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

An Assessment of Existing Sport-Related Concussion Guidelines in Ireland: The Need for a United Approach

In 2014, an Irish parliament white paper called for greater addressing of sport-related concussions (SRCs) in Ireland, requesting the adoption of the Concussion in Sport Group's (CISGs) guidelines and greater consistency in SRC return to play (RTP) management. Ten years later, it is unclear how these requests have been addressed. Recently, the United Kingdom's government centralised guidelines to one SRC document for all grassroots sports. This study aimed to investigate all publicly available SRC guidance in Irish sports and national governing bodies (NGBs) to determine if centralised guidelines are warranted. Sport Ireland and the Irish Federation of Sports were searched for all recognised NGBs and sports in Ireland. Websites were searched for any information pertaining to SRCs and data were extracted and collated in Microsoft Excel. In total, 15 of 83 sports and/or NGBs included SRC guidance, nine of which provided RTP protocols. Various iterations of the CISGs guidance and tools were implemented. Several sports with a documented SRC risk had no guidelines present. The findings indicate disjointed and outdated guidance across Irish sport. Additionally, there are sports with a documented concussion risk that have no SRC guidance available. This study provides support for centralised guidelines to be adopted in Irish grassroots sports.

Effects of transcranial direct current stimulation and sensorimotor training in anterior cruciate ligament patients: a sham-controlled pilot study

BACKGROUND

Studies showed changes in the central nervous system in patients who sustained an anterior cruciate ligament tear. There is a lack of evidence regarding the effectiveness of transcranial direct-current stimulation in such patients.

METHODS

A sham-controlled randomised study. One group of patients (n = 6) underwent 6 weeks of sensorimotor training after an anterior cruciate ligament tear during transcranial direct-current stimulation. The stimulation consisted of 20 minutes (3 sessions/week; 2 weeks) of 2 mA anodal transcranial direct-current stimulation over the primary motor and premotor cortex. The second group (n = 6) received sham stimulation with 6 weeks of sensorimotor training. Centre of pressure deviations in the medio-lateral and anterior-posterior direction and centre of pressure velocity were measured.

RESULTS

The results demonstrated a significant effect of sensorimotor training on the centre of pressure in medio-lateral and anterior-posterior direction (p=0.025) (p=0.03) in the leg in which an anterior cruciate ligament tear occurred. The type of training did not affect the results. Post-hoc tests showed no significant effect of training in the subgroups (p≥0.115).

CONCLUSION

Sensorimotor training led to a decrease in sway of the centre of pressure in patients who sustained an anterior cruciate ligament tear, but the addition of anodal transcranial direct-current stimulation placed over the primary motor cortex did not potentiate the adaptive responses of the sensorimotor training.

Injury Risk Analysis among Judo Athletes with Intellectual Disabilities

The main aim of this study was to evaluate injury prevalence, incidence rate, and burden in judo athletes with intellectual disabilities (ID) who participate in international competitions. This retrospective cross-sectional study analyzed data from the past year for 182 judo athletes with ID. Data was collected using a self-reported questionnaire, adapted from previous research, that included questions about injuries impacting training or competition, injury type, mechanism, severity, diagnosis, and location on the body. The injury prevalence among judo athletes with ID occurred most often during training (68.2%) and primarily affected the lower extremities (35%). Age group and injury prevalence were significantly related (χ2=7.91; P=0.04), while gender, weight, and ability level were not. Results were closer to those previously reported for conventional judo, which is likely due to the lower practice intensity among judo athletes with ID. Injury prevalence was lower than in prior studies, but the incidence rates aligned when considering training time in judo athletes with ID. Injury burden analysis revealed that females had a lower burden than males, while older athletes experienced a higher burden than younger athletes. Most injuries occur during training, which is likely attributable to safety-focused competition rules.

Direct contact and very rapid valgus distortion characterise the injury mechanism of anterior cruciate ligament ruptures in judo

PURPOSE

To analyse anterior cruciate ligament (ACL) rupture (ACLR) injury mechanisms in competitive judo using systematic video analysis, focusing on contact situations and biomechanics.

METHODS

Seventeen videos of judo competitions wherein athletes developed ACLRs were included and retrospectively evaluated by five analysts. In all videos, the moment of initial contact and the index frame were defined. The judo techniques leading to the injury; the occurrence of direct contact, indirect contact or noncontact mechanisms; the time interval between the initial contact and index frame; the positions of the hip, knee and foot in relation to the initial contact and index frame; and the balance status during the initial contact and index frame were recorded.

RESULTS

Eleven (65%) of ACLRs in judo involved direct contact. The mean time interval between initial contact and index frame was 15 ± 22 ms. Thirteen (77%) athletes were not balanced at initial contact. In the index frame, the hip was abducted in all cases and in combination with internal rotation in 12 (71%) cases. From initial contact to index frame, hip flexion increased in all cases; at index frame, the knee joint was internally rotated relative to the trunk in 12 (71%) cases, and the knee flexion angles increased from the initial contact. In the index frame, the foot was externally rotated relative to the knee in 12 (71%) cases, and severe valgus development of the knee with valgus collapse was observed in 14 (82%) cases.

CONCLUSIONS

A direct attack on the knee was the most common injury mechanism observed. Valgus distortion appears to be the most important component of the mechanism of injury. With this knowledge, 'modified defence reactions' for specific judo techniques can be developed to reduce the injury risk.

LEVEL OF EVIDENCE

Level IV.

Martial Arts: Orthopaedic Injuries and Related Biomechanics

Martial arts are various systems of combat skills encompassing striking and grappling. Many styles have evolved into modern sports, and some have been included in the Olympics. The physicality of these can predispose practitioners to musculoskeletal injuries, such as anterior cruciate ligament ruptures; patellar, shoulder, or elbow instabilities; extremity fractures; and hand and spine injuries, which have been studied both clinically and biomechanically. The most common injury related to longer time loss from participation is an anterior cruciate ligament rupture. Higher injury incidence is associated with a higher level of experience and competition. Orthopaedic management of martial arts injuries should reflect the specific needs of each martial artist and the biomechanics of motions common to each style. Full-contact practitioners may benefit from broader surgical indications and special attention to the choice and positioning of implants; nonsurgical treatment may be appropriate for certain pediatric or noncontact practitioners. Approximately 60% of martial artists can return to the preinjury level of participation after a major injury. Injury prevention and rehabilitation programs should optimize neuromotor control and core engagement to ensure proper body mechanics. Gradual incorporation of martial arts movement into the postoperative physical therapy curriculum can benefit physical progress and help gain confidence toward full participation.

Prevalence of cauliflower ear in high level judoka

Judo is an Olympic sport, and the way of its performing can lead to repetitive blunt injuries on head and ears. The chronic consequences of such traumata on the auricle are the formation of so-called cauliflower ear. This condition is painful, can lead to interruptions in the training process and long-term consequences for the athlete's health. There is limited knowledge of epidemiological data about cauliflower ear deformities in judo. Evaluation of the prevalence of cauliflower ear among judokas based on their profile pictures on the international judo federation was performed. A large cohort of judo athletes from around the world was studied. Two different classifications for the severity of ear deformities were used. Statistical calculations of the collected data and correlations to different parameters were performed. Images of 1632 top athletes were evaluated in the study. Ear deformities were found in 55.5% of the judokas. There was gender-specific differences. Male athletes were affected much more often than female athletes. In addition, ear deformities were more pronounced in male athletes. A correlation was found between the age of the athletes and the presence of an ear deformity. It has also been shown that judokas with a high world ranking are more likely to have an ear deformity. Ear deformities are a common consequence of injury among leading judo athletes. The current study represents the largest and high heterogeny cohort ever conducted on the prevalence of cauliflower ear in judoka. Knowledge of the prevalence of cauliflower ear in judoka based on reliable data from this study, may be important prerequisites for further studies on the impact of this traumatic consequence on training preparation and judoka health.

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.

Incidence of anterior cruciate ligament injury patterns in Japanese judo players from a nationwide insurance database

Objective

This study aimed to characterize the age- and sex-specific Anterior cruciate ligament (ACL) injury rates and related injury patterns in judo players in Japan using the nationwide insurance database.

Methods

This was a descriptive epidemiological study. We examined a total of 2142 adolescents with anterior cruciate ligament injuries registered in the insurance system of the Japan Sports Council between January 2009 and December 2018. The age- and sex-specific incidences were estimated for the levels of 7th, 8th, and 9th grades of junior high school and 10th, 11th, and 12th grades of high school. The anterior cruciate ligament injury circumstances were classified into three patterns based on the impact to the involved knee: high-impact valgus force, low-impact trunk displacement, or no-impact knee twisting.

Results

The incidence of anterior cruciate ligament injury from the 7th to 12th grades were 0.5, 0.9, 0.9, 6.9, 8.6, and 6.1 per 1000 athlete-years in male players and 1.3, 3.8, 3.4, 16.8, 19.5, and 13.6 per 1000 athlete-years in female players. The most prevalent injury pattern was a low-impact contact injury (42.6%) with Osoto-gari, followed by a high-impact contact injury (29.8%). The concomitant medial collateral ligament (MCL) injury rate was 18.1%, which was correlated with a high-impact contact injury (p = 0.005) by multiple regression analysis.

Conclusions

The highest incidence of age- and sex-specific anterior cruciate ligament injury was 19.5 per 1000 athlete-years in female high school students in the 11th grade. The most frequent injury pattern was low-impact contact injury with trunk displacement, indicating that trunk stabilization training could help prevent anterior cruciate ligament injury in judo.

Epidemiology of Injuries during Judo Tournaments

Objective

To determine the injury incidence proportion, distribution of injuries by anatomical location; injury type; injury severity, time loss; mechanism and situations of injuries; and the relative risk of injuries by gender, age, and weight categories during judo tournaments. Study Design. It is a systematic review. Data Sources. A systematic review of the literature was conducted via searches in PubMed, EMBASE, Web of Science, CINAHL, SPORTDiscus, Google Scholar, and PEDro. Eligibility Criteria. All original studies on the incidence of injuries during judo tournaments were included.

Results

Twenty-five studies were included out of the 1979 studies. Using the modified AXIS tool score for quality assessment, seven were rated as having good quality, nine were rated as having fair quality, and four were rated as having poor quality. The injury incidence proportion during tournaments ranged from 2.5% to 72.5% for injuries requiring medical evaluation and 1.1% to 4.1% for injuries causing time loss (i.e., inability to continue game participation). The most commonly reported injury location was the head, followed by the hand, knee, elbow, and shoulder. The most frequent types of injury were sprains, followed by contusions, skin lacerations, strains, and fractures. In judo tournaments, injuries were more often sustained during standing fights (tachi-waza) than in ground fights (ne-waza).

Conclusion

The tournament injury incidence proportion ranged from 2.5% to 72.5% for injuries requiring medical attention and 1.1% to 4.1% for injuries causing time loss. The head was the most frequently injured body part, and sprain was the most frequent injury type. However, current reports on injuries during judo tournaments are heterogeneous and inconsistent, limiting our understanding of in-match injury risks. Future studies should utilize the guidelines of the International Olympic Committee consensus meeting statement on the methodological approach to injury reporting. We recommend a judo-specific extension of this statement to fit the unique features of judo sports practice.

Psychological readiness is related to return to sport in judo injuries: a cross-sectional study

BACKGROUND

The aim of this study is to investigate the influence of a judoka's psychological readiness in relation to his ability to return to sport. At the present time, the relationship between physical and psychological readiness to return to sport has not been adequately elucidated.

METHODS

This is a cross-sectional study. An online survey was distributed via social networks and the German Judo Association collecting data from competitive and recreational judo athletes. The survey collected data on participants' characteristics, history of injury, and psychological readiness to return to sport after injury as determined by either the Anterior Cruciate Ligament-Return to Sport after Injury Scale, the Shoulder Instability-Return to Sport after Injury Scale, or a modified version of the Return to Sport after Injury Scale depending on the respective type of injury.

RESULTS

The study included 383 judo athletes (272 competitive judo athletes and 112 recreational judo athletes). Regardless of injury location, athletes who achieved return to sports (M = 70.67; SD = 16.47) had higher RSI scores than athletes that did not return to sports (M = 53.88; SD = 19.12; p < 0.0001). Male athletes (M = 65.60; SD = 19.34) did show significantly higher RSI scores than female athletes (M = 60.45; SD = 19.46). The RSI score differed for different time loss categories, F(7, 375) = 11.309, p < 0.001, η² = .174 with decreasing RSI scores for longer time loss and lowest RSI scores in athletes, who never returned to sports. RSI scores of athletes with knee injuries differed from athletes with other injury locations (10.23, 95% CI [4.08, 16.38]). After adjusting for time loss due to injury, competitive athletes had higher RSI scores than competitive athletes (F (1, 382) = 7.250, p < 0.001, partial η² = .02). Conservatively treated athletes (M = 66.58; SD = 18.54) had higher RSI scores than surgically treated athletes (M = 59.05; SD = 20.01; p < 0.05).

CONCLUSION

Based on the data of this study, type of injury, sport level, treatment method, and gender appear to influence psychological readiness on judoka and their ability to return to sport. The multiple factors that influence a judoka and their ability to return to sport argue for individualized treatment of judoka and their psychological state after injury in the return to sport process.

Effectiveness of a judo-specific injury prevention programme: a randomised controlled trial in recreational judo athletes

OBJECTIVES

To evaluate the effectiveness of a trainer-supervised judo-specific injury prevention warm-up programme on overall injury prevalence.

METHODS

We conducted a two-arm, cluster randomised controlled trial; the Injury Prevention and Performance Optimization Netherlands (IPPON) study. Judo athletes aged≥12 years were randomised by judo school to IPPON intervention or control group who performed their usual warm-up. Primary outcome was overall injury prevalence (%) over the follow-up period (16-26 weeks) measured fortnightly with the Oslo Sports and Trauma Research Centre Questionnaire. A modified intention-to-treat analysis was performed due to COVID-19, with estimates for the primary outcome obtained using generalised linear mixed models. Secondary outcomes included: prevalence of severe injuries, overall incidence, time-loss injuries, exposure, adherence and experiences of trainers and athletes.

RESULTS

269 judo athletes (IPPON: 117, Control: 152) were included. Mean injury prevalence over 16-26 weeks was 23% (95% CI 20% to 26%) in the IPPON and 28% (95% CI 25% to 30%) in the control group. We observed no significant difference of all reported injuries (OR 0.72 in favour of the IPPON group; 95% CI 0.37 to 1.39). Secondary outcomes also demonstrated no significant differences between groups. Specifically, no significant difference of severe injuries was reported (OR 0.80 in favour of the IPPON group; 95% CI 0.36 to 1.78). All trainers and 70% of athletes perceived the IPPON intervention as successful.

CONCLUSION

The IPPON intervention did not significantly reduce the overall and severe injury prevalence. Despite this, we suggest the IPPON intervention be considered as an useful alternative to regular judo warm-up, given the high adherence and the positive clinical experiences of trainers and athletes.

TRIAL REGISTRATION NUMBER

NTR7698.

PREVENTION OF KNEE JOINT INJURIES IN WINTER SPORTS TRAINING

ABSTRACT Introduction: With the 2022 Winter Olympic Games launch, ice and snow sports have come into the spotlight, receiving government incentives to encourage their practice. Objective: Examine the causes of knee injury in skiers, proposing preventive measures for joint injury. Methods: The current situation of joint injury in skiers’ knees, joint movement in skiing, the cause of joint injury, and the prevention of joint injury were analyzed, and scientific prevention and corresponding treatment plan were developed according to the results of the analysis. Results: The injury rate among skiers is high. Ligament injury, tendon injury, and muscle strain are the three main types of injury. There are 57 mild injuries of various types to the knee joint - 53.27% of all injuries; 41 moderate injuries, representing 38.32% of all injuries; 9 serious injuries, representing 8.41% of all injuries, with minor injuries. Conclusion: This article examines knee motion and the causes of knee injury in skiers and proposes preventive measures for joint injury. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Neuromuscular characteristics of agonists and antagonists during maximal eccentric knee flexion in soccer players with a history of hamstring muscle injuries

BACKGROUND

Muscle strain injuries (MSIs) in the hamstrings are among the most prevalent injuries in elite soccer. We aimed to examine the relation between biomechanical maladaptation in eccentric strength and neuromuscular factors separated by their time and frequency domains.

METHODS

20 elite soccer players with a previous history of unilateral MSI in the M. biceps femoris (BF) long head and 20 without MSI participated. Knee flexion torques, rate of torque development (RTD) and electromyographic signals (EMG) of the BF, the M. semitendinosus (SMT) and knee extensors were obtained during unilateral maximal eccentric knee flexions performed at slow (30°/s) and fast (120°/s) angular speeds. Root mean squares and mean power frequency (MF) was calculated.

RESULTS

In the group with a history of MSI, reduced maximal eccentric flexion torque (slow eccentrics -8±11, p<0.05; fast eccentrics -18±13 N*m, p<0.05) and RTD (-33±28 N*m/s, p<0.05; -95±47 N*m/s, p<0.05) concomitantly occurred with diminished agonistic myoelectrical activities (-4±5% of MVC, p<0.05; -10±7% of MVC, p<0.05) and MFs (-24±13 Hz, p<0.05; -24±18 Hz, p<0.05) in the BF. Simultaneously, antagonistic myoelectric activity was elevated (+4±3% of MVC, p<0.05; +3±3% of MVC, p<0.05) in MSI affected legs as compared to unaffected legs for both eccentric contractions. Deficits in myoelectrical activity (r2 = 0.715, p<0.05; r2 = 0.601, p<0.05) and MF (r2 = 0.484, p<0.05; r2 = 0.622, p<0.05) correlated with deficits in maximal torque in the affected leg in the MSI group. Analysis of SMT demonstrated no significant differences.

CONCLUSION

Positive relationships between neuromuscular deficits and the reduced eccentric strength profile underpin neuronal inhibition after MSI. This persistent involvement of dysfunctional synergist and antagonist neural hamstring function in strength weakness is of clinical relevance in sports medicine for prevention and rehabilitation.

Survey on Sports-Related Concussions among Japanese University Students

In recent years, head injuries in sports have garnered attention, and in particular, international discussions have been held on the prevention of and response to sports-related concussions (SRCs). The purpose of this study is to investigate past SRCs experienced by university students in Japan, clarify the state and mechanism of such injuries in each sport, and consider the creation of an environment for future SRC prevention and responses. A questionnaire survey on past SRC experience was conducted among 1731 students who belonged to Fukuoka University in Japan and took “sports medicine” classes in 2020. Responses from 1140 students (collection rate: 65.9%) were obtained. According to this survey, it was revealed that 39 students (3.7%) had experienced SRC. The male–female ratio of those who had experienced SRC was 31 males (79.5%) and 8 females (20.5%). Two males had experienced SRC twice. In this study, SRCs were recognized in a variety of sports, not just in a few contact sports. It is necessary to further disseminate education on head injury prevention and SRCs among both athletes and coaches, because SRCs have been frequently recognized in various sports.

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.

Injuries in Judo Athletes With Disabilities: Prevalence, Magnitude, and Sport-Related Mechanisms

CONTEXT

The participation of judo athletes with disabilities in competitions has increased over the years as well as the burden of sports-related injuries and illnesses in this population. However, there is limited knowledge about sports-related injuries in judo athletes with different disabilities.

OBJECTIVE

To investigate the prevalence of injuries in judo athletes with disabilities, considering the different impairment groups, magnitude of injury (ie, mechanism, nature, and severity of injury), and specific body parts.

DESIGN

Cross-sectional study (level of evidence, 3).

SETTING

Brazilian Judo athletes with disabilities.

PATIENTS

Fifty-one judo athletes with disabilities (15 men and 36 women) participated in this study.

MAIN OUTCOME MEASURES

Data were obtained from an adapted injury report form. The prevalence of injuries was assessed, considering type of impairment, body parts, mechanisms, and severity as well as differences between male and female athletes, with the significance level set at P < .05.

RESULTS

The results demonstrated a high prevalence of injuries in female athletes with visual impairment (n = 11, 73.3%) and male athletes with amputations (n = 14, 38.8%). A high prevalence was found in the national group, especially for male athletes (n = 29, 80.5%). Among athletes who had injuries, 69.4% (n = 12) of male and 80.0% (n = 25) of female athletes' injuries occurred due to direct contact with other athletes, and 72.2% (n = 26) of male and 86.6% (n = 13) of female athletes' injuries were in the training environment. The magnitude of injuries ranged from moderate to severe for male and female athletes. The knee (n = 25, 49.0%) and shoulder (n = 12, 23.5%) were the body parts most affected by injuries in both male and female athletes.

CONCLUSION

A large percentage of judo athletes with disabilities reported experiencing an injury during the previous 2 years; percentages were greater in athletes with visual and physical impairment. Moreover, most injuries occurred in the knee or shoulder, during training, and in direct contact with other athletes and were of severe magnitude.

Factors affecting the shoulder functional profile in elite judo athletes

AbstractThe aim was to investigate the effects of sex, age, preferred judo technique, dominance, and injury history on the shoulder functional status of elite judo athletes. Sixty-one elite judo athletes (38 males, age: 18.1 ± 1.2 years, body mass: 69.3 ± 13.3 kg, body height: 172.2 ± 9.8 cm, brown belt to second-degree black belt) completed three questionnaires: Western Ontario Shoulder Instability, Western Ontario Rotator Cuff, and Shoulder Instability-Return to Sport after Injury. They performed four physical tests: the glenohumeral rotator isometric strength test, upper quarter Y-balance test, unilateral seated shot put test, and modified Closed Kinetic Chain Upper Extremity Stability Test. The results showed that the female athletes had less shoulder functional abilities than the male athletes (p < 0.001 to p = 0.02). The younger athletes had poorer shoulder stability and upper extremity power than the older athletes (p < 0.001 to p = 0.02), but their glenohumeral muscles were stronger in both internal (p = 0.03) and external (p = 0.005) rotations. All the judo athletes had similar bilateral differences in shoulder functional status, except for judokas who preferred throwing techniques (p = 0.01). Injury history affected self-perceived functional status (p < 0.001), as well as upper extremity muscle capacity and neuromuscular control (p = 0.01 to p = 0.05). This study provides new insight into the shoulder functional status of elite judo athletes, which may aid in the development of sports-specific injury prevention and return-to-sport programs to reduce the risk of shoulder injury occurrence and recurrence.

Diagnostics of tissue involved injury occurrence of top-level judokas during the competition: suggestion for prevention

Background

Judo, as a high-intensity contact sport, may lead to the occurrence of injuries, especially in competitions. This work aims to assess the likelihood of soft and hard tissue injuries in top-level judokas during competition with defining factors that determine the probability of injury occurrence.

Methods

The injuries that occurred in 123 official international competitions from 2005-2019 were recorded by the European Judo Union (EJU) Medical Commission as a survey that was a part of the EJU Injury Registration form with internal consistency shown by a Crombach Alpha of 0.69. This survey data identified factors such as: sex, anatomical localisation of injury, type of injury, tissue involved and mechanisms of the injury. A total of 650 tissue injuries were reported correctly in terms of tissue injury definition.

Results

The most frequent soft tissue injury (STI) reported was a ligament STI (48.15%), closely followed by skin STI (12.15%) and muscles STI (11.38%). In turn, the most frequent hard tissue injury occurred in bones (8.56%). The highest rates of injuries occurred during the fight in the standing position (78%). Injuries in the standing position mainly occurred while executing a throw (25.85%) and followed by the attempt to throw, i.e., the action of reaching the throwing position (22.30%), grip fighting (15.07%), and during falls (14.77%). Opposite to this, fight in groundwork reached only 18.30% soft and hard tissue injuries combined. The ongoing registration of injuries during judo combat and training and the early diagnosis of risk factors for injuries are the basis for the development of effective strategies for injury prevention and further treatment.

Video Biomechanical Analysis of Shoulder Impact Kinematics in Tai-Otoshi and Morote-Seoi-Nage Judo Throws: A Cross-Sectional Study

Background: Shoulder injuries in judo are common as the falling player (uke) lands. Two throws implicated in shoulder injury are tai-otoshi and morote-seoi-nage. Kinematic investigation can provide insight into possible shoulder injury mechanisms and allow for appropriate preventative measures to be suggested. We used two-dimensional (2D) video analysis to measure and compare: (a) the peak acceleration and (b) the peak velocity of uke’s shoulder when tai-otoshi and morote-seoi-nage were performed by elite adult judoka. Methods: Eight male participants were recruited from the Budokwai Judo Club in London, UK. The mean age, height, and weight of participants were 25.4 ± 5.2 years (18–34), 1.7 ± 0.0 m (1.7–1.8), and 75.0 ± 5.2 kg (66–80), respectively. Throws were recorded using an iPhone 6S camera and uploaded onto Kinovea for subsequent processing. Results: The peak acceleration (m/s2) was greater in tai-otoshi (71.6 ± 12.4) compared to morote-seoi-nage (67.9 ± 9.9), although this was statistically insignificant. The peak velocity (m/s) was significantly greater (p = 0.030) in tai-otoshi (5.1 ± 0.8) than in morote-seoi-nage (4.5 ± 0.6). Conclusions: A greater peak velocity in tai-otoshi suggests that the shoulder is subjected to increased loads upon impact. This may indicate that tai-otoshi carries a greater risk of shoulder injury. Nage-komi (repetitive throwing) practices in training should follow gradual loading principles—beginning with morote-seoi-nage, before moving to tai-otoshi, for example. We must be aware of any assumptions made in estimations of impact force, and future in vivo research is required to provide more definitive values. Meanwhile, coaches must continue to ensure that correct ukemi (breakfall) technique is displayed by athletes before performing throws.

Knowledge of, and Attitudes Toward, Concussion in Japanese Male Collegiate Athletes

Japan has no streamlined concussion education for collegiate athletes, and guidelines vary by sport. In particular, research on knowledge of, and attitudes toward, concussion is necessary for the establishment of concussion education for Japanese collegiate athletes. The aim of the present study was to assess the knowledge of, and attitudes toward, concussion in Japanese male collegiate athletes and to investigate their experiences with suspected concussion symptoms. An online questionnaire was administered to 390 collegiate athletes participating in the following five sports with a high incidence of concussion: rugby union, soccer, basketball, American football, and judo. Of the 121 valid responses, 91 (77.1%) indicated that they had experienced suspected concussion symptoms at least once and 46 of these 91 respondents had not reported their symptoms of suspected concussion at least once. Athletes who had never experienced concussion symptoms were significantly less likely to recognize the symptoms of concussion (p &lt; 0.001). Most athletes recognized headache and dizziness as suspected concussion symptoms. However, the recognition rate for several symptoms was lower than the prevalence of these symptoms as shown in previous studies. This suggests that educational initiatives might be important to bridge the gap between athletes' knowledge and understanding of frequently occurring concussion symptoms and to improve reporting behavior.

Injury Patterns, Risk Factors, and Return to Sport in Brazilian Jiu Jitsu: A Cross-sectional Survey of 1140 Athletes

Background

Brazilian jiu jitsu (BJJ) is a growing martial art that focuses on grappling techniques.

Purpose

To quantify the 3-year incidence of BJJ-related injuries and detect common injury patterns as well as risk factors among those practicing BJJ. It was hypothesized that there would be a high incidence of injuries, they would be caused by submissions in sparring situations, and they would occur predominantly at the extremities.

Study Design

Descriptive epidemiology study.

Methods

Active BJJ athletes were invited to take an English-language online survey developed by orthopaedic surgeons together with BJJ athletes and a sports scientist. Data were recorded regarding athlete demographics, sporting activity level, injuries within the past 3 years that caused at least a 2-week time loss, injury mechanisms, and return to sport.

Results

Overall, 1140 responses were received from 62 different countries; 88.9% of all athletes were male, and 63.9% were regular competitors. Within the investigated cohort, 1052 injuries were recorded in 784 athletes, for an injury incidence of 308 per 1000 athletes per year. The lower extremity (45.7%) and upper extremity (30.2%) were predominant sites of injury, with injuries to the knee (27.1%) being the most common. The most frequent knee injuries were meniscal injuries (n = 65), anterior cruciate ligament (ACL) tears (n = 36), and medial collateral ligament injuries (n = 36). ACL tears were especially associated with long time frames for return to sport. Most injuries occurred during sparring (77.6%) and were caused by submissions (29.7%) and takedowns (26.4%). Competing regularly (P = .003), older age (P < .001), and higher belt rank (P = .003) were significant risk factors for injury.

Conclusion

Injury incidence was high among BJJ athletes surveyed, with 2 out of 3 athletes reporting at least 1 injury within a 3-year period that caused a 2-week absence from training. Most injuries occurred during sparring, and we believe that a high potential for injury reduction lies in drawing awareness to common injury patterns and sites in athletes.

Monitoring of Eccentric Hamstring Strength and Eccentric Derived Strength Ratios in Judokas from a Single Weight Category

Background: This study was designed to perform isokinetic knee testing of male judokas competing in the under 73 kg category. The main aims were: to establish the concentric (CON) and eccentric (ECC) strength profile of hamstrings (H) and CON profile of quadriceps (Q) muscles; to evaluate the differences in CON and ECC peak torques (PT) with various strength ratios and their bilateral asymmetries; the calculation of the dynamic control ratio (DCR) and H ECC to CON ratio (HEC); Methods: 12 judokas competing on a national and international levels with a mean age of 19 ± 4 years, a weight of 75 ± 2 kg and with a height of 176 ± 5 cm were tested. All the subjects were right-hand dominant. Isokinetic testing was performed on iMOMENT, SMM isokinetic machine (SMM, Maribor, Slovenia). The paired t-test was used to determine the difference between paired variables. The level of significance was set at p ≤ 0.05; Results: Statistical differences between left (L) and right (R) Q PT (L 266; R 241 Nm), H ECC PT (L 145; R 169 Nm), HQR (L 0.54; R 0.63), DCR (L 0.55; R 0.70), HEC (L 1.02; R 1.14) and PTQ/BW (L 3.57; R 3.23 Nm/kg) were shown. Bilateral strength asymmetries in CON contraction of 13.52% ± 10.04 % for Q, 10.86% ± 7.67 % for H and 22.04% ± 12.13% for H ECC contraction were shown. Conclusions: This study reports the isokinetic strength values of judokas in the under 73 kg category, emphasising eccentric hamstring strength and eccentric derived strength ratios DCR and HEC. It was shown that asymmetries are better detected using eccentric testing and that the dominant leg in judokas had stronger eccentric hamstring strength resulting in higher DCR and HEC.

KNEE INJURIES PREVALENCE IN BRAZILIAN JIU-JITSU: EPIDEMIOLOGICAL STUDY

OBJECTIVE

To evaluate the epidemiological and clinical characteristics of knee injuries in Brazilian Jiu-Jitsu (BJJ) practitioners.

METHODS

Cross-sectional study, using a mixed questionnaire, based on the Referred Morbidity Index.

RESULTS

198 amateur and professional BJJ fighters, of both sexes, aged between 18 and 60 years, participated in the study. The majority (88%) of the fighters had only one knee injury (p < 0.001). In total, 29.8% proportion of knee injuries (p < 0.001) was identified, which were mainly from the medial collateral ligament (38%), caused by a sprain mechanism (86%) and conservative treatment (65%).

CONCLUSION

A high prevalence of knee injuries in JJB fighters was found, compared to other sports that also perform rotational movements and have great body contact, such as mixed martial arts (MMA), judo, soccer, basketball and handball. Some JJB strikes, such as the key and the projection, can cause greater knee joint stress, both in the attacking fighter and in the opponent. The knowledge of the epidemiological characteristics of sports injuries is important in the elaboration of prevention and training protocols more specific to the sport and for the understanding of the complex mechanisms involved with this outcome in sport. Level of Evidence IV, Case Series.

Epidemiology of Injuries in Olympic Sports

Injuries effect the performance of athletes. Severity of injuries is determined by time loss and sporting performance reduction. To treat injuries adequately, it is necessary to get an overview of varied injuries types in different sports disciplines. In a retrospective study 7.809 athletes from Germany, Switzerland and Austria competing in competitive or recreational levels of sports were included. Injury prevalence was highest in team sports (75%), followed by combat (64%), racquet (54%) and track and field (51%). Knee (28%) and shoulder (14%) were the most at risk joints. Time loss in sporting activity after injury was longest in the region of knee (26 weeks). Of all reported injuries, 48% were accompanied by a reduced level of performance. The highest injury prevalence occurred in the year 2016 (45%). More injuries occurred during training (58%) compared to competition (42%). Across Olympic disciplines, a large number of injuries occurred during training sessions. Injury frequency increased as the Olympic games drew closer. Knee and shoulder injuries were the most severe injuries with respect to time loss and reduction sporting performance.

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.

Comparison of incidence, prevalence, severity and profile of health problems between male and female elite youth judokas: A 30-week prospective cohort study of 154 athletes

OBJECTIVES

To describe and compare the incidence, prevalence, severity, and profile of injuries (acute and overuse) and illness between female and male youth elite judokas during 30 weeks of a sports season.

DESIGN

Prospective cohort study.

METHODS

A total of 154 elite youth judokas (83 males and 71 females) were assessed from January to August 2019 in a training period organized by the Brazilian Judo Confederation. We conducted a prospective 30-week follow-up study on acute and overuse injuries and illness among youth female and male judokas through the Oslo Sports Trauma Research Center questionnaire on health problems (OSTRC-H). Every week, the OSTRC-H was sent to all youth judokas electronically, starting in the first week of preseason. The incidence rate, prevalence, and severity of illnesses and acute and overuse injuries were compared between sexes using an independent t-test (variables with normal distribution) or Mann Whitney U test (variables with non-normal distribution) with α set a 0.05.

RESULTS

Female and male judokas showed 16.96 and 16.57 injuries per 1000 athletic exposures, respectively (p = 0.383). Female judokas showed a higher average weekly prevalence of health problems (38.8%) than male judokas (29.0%). In addition, females had a greater prevalence of substantial health problems (p < 0.001), injuries (p < 0.001), and overuse injuries (p < 0.001) than males.

CONCLUSION

There were no differences in the incidence rate of injuries between sexes. Youth female judokas showed a higher prevalence of all health problems than youth male judokas. For both sexes, the knee and shoulder were the most affected joints for acute and overuse injuries, respectively.

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 ± 13-17). 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.

MRI-Detected Knee Ligament Sprains and Associated Internal Derangement in Athletes Competing at the Rio de Janeiro 2016 Summer Olympics

Purpose

Describe the frequency and severity of knee ligament sprains diagnosed by MRI in athletes participating at the 2016 Summer Olympic Games, their association with certain sports and assess correlations with additional knee structural injury.

Patients and Methods

All knee MRIs performed in the Olympic Village and polyclinics during the 2016 Olympics were retrospectively, blindly reviewed for ligament sprains and associated knee injuries. In addition to the absence or presence of these abnormalities, athletes were stratified by age, gender and sport.

Results

11,274 athletes participated in the 2016 Olympic Games: 113 athletes received at least one knee MRI with some having bilateral or repeat MRI on the same knee. Anterior cruciate and medial collateral ligament (ACL/MCL) sprains were most common, accounting for 32 of the 43 sprains (74.4%). Wrestling (10), hockey (7), athletics (7), and judo (5) accounted for over half of ligament sprains. ACL sprains showed a significant positive correlation with medial, lateral meniscal tears and bone contusions. The positive correlation between posterior cruciate ligament (PCL) sprains with MCL/lateral collateral ligament sprain, and popliteus tendon tear was statistically significant with 50% of total PCL sprains occurring in hockey. When athletes were stratified by gender, ligament sprains had a similar occurrence and distribution between men and women.

Conclusion

Knee ligament sprains, at the Rio 2016 Games, were most common in wrestling, hockey, athletics and judo with ACL and MCL sprains most frequent. Meniscal tears and bone contusions occurred often with ACL sprains. PCL sprains tended to be multi-ligamentous injuries. Sustained ligament sprains had similar occurrence between genders, while men had a peak incidence of sprains at a younger age and women at an older age.

Judo Injuries Frequency in Europe's Top-Level Competitions in the Period 2005-2020

Background: The present study assesses the frequency of injury in Europe’s top-level judokas, during top-level competitions, and defines risk factors. Methods: The members of the EJU Medical Commission collected injury data over the period of 2005 to 2020 using the EJU Injury Registration Form at Europe’s top judoka tournaments. Results: Over the 15 years of the study, 128 top-level competitions with 28,297 competitors were included; 699 injuries were registered. Of all competitors, 2.5% needed medical treatment. The knee (17.4%), shoulder (15.7%), and elbow (14.2%) were the most common anatomical locations of injury. Sprains (42.2%) were by far the most frequent injury type, followed by contusions (23.1%). Of all contestants, 0.48% suffered an injury which needed transportation to hospital. There was a statistically significant higher frequency of elbow injuries in female athletes (p < 0.01). Heavy-weight judokas suffered a remarkably low number of elbow injuries, with more knee and shoulder injuries. Light-weight judokas were more prone to elbow injuries. Conclusions: We found there was a low injury rate in top-level competitors, with a greater frequency of elbow injuries in female judokas. During the 15 years of injury collection data, an injury incidence of 2.5% was found, with a remarkable high injury rate in the women’s −52 kg category, and statistically significantly more elbow injuries in women overall.

[Development of an injury surveillance system (ISS) in judo]

BACKGROUND

 Judo is a popular combat sport with a high risk of injury. To date, information on injuries in non-competitive and amateur judo is sparse. Injuries in Swiss judo have not been recorded systematically. The objective of this project was to develop an injury surveillance system for judo. Such a system not only provides a possibility for the systematic monitoring of injuries, but also allows for the planning and assessing of strategies for injury prevention.

METHODS

 A survey was conducted to obtain an overview of injuries sustained in Swiss judo. The results served as a basis to develop and implement a database with a web interface, which is called injury surveillance system. Several judo athletes tested the new system in a trial.

RESULTS

 Amateur judokas provided 34.2 % of the answers of the survey. Upper extremity injuries, especially of the shoulder, were most frequently reported, followed by lower extremity injuries, particularly of the knee. In due consideration of the results and experiences gained from the survey, the SJISS (Swiss Judo Injury Surveillance System) was established. SJISS is a web-based injury surveillance system designed for Swiss judo.

CONCLUSION

 This is the first system developed to provide an ongoing and systematic recording of injuries in Swiss judo. The system allows for injury monitoring and may serve as a starting point for developing and evaluating injury prevention programmes.

Seasonal Changes in Anthropometry, Body Composition, and Physical Fitness and the Relationships with Sporting Success in Young Sub-Elite Judo Athletes: An Exploratory Study

This exploratory study aimed to monitor long-term seasonal developments in measures of anthropometry, body composition, and physical fitness in young judo athletes, and to compute associations between these measures and sporting success. Forty-four young judoka (20 females, 24 males) volunteered to participate. Tests for the assessment of anthropometry (e.g., body height/mass), body-composition (e.g., lean body mass), muscle strength (isometric handgrip strength), vertical jumping (e.g., countermovement-jump (CMJ) height), and dynamic balance (Y-balance test) were conducted at the beginning and end of a 10-month training season. Additionally, sporting success at the end of the season was recorded for each athlete. Analyses revealed significant time × sex interaction effects for lean-body-mass, isometric handgrip strength, and CMJ height (0.7 ≤ d ≤ 1.6). Post-hoc analyses showed larger gains for all measures in young males (1.9 ≤ d ≤6.0) compared with females (d = 2.4) across the season. Additionally, significant increases in body height and mass as well as Y-balance test scores were found from pre-to-post-test (1.2 ≤ d ≤4.3), irrespective of sex. Further, non-significant small-to-moderate-sized correlations were identified between changes in anthropometry/body composition/physical fitness and sporting success (p > 0.05; -0.34 ≤ ρ ≤ 0.32). Regression analysis confirmed that no model significantly predicted sporting success. Ten months of judo training and/or growth/maturation contributed to significant changes in anthropometry, body composition, and physical fitness, particularly in young male judo athletes.

Systematic development of an injury prevention programme for judo athletes: the IPPON intervention

Objectives

To systematically develop an injury prevention programme in judo and test its feasibility: Injury Prevention and Performance Optimization Netherlands (IPPON) intervention.

Methods

We used the five-step Knowledge Transfer Scheme (KTS) guidelines. In the first two steps, we described the injury problem in judo and showed possibilities to reduce the injury rates. In the third step, the Knowledge Transfer Group (KTG) translated this information into actions in judo practice. Expert meetings and practical sessions were held. In the fourth step, we developed the injury prevention programme and evaluated its feasibility in judo practice in a pilot study. As a final step, we will evaluate the injury prevention programme on its effectiveness to reduce injuries.

Results

In the first two steps, information collected indicated the need for reducing judo injuries due to high incidence rates. Injury prevention programmes have shown to be effective in reducing injuries in other sports. For judo, no injury prevention programme has yet been systematically developed. In the third step, the KTG reached consensus about the content: a trainer-based warm-up programme with dynamic exercises focusing on the shoulder, knee and ankle. In the fourth step, the intervention was developed. All exercises were approved in the pilot study. Based on the pilot study’s results, the IPPON intervention was extended and has become suitable for the final step.

Conclusion

We developed the IPPON intervention using the systematic guidance of the KTS. This trainer-based programme focuses on the prevention of shoulder, knee and ankle injuries in judo and consists of 36 exercises classified in three categories: (1) flexibility and agility, (2) balance and coordination and (3) strength and stability. The effectiveness and feasibility of the intervention on injury reduction among judo athletes will be conducted in a randomised controlled trial.

Epidemiology of Judo-Related Injuries in 21 Seasons of Competitions in France: A Prospective Study of Relevant Traumatic Injuries

Background

Judo is a full-contact fighting sport that may lead to severe injuries. There are limited data available on the incidence of judo-related injuries. The French Judo Federation has established a surveillance system to document the frequency and type of injuries during judo competitions.

Purpose

To describe the incidence rates and types of judo-related traumatic injuries during 21 seasons of competitions in France with respect to athlete (judoka) age, sex, and level of performance.

Study Design

Descriptive epidemiology study.

Methods

Between 1993 and 2014, each physician in charge of each judo competition filled out a form in which he/she documented the number of competing judokas, the number of fights, the number of medical interventions, the specific type of traumatic injuries for each intervention, the number of fight interruptions, and the number of athletes removed from the competition venue because of an injury. The age, sex, and level of performance of each judoka were also documented. Variance analysis was applied to assess whether differences in incidence rates of injuries between groups were significant (Student t test and chi-square test).

Results

Surveillance of 421,670 fights demonstrated 3511 injuries in 316,203 judokas (incidence proportion, 1.1%). Among the injuries recorded, the most common were sprains (54.3%), fractures (15.6%), and dislocations (12.5%). Female athletes exhibited significantly higher incidence rates for knee sprains and elbow dislocations, whereas male athletes exhibited a higher incidence rate for shoulder dislocations (P < .001 for all). Regarding age, higher incidence rates were observed in young adults (aged 18-20 years) for acromioclavicular sprains and in children (aged 10-14 years) for clavicle fractures compared with adults (aged 21-35 years) (P < .001 for both). Both young adult and adult athletes had a higher incidence rate of shoulder dislocations (P < .001). Regarding the level of performance, athletes competing at higher levels had a higher incidence rate of sprains to the knee (P < .001).

Conclusion

During 21 years of surveillance of injuries in judo competitions in France, the incidence proportion of injuries was 1.1%. Significant differences in incidence rates demonstrated when considering age, sex, and level of performance may help in developing strategies to prevent traumatic injuries in the future.