was referred to our emergency department with swelling on her left upper arm after playing volleyball. Paresis or paralysis was not observed. The pulse of the left brachial artery was palpable, but relatively weak. An ultrasound examination and a computed tomography, both, revealed a pseudoaneurysm on the posterior wall of the left brachial artery in the antecubital fossa. A massive hematoma was also observed beneath the artery. The examination ruled out any concomitant injuries such as fracture and dislocation of the joints. An emergency surgery was performed. A hockey stick skin incision was made from the distal brachium to the antecubital fossa. The left brachial artery was detected in the hematoma. A 15 mm-long laceration was observed on the posterior wall of the artery. The condition of the vessel wall around laceration was poor. Therefore, we resected the injured lesions. The defect was so long that the lesion was interposed by a reversed saphenous vein graft. Heparin was administered one day after the surgery, which was later changed to apixaban on the sixth day after the surgery. Apixaban was discontinued after a month post-surgery. During the follow-up period, the patient did not report any complications and the graft was unobstructed.

Trunk muscle size and function in volleyball players with and without injuries to the head, neck and upper limb

OBJECTIVE

To investigate trunk muscle size and function in elite and community volleyball players with and without a history of head, neck or upper limb injury.

DESIGN

Cross-sectional observational study.

SETTING

Volleyball training camp or training sessions.

PARTICIPANTS

86 volleyball players (elite = 29; community = 57).

MAIN OUTCOME MEASURES

Information regarding history of head, neck or upper limb injuries was collected by self-report questionnaires. Trunk muscle size (multifidus, transversus abdominis, internal oblique and quadratus lumborum) and voluntary contraction (multifidus, transversus abdominis, internal oblique) were assessed using ultrasound imaging.

RESULTS

For trunk muscle size, no significant differences were found between elite and community volleyball players with and without a history of injury (all p > 0.05). A significant difference was found for voluntary contraction of the multifidus and transversus abdominis muscles for elite and community volleyball players with and without a history of injury (all p < 0.05).

CONCLUSION

A difference in trunk muscle contraction but no change in trunk muscle size in players with a history of head, neck or upper limb injuries may represent an altered muscle recruitment pattern rather than a deficiency in trunk muscle strength. Prospective studies are required to determine if these adaptations are compensatory (and protective) or predispose players to further injuries.

Bilateral counter movement jump, squat, and drop jump performances in deaf and normal-hearing volleyball players: a comparative study

Since deaf athletes do not have any physical deficiencies, it is known that they can easily participate in sports competitions if their communication problems are resolved. This study aimed to compare the performances of olympic deaf and elite normal-hearing volleyball players in different jumping test protocols. A total of 26 male volleyball players participated in the study, comprised of 12 olympic level deaf and 14 elite level normal-hearing. Following anthropometric measurements, athletes performed bilateral counter movement, squat and drop jump tests on a force plate. Each test was performed 3 times with maximal effort separated by 45 seconds of passive recovery and the mean of the three trials was selected for analysis. Independent Samples t-test was used to compare the differences in mean values of jumping test parameters between the groups. Normal-hearing athletes are observed to have significantly better scores than deaf athletes in all test protocols. Considering that the number of studies on athletic performance in deaf athletes is limited, it can be said that our study will contribute to researchers and coaches in respect of detecting a key ability in volleyball, such as jumping, in different jump protocols.

Combined Non-Invasive Cardiac Imaging and Genetic Testing of Elite Volleyball Players: A Ten-Year Experience

Sudden cardiac death in athletes is a devastating event. Although significant progress has been made in identifying the underlying pathophysiology and genetic basis for sudden cardiac death in young athletes, controversy exists regarding cost-effective screening measures to identify at-risk individuals. In this report we describe our ten-year experience performing cardiovascular assessments on 150 members of the United States Men’s and Women’s National Volleyball teams. Through a combination of history, physical, echocardiography and genetic testing, we have identified one previously undiagnosed athlete with Marfan syndrome, along with four others with a possible aortopathy. Taken together, this approach is a cost-effective strategy for the identification of at-risk tall athletes leading to potentially lifesaving interventions, and raises the issue of the feasibility of screening for all tall individuals.

Reliability of 2D kinematics during landing of volleyball athletes after exhaustion

INTRODUCTION

It is possible to quantify changes in movement patterns through kinematic analysis of landing, especially to quantify changes in pre and post exhaustion situations, however the reliability of this post exhaustion analysis is not known.

OBJECTIVE

To verify the inter and intra-examiner reliability of two-dimensional kinematic analysis during the landing of a vertical jump of volleyball athletes, pre and post exhaustion protocol.

EXPERIMENTAL

Thirty volleyball athletes were recruited, and kinematic analysis was performed during landing, pre and post exhaustion protocol. The angular measurements analyzed were: 1) frontal plane: knee valgus and 2) sagittal plane: anterior trunk inclination, knee flexion and tibiotarsal angle, performed by two examiners. The reliability calculation used the intraclass correlation coefficient (ICC), in addition to the error of measurement (SEM), the coefficient of variation (CV) and the minimum detectable difference (MDD).

RESULTS

Regarding reliability: ICC = 0.95-0.98 (pre) and ICC = 0.83-0.98 (post exhaustion). The CV presented heterogeneous values for the knee valgus and the inclination of the trunk, both pre and post protocol. The SEM from all angles presented values that varied from 0.74°-2.33° and the MDD ranged from 2.55°-5.54° pre protocol and 2.05°-6.45° post protocol.

CONCLUSION

2D kinematic evaluation can be used during landing, before and after the application of an exhaustion protocol, but professionals should pay attention to the angles of the knee valgus and the inclination of the trunk, as they have a large CV.

The effect of a shoulder injury prevention programme on proprioception and dynamic stability of young volleyball players; a randomized controlled trial

BACKGROUND

The "FIFA 11 + Shoulder" programme has been reported to reduce the incidence of upper extremity injuries among soccer goalkeepers. It has also been recommended for overhead sports. The purpose of this study was therefore to investigate the effect of an 8-week "FIFA 11 + shoulder" (11 + S) programme on shoulder joint position sense (JPS), threshold to detect passive motion (TTDPM) and upper quarter Y Balance Test in young male volleyball players.

METHODS

Thirty-two healthy young elite male volleyball players (17.49 ± 1.47 years) participated in this quasi-experimental study. Participants, recruited from two clubs participating in Iranian premier league, were randomly assigned into two groups; (1) the intervention group who performed the "FIFA 11 + shoulder" programme as their warm up protocol, three times per week, and (2) the control group who kept their routine warm up protocol meanwhile. Proprioception tests including JPS and TTDPM of internal and external rotator muscles of the dominant shoulder were recorded via the isokinetic system pro 4. The upper quarter Y Balance Test determined the shoulder dynamic stability.

RESULTS

No statistically significant differences were observed for JPS and TTDPM of shoulder internal and external rotator muscles; shoulder stability however significantly increased only in the intervention group (p = 0.03, ηp2=0.02).

CONCLUSION

Upper quarter dynamic stability improvement due to the 11+S programme leads to volleyball players' performance and may therefore contribute to a reduction in risk of sustaining injury if applied long-term.

TRIAL REGISTRATION

The trial was retrospectively registered atIranian Registry of Clinical Trials with the number of IRCT20201030049193N1 at 04/12/2020.

Sex differences in the consumption of over-the-counter analgesics among amateur volleyball players

Background

Compared with the normal adult population, athletes of several sport disciplines, such as endurance sports, ball sports, cycling and swimming, have higher use of over-the-counter analgesics (OTC analgesics). The aim of this study was to describe the epidemiology of OTC analgesic use in volleyball players as a typical competitive sport discipline. One particular focus was placed on the analysis whether the athletes’ use of OTC analgesics was influenced by their performance motivation.

Methods

A cross-sectional survey among amateur volleyball players was carried out using a web-based sports questionnaire. The study included athletes of both sexes, 18 years and older, currently playing in a German volleyball league. The athletes’ sport-related complaints were evaluated regarding the use of OTC analgesics. The use of OTC analgesics by athletes was compared with their performance motivation, based on the „Achievement Motives Scale - Sport” (AMS-Sport) questionnaire.

Results

The analysis of 114 completed questionnaires of amateur athletes revealed that the use of OTC analgesics was sex dependent, with a higher prevalence of use in female players (60%) versus male players (38%). The main reasons for consumption of OTC analgesics were pain in the head, knee and shoulder. The most frequently taken drug was ibuprofen, most often taken at competitions and over a period of 4 years (median). The analysis of the AMS-Sport questionnaire revealed that a logistic regression model for estimating the probability of drug use can be explained by the factors hope of success and years of playing practise in female players but not male players. In females, an increase in the factor hope of success resulted in a lower probability of OTC analgesic use, while an increase in years of playing practise resulted in a higher probability of use.

Conclusion

The average duration that volleyball players in this study took OTC analgesics was higher than that of the German population, and OTC analgesic use was more prevalent in female than male volleyball players. Thus, to reduce the prevalence of OTC analgesic use, educational programs should be implemented in sports teams; and, to reduce direct and indirect social pressure, sports teams should also receive sex-specific psychological support.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-021-00273-5.

Did the prevalence of suprascapular neuropathy in professional volleyball players decrease with the changes occurred in serving technique?

Objectives: Suprascapular neuropathy is more frequent in volleyball as compared to other overhead sports. This study aims to report the actual prevalence of suprascapular neuropathy among elite volleyball players. The hypothesis is that becoming jump topspin serves the most common serving technique, suprascapular neuropathy reduced its frequency. Methods: A total of 82 professional players were enrolled in the study. The presence of symptoms and the type of serve preferably performed were investigated. The strength and trophicity of the supraspinatus and infraspinatus muscles were evaluated. Patients with positive clinical findings underwent MRI of the shoulder. Results: The jump topspin serve was found to be the most popular type of serve both in males and females. At physical examination, 9% of the males and 12% of the females presented with infraspinatus muscle hypotrophy. Each case was accompanied by external rotation weakness. None of them complained of pain or reduced performance when they played. MRI confirmed infraspinatus muscle atrophy in all subjects. Conclusion: A lower prevalence of suprascapular neuropathy was found as compared with that previously reported in the 1980s and 1990s. A reduction in the popularity of the float serve seems to be a possible explanation. Thus, the jump topspin serve could be safe for suprascapular neuropathy and associated injuries in volleyball. The findings of this study should be considered by athletes and coaches for the prevention of activity-related injuries.

Cardiovascular fitness and health effects of various types of team sports for adult and elderly inactive individuals - a brief narrative review

Recreational team sports offer an alternative form of exercise to inactive individuals across the lifespan and sexes. Soccer is the most investigated recreational team sport reporting a wide range of health benefits, including cardiovascular (CV) health. The quest for novel paradigms to promote exercise in the general population, recently extended its interest to other team sports besides soccer. The available research supports the importance of recreational team handball, floorball, basketball, touch rugby, futsal and volleyball as training paradigms to improve CV fitness and other health-related variables in inactive individuals across ages and sexes. In most cases, recreational team sports programs assume the form of small-sided games, eliciting mean heart rates of 72-85% of the individual maximal. The majority of the training interventions were carried out for 12weeks with a reported mean attendance of 2 times 40-60min per week. Maximal oxygen uptake improvements were different in magnitude across the recreational team sports, with recreational team handball providing significant and clinically relevant increases (>3.5ml·kg^-1·min^-1). Game format, training exposure and pre-intervention health and fitness status are issues that need further investigation with the aim to optimize recreational team sports exercise programs implementation. Furthermore, the nature and effects of grassroots team sports should be further studied in order to provide as many as possible effective training tools for former practitioners and for the general population that has none or little experience of sport. Given the potential positive impact of recreational team sports practice on world population's health, large-scale randomized controlled trials are warranted.

Postural control in top-level female volleyball players

Background

The aim of this study was to compare the postural control of the Poland national women’s volleyball team players with a control group of non-training young women. It was hypothesized that volleyball players use a specific balance control strategy due to the high motor requirements of their team sport.

Methods

Static postural sway variables were measured in 31 athletes and 31 non-training women. Participants were standing on a force plate with eyes open, and their center of pressure signals were recorded for the 20s with the sampling rate of 20 Hz in the medial-lateral (ML) and anterior-posterior (AP) planes.

Results

In both AP and ML planes, athletes had lower range and higher fractal dimension of the COP. They had also higher peak frequency than control group in the ML plane only. The remaining COP indices including variability, mean velocity and mean frequency did not display any intergroup differences.

Conclusion

It can be assumed that due to the high motor requirements of their sport discipline Polish female volleyball players have developed a unique posture control. On the court they have to distribute their sensory resources optimally between balance control and actions resulting from the specifics of the volleyball game. There are no clearly defined criteria for optimal postural strategies for elite athletes, but they rather vary depending on a given sport. The results of our research confirm this claim.

Trial registration

The tests were previously approved by the Bioethical Commission of the Chamber of Physicians in Opole. (Resolution No. 151/13.12.2007). This study adheres to the CONSORT guidelines.

Evaluation of patellar tendinopathy using the single leg decline squat test: Is pain location important?

STUDY DESIGN

A cross-sectional study of non-elite volleyball players aged 13-17years.

OBJECTIVES

To evaluate the presence and location of pain during the single leg decline squat (SLDS) and compare patellar tendon thickness, structure, neovascularisation and symptom severity between SLDS-derived groups.

METHODS

32 male and 25 female participants attending a 5-day volleyball training camp underwent clinical evaluation by SLDS, describing the location of pain during this test using a pain map. The patellar tendon was examined using ultrasound imaging, performed by an assessor blinded to other assessments. Differences between participants experiencing local patellar tendon pain (PTP), other knee pain (OKP) or no-pain during the SLDS were evaluated.

RESULTS

Fifteen (26.3%) participants experienced pain during the SLDS. Local PTP was recorded for 12.3% and OKP for 10.5% of right legs. The PTP group was distinguished from the other groups by larger thickness and cross-sectional area of the mid-patellar tendon (p < 0.001), more frequent neovascularisation (p = 0.005) and greater pain and disability (p < 0.036). No differences between OKP and no-pain groups was observed.

CONCLUSION

Adolescent non-elite volleyball players reported symptoms indicative of patellar tendinopathy. In this cohort, the SLDS test combined with a pain map was associated with imaging and questionnaire-based outcomes.

LEVEL OF EVIDENCE

Diagnosis, Level 2; Cross-sectional study.

Nailfold capillaroscopic findings in a semi-professional volleyball player

Volleyball players are exposed to the possibility of several well recognized injuries, among which microvascular abnormalities are the less described and studied, although they could diminish their ability and performance. Capillaroscopy is a simple, non-invasive method to diagnose vascular abnormalities in athletes suffering for the consequences of repeated application of pressure by local trauma on the fingertips. The detected capillaroscopic picture will be the base for the follow-up and will indicate the possible need for further investigations aimed at excluding other occulted conditions. At our knowledge, this is the first report describing and documenting the related microvascular abnormalities in a volleyball player. This case emphasizes the fact that volleyball players among other athletes, whose hands are exposed to repeated fingertips trauma may suffer from microcirculation damage, for which reason they should be able to access an effective health surveillance program able to detect the first signs and offer the most appropriate clinical support.

The effects of ball impact position on shoulder muscle activation during spiking in male volleyball players

Background

The ball impact position during spiking in volleyball may influence the pattern of activation of shoulder girdle muscles and, therefore, could be a significant risk factor for shoulder injury.

Methods

Activation of 10 muscles in the dominant shoulder was evaluated using surface electromyography (EMG) in 11 male volleyball players, during spiking in a static standing position, with the goal being to precisely control the specified ball impact positions, without a run-up or ball setting. The following 4 ball impact positions were evaluated: standard, posterior, medial, and lateral. The EMG amplitude, normalized to the maximal voluntary isometric contraction of the respective muscles, was compared for each phase of the spiking movement between the standard position and the other 3 different impact positions, using the Dunnett test.

Results

The following between-position differences were noted for the deltoid muscle: increased activation of the anterior deltoid during the acceleration phase for the posterior position (P = .041), increase in the posterior deltoid during the acceleration phase for the lateral position (P = .04), and increase in the middle deltoid during the deceleration phase for the lateral position (P = .005).

Conclusion

A posterior or lateral shift in the position of ball impact may cause an increase in the activity of the deltoid muscle that would cause a decrease in the centripetal force of the humeral head through the acceleration and deceleration phases. As such, neuromuscular exercises, combined with strengthening of the rotator cuff muscle, might reduce the risk of shoulder injury during performance of the volleyball spiking movement.

Association between lower back pain and lower extremity pain among young volleyball players: A cross-sectional study

BACKGROUND

Lower back pain (LBP), as well as lower extremity injuries, are major problems among young volleyball players. Nevertheless, only few studies have focused on the relationship between lower extremity injuries and LBP.

OBJECTIVE

This study investigated the association between LBP and lower extremity pain, including knee and ankle pain, among young volleyball players.

DESIGN

Cross-sectional study.

SETTING

Amateur sports association.

PARTICIPANTS

Elementary and middle school-aged athletes (6-15 years of age).

MAIN OUTCOME MEASURES

LBP and lower extremity pain.

RESULTS

A total of 566 young volleyball players participated in this study. The point prevalence of LBP among young volleyball players was 9.5%. Using absence of lower extremity pain as a reference, the adjusted odds ratio (95% confidence interval) for LBP was 11.07 (5.64-21.71) in the presence of lower extremity pain.

CONCLUSIONS

LBP is associated with Lower extremity pain among young volleyball players. Careful attention should be paid to lower extremity complaints to prevent and treat LBP among young volleyball players.

Recovery after volleyball: a narrative review

Volleyball is a popular sport, but there has been little research to date investigating the recovery process. Volleyball involves short bouts of high intensity exertion, often with limited time to rest between matches. This literature review highlights the specific methods used to recover after playing volleyball and evaluates their effectiveness. Recovery strategies have been shown to increase performance and prevent injury. Specific techniques identified include nutritional strategies, proper sleep, mental and psychological techniques, cold water immersion, and laser therapy. Some, such as nutrition and sleep, have been definitively shown to benefit volleyball players, while others, such as cold water immersion and laser therapy, have shown promise but require further research to determine their overall effect. Other areas of future research include evaluating the effectiveness of combined recovery techniques as well as determining which are best for rapid recovery.

Injuries associated with Japanese high-school men's volleyball: a two-year survey and analysis

[Purpose] There are many factors associated with sports injuries in volleyball that remain unclear; therefore, many of these injuries are still not being effectively prevented. This study aimed to help effectively prevent injuries among and provide conditioning guidance to participants of a high-school men's volleyball team. [Participants and Methods] The participants were 36 males of a high-school men's volleyball team, and the circumstances of injury occurrence, injury type, injury site, exposure time, and injury rate per 1,000 player-hours were evaluated among these participants. [Results] Over the 2 year period, 68 injuries occurred, and the injury rate was 1.51/1,000 player-hours. Specifically, the injuries comprised 40 cases of trauma (58.8%) and 28 cases of disorders (41.2%). Additionally, injuries occurring during training tended to be disorders, and injuries occurring during matches tended to be traumas. The most common site of injury was the ankle joint. [Conclusion] The results suggest that it is important for players to have appropriate knowledge about the injuries, acquire accurate form, and undergo various types of site-specific training in order to prevent injury. In the future, the causes and circumstances of occurrence of injury must be verified in a larger number of participants.

Factors associated with low back pain in elite high school volleyball players

[Purpose] To determine the relationship between low back pain and a range of demographic, environmental, and injury history factors to identify potential factors for the management of low back pain. [Participants and Methods] The participants were 123 elite high school male and female volleyball players. They answered an extensive questionnaire regarding demographic details, low back pain in the previous year, volleyball-specific movements, previous regional injuries, and years of volleyball experience. Questionnaire responses were analyzed. Data were analyzed using a multivariate logistic regression analysis using the presence and absence of low back pain within 1 year as the explanatory variable. [Results] Of the 123 volleyball players, 48.0% reported low back pain. The volleyball-specific movements that induced pain were diverse (e.g., spike, serve, and pass) with no common factor. The factors associated with low back pain were an ankle injury within the previous year and years of volleyball experience. [Conclusion] The associations found in this survey indicate that particular attention should be given to more experienced players with a history of ankle injury to manage low back pain in high school volleyball players.

Current Approaches to the Use of Artificial Intelligence for Injury Risk Assessment and Performance Prediction in Team Sports: a Systematic Review

Background

The application of artificial intelligence (AI) opens an interesting perspective for predicting injury risk and performance in team sports. A better understanding of the techniques of AI employed and of the sports that are using AI is clearly warranted. The purpose of this study is to identify which AI approaches have been applied to investigate sport performance and injury risk and to find out which AI techniques each sport has been using.

Methods

Systematic searches through the PubMed, Scopus, and Web of Science online databases were conducted for articles reporting AI techniques or methods applied to team sports athletes.

Results

Fifty-eight studies were included in the review with 11 AI techniques or methods being applied in 12 team sports. Pooled sample consisted of 6456 participants (97% male, 25 ± 8 years old; 3% female, 21 ± 10 years old) with 76% of them being professional athletes. The AI techniques or methods most frequently used were artificial neural networks, decision tree classifier, support vector machine, and Markov process with good performance metrics for all of them. Soccer, basketball, handball, and volleyball were the team sports with more applications of AI.

Conclusions

The results of this review suggest a prevalent application of AI methods in team sports based on the number of published studies. The current state of development in the area proposes a promising future with regard to AI use in team sports. Further evaluation research based on prospective methods is warranted to establish the predictive performance of specific AI techniques and methods.

Electronic supplementary material

The online version of this article (10.1186/s40798-019-0202-3) contains supplementary material, which is available to authorized users.

Association between changes in molecular biomarkers of cartilage matrix turnover and changes in knee articular cartilage: a longitudinal pilot study

Background

An early detection of Osteoarthritis is urgently needed and still not possible until today. The aim of the study was to assess whether molecular biomarkers of cartilage turnover are associated with longitudinal change in knee cartilage thickness during a 2 year period in individuals with increased risk of developing knee osteoarthritis. A secondary aim was to assess whether prior knee injury or subjective patient-reported outcomes at baseline (BL) were associated with articular cartilage changes. Nineteen volleyball players (mean age 46.5 ± 4.9 years, 47% male) with a 30-year history of regular high impact training were recruited. The serum biomarkers Cpropeptide of type II procollagen (CPII), cartilage oligomeric matrix protein (COMP), collagenase generated carboxy-terminal neoepitope of type II collagen (sC2C), cartilage intermediate layer protein 2 (CILP-2), and the urine biomarkers C-telopeptide of type II collagen (CTX-II) and collagenase-generated peptide(s) of type II collagen (C2C-HUSA) were assessed at BL and at 2 year follow up (FU). Femorotibial cartilage thinning, thickening and absolute thickness change between BL and FU was evaluated from magnetic resonance imaging. Subjective clinical status at BL was evaluated by the International Knee Documentation Committee Subjective Knee Form and the Short-Form 36 Physical Component Score.

Results

CILP-2 was significantly higher at FU and linearly associated with the absolute cartilage thickness change during the experimental period. Prior injury was a predictor of increased absolute cartilage thickness change.

Conclusion

Measuring the change in the cartilage biomarker CILP-2 might be a valid and sensitive method to detect early development of knee osteoarthritis as CILP-2 appears to be related to cartilage thickness loss in certain individuals with increased risk of developing knee osteoarthritis. Prior knee injury may be predictive of increased articular cartilage thickness change.

Improvement of Upper Limb Motor Control and Function After Competitive and Noncompetitive Volleyball Exercises in Chronic Stroke Survivors: A Randomized Clinical Trial

OBJECTIVES

To investigate the effects of competitive and noncompetitive volleyball exercises on the functional performance and motor control of the upper limbs in chronic stroke survivors.

DESIGN

Randomized clinical trial.

SETTING

Outpatient rehabilitation center.

PARTICIPANTS

Chronic stroke survivors (N=48).

INTERVENTIONS

Participants were randomly assigned to competitive (n=16) or noncompetitive (n=16) volleyball exercise groups (60min/d volleyball exercise+30min/d traditional rehabilitation, 3d/wk for 7wk) and control group (n=16).

MAIN OUTCOME MEASURES

Reach and grasp motor control measures were evaluated through kinematic analysis. Functional outcomes were assessed via Motor Activity Log, Wolf Motor Function Test (WMFT), Box and Block Test, and Wrist Position Sense Test.

RESULTS

Significant improvement of functional performance was observed in both competitive (P<.0001) and noncompetitive volleyball exercise groups (P<.01), but not in the control group (P>.05), with the exception of WMFT score. Volleyball training, in general, resulted in more efficient spatiotemporal control of reach and grasp functions, as well as less dependence on feedback control as compared to the control group. Moreover, the competitive volleyball exercise group exhibited greater improvement in both functional performance and motor control levels.

CONCLUSIONS

Volleyball team exercises, especially in a competitive format, resulted in enhancing the efficacy of the preprogramming and execution of reach and grasp movements, as well as a shift from feedback to feedforward control of the affected upper limb in chronic stroke survivors. This may well be a potential underlying mechanism for improving functional performance.

Influence of pelvic padding and Kinesiology Taping on pain perception, kinematics, and kinetics of falls in female volleyball athletes

BACKGROUND

Volleyball digging techniques may cause pelvic injuries among female volleyball athletes. Pelvic padding and Kinesiology Taping (KT) may reduce impact force and pain and improve posture during a fall. This study examined the effects of pelvic padding and KT on pain perception, fall kinematics, and kinetics among female volleyball athletes.

METHODS

Twenty-four female volleyball athletes were exposed to two pelvic padding scenarios (with and without padding) and two KT conditions (with and without KT applied on the rectus abdominis muscle) during a fall in the forward direction. The maximum impact force during landing and maximum acceleration of the pelvis were registered using a force platform and an accelerometer, respectively. The maximum lumbar (hyper) extension angle, forward reach distance, and total fall time were measured by video analysis. Pain level was quantified using a visual analog scale.

RESULTS

The application of pelvic padding (with and without KT) reduced pain when compared to the no padding condition (p < 0.008). Applying KT alone reduced forward reach distance when compared to the 'pelvic padding and KT' condition (p < 0.010). In fact, when both pelvic padding and KT were applied, participants reached further when compared to the 'no pelvic padding and no KT' condition (p < 0.001). No significant main and interaction effects were found in all other outcomes.

CONCLUSIONS

Volleyball shorts with pelvic pads are recommended for female volleyball athletes to reduce pain in the digging maneuver and may help to increase their forward reach distance. However, KT is not recommended as it reduces the forward reach distance and cannot reduce pain or improve fall kinematics and kinetics.

Anterior cruciate ligament reconstruction in patients older than fifty years: a comparison with a younger age group

PURPOSE

To evaluate functional and radiological results in patients older than 50 years who underwent an anatomic anterior cruciate ligament (ACL) reconstruction with semitendinosus and gracilis tendons and to compare these results with those of patients younger than 40 years.

METHODS

Thirty-six patients over the age of 50 years with a diagnosis of ACL complete lesion and 36 consecutive patients under 40 years were included in this prospective study. Follow-up included clinical evaluation using Lysholm, IKDC, and Tegner scores and a KT-1000 arthrometric evaluation. Bilateral weight-bearing radiographs were obtained before surgery and at final follow-up of five years to evaluate the degree of osteoarthritis. All patients were evaluated at a one year follow-up (T1) (range 13-17 months) and at final follow-up (T2) (range 60-72 months).

RESULTS

No statistically significant difference was found between the two groups at the subjective and objective evaluations. At a KT-1000 arthrometric evaluation, the mean side to side maximum manual difference was 1.6 mm in the over 50 (group I) and 2.7 mm in the under 40 (group II) (p = 0.009). At 30 lb, the mean side to side difference was 1.7 mm in the over 50 group and 2.6 mm in the under 40 group (p = 0.040). No statistically significant increase in the degree of osteoarthritis was found at follow-up in the over 50 group.

CONCLUSIONS

The results of this study seems to confirm that ACL reconstruction in patients older than 50 years is a safe procedure with good to excellent subjective, objective, and radiological outcomes that are comparable to those for younger patients.

Diagnostic properties of the SPIQuestionnaire to detect Posterior Circumflex Humeral Artery Disease in elite volleyball players: a cross-sectional study

OBJECTIVES

Sports related aneurysmal degeneration and thrombosis of the Posterior Circumflex Humeral Artery (PCHA) has been known to cause symptoms of digital ischemia (DI) in elite volleyball players. Studies have reported symptoms of DI in as much as 28% of the elite indoor volleyball players. The purpose of this study was to determine the diagnostic value of the Shoulder PCHA Pathology and digital Ischemia - Questionnaire (SPI-Q) for detection of sports related PCHA disease using ultrasound data as the standard of reference.

METHODS

The SPI-Q was completed by elite indoor volleyball players from the highest and single highest Dutch volleyball division and by elite beach volleyball players participating in the 2014 Grand Slam Beach Tournament The Hague (GSBTH). Ultrasound assessment of the dominant shoulder was performed on-site using the SPI-US protocol. The SPI-Q sensitivity, specificity, positive - and negative predictive value and positive - and negative likelihood ratios, and the diagnostic odds ratio were calculated for detection of sports related PCHA disease, using ultrasound as the standard of reference.

RESULTS

Two hundred twenty-four elite male indoor volleyball players from the Dutch division were included in this study and 62 elite male and female beach volleyball players participating in the GSBTH: a total of 278 players. Thirty-five percent of the players reported symptoms of DI. The prevalence of PCHA disease was 6.1%. For the SPI-Q we found a sensitivity of 18% (95% CI 4-43), specificity of 64% (95% CI 58-70), positive predictive value of 3% (95% CI 0.7-8.9) and negative predictive value of 92% (95% CI 87-96), positive likelihood ratio of 0.50 (95% CI 0.18-1.40), negative likelihood ratio of 1.28 (95% CI 1.01-1.62) and a diagnostic odds ratio of 0.39 (95% CI 0.11-1.38).

CONCLUSION

The diagnostic value of the SPI-Q to detect PCHA disease in elite volleyball players is poor, which makes it unsuitable as a diagnostic instrument for sports related PCHA disease specifically. However, it can be used to assess all-cause symptoms of DI and raise awareness within athletes and sports physicians, which is important for preventing ischemic complications.

Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning

There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg), who participated in plyometric- (n = 21), or skill-based-conditioning-program (n = 20). Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM), countermovement jump (CMJ), standing broad jump (SBJ), medicine ball throw, (MBT) and 20-m sprint (S20M). All tests were assessed at the study baseline (pre-) and at the end of the 12-week programs (post-testing). Two-way ANOVA for repeated measurements showed significant (p<0.05) "Group x Time" effects for all variables but body-height. Plyometric group significantly reduced body-mass (trivial effect size [ES] differences; 1% average pre- to post-measurement changes), and improved their performance in S20M (moderate ES; 8%), MBT (very large ES; 25%), CMJ (large ES; 27%), and SBJ (moderate ES; 8%). Players involved in skill-based-conditioning significantly improved CMJ (large ES; 18%), SBJ (small ES; 3%), and MBT (large ES; 9%). The changes which occurred between pre- and post-testing were more inter-correlated in plyometric-group. Although both training-modalities induced positive changes in jumping- and throwing-capacities, plyometric-training is found to be more effective than skill-based conditioning in improvement of conditioning capacities of female senior volleyball players. Future studies should evaluate differential program effects in less experienced and younger players.

How do we learn to "kill" in volleyball?: The role of working memory capacity and expertise in volleyball motor learning

This study examines young volleyball players' learning of increasingly complex attack gestures. The main purpose of the study was to examine the predictive role of a cognitive variable, working memory capacity (or "M capacity"), in the acquisition and development of motor skills in a structured sport. Pascual-Leone's theory of constructive operators (TCO) was used as a framework; it defines working memory capacity as the maximum number of schemes that can be simultaneously activated by attentional resources. The role of expertise in motor learning was also considered. The expertise of each athlete was assessed in terms of years of practice and number of training sessions per week. The participants were 120 volleyball players, aged between 6 and 26 years, who performed both working memory tests and practical tests of volleyball involving the execution of the "third touch" by means of technical gestures of varying difficulty. We proposed a task analysis of these different gestures framed within the TCO. The results pointed to a very clear dissociation. On the one hand, M capacity was the best predictor of correct motor performance, and a specific capacity threshold was found for learning each attack gesture. On the other hand, experience was the key for the precision of the athletic gestures. This evidence could underline the existence of two different cognitive mechanisms in motor learning. The first one, relying on attentional resources, is required to learn a gesture. The second one, based on repeated experience, leads to its automatization.

Can psychological well-being scales and hormone levels be used to predict acute performance of anaerobic training tasks in elite female volleyball players?

The purpose of this study was to examine relationships between pre-training psychological well-being assessment scales (General Health Questionnaire-28-GHQ-28, Competitive State Anxiety Inventory-2-CSAI-2, Sport Competition Anxiety Test-SCAT, State-Trait Anxiety Inventory-S-STAI-S, Oviedo Sleep Questionnaire-OSQ and Psychological Characteristics Related to Sport Performance-PCSP), and pre-training stress hormone concentrations (cortisol-C, total testosterone-TT, free testosterone-FT, adrenocorticotropic hormone-ACTH and testosterone/cortisol-T/C ratios), on acute neuromuscular performance (ANP) in female volleyballers. Forty elite female volleyballers (27±4yrs.; 178.3±8.5cm; 67.9±7.2kg) participated. Bivariate correlations were performed between psychological assessments and hormone levels with ANP. All psychological scales presented at least one significant (p<0.05) relationship or prediction of ANP. Contrastingly, among hormones, the only significant relationship was between TT/C ratio and Overhead Medicine Ball Throw (r=0.34; p<0.05). Therefore, our data shows that results of general and sport-specific psychological well-being scales prior to training are more consistently related to performance in elite female volleyballers than pre-training stress hormone concentrations.

The prevention of musculoskeletal injuries in volleyball: the systematic development of an intervention and its feasibility

Background

A scientific research project has started in the Netherlands with the aim of developing and implementing an evidence-based intervention to prevent the occurrence of musculoskeletal injuries among young and adult recreational volleyball players. This article describes (i) the systematic development of the intervention; and (ii) the assessment of its feasibility in terms of relevancy, suitability and usability.

Systematic development of the intervention

The development of the intervention was based on the Intervention Mapping structured and systematic process. First, the needs assessment conducted among the main actors within recreational volleyball revealed that an intervention was needed for injury prevention, ideally embedded prior to a volleyball activity (training or match) within the warm-up, delivered by trainers/coaches, and available in an application for smartphone/tablet or website. Second, the objective and target groups of the intervention were defined, namely to prevent or reduce the occurrence of finger/wrist, shoulder, knee and ankle injuries among both young and adult recreational volleyball players. Third, preventive measures and strategies (e.g. core stability, strength and balance) were selected in order to accomplish a decrease in injury incidence. Last, the intervention ‘VolleyVeilig’ was finally developed, a warm-up programme including more than 50 distinct exercises and lasting 15 min.

Feasibility of the intervention

A quasi-experimental research based on a one-group post-test design was conducted over a period of 3 weeks among 41 volleyball players and five coaches from five adult recreational teams, who were asked to use the intervention. Degree of relevancy, suitability and usability of the warm-up programme ‘VolleyVeilig’ were measured among players and coaches on an 11-point scale (varying from ‘completely disagree’ to ‘completely agree’).

All groups of exercises within the warm-up programme were positively assessed with regard to their relevancy, suitability and usability, mean scores ranging from 7.7 to 8.3. Group interviews revealed especially that the warm-up programme in its current form was not suitable as a pre-match warm-up.

Conclusion

The warm-up programme ‘VolleyVeilig’ developed in order to prevent or reduce the occurrence of musculoskeletal injuries in recreational volleyball was positively assessed by volleyball players and coaches with regard to its relevancy, suitability and usability. Before its nationwide implementation, the effectiveness of the intervention on injury reduction among volleyball players should be conducted.

Preventing musculoskeletal injuries among recreational adult volleyball players: design of a randomised prospective controlled trial

Background

Both acute and overuse injuries are common among recreational volleyball players, especially finger/wrist, ankle, shoulder and knee injuries. Consequently, an intervention (‘VolleyVeilig’) was developed to prevent or reduce the occurrence of finger/wrist, shoulder, knee and ankle injuries among recreational volleyball players. This article describes the design of a study evaluating the effectiveness of the developed intervention on the one-season occurrence of finger/wrist, shoulder, knee and ankle injuries among recreational adult volleyball players.

Methods

A randomized prospective controlled trial with a follow-up period of one volleyball season will be conducted. Participants will be healthy recreational adult volleyball players (18 years of age or older) practicing volleyball (training and/or match) at least twice a week. The intervention (‘VolleyVeilig’) consists of a warm-up program based on more than 50 distinct exercises (with different variations and levels). The effect of the intervention programme on the occurrence of injuries will be compared to volleyball as usual. Outcome measures will be incidence of acute injury (expressed as number of injuries per 1000 h of play) and prevalence of overuse injuries (expressed as percentage).

Discussion

This study will be one of the first randomized prospective controlled trials evaluating the effectiveness of an intervention on the occurrence of both acute and overuse injuries among recreational adult volleyball players. Outcome of this study could possibly lead to the nationwide implementation of the intervention in all volleyball clubs in The Netherlands, ultimately resulting in less injuries.

Trial registration

Dutch Trial Registration NTR6202, registered February 1st 2017. Protocol: Version 3, February 2017.

MRI findings of knee abnormalities in adolescent and adult volleyball players

Background

To longitudinally and cross-sectionally evaluate knee abnormalities by sex and age in adolescent and adult volleyball athletes over 2 years using magnetic resonance imaging (MRI).

Methods

Thirty-six high-level volleyball athletes (18 adolescents: 56% female, mean age 16.0 ± 0.8 years; and 18 adults: 50% female, mean age 46.8 ± 5.1 years) were imaged by MRI at BL and at 2-year follow-up (FU). Prevalence and severity of cartilage lesions, subarticular bone marrow lesions (BMLs), subarticular cysts, osteophytes, and ligament and meniscus integrity were evaluated by sex and by age cohort (adolescents and adults) using the whole-organ MRI score (WORMS).

Results

There were no significant longitudinal changes in any of the features within any of the sex or age groups. No significant differences were found in overall prevalence or severity of any of the features between males and females, although at FU, males had a significantly higher prevalence of osteophytes in the medial femorotibial joint (MFTJ) than females (p=0.044). Compared to adolescents, adult volleyball players had a significantly greater prevalence and severity of cartilage lesions (p<0.001 for both), BMLs (p=0.0153 and p=0.005), and osteophytes (p≤0.003 and p<0.001), and more severe meniscal lesions (p≤0.021).

Conclusion

We found significant differences in the prevalence and severity of knee abnormalities between adolescent and adult volleyball players, but no overall differences by sex. These findings lay the groundwork for further investigations with larger cohorts and longer FU times to determine whether or not these knee abnormalities are associated with the development of OA.

Differences in biomarkers of cartilage matrix turnover and their changes over 2 years in adolescent and adult volleyball athletes

BACKGROUND

This study aimed the feasibility to assess longitudinal changes in biomarkers of cartilage turnover and to determine their relationship with patient-rated outcomes over 2 years in volleyball athletes.

METHODS

Thirty-seven athletes were studied: 18 adolescents (age 15.9 ± 0.64 years) in a 2-year intensive volleyball training program and 19 adult recreational volleyball players (age 46.5 ± 4.9 years). Blood and serum samples were taken at baseline (BL) and 2-year follow-up (FU). Subjects completed the International Knee Documentation Committee (IKDC) Subjective Knee Form and the Short-Form 36 (SF-36) at BL.

RESULTS

Thirteen adolescents (72%) had open growth plates at BL (BL open adolescents), the rest had closed growth plates at BL (BL closed adolescents), and all but one adolescent had closed growth plates at FU as assessed by MRI. BL open and closed adolescents had greater levels of the cartilage degradation-based biomarkers 45 mer collagenase peptide of type II collagen (C2C-HUSA) and C-telopeptide of type II collagen (CTX-II) than adults. BL open adolescents showed decreases in C2CHUSA, collagen synthesis marker C-propeptide of type II procollagen (CPII), and CTXII, and adults showed increases in cartilage intermediate layer protein 2 (CILP-2) and C2C-HUSA. In adolescents, IKDC scores were correlated with CPII changes. In adults, SF-36 Physical Component Scores were correlated with cartilage oligomeric matrix protein (COMP) changes.

CONCLUSION

Significant differences in biomarker levels over time show the feasibility to assess their changes. Greater levels of C2C-HUSA and CTX-II in adolescents than in adults may reflect increased cartilage turnover in response to higher joint loading. CPII and COMP may be more reflective of subjective patient outcomes. These biomarkers may thus be useful in assessing mechanical loading-induced cartilage changes, their associated symptoms, and Osteoarthritis risk in athletes.