Care of Water Polo Players

A Dual Inertial Measurement Unit System for Classifying Standard Overhead Drill Movements in Elite Women's Water Polo

INTRODUCTION

Water polo upper limb external load monitoring cannot be currently measured accurately because of technological and methodological challenges. This is problematic as large fluctuations in overhead movement volume and intensity may affect performance and alter injury risk. Inertial measurement units (IMU) and machine learning techniques have been shown to accurately classify overhead movements in other sports. We investigated the model accuracy and class precision, sensitivity, and specificity of IMU and machine learning techniques to classify standard overhead drill movements in elite women's water polo.

METHODS

Ten women's water polo players performed standard drills of swimming, blocking, low-intensity throwing and high-intensity throwing under training conditions. Athletes wore two IMU: one on the upper back and the other on the distal forearm. Each movement was videoed and coded to a standard overhead drill movement. IMU and coded video data were merged to verify the IMU-detected activity classification of each movement to that of the video. Data were partitioned into a training and a test set and used to form a decision tree algorithm. Model accuracy and class precision, sensitivity, and specificity were assessed.

RESULTS

IMU resultant acceleration and angular velocity values displayed drill-specific values. A total of 194 activities were identified by the model in the test set, with 8 activities being incorrectly classified. Model accuracy was 95.88%. Percentage class precision, sensitivity, and specificity were as follows: blocking (96.15, 86.21, 99.39), high-intensity throwing (100, 100, 100), low-intensity throwing (93.48, 93.48, 97.97), and swimming (94.81, 98.65, 96.67).

CONCLUSIONS

IMU and machine learning techniques can accurately classify standard overhead drill movements in elite women's water polo.

The Association of Serum Calprotectin with Fitness Indicators and Biochemical Markers in High-Level Athletes: A Continuous Dynamic Monitoring during One Competitive Season

The objective was to determine the associations between several biochemical indicators and the dynamics of concentration change across four physical fitness phases over the period of a competitive season. Furthermore, associations between serum calprotectin and biomarkers of inflammation or muscle injury and physical indicators were examined.

SUBJECTS AND METHODS

Twenty professional male water polo players (median age: 28 (22-42)) were included in this study. Serum creatine kinase activity was determined by the automated photometric UV method. The concentrations of calprotectin, C-reactive protein, and myoglobin were measured using an automated immunoturbidimetric method, while an automated immunochemistry method was employed for interleukin-6, troponin I, and cortisol determination. Tests of repeated strength, maximal strength, and static strength were used to evaluate physical activity.

RESULTS

Serum calprotectin concentrations expressed in median and IQR were significantly different: T1: 2.92 g/mL (2.47; 3.86); T2: 2.35 g/mL (1.26; 2.87); T3: 2.27 g/mL (1.60; 3.27); and T4: 1.47 g/mL (1.04; 2.85) (p = 0.004). Cortisol concentration and CK activity showed significant changes among phases (p = 0.049 and p = 0.014, respectively). Each physical activity examined showed a significant seasonal decrease (all p values were 0.001). Calprotectin serum concentration and indicators of muscular injury, inflammation, and physical activity were found to be correlated during particular stages of the seasonal examination.

CONCLUSIONS

Calprotectin values determined throughout one competitive season decreased as training intensity among water polo players increased. Serum calprotectin concentrations and indicators were related to biochemical markers of inflammation and muscle damage.

The Oral Microbiome Profile of Water Polo Players Aged 16-20

OBJECTIVES

Chlorine has a strong antibacterial property and is the disinfectant most frequently used in swimming pools. Therefore, the microbiota community in the oral cavity of those who practice water sports is assumed to be special due to their regular immersion in water. Adverse changes in the composition of oral cavity microbiota may have serious health consequences. We aimed to compare the oral microbiome between water polo players and non-athletes. We hypothesized that the oral cavity microbiota community differed between water polo players and non-athletes.

MATERIALS AND METHODS

Altogether, 124 water polo players (62 males and 62 females, aged between 9 and 20 years) and 16 non-athlete youths (control group, eight males and eight females, aged between 16 and 20 years, mean age + SD = 17.1 + 1.4 years) who participated in body structure examinations voluntarily agreed to participate in the study. In a randomly selected subsample of water polo players (n: 29, aged between 16 and 20 years, mean age + SD = 17.3 + 1.0 years), saliva samples were also collected. Saliva samples were collected from all non-athlete youths (n: 16, aged between 16 and 20 years). The oral microbiome was determined from a saliva sample, and DNA was isolated using the QIAmp DNA Blood Mini Kit. The 16S rRNA gene amplicon sequencing method was used to analyze the microbiome community. PCR primers were trimmed from the sequence reads with Cutadapt. R library DADA2 was used to process reads in the abundance analysis.

RESULTS

In general, Streptococcus, Veilonella, and Prevotella genera constituted more than 50% of the oral microbiome community in the two participant groups combined (n = 45). The oral microbial profile had significant sexual dimorphism and differed between water polo players and the non-athletes. Compared to females, males had a higher (p < 0.05) relative abundance of the Atopobium (medium effect size) and Pravotella_7 (very large effect size) genera and a lower (p < 0.05) relative abundance of the Fusobacterium (large effect size), Gemella (large effect size), and Streptococcus (large effect size) genera. Compared to non-athletes, water polo players had higher (p < 0.05, medium effect size) relative abundance of the genus Veillonella and lower (p < 0.05, large effect size) relative abundance of the genus Gemella.

CONCLUSIONS

The results suggest that regular water training can unfavorably alter the composition of the oral microbial community.

Epidemiology of Acute and Overuse Injuries in Underwater Rugby

Background

Underwater rugby (UWR) is a team sport. Athletes require a high degree of strength, endurance, speed, and coordination involving intense physical contact. Currently, a paucity of literature exists regarding injury occurrence in UWR.

Purpose

To examine the nature and prevalence of acute and overuse injuries in UWR.

Study Design

Descriptive epidemiology study.

Methods

Between November 2020 and March 2021, a total of 720 German UWR athletes were invited to take an online survey developed by orthopaedic specialists with UWR athletes. Data were recorded regarding general and health-related information, training habits, acute injuries that necessitated an interruption in training and/or doctor consultation, as well as overuse injuries. Overuse injuries were evaluated using the Oslo Sports Trauma Research Centre Overuse Injury Questionnaire. Statistical analyses included t tests or rank sum tests depending on normality of distribution. A nonparametric Kruskal-Wallis 1-way analysis of variance on ranks was used for nonnormally distributed data among several groups.

Results

This study included 161 active athletes (mean ± SD, 36.1 ± 11.9 years old; 75.3% male) for analysis, of whom 90.1% were competing regularly. The performance-level distribution was as follows: first German national league (n = 73), second German national league (n = 46), state league (n = 17), district league (n = 1), and no league (n = 24). The mean ± SD sport-specific training workload was 5.6 ± 3.0 h/wk, including UWR training, additional swimming (n = 71; 44.1%), strength (n = 70; 43.5%), and/or endurance training (n = 102; 63.4%). Acute injuries were recorded in 78.9% of all athletes. The most typical locations for acute injuries were hand/finger (42.4%), head/face (concussion, ruptured eardrum; 18.1%), wrist (5.5%), or spine (5.0%). Overuse injuries were reported by 42.9% of the participants. The predominant locations for overuse injuries were hand/finger (18.8%), shoulder/clavicle (14.1%), spine and wrist (10.7% each), head/face (8.7%), and ankle joint and knee (6.7% each).

Conclusion

In the current study, 3 of 4 athletes reported at least 1 acute injury, and 2 of 5 athletes reported at least 1 overuse injury. Leading injury regions were the hand/finger, head/ear, wrist, and spine.

Artistic Swimming Injuries in Young Elite Athletes: An 11-year Follow-Up

OBJECTIVE

Artistic swimming is a highly challenging discipline, requiring physical skills and creativity. There are almost no published data on trauma. We aimed to assess the incidence and the nature of injuries in artistic swimmers.

DESIGN

An 11-year retrospective single-center cohort study.

SETTING

Department of Sport Medicine of a University Hospital.

PATIENTS

One hundred and twenty-four elite female artistic swimmers aged 12.9 ± 1.6 years.

INTERVENTIONS

The cohort was divided into 3 groups according to the competition categories (from 9 to 12 years old called "future", 12-15 years old called "youth", 15-19 years old called "junior").

MAIN OUTCOME MEASURES

Injury rate per season and per athlete was assessed.

RESULTS

The injury rate was 0.95 injuries/season/athlete and 1.05 injuries/1000 hours of practice. The most frequent injuries were rotator cuff tendinopathy (13.6%), acute low back pain (13.6%), and patellofemoral syndrome (11.9%). Swimmers in the youth and junior categories had significantly more injuries than those in the future category (P = 0.009), possibly because of more training hours (P < 0.001). Twelve major injuries occurred, all in the same group of youth swimmers.

CONCLUSION

This is the first study investigating trauma during artistic swimming practice. A better knowledge of the main injuries is necessary for the physician to provide optimal care for athletes and to develop prevention. Attention should be particularly paid to the swimmers' shoulders and knees.

The Correlation Between the Strength of the Shoulder and Trunk Muscular Systems in Elite Adolescent Water Polo Athletes

Introduction

Water polo is a competitive team sport played in the water between two teams of seven players each. Water polo players must have swimming speed, strong abdominal and back muscles, and strong shoulder muscles to cope with this sport's special conditions. In this study, we investigate the possible association of shoulder and trunk muscle systems in adolescent water polo athletes of high demands.

Materials and methods

The research included 42 water polo players aged 14-16, who train regularly for at least five years, six times a week, and participate in national championships and national teams. The athletes were evaluated on the strength and torque of these muscular systems using the isokinetic dynamometer Biodex System 4 Pro (Biodex Medical Systems, Inc, Shirley, NY). The correlation of the results was done using the statistical package SPSS 21.

Results

The correlations revealed statistically significant differences in trunk extension in combination with the shoulder external/internal rotation ratio. Also, most of the correlations occurred between the trunk and non-dominant limb of the athletes and, more often, in the female athletes. Furthermore, for the hand grip, the male athletes showed a greater difference in strength between the dominant and the non-dominant member than female athletes. Finally, the evaluation of the trunk extension/flexion ratio and external/internal rotation ratio for the shoulder joint showed that many athletes are outside the normal range and need targeted strengthening.

Conclusion

The negative correlation coefficient between trunk extension/flexion and shoulder external/internal rotation indicates that the trunk extension mechanism helps for better internal rotation of the shoulder. Therefore, water polo players should focus on the training of the stretching mechanism of the trunk and also give weight to achieving a balance between the competing muscular systems of the trunk and the shoulder. Thus, athletes can maximize their skills and, at the same time, protect themselves from injuries.

Shoulder impingement syndrome in water polo players: muscle shortening manoeuvre controls pain intensity, recovers function and normalizes sonographic parameters

PURPOSE

To evaluate the effects of muscle shortening manoeuvre (MSM) by sonography (US) in professional water polo players with shoulder impingement syndrome (SIS).

METHODS

Twenty-four professional water polo players (mean age: 22.13 ± 3.34) with SIS were assigned to one of 2 different treatment interventions: Group (1) MSM: a series of fast accelerations in the upward direction was applied to the upper limb that's connected to a spring through a metal plate with a ring. The ring was linked to a pulley system that was submitted to forces acting in the opposite direction (added mass). Group (2) Simple traction: the series of fast accelerations were performed without the springs. Pain intensity, Yocum and Hawkins tests for SIS, Neer's impingement sign, range of motion, muscle strength and shoulder US were assessed. The examination was performed before, immediately after and 30 days after each treatment to study the US width of subacromial-subdeltoid bursa (SSB), thickness of supraspinatus (ST), long biceps tendons (LBT); hypoechoic halo of surrounding the long biceps (LBH) and subscapular tendons (STH); width of acromio-clavicular joint capsule (ACJ) and the distance between bone heads (ACD). Impingement sign (IS) was evaluated by dynamic examination.

RESULTS

Immediately after treatment with MSM, pain was much reduced (p = 0.002); Yocum and Hawkins tests were decreased (p = 0.008, p = 0.031); Neer's impingement sign was negative; range of motion and muscle strength were increased. US showed that the following parameters were significantly reduced: SSB (p = 0.001), LBT (p = 0.014), LBH (p = 0.014), SSH (p = 0.002), ACJ (p = 0.004), ACD (p = 0.001). IS was no more detected. After 30 days, the improvement of clinical and US findings was maintained. In the control group, after simple traction, no clinical amelioration of US parameters was found immediately after the procedure.

CONCLUSION

These data show that MSM could be significantly and rapidly effective against pain and the loss of function due to shoulder impingement in water polo players.

Injuries Affecting Intercollegiate Water Polo Athletes: A Descriptive Epidemiologic Study

Background

There are few data on injuries suffered by collegiate water polo athletes.

Purpose

To describe the epidemiology of injuries suffered by National College Athletic Association (NCAA) male and female water polo players by using injury surveillance data over a 5-year period.

Study Design

Descriptive epidemiology study.

Methods

Deidentified data on all water polo injuries and illnesses recorded in the Pac-12 Sports Injury Research Archive from July 2016 through June 2021 were obtained and analyzed. Three men's and 4 women's teams were observed for the entire 5-year period, and 1 men's and 1 women's team was observed from July 2018 through June 2021.

Results

During the observation period, 729 injuries were recorded in the database, with no differences in overall injury rates between male and female athletes (relative risk [RR] = 1.0; 95% CI, 0.9-1.2); 33.7% of injuries required a physician encounter, and 3.6% required surgery. The shoulder was the most injured body part, making up 20.6% of all injuries, followed by the head/face (18.8%) and hand/wrist/forearm (11.7%). Shoulder tendinopathy was the most common shoulder injury diagnosis (4.5% of all injuries). Concussion was the most common injury diagnosis overall, making up 11.4% of injuries, and 81.9% of concussions occurred outside of competition. Male athletes were significantly more likely than female athletes to have a concussion in an off-season practice (RR, 3.25; 95% CI, 1.2-8.8) and via contact with another player (RR, 2.9; 95% CI, 1.3-6.4). Half of the 26 surgical procedures occurring over the observation period were for chronic joint trauma of the groin/hip/pelvis/buttock, with 9 of those 13 being for femoroacetabular impingement specifically.

Conclusion

Among NCAA water polo athletes, the shoulder was the most injured body part; however, shoulder injuries rarely required missed time from sport or necessitated surgical intervention. Concussions were the most common injury diagnosis, had the worst return-to-play outcomes among common diagnoses, and were mostly sustained outside of competition. Femoroacetabular impingement was found to be the dominant diagnosis for which surgical intervention was required.

The Effectiveness of Shoulder Mobility and Strength Programs in Competitive Water-Polo Players

Background: Water-polo is the water sport with the highest incidence of injuries, with shoulder pain being the most common one. The understanding of risk factors and guidance on preventive measures is essential in this sport discipline. The aim of this study was to determine the effects of a specific 6-week training plan on range of motion (ROM) and joint strength levels in a group of professional water-polo players. Methods: Quasi-experimental study with a sample of 28 participants (age: 20.1 ± 2.5 years; height: 176.9 ± 6.2 cm; body mass: 74.6 ± 8.1 kg). Three study groups, which consisted of one control group and two experimental groups, were established. Two repeated measurements, pre and post intervention, were performed. During these measurements, ROM of the glenohumeral joint was analyzed both in external (ER) and internal (IR) rotation, as well as the maximal isometric strength. Conclusions: The application of a training program improved glenohumeral joint ROM. ER and IR evolve differently in both shoulders. ER improved only in the throwing arm only in the group undergoing intervention but for the non-dominant side, improvements were observed in both ER and IR, regardless of whether or not they had followed the intervention plan. No improvements were observed in either the isometric strength or contralateral asymmetries.

Saliva testing as noninvasive way for monitoring exercise-dependent response in teenage elite water polo players: A cohort study

Excessively increased training volume and/or intensity and competition can lead to development of overtraining syndrome, causing a performance decrement in athletes. Tracking individual response to exercise intensity is crucial for establishing recovery strategies.We assessed the exercise intensity-dependent variability of stress response biomarkers, namely cortisol (C), testosterone (T), s-IgA, and advanced oxidation protein products (AOPP), in saliva samples of teenage elite water polo players. Saliva was collected on a day of training match (T1) and a day of competitive match (T2), at morning, before and after match.Cortisol/proteins and testosterone/proteins concentrations decreased throughout day T1, whereas increased throughout day T2. The highest values were measured after match on day T2 (2.5 ± 0.5 vs 14.6 ± 6.3 ng/mg; 0.061 ± 0.024 vs 0.371 ± 0.15 ng/mg, respectively). sIgA/proteins and AOPP/proteins concentrations increased throughout both days, and were higher after T2 match than T1 one (respectively, 1073.0 ± 438.2 vs 71.0 ± 17.3 μg/mg; 78.05 ± 24.2 vs 15.98 ± 3.16 nmol/mg, P = .003). Significant differences between concentrations of different biomarkers recorded on T1 and T2 were found only for AOPP, suggesting an increased oxidative stress on day T2. Free testosterone/cortisol ratio on day T2 was lower than that at morning (0.053 ± 0.021 vs 0.107 ± 0.031), indicating an increased catabolic response after competitive match.A highly significant positive correlation was found between Cortisol/Proteins and Testosterone as well as s-IgA/Proteins on day T1, and between Cortisol/Proteins and AOPP on day T2.In conclusion, we found that different types of activities, such a training or competitive session can affect the hormonal response, immunity, and oxidative stress, thereby modulating athletic performance.Our findings also confirm the usefulness of saliva testing as noninvasive way for monitoring the individual response to changes in exercise intensity in teenage elite water polo players.

Prevalence and mechanisms of injuries in water polo: a systematic review

Objective

To summarise the information available in the literature on the prevalence of injuries in water polo and injury risk factors.

Methods

Protocol was registered on Open Science Framework. MEDLINE, CINAHL, Embase and SPORTDiscus databases were searched for keywords relating to water polo and injuries on 3 February 2021. References were searched for additional studies. Only original research papers in English or French were included, and studies without an injured group were excluded. A data extraction file was made based on the Cochrane Collaboration recommendations. Study quality was evaluated with the Newcastle-Ottawa scales for cohorts and a modified version for cross-sectional studies.

Results

The initial search yielded 581 articles, with 5 more added from reference lists, but only 41 remained after removing duplicates and applying inclusion/exclusion criteria. Thirty-one articles identified the head, fingers and shoulders as the most common sites of injury. Ten articles on mechanism of injury focused mainly on the shoulder, with degenerative changes, posture, scapular alignment, strength, flexibility and overhead shooting kinematics as the main injury risk factors. Publication types included cohort studies, cross-sectional studies, and one case series.

Conclusions

Most traumatic injuries affect the hands and the head from unexpected contact with the ball or opponents. Conversely, training injuries seem to affect mainly the shoulder area. Low level evidence suggests a correlation between shoulder injuries and lack of strength or flexibility as well as large volumes of overhead throwing. Further prospective research is needed to investigate risk factors for other body areas.

Analysis of water polo injuries during 8904 player matches at FINA World Championships and Olympic games to make the sport safer

OBJECTIVE

To analyse injuries of water polo players reported during four Summer Olympic Games (2004, 2008, 2012, 2016) and four Federation Internationale de Natation World Championships (2009, 2013, 2015, 2017).

METHODS

Injuries during training and matches were reported daily by the team physicians and the local medical staff at the sports venues using an established surveillance system.

RESULTS

A total of 381 injuries were reported, equivalent to 14.1 injuries per 100 players (95% CI ±1.42). The most frequent diagnoses were laceration (12.7%) and contusion (10.9%) of head, followed by (sub-)luxation/sprain of hand (9.5%) and contusion of trunk (6.5%) or hand (6.2%). More than half of the injuries (57.0%) occurred due to contact with another player. A quarter of the injuries (25.4%) were expected to result in absence from training or match; 10 (2.9%) resulted in an estimated time-loss of 3 or more weeks. About three-quarters of injuries (75.6%) occurred during matches, 86 during training. The incidence of match injuries was on average 56.2 injuries per 1000 match hours (95% CI ±6.74). The incidence of time-loss match injuries (14.7; 95% CI ±3.44) was significantly higher in men than in women.

CONCLUSIONS

A critical review of water polo in-competition rules and the implementation of a Fair Play programme may help to mitigate the high incidence of contact injuries incurred during matches. A water polo-specific concussion education programme including recognition, treatment and return to play is recommended. Finally, a prospective injury surveillance programme would help to better define water polo injuries outside of the competition period.