Common Variants in MAGI2 Gene Are Associated with Increased Risk for Cognitive Impairment in Schizophrenic Patients

Schizophrenia is a complex psychiatric disorder characterized by positive symptoms, negative symptoms, and cognitive impairment. MAGI2, a relatively large gene (∼1.5 Mbps) that maps to chromosome 7q21, is involved in recruitment of neurotransmitter receptors such as AMPA- and NMDA-type glutamate receptors. A genetic association study designed to evaluate the association between MAGI2 and cognitive performance or schizophrenia has not been conducted. In this case-control study, we examined the relationship of single nucleotide polymorphism (SNP) variations in MAGI2 and risk for schizophrenia in a large Japanese sample and explored the potential relationships between variations in MAGI2 and aspects of human cognitive function related to glutamate activity. Based on the result of first schizophrenia genome-wide association study in a Japanese population (JGWAS), we selected four independent SNPs and performed an association study using a large independent Japanese sample set (cases 1624, controls 1621). Wisconsin Card Sorting Test (WCST) was used to evaluate executive function in 114 cases and 91 controls. We found suggestive evidence for genetic association of common SNPs within MAGI2 locus and schizophrenia in Japanese population. Furthermore in terms of association between MAGI2 and cognitive performance, we observed that genotype effect of rs2190665 on WCST score was significant (p = 0.034) and rs4729938 trended toward significance (p = 0.08). In conclusion, although we could not detect strong genetic evidence for association of common variants in MAGI2 and increased schizophrenia risk in a Japanese population, these SNPs may increase risk of cognitive impairment in schizophrenic patients

Der Aufschlag im Nachwuchsleistungstennis

Das Ziel dieser Dissertation war 1) eine differenzierte Identifikation von leistungsbestimmenden Prädiktoren des Tennisaufschlags 2) eine vertiefte kinematische Betrachtung von Qualitätsmerkmalen der Aufschlagtechnik sowie 3) die Erfassung leistungslimitierender Faktoren und Verletzungsprävalenzen für die am Tennisaufschlag primär beteiligten Strukturen des aktiven und passiven Bewegungsapparats vorzunehmen. Die Ergebnisse zeigten, dass hinsichtlich physischer und anthropometrischer Leistungsfaktoren die Kraft und Power der oberen Extremität sowie die Körpergröße und das -gewicht bedeutende Prädiktoren der Aufschlaggeschwindigkeit darstellten. Hinsichtlich der kinematischen Betrachtung der Aufschlagtechnik zeigten die Ergebnisse, dass sowohl zahlreiche kinematisch differierende Bewegungsmerkmale als auch eine differierende Ballkinematik zwischen den Aufschlagseiten identifiziert werden konnten. Weiter wurden mittlere bis hohe Verletzungsprävalenzen bei den Spieler*innen festgestellt

Kinematic characteristics of the tennis serve from the ad and deuce court service positions in elite junior players

$\bf Purpose$ According to the official rules of the International Tennis Federation, players have to serve alternately from two different positions: the deuce (right, D) and the ad court (left, AD) side. This study aimed to compare body and ball kinematics of flat serves from both service sides. $\bf Methods$ In a controlled, semi-court laboratory setting, 14 elite male junior players served eight flat first serves to a target field directed to the receiver’s body from both service positions in a matched and counterbalanced order. An 8-camera-Vicon-System was used to capture the 3D-landmark trajectories. $\bf Results$ The mean service velocity was found to be similar on both sides (D: 151.4 $\pm$ 19.8 vs. AD: 150.5 $\pm$ 19.4 km/h), while multiple characteristics of the serve and ball kinematics differed significantly (p < .05). At starting, the front-foot angle relative to the baseline (D: 39.7$\pm$17.6° vs. AD: 31.1$\pm$17.4°) and lateral distance between the feet (D: 16.3 $\pm$ 12.9 cm vs. AD: 26.2 $\pm$ 11.9 cm) were significantly different. During the service, upper torso range of motion from maximum clockwise rotation until impact was significantly greater on the deuce court (D: 130.5 $\pm$ 19.8° vs. AD: 126.7 $\pm$ 21.1°). This was especially pronounced in foot-back technique players. Further, differences in the lateral ball impact location (D: 30.0 $\pm$ 24.1 cm vs. AD: 10.3 $\pm$ 23.3 cm) were observed. $\bf Conclusions$ Changing the service side affects the serve and ball kinematics in elite junior tennis players. Our results underline biomechanical differences regarding the starting position (feet and upper torso) as well as the movement and ball kinematics which could be relevant for skill acquisition, injury prevention and performance enhancement

Back pain in elite sports

$\bf Objectives$ To establish the prevalence of back pain in German elite athletes; examine the influence of age, sex, sports discipline and training volume; and compare elite athletes with a physically active control group. $\bf Methods$ A standardized and validated online back pain questionnaire was sent by the German Olympic Sports Confederation to approximately 4,000 German national and international elite athletes, and a control group of 253 physically active but non-elite sports students. $\bf Results$ We received responses from 1,114 elite athletes (46.5% male and 53.1% female, mean age 20.9 years $\pm$ 4.8 years, mean height 176.5 $\pm$ 11.5 cm, mean weight 71.0 $\pm$ 10.3 kg) and 166 physically active sports students (74.7% male and 24.1 female, mean age 21.2 $\pm$ 2.0 years, mean height 180.0 $\pm$ 8.0 cm, mean weight 74.0 $\pm$ 14.5 kg). In elite athletes, the lifetime prevalence of back pain was 88.5%, the 12-month prevalence was 81.1%, the 3-month prevalence was 68.3% and the point prevalence was 49.0%, compared with 80.7%, 69.9%, 59.0% and 42.8%, respectively in the control group. The lifetime, 12-month and 3-month prevalences in elite athletes were significantly higher than in the control group. Regarding the individual sports disciplines, the prevalence of back pain was significantly higher in elite rowers, dancers, fencers, gymnasts, track and field athletes, figure skaters and marksmen, and those who play underwater rugby, water polo, basketball, hockey and ice hockey compared with the control group. The prevalence of back pain was significantly lower in elite triathletes. $\bf Conclusions$ Back pain is a common complaint in German elite athletes. Low back pain seems to be a problem in both elite athletes and physically active controls. A high training volume in elite athletes and a low training volume in physically active individuals might increase prevalence rates. Our findings indicate the necessity for specific prevention programs, especially in high-risk sports. Further research should investigate the optimal dose-effect relationship of sporting activity for the general population to prevent back pain

Prevalence of back pain in a group of elite athletes exposed to repetitive overhead activity

$\bf Background$ The prevalence of back pain in athletes has been investigated in several studies, but there are still under- or uninvestigated sports discipline like sports exposed to repetitive overhead activity. Elite athletes spend much time in training and competition and, because of the nature of their disciplines, subject their bodies to a great deal of mechanical strain, which puts a high level of stress on their musculoskeletal systems. From this it is hypothesized that elite athletes who engage in repetitive overhead motions experience a higher strain on their spine and thus possibly a higher prevalence of back pain compared with an active control group. $\bf Objectives$ To examine the prevalence of back pain and the exact location of pain in a cohort of elite athletes with repetitive overhead activity and in a control group of physically active sport students. Additionally, to examine different characteristics of pain, and to evaluate the influence of confounders on back pain. $\bf Methods$ A standardized and validated online back pain questionnaire was sent by the German Olympic Sports Confederation to German national and international elite athletes, and a control group of physically active but non-elite sports students. $\bf Results$ The final sample comprised 181 elite athletes of the sports disciplines badminton, beach volleyball, handball, tennis and volleyball and 166 physically active controls. In elite athletes, lifetime prevalence of back pain was 85%, 12-month prevalence was 75%, 3-month prevalence was 58% and point prevalence was 38%; for the physically active control group, these prevalences were 81%, 70%, 59% and 43%, respectively. There was no significant group difference in prevalence over all time periods. The lower back was the main location of back pain in elite athletes across all disciplines and in controls; additionally a distinct problem of upper back pain was found among volleyball players. $\bf Conclusion$ Despite the high mechanical load inherent in the sport disciplines included in this study, the elite athletes who engaged in repetitive overhead activities did not suffer more from back pain than the physically active controls. This suggests that other mechanisms may be influencing back pain prevalences in a positive way in these athletes. Furthermore, these disciplines may practice preventive factors for back pain that outweigh their detrimental factors. Therefore, we posit that extensive prevention work is already being implemented in these sports and that there are additional individual protection factors in play. More research is required to explore these suppositions, and should include investigations into which preventive training programs are being used. Nevertheless, in volleyball particularly, a focus on stabilization/preventive training should be applied to the upper back and neck

Prävalenz von Rückenschmerzen bei Elitesportlern

$\bf Objectives:$ The primary objectives of this investigation were to provide an overview of data about back pain prevalence in athletes, to analyse the prevalence in the German elite athletic population, and to compare it with physically-active individuals. $\bf Methods:$ 1. A comprehensive analysis of the literature was undertaken, using specifically developed search strategies for relevant epidemiological research on back pain. 2. An online back pain questionnaire was sent to approximately 4,000 German elite athletes and a control group of 253 physically-activeindividuals. $\bf Results:$ Lifetime and point prevalence were the most commonly researched episodes and the lower back was the most common location of pain. Lifetime prevalence of low back pain in athletes was 1-94%, and point prevalence was 18-65%. In German elite athletes,prevalence rates were 77% and 34%, respectively, and were slightly higher in athletes than inactive controls (71% and 29%, respectively) and the general population (11-84% and 7-33%, respectively). Prevalence of back pain varied between athletes of different disciplines. $\bf Conclusion:$ Back pain is a common complaint in athletes and in the general population. A high training volume in athletes and a low training volume in the general population might increase prevalence rates. Our findings indicate the necessity for specific prevention programs, especially in high-risk sports. Further research should investigate the optimal dose-effect relationship of sporting activity to prevent back pain.$\bf Ziele:$ Hauptziel dieser Untersuchung war es, eine Übersicht zur Rückenschmerzprävalenz von Sportler*innen zu erstellen, die Prävalenz in der deutschen Leistungssportelite zu analysieren und diese mit körperlich aktiven Personen zu vergleichen. $\bf Methodik:$ 1. Es wurde eine umfassende Literaturanalyse mit speziell entwickelten Suchstrategien für relevante epidemiologische Rückenschmerzforschung durchgeführt. 2. Ein Online-Rückenschmerzfragebogen wurde an ca. 4000 deutsche Leistungssportler*innen und eine Kontrollgruppe von 253 körperlich aktiven Personen verschickt. $\bf Ergebnisse:$ In der internationalen Literatur waren Lebenszeit- und Punktprävalenz die am häufigsten untersuchten Episoden und der untere Rücken war die häufigste Lokalisation für Schmerzen. Die Lebenszeitprävalenz von Rückenschmerzen bei Sportler*innen betrug 1-94% und die Punktprävalenz betrug 18-65%. Bei deutschen Spitzensportler*innen lagen die Prävalenzen bei 77% bzw. 34% und waren höher im Vergleich zur aktiven Kontrollgruppe (71% bzw. 29%) und der Allgemeinbevölkerung (11-84% und 7-33%). Die Prävalenz von Rückenschmerzen variierte zwischen Sportler*innen verschiedener Disziplinen. $\bf Schlussfolgerung:$ Rückenschmerzen sind ein häufiges gesundheitliches Problem bei Sportler*innen und in der Allgemeinbevölkerung. Ein hohes Trainingsvolumen bei Sportler*innen und ein niedriges Trainingsvolumen in der Allgemeinbevölkerung könnten die Prävalenzraten erhöhen. Die vorliegenden Ergebnisse weisen auf die Notwendigkeit spezifischer Präventionsprogramme hin, insbesondere in risikoreichen Sportarten. Weitere Forschung sollte die optimale Dosis-Wirkungs-Beziehung sportlicher Aktivität untersuchen, um Rückenschmerzen zu verhindern