Return to sport after conservative treatment of elbow dislocation in judoka.

BACKGROUND: Injuries to the elbow are frequent in judo combat, but studies on down-time and effect on performance after conservative treatments are rare. This issue is particularly relevant for elbow dislocations in high-performance patients such as elite athletes. The purpose of this study was to evaluate (1) time-loss and (2) the regained level of performance in judoka after conservative treatment of simple elbow dislocation. METHODS: In cooperation with the European Judo Union, judoka were asked to complete a 139-item survey regarding elbow injuries they suffered during their career. Besides demographics, injury data, diagnosis and treatment options, the athletes were asked about down-time and reductions in performance level. This study enrolled 108 judoka with conservative treatment of elbow dislocation out of a population of 5426 volunteers. RESULTS: 69% (n=74) reported a time-loss of less than three months; 6% reported a time-loss of more than six months. The majority (68%, n=73) reported that they had returned to their previous performance level, while 22% (n=24) suffered from a slightly reduced level of performance. In the subgroup of international and national athletes (n=54), 63% returned to judo after less than three months, with 72% achieving the same level and 15% reporting a slightly reduced performance level. Level of performance and time lost after conservative treatment for elbow dislocations were comparable for male and female judoka. CONCLUSION: Approximately two out of three judoka returned to the same level of performance after three months of down-time after undergoing conservative therapy for simple elbow dislocations. Despite the high performance level of the study population, conservative treatment of simple elbow dislocation resulted in satisfactory outcomes. The presented data can guide medical professionals and competitive-level contact-sport athletes with respect to expectations in the process of returning to sport.

Scale-Up to Pilot of a Non-Axenic Culture of Thraustochytrids Using Digestate from Methanization as Nitrogen Source.

The production of non-fish based docosahexaenoic acid (DHA) for feed and food has become a critical need in our global context of over-fishing. The industrial-scale production of DHA-rich Thraustochytrids could be an alternative, if costs turned out to be competitive. In order to reduce production costs, this study addresses the feasibility of the non-axenic (non-sterile) cultivation of Aurantiochytrium mangrovei on industrial substrates (as nitrogen and mineral sources and glucose syrup as carbon and energy sources), and its scale-up from laboratory (250 mL) to 500 L cultures. Pilot-scale reactors were airlift cylinders. Batch and fed-batch cultures were tested. Cultures over 38 to 62 h achieved a dry cell weight productivity of 3.3 to 5.5 g.L-1.day-1, and a substrate to biomass yield of up to 0.3. DHA productivity ranged from 10 to 0.18 mg.L-1.day-1. Biomass productivity appears linearly related to oxygen transfer rate. Bacterial contamination of cultures was low enough to avoid impacts on fatty acid composition of the biomass. A specific work on microbial risks assessment (in supplementary files) showed that the biomass can be securely used as feed. However, to date, there is a law void in EU legislation regarding the recycling of nitrogen from digestate from animal waste for microalgae biomass and its usage in animal feed. Overall, the proposed process appears similar to the industrial yeast production process (non-axenic heterotrophic process, dissolved oxygen supply limiting growth, similar cell size). Such similarity could help in further industrial developments.

Modified defense reaction reduces biomechanical and myoelectrical ACL injury risk factors in elite Judo.

In judo, an anterior cruciate ligament (ACL) injury is the most severe injury an athlete could experience. Most ACL ruptures occur when defending against an osoto-gari attack. This study aims to identify ACL risk factors during osoto-gari defence and implement a modified osoto-gari defence reaction, which is assumed to improve myoelectric patterns and ameliorate critical biomechanical risk factors for ACL injuries. Twenty-six elite judokas were enrolled in the cross-over trial (female: 6; male: 20). 3D kinematics and force dynamometrics were combined with electromyographical recordings to assess the effects of the common and the modified osoto-gari defence reaction. Compared to the common osoto-gari defence reaction (maximal knee flexion: 29 ± 12°; maximal valgus: 10 ± 5°; maximal valgus moment: 58 ± 17 Nm; peak internal rotation: 9 ± 5°), the modified osoto-gari defence reaction showed significantly reduced knee angles (31 ± 10° p < 0.05; 1 ± 0° p < 0.05; 31 ± 9 Nm p < 0.05; 3 ± 0° p < 0.05). The myoelectric activity of the hamstring increased (+5±% to +27±%, p < 0.05) in the modified compared to common defence reaction. The modified osoto-gari defence reaction reduced critical biomechanical risk factors and increased hamstring myoelectric activity. We recommend the implementation of the modified osoto-gari defence reaction in judo practice and seek to evaluate its long-term effectiveness in decreasing ACL injury incidences in elite judo.

Prevalence of sport injuries in Olympic combat sports: a cross-sectional study examining one Olympic period.

BACKGROUND: Due to full contact impacts in combat sports, the risk of injuries is elevated. The aim of this study is to report severe injuries among athletes in Olympic combat sports. Specific injury types, time loss, and the performance level after injury are examined. METHODS: Survey to investigate injuries in Olympic combat sports during the time period from 2012-2016. Reported injuries were analyzed by anatomical location, injury type, gender, time loss, and performance level. RESULTS: The three injuries resulting in the longest time loss (ACL rupture: judo= 37 weeks; karate = 49 weeks; shoulder dislocation: wrestling = 41 weeks; shoulder rotator cuff injury: wrestling = 32 weeks) also accounted for the largest proportion of athletes with career-ending injuries (ACL rupture: judo = 28%; karate = 67%; shoulder dislocation: wrestling = 40%; shoulder rotator cuff injury: wrestling = 50%). Taekwondo and fencing had the shortest time loss (<12 weeks) among all combat sports. More injuries occurred during training (58%) as compared to competition (42%). Injury prevalence of competitive athletes was significantly higher as compared to recreational athletes. Male athletes suffered significantly more anterior cruciate ligament injuries (72% vs. 56%; P<0.05), unspecific shoulder injuries (89% vs. 47%; P<0.01), and elbow ligament injuries (57% vs. 30%; P<0.05) during training. CONCLUSIONS: The study shows that there are important differences between "punching and kicking" and "throwing" martial arts in terms of specific injury types. In judo and wrestling, the injuries are more likely to affect the joints (knee and shoulder). Therefore, injury prevention these sports should focus on strength training of the muscles surrounding the joints and on defensive reactionary movements to avoid dangerous biomechanical joint angles. In "punching and kicking" sports, injuries of the hands and feet, due to the large impact forces of strikes and kicks, could be reduced by improved protective equipment on hands and feet.

Development of a modified cross-over hop test to reduce measurement errors in return-to-competition testing.

CONTEXT: Hop tests play an important role in the rehabilitation process after injuries. A comparison of the jumping distances of both extremities allows for an evaluation of the injured limb. In the conventional cross-over hop test for distance, the jump width (medial vs. lateral) that the athlete has to cross during the jump is not standardised and therefore highly variable. This affects the absolute jump length in each jump series. HYPOTHESIS: Modifying the test may reduce the jump length variance between test series of an athlete as well as the test-dependent variations in the cross-over hop for distance. METHODS: N = 47 athletes from the German and French national Judo youth teams were included in the study (age: 15.3 years ±â€Š13-17). A modified version of the cross-over hop for distance was developed with a cross-over width of 50 cm and a fixed landing zone of 10 cm. The jump lengths of the conventional test and the modified test were documented. The change in jump length variations of the two sexes were compared. RESULTS: The mean value of the coefficient of variation decreased significantly from 4.09 % to 2.83 % (p < 0.01) due to the test modification. This resulted in an absolute improvement in accuracy of 1.26 % and a relative improvement of 30.8 %. A comparison of the limb symmetry index between the conventional and the modified cross-over hop for distance revealed no significant differences. CONCLUSION: The modified cross-over hop for distance showed a significantly lower variation in jump lengths compared with the conventional cross-over hop for distance. As a result, more accurate statements can be made regarding the patient's return-to-competition progress.

Return to competition after anterior cruciate ligament injuries in world class judoka.

OBJECTIVES: The purpose of this study was to quantify how the return to competition after an anterior cruciate ligament rupture in Judo is perceived by athletes as compared to doctors and physiotherapists. Is there a difference between the perspectives of doctors and physiotherapists and athletes regarding surgery, time loss due to injury, or the level of performance after the injury? Which functional tests are used to define when or if athletes are ready for the return to competition? METHODS: A survey-based retrospective study design with two surveys regarding the treatment methods of an anterior cruciate ligament rupture was established: one version for athletes and one for doctors and physiotherapists. Surveys were equivalent for both populations despite the athletes' individual data. Variance analysis was applied to assess if statistically meaningful differences exist between the two groups. RESULTS: From 232 judoka interviewed during the Junior World Judo Championships 2017, 23 suffered an anterior cruciate ligament rupture in the last 2 years. As high as 52% underwent surgery. According to doctors and physiotherapists, 82% of athletes underwent reconstructive surgeries. Athletes returned to competition after 5.5 months, whereas doctors and physiotherapists assumed a time loss of 8.4 months. Only 44% of the doctors and physiotherapists used functional tests like hop tests for defining return to competition and 22% used mental tests. When asking athletes, the use of hop tests (8%) and mental tests (0%) was even lower. CONCLUSION: The study demonstrated for the first time significant discrepancies between the medical treatment regarding the recommendations of doctors and physiotherapists compared to athletes behavior. To support a conclusive statement, we should encourage the doctors and physiotherapists to use functional test batteries for the decision-making process regarding return to competition.

Side Differences Regarding the Limb Symmetry Index in Healthy Professional Athletes.

Side differences in the limb symmetry index during hop tests have been rarely investigated in uninjured athletes. Unknown differences can result in false interpretation of hop tests and affect return to sport decision. Hypothesis was that un-injured athletes in Judo and Taekwondo have side differences in hop test and that asymmetries can be predicted based on the athletes fighting display. Differences, risk relationships were analyzed using the chi-squared test and the odds ratio. A two-tailed p value of<0.05 was considered statistically significant. 115 athletes from the national teams were included (mean age 18.4 years; range 13-27 years). 93, 97.4 and 98.3% did not have symmetric hop distance for three hop tests. Up to a quarter did not reach a limb symmetry index of>90. Moreover, 57.4% (n=66) reached longer jumping distance with the standing leg. Ignoring such pre-existent side differences in evaluation of hop tests and not knowing which limb was dominant prior the injury, can lead to premature or delayed return to sports in the rehabilitation process. Therefore, it might be helpful to refer to individual jump lengths for each limb in case of injury by using hop tests in pre-season screening in professional athletes in Judo and Taekwondo.

Epidemiology of injuries in judo: a cross-sectional survey of severe injuries based on time loss and reduction in sporting level.

BACKGROUND: Sport injury severity can be detected by duration of time loss and reduction of sporting performance. AIM: To detect injury type-specific time loss duration and sporting performance reduction in judo. METHODS: An online survey of active and former judo athletes was conducted (exclusion criterion: incomplete questionnaire). Only injuries causing more than 3 weeks' time loss were recorded. Athletes classified themselves into performance classes. Injury type-specific frequencies were recorded according to gender, age and performance level. Injury severity was assessed by time loss duration and performance reduction. RESULTS: The study included 4659 athletes (65% male, 38% competitive sports). The most commonly injured body regions were the upper extremity (41%) and the lower extremity (39%). Anterior cruciate ligament (ACL) ruptures were the most severe injury type (time loss: 4% of cases 3-6 weeks, 6% 6-12 weeks, 26% 3-6 months, 32% 6-9 months, 18% 9-12 months, 14%>12 months; performance reduction: 32% same level, 39% slightly reduced, 24% strongly reduced, 5% stopped judo). The second most severe type of injury was a vertebral disc prolapse (time loss: 26% 3-6 weeks, 31% 6-12 weeks, 20% 3-6 months, 7% 6-9 months, 3% 9-12 months 13%>12 months; reduction of sporting performance: 39% same level, 34% slightly reduced, 20% strongly reduced, 8% stopped judo). CONCLUSION: Across genders and performance levels, ACL ruptures and vertebral disc prolapses were the most severe injuries with respect to time loss and sporting performance reduction.

Impact of 20:4n-6 supplementation on the fatty acid composition and hemocyte parameters of the Pacific oyster Crassostrea gigas.

Arachidonic acid (20:4n-6, ArA) and its eicosanoid metabolites have been demonstrated to be implicated in immune functions of vertebrates, fish, and insects. Thus, the aim of this study was to assess the impact of ArA supplementation on the FA composition and hemocyte parameters of oysters Crassostrea gigas. Oyster dietary conditioning consisted of direct addition of ArA solutions at a dose of 0, 0.25, or 0.41 microg ArA per mL of seawater into tanks in the presence or absence of T-Iso algae. Results showed significant incorporation of ArA into gill polar lipids when administered with algae (up to 19.7%) or without algae (up to 12.1%). ArA supplementation led to an increase in hemocyte numbers, phagocytosis, and production of reactive oxygen species by hemocytes from ArA-supplemented oysters. Moreover, the inhibitory effect of Vibrio aestuarianus extracellular products on the adhesive proprieties of hemocytes was lessened in oysters fed ArA-supplemented T-Iso. All changes in oyster hemocyte parameters reported in the present study suggest that ArA and/or eicosanoid metabolites affect oyster hemocyte functions.