Wetenschap en waterpolo


Polo Player Garcia Makes Waves at NHGRI

Since arriving in the United States from her native Puerto Rico 6½ years ago, Angelica Marie Garcia has made quite a splash both in her current post as an IRTA scientist and with her beloved pastime, water polo.
Garcia works in the laboratory of NHGRI’s Dr. William Gahl, under the supervision of Dr. Meral Gunay-Argun. Her research focuses on autosomal recessive polycystic kidney disease. A 2005 graduate of California State University at Long Beach, where she made the dean’s list, the young researcher, when not in the lab, spends much of her time in the water. As a member of the Puerto Rican women’s national water polo team, she and her teammates have set their sights on the 2008 Olympic Games in China. This past summer, the squad participated in the Pan American Games in Brazil.
“I’ve always loved the game,” said Garcia, who began playing water polo when she was 14. The sport demands exceptional physical conditioning and swimming skills. The young investigator thrives not only on the physical demands of the game, but also on the intense competition. She thought seriously about going professional, but ultimately opted for research and medicine.
Before coming to NIH, Garcia was a fellowship scholar under the Research Initiative for Scientific Enhancement, an NIGMS-supported program at Cal State. While an undergraduate, she was named an NCAA first-team All-American in water polo, one of only seven female collegians picked for the honor.
Her athletic prowess and accomplishments notwithstanding, Garcia plans to attend medical school. Afterwards, she said, “What I really hope is to eventually work with underserved communities that don’t have access to medical care. There is a great need for this service.”
When not in her NHGRI lab or the pool, Garcia volunteers in outreach programs in the D.C. area and also enjoys traveling, dancing and reading.
She says both water polo and scientific research have their own respective challenges. Regarding water polo, “it’s a physical thing,” and with medicine, added Garcia, “you always have your academic and intellectual challenges. I find it very stimulating.”—Jan Ehrman

Custom-made mouthguards and prevention of orofacial injuries in sports
Acta Med Croatica. 2007;61 Suppl 1:9-14.
Badel T, Jerolimov V, Panduric J, Carek V.
Zavod za stomatolosku protetiku, Stomatoloski fakultet, Sveuciliste u Zagrebu, Zagreb, Hrvatska.

The importance of sports dentistry has become even greater due to the role that sports have in modern society. As the risk of sports-related injuries appears already in the period of children's play and is constantly present in various risk-related sporting activities, the role of dental profession has become extremely important. Custom-made mouthguards are the most highly recommended mouthguards used for successful prevention of orofacial and dental injuries. It is important to inform athletes of the best characteristics of a custom-made mouthguard such as retention, comfort, fit, ease of speech, resistance to tearing, ease of breathing as well as good protection of the teeth, gingiva and lips. The shape and surface of the mouthguard which encloses the teeth, the gingival and the hard palate can vary depending on the anatomical features of the athlete's jaw, his/her dental arch, the type of sports activity, as well as the materials used in the manufacture of the mouthguard. Mouthguards should not extend distally further than the first molars because some athletes complain of the vomiting reflex. In addition, mouthguards may interfere with breathing.They should reach the mucogingival border labially and extend a few millimeters palatally in order to provide the best protection for the labial gingival and good retention. The labial flange should extend up to 2 mm of the vestibular reflection. The palatal flange should extend about 10 mm above the gingival margin thus enclosing the greatest part of the anterior palate surface with a slight narrowing distally not further than the first molars. Materials used in the manufacture of mouthguards should satisfy a number of physical, mechanical and biological requirements. Essential properties of materials used in the manufacture of mouthguards include water absorption, density, thickness as well as temperature transmission, energy absorption and drawing strength (tensile strength) of custom-made mouthguards. Such materials should have an optimal consistency in order to cushion the traumatic impact. Currently, ethylene-vinyl acetate (EVA) is the most commonly used mouthguard material. An optimal thickness of the mouthguard is achieved by the application of vacuum forming pressure-lamination technique in two layers of a thermoplastic sheet of EVA copolymer and if needed, by placing two layers of protective air-cells against the critical area. Some investigations in the Croatian samples showed that the most common injuries in water polo occur in the orofacial region (96.4% of cases), of which 80% are injuries of lips, tongue and cheek. In the period from 1997 to 2005 the number of orofacial injuries increased by 62%. Dental trauma occurs in 7.6% of cases. In basketball players soft tissue injury in the orofacial complex was established in 69.4% and dental trauma in 11.3% of the respondents. In the selected sample of handball players, soft tissue injuries were established in 78.8%, dental trauma and loss of teeth in 13.6% and temporomandibular joint injuries in 6.8% of the cases. In tae-kwon-do players 88% of orofacial injuries were lacerations, but only 12% reported dental and temporomandibular joint trauma. Only a half of the examined professional basketball players wore mouthguards, and none of the examined tae-kwon-do players. Clinical value of intraoral custom-made mouthguards was proven. Dentists play the key role in the prevention and treatment of sports-related dental and orofacial injuries, collection and dissemination of relevant information, as well as promotion of research on the preventive procedures related to injuries of such a specific aetiology.

Partial rupture of the distal biceps brachii tendon in elite waterpolo goalkeeper: a case report of conservative treatment.
J Sports Med Phys Fitness. 2007 Mar;47(1):79-83
Giombini A, Innocenzi L, Di Cesare A, Di Salvo W, Fagnani F, Pigozzi F.
National Institute of Sports Medicine, Rome, Italy.

The aim of this study was to describe a case of a 27-year-old male elite waterpolo goalkeeper, who had a partial rupture of the distal biceps tendon of his dominant arm while he was trying to save a strong outside shot. Pain on the antecubital fossa was the chief complaint. Ultrasound and magnetic resonance imaging completed the instrumental set-up. This case had the resolution of the pain and impairment after 3 months of conservative treatment. At 1-year follow-up, the athlete is asymptomatic and the isokinetic test provided almost complete recovery of the strength for elbow flexors and supinators muscles.

Carotid artery false aneurysm caused by blunt trauma. A case report.
Int Angiol. 2007 Mar;26(1):72-4.
Davidoviå LB, Vasiå DM, Markoviå DM, Sindjeliå RP, Pavloviå SU, Kuzmanovic IB.
Institute for Cardiovascular Diseases, Clinical Center of Serbia, Belgrade, Serbia and Montenegro.

Different mechanisms of blunt trauma producing carotid artery false aneurysms are described in literature. We report one such case caused by combination of two mechanisms: accidental hyperextension of the neck, and subsequent sudden forceful hit by a ball during the water polo match.

The bone response to non-weight-bearing exercise is sport-, site-, and sex-specific.
Clin J Sport Med. 2007 Mar;17(2):123-8.
Magkos F, Kavouras SA, Yannakoulia M, Karipidou M, Sidossi S, Sidossis LS.
Laboratory of Nutrition and Clinical Dietetics, Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.

OBJECTIVE: To examine whether skeletal adaptations to chronic non-weight-bearing exercise depend on the type of aquatic exercise (swimming or water polo) as well as on sex (men or women).
DESIGN, SETTING, AND PARTICIPANTS: This was a cross-sectional study at the Laboratory of Nutrition and Clinical Dietetics, Department of Nutrition and Dietetics, Harokopio University, Athens, Greece. A total of 43 water polo players, 26 swimmers, and 30 sedentary individuals, aged 17 to 34 years, were recruited (52 men, 47 women).
MAIN OUTCOME MEASURES: Bone mineral content (BMC) and areal bone mineral density (aBMD) of the total body and of various subregions.
RESULTS: : Compared with controls, swimmers had lower leg and total aBMD (P < 0.05), whereas water polo players had lower leg but higher arm and trunk aBMD (all P < 0.05). Swimmers and water polo athletes differed at the arms (men only), trunk, and total body (all higher in water polo players, at P < 0.05). Bone adaptations to water polo playing were unaffected by sex. Female swimmers, but not male swimmers, had 13% higher arm BMC than controls (P < 0.05), whereas male swimmers, but not female swimmers, had 12% lower leg BMC than controls (P < 0.05).
CONCLUSIONS: Athletes participating in long-term water polo playing and swimming have substantially different total and regional aBMD. The effect is not mediated by sex in water polo players; however, sex may mediate the differences between swimmers and controls. Whether the observed differences between athlete groups and sexes arise from different bone adaptations to activity or from other factors cannot be answered by the current data.
CLINICAL RELEVANCE: Water polo playing may be preferable over swimming for maintaining bone health; both types of aquatic exercise at the elite level of participation, however, have unfavorable effects on the lower limb bones.

A cumulative effect of physical training on bone strength in males.
Int J Sports Med. 2007 Jun;28(6):449-55.
Falk B, Galili Y, Zigel L, Constantini N, Eliakim A.
Ribstein Center for Sport Medicine Sciences and Research, Wingate Institute, Netanya, Israel.

Weight-bearing, high-impact exercise, as opposed to nonimpact exercise, has been demonstrated to increase bone mineral density. This was traditionally demonstrated with dual energy X-ray absorptiometry. Our objective was to assess the differences in bone properties, using quantitative ultrasound (QUS, Sunlight Omnisense, Sunlight Medical, Ltd., Tel Aviv, Israel), in male athletes involved in a weight-bearing, impact sport (soccer, SC) or a nonimpact sport (swimming and water polo, AQ), compared with nonathletic control (C) males. A total of 266 boys and men, aged 8 - 23 years, were divided into children (11.1 +/- 1.0 years; 34 SC, 34 AQ, 25 C), adolescents (14.7 +/- 1.2 years; 32 SC, 31 AQ, 31 C), and young adults (19.8 +/- 1.1 years; 31 SC, 24 AQ, 24 C) . Training experience varied between 1.5 years in the children to 15 years in the adults. Bone speed of sound (SOS) was measured bilaterally at the distal radius and the mid-tibia. Body fat was significantly lower in athletes compared with C. AQ were generally heavier and had a higher fat-free mass compared with SC and C, with no significant differences in height between groups. Radial SOS increased with age, but no differences were observed between activity groups or between the dominant (D) and nondominant (ND) arm. Tibial SOS also increased with age. In the children and adolescents, no differences were observed between activity groups. However, among adults, both SC and AQ had higher tibial SOS compared with C. These differences were mainly explained by differences in fat-free mass. Among young adults but not among children and adolescent males, both soccer and aquatic sports appear to be associated with higher bone SOS in the lower, but not the upper, extremities. Further studies are needed to assess possible sport-specific mechanisms which affect bone properties and to determine the minimal cumulative effect which is needed to influence bone properties.

Identifying swimmers as water-polo or swim team-mates from visual displays of less than one second.
J Sports Sci. 2007 Sep;25(11):1251-8.
Steel KA, Adams RD, Canning CG.
School of Physiotherapy, The University of Sydney, Lidcombe, NSW, Australia.

Opportunities for ball passing in water-polo may be brief and the decision to pass only informed by minimal visual input. Since researchers using point light displays have shown that the walking or running gait of familiars can be identified, water-polo players may have the ability to recognize team-mates from their swimming gait. To test this hypothesis, members of a water-polo team and a competition swim team viewed two randomized sets of video clips, each less than one second long, of swimmers from both teams sprinting freestyle past a fixed camera. The arm stroke clip sequence showed only the upper body, and the kick sequence showed only the lower body. After viewing each video clip, observers rated their level of certainty as to whether the swimmer presented was a team-mate or not. Discrimination was significantly above chance in both groups. Water-polo players were better able to identify team-mates from their kick, whereas swimmers were better able to do so by viewing arm stroke. Our results suggest that, as with walking and running gait, small amounts of visual information about swimmers can be used for recognition, and so raise the possibility that specific training may be able to improve team-mate classification in water-polo, particularly in newly formed teams.

Drummer's fracture of the third metatarsal bone

Clin Nucl Med. 2007 Sep;32(9):737-8.
Cusi M, Tsung J, Nouh F, Wong L, Mansberg R, Van der Wall H.
Orthosports, Sydney, Australia.

A 14-year-old girl presented with a painful right foot. She was an elite water-polo player and could recall no history of specific trauma to the foot. On close and persistent questioning, she admitted to having taken up playing the drums recently, with practice sessions of up to 4 h/d. She used the foot drum with her right foot and had noticed that this was becoming increasingly painful and prevented her playing the instrument for the last 2 days. Plain films of the foot were originally reported as normal, but revised to abnormal after the scintigraphic study. Bone scintigraphy confirmed a stress fracture of the right 3rd metatarsal bone. Stress fractures of the 3rd metatarsal bone are rare with only 2 previous reports in the literature.

Shoulder pain in water polo: A systematic review of the literature.
J Sci Med Sport. 2007 Sep 20.
Webster MJ, Morris ME, Galna B.
School Physiotherapy, The University of Melbourne, Parkville, Australia.

The main aim of this systematic review is to synthesize and critically evaluate literature on the incidence and clinical presentation of shoulder pain in water polo. A secondary aim is to examine the contributing factors to shoulder pain in water polo. Medline, Cinahl, Embase, Ausport, Ovid, Sports Discus, Pubmed and Google Scholar data bases were electronically searched. Data were extracted regarding research design, injuries, pain, incidence, interventions and therapy outcomes. Of an initial yield of 23 papers, 11 fulfilled the inclusion criteria and were categorized into studies on incidence, shoulder pain, shoulder mobility, strength and throwing injuries. Methodological limitations included sampling and measurement biases, inadequate internal validity of measurement tools, poor specification of testing protocols and limitations in statistical analysis. The review found a high incidence of shoulder pain in water polo. Although there was limited evidence regarding causation, the repeated action of throwing was identified as a contributing factor to shoulder pain. Future studies need to explore the relative contributions of hyper-mobility and muscle strength imbalance to shoulder pain in water polo.

Physiological demands of water polo goalkeeping.
J Sci Med Sport. 2007 Dec 10
Platanou T.
Department of Aquatic Sports, Faculty of Physical Education and Sport Science, University of Athens, Greece.

The purpose of this study was to investigate the physiological demands of water polo goalkeepers during competition and to examine whether the playing intensity of the goalkeeper decreases as the game time progresses. During eight official games the following measurements were performed on eight elite water polo goalkeepers: (1) video analysis of activities, (2) monitoring of blood lactate (BLa) and (3) continuous recording of heart rate (HR) responses. Mean HR of total mixed playing time, excluding breaks among quarters, was 134.3+/-20.3bpm for 36 (4x9) min of game duration. The large portion of the game (85.6%) was performed with a HR lower than 151.4+/-2.7bpm (82.1+/-1.4% of HRpeak) an intensity corresponding to the players' anaerobic threshold (3.49+/-0.60mmolL(-1)). However, an important part of the game (14.4%) contained activities with sudden HR increases above the anaerobic threshold. Mean BLa accumulation at the end of each game period was 3.93+/-1.64mmolL(-1). Individual lactate values varied from 2.0 to 8.3mmolL(-1). Goalkeeper exercise intensity reached its peak value (152.5+/-10.1bpm) whenever his team competed with one player less due to player exclusion. No significant differences were found in HR, BLa and the percentage of time spent in each of the activity categories between game periods. In conclusion, goalkeeper's game can be described as of intermittent nature with great variability in the intensity performed. The greater part of the game is associated with a low aerobic demand while an important part of the game contains activities with sudden HR increases above the anaerobic threshold implying also a considerable demand on anaerobic metabolism. The intensity of exercise of the goalkeeper does not differ from period to period.