Wetenschap en waterpolo


Epidemiology of non-submersion injuries in aquatic sporting and recreational activities.
Sports Med. 2003;33(10):745-70
Chalmers D, Morrison L.
Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.

Although the issues of drowning and near-drowning in aquatic sporting and recreational activities receive considerable attention in the epidemiological literature, there is not a recognised literature on non-submersion injuries occurring in these activities. This review draws together the epidemiological literature on non-submersion injuries and describes the incidence, nature and causes of these injuries, common risk factors, and strategies for prevention.Activities covered by the review include swimming, diving, boating, surf sports, fishing, water polo and water sliding. For most activities there is a dearth of good quality descriptive studies, with most involving cases-series designs and few providing estimates of incidence. Inconsistencies in inclusion criteria and the reporting of incidence rates makes comparisons within and between activities difficult. Incidence rates were identified for most activities and in general the incidence of injury was low, especially for more serious injury. However, some activities were associated with severely disabling injury, such as spinal cord injury (diving) and amputation (from propeller strikes in water skiing and swimming).Only three studies reporting the significance of postulated risk factors were identified. Lack of knowledge about the water being entered and alcohol consumption are significant risk factors in recreational diving; increased blood alcohol concentrations were reported to increase the risk of death in boating; and obesity and tandem riding were reported to increase the risk of injury on public water slides. Few evaluations of preventive measures were identified. Two studies reported reductions in the incidence of water slide injuries following the introduction of design changes and supervision, but neither had a non-intervention comparison group. Improvements in swimming and diving skills were reported in three studies, but these were not designed to measure changes in the risk of injury.This review demonstrates that there is a need for well-designed epidemiological research on non-submersion injury in aquatic sporting and recreational activities. The first priority should be for studies designed to describe accurately the incidence, nature, severity and circumstances of these injuries, followed by research on the significance of postulated risk factors. Once this research has been undertaken, interventions targeted at reducing the incidence of injury in aquatic sporting and recreational activities can be designed and evaluated.

Arthroscopic capsular shrinkage for posterosuperior internal impingement of the shoulder
Acta Orthop Traumatol Turc. 2003;37 Suppl 1:105-11
Kilicoglu O, Demirhan M, Esenyel CZ.
Department of Orthopedics and Traumatology (Ortopedi ve Travmatoloji Anabilim Dali), Medicine Faculty of Istanbul University, Capa, Istanbul, Turkey.

OBJECTIVES: We evaluated clinical and radiological findings and functional results following arthroscopic capsular shrinkage in patients with internal impingement of the shoulder.
METHODS: The study included four patients (2 females, 2 males; mean age 27.5 years; range 25 to 32 years) who underwent arthroscopic capsular shrinkage between 1997 and 2001. Three patients were overhead athletes (2 volleyball, 1 water polo player), the fourth was a clerk. All the patients suffered from shoulder pain upon abduction and external rotation and all received a preoperative unsuccessful rehabilitation for at least three months (range 3 to 10 months). Following arthroscopic examination of the glenohumeral joint, anterior joint capsule was shrunk using a radiofrequency probe. A specific rehabilitation program was applied postoperatively. The mean follow-up was 3.5 years (range 2 to 6 years).
RESULTS: The Neer test was positive in all cases, and the relocation test in 3 cases, preoperatively. Magnetic resonance imaging showed contact between the glenoid rim and the greater tuberosity in three cases, degeneration in the rotator cuff in two cases, a partial tear in one patient, and a subchondral cyst in another. Arthroscopic examination revealed glenoid-rotator cuff contact in all cases and degeneration in the contact areas. Drive-through sign was positive in all cases. Kissing lesion was present in one case. No SLAP lesion was identified. The patients' complaints disappeared and the three athletes were able to resume their professional sporting activities.
CONCLUSION: Arthroscopic shrinkage of the stretched anterior capsule proved successful throughout a follow-up period of at least two years.

The effect of a flexed elbow on bowling speed in cricket.
Sports Biomech. 2003 Jan;2(1):65-71
Marshall R, Ferdinands R.
Faculty of Health and Sport Science, Eastern Institute of Technology, Taradale, Hawkes Bay, New Zealand.

The laws of bowling in cricket state 'a ball is fairly delivered in respect of the arm if, once the bowler's arm has reached the level of the shoulder in the delivery swing, the elbow joint is not straightened partially or completely from that point until the ball has left the hand'. Recently two prominent bowlers, under suspicion for transgressing this law, suggested that they are not 'throwing' but due to an elbow deformity are forced to bowl with a bent bowling arm. This study examined whether such bowlers can produce an additional contribution to wrist/ball release speed by internal rotation of the upper arm. The kinematics of a bowling arm were calculated using a simple two-link model (upper arm and forearm). Using reported internal rotation speeds of the upper arm from baseball and waterpolo, and bowling arm kinematics from cricket, the change in wrist speed was calculated as a function of effective arm length, and wrist distance from the internal rotation axis. A significant increase in wrist speed was noted. This suggests that bowlers who can maintain a fixed elbow flexion during delivery can produce distinctly greater wrist/ball speeds by using upper arm internal rotation.

Arthroscopic treatment of osteochondritis dissecans of the capitellum: Report of 5 female athletes.
Arthroscopy. 2003 Feb;19(2):210-4.
Krijnen MR, Lim L, Willems WJ.
Department of Orthopaedics, Onze Lieve Vrouwe Gasthuis Hospital, Amsterdam, The Netherlands.

The management of osteochondritis dissecans of the capitellum of the adolescent elbow is still controversial. We report on 5 cases of female high-level athletes aged from 10 to 19 years (4 gymnasts, 1 waterpolo player). All these athletes had a symptomatic osteochondritis dissecans of the capitellum, which was treated arthroscopically in all cases. Follow-up time averaged 5 months (1 to 6.5 months). During the arthroscopy, loose osteochondral fragments of the capitellum and radial head were removed, and the defect was debrided. Thorough evaluation of the anterior and posterior joint including the olecranon fossa was performed. One of the 5 patients had a loose body requiring arthroscopic removal. Within 6 months after surgery, all except 1 elbow, the elbow with a loose body, regained maximum range of motion. Two patients returned to a high level of gymnastics and 1 was considering return. The short-term results of this treatment suggest that arthroscopic debridement of the loose osteochondral fragments provides a good result.

Effect of water polo practice on cytokines, growth mediators, and leukocytes in girls.
Med Sci Sports Exerc. 2003 Feb;35(2):356-63
Nemet D, Rose-Gottron CM, Mills PJ, Cooper DM.
Center for the Study of Health Effects of Exercise in Children, University of California, Irvine, CA 92868, USA.

PURPOSE: The effects of exercise on growth and development are mediated through a complex interaction between the endocrine, immune, and nervous systems. Very little is known about how these systems respond to exercise in children or adolescents. Moreover, there are few studies that have examined growth factors, inflammatory cytokines, and leukocyte responses to "real-life" or field exercise solely in girls. Thus, the goal of the present study was to determine the acute exercise-induced alterations in the growth hormone --> insulin-like growth factor-I axis, inflammatory cytokines, and certain aspects of immune function in a group of adolescent girls after a typical water polo practice.
METHODS: Ten, healthy, high-school female subjects, 14-16 yr old, performed a single, typical, 1.5-h water polo practice session. Blood was sampled before and after the session.
RESULTS: The exercise resulted in an increase in HR (from 82 +/- 2 to 161 +/- 5 beats.min(-1) at 30 min, P < 1.4.10(-6) ), as well as in circulating lactate levels (375 +/- 66%, P < 0.0005). Significant increases where noted in circulating IL-6 (396 +/- 162%, P < 0.005) and IL-1ra (71 +/- 20%, P < 0.015). A substantial increase in the level of IGFBP-1 (1344 +/- 344%, P < 0.001) was also observed. Interestingly, TNF-alpha levels decreased after the exercise (-10.4 +/- 3.8%, P < 0.04) as did insulin (55 +/- 12%, P < 0.005). The exercise led to significant increases in granulocytes, monocytes, and lymphocytes. The exercise significantly influenced adhesion molecules (such as CD62L and CD54), which has not been previously studied in adolescent girls.
CONCLUSIONS: These data demonstrate that an intense "real-life" exercise bout in adolescent females leads to profound increases in inflammatory cytokines and reductions in anabolic mediators with substantial alterations in white blood cell subpopulations and adhesion molecules. The role of these frequent, almost daily immune and cytokine changes on growth and development have yet to be determined.

Analysis of indicators of load during the game in activity of the second line attacker in water polo.
Coll Antropol. 2003 Jun;27(1):343-50
Lozovina V, Pavicic L, Lozovina M. Split College of Maritime Studies, Split, Croatia.

Water polo, as an activity, belongs in the category of polystructural complex move sports. The activities of a player's in role of second line attacker is observed on the sample of competitive games in the First national league. The study is aimed to define a set of new measurement variables for the objective recording of amount, intensity and duration of player's activities, and its evaluation by means of factor validity criteria. On the sample of 87 players, 29 variables were applied. Competent, trained officials made measurements. Basic statistics of all measured variables is presented as referent values of various player activities. In the factor analysis, three factors are found to be significant, explaining 84.6% of source variability, which is a subset of multivariate normally, distributed variables. Factors are interpreted as: "quantity of actions", "intensity of activity in the vertical body posture", and "intensity and extensity of activity in horizontal body posture". Of the last two, body posture is found to be specific in water polo, due to specifics of the game that is played in water. It is concluded that the proposed variables and measurement procedures are very well suited and objectively instrument for the purpose of measurement of the energetic aspect of kinesiological activity analysis.

A study of the effects on the ovarian cycle of athletic training in different sports.
J Sports Med Phys Fitness. 2003 Sep;43(3):398-403
Sambanis M, Kofotolis N, Kalogeropoulou E, Noussios G, Sambanis P, Kalogeropoulos J.
Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Greece.

AIM: The purpose of this research was to investigate the effects of sports training on the ovarian cycle of athletes of various disciplines, and of non-athletes, their participation and their performance in competition as well as the appearance of symptoms of discomfort pre and during the duration of menstruation.
METHODS: Athletes from the disciplines of basketball, track athletics, gymnastics, swimming, synchronized swimming and water polo as well as non-athletes took part in this research. All the participants, both athletes and non-athletes were selected and completed a specially designed questionnaire.
RESULTS: The results of the research showed that there are no significant differences in the menarche to the duration of the ovarian cycle and to the duration of the menstrual flow. Also, the involvement in different athletic disciplines appears to affect to different degrees the regularity of the cycle although this does not prevent the athlete from participating in training and in competition. The effects are sometimes beneficial to their performance and sometimes they could have a negative effect on their performance. Regarding the symptoms and the discomforts which occasionally appeared pre and during the duration of menstruation e.g. headache symptoms, these appear to be greatly decreased in the athletes of swimming, synchronized swimming and water polo and perhaps this is a result of the beneficial effects of the water. The percentage for abdominal pain appeared decreased for certain disciplines (such as swimming) or stable both pre and during the duration of menstruation. Concerning the pain in the thoracicolumbar region, the percentages were different for every sport: a noticeable decrease was recorded for the athletes of swimming, gymnasts, synchronized swimming, water polo, track athletes and the non-athletes, but with an increase for the basketball players. For the symptoms of weakness and fatigue, the percentages were increased for all the athletic disciplines as well as for the non-athletic during the duration of menstruation compared with pre menstruation, although for the percentages for symptoms of nervousness, the picture was different, that is, the percentages appeared decreased during the duration of menstruation.
CONCLUSION: In conclusion, where problems appear in the function of the ovarian cycle, the assistance of a specialist gynaecologist is considered essential when we are sure that these problems are not caused by training, malnutrition or psychological factors.

Effect of different sports on body cell mass in highly trained athletes
Acta Diabetol. 2003 Oct;40 Suppl 1:S122-5.
Andreoli A, Melchiorri G, Brozzi M, Di Marco A, Volpe SL, Garofano P, Di Daniele N, De Lorenzo A.
Division of Human Nutrition, University of Tor Vergata, Via Montpellier 1, I-00173, Rome, Italy.

The objective of this study was to verify the impact of various sports on body cell mass (BCM). Ninety-eight male subjects, 17-33 years of age, participated in the study. The sample included athletes from three professional Italian football (soccer) teams, representing three different divisions (A, n=16; B, n=14; and C, n=18), judo athletes (J, n=10), and water polo athletes (W, n=14) who all competed at the national level. Twenty-six age-matched individuals served as the control group (CG). Fat-free mass (FFM), fat mass (FM), percent body fat (%BF), and BCM were assessed using bioimpedance spectroscopy (BIS). There were no significant differences in body weight and FFM among the groups. A and B were significantly taller than J and CG. B had a significantly lower body mass index (BMI; kg/m(2)) than CG, while C had a significantly lower BMI than J and CG. CG had a significantly greater FM and %BF than A, B, and C. C had a significantly lower BCM than Aand B. CG had a significantly lower BCM than A, B, J, and W. In conclusion, differences in BCM exist among athletes of different sports, and among athletes within the same sport who compete at different levels.