Search

To the best of our knowledge, most previous studies regarding the epidemiology of injuries in rugby union (rugby) players have focused on professional players. Therefore, data on injuries in collegiate rugby players in Japan is limited. The purpose of this study was to conduct a prospective injury survey of Japanese male collegiate rugby players over several years and to analyze the injuries that occurred during matches and training according to field position, type of injury, and mechanism of injury. This prospective study initially registered 128 rugby players from one university club. The occurrence of injuries was recorded by athletic trainers during the rugby seasons between 2017 and 2019. The total injury rate (IR) was 7.26 injuries/1000 player-hours (1000 PHs). The match IR (122.73 injuries/1000 PHs) was almost 31.9 times higher than the training IR (3.84 injuries/1000 PHs). Ankle sprains/ligament injuries (17.7%; 1.28 injuries/1000 PHs) were the most common injuries, in addition to acromioclavicular joint injuries in forwards and hamstring strain injuries in backs. The most common injury mechanism was tackling (16.4%). Injury characteristics differed according to field position; therefore, preventive measures according to field position are necessary. Moreover, the high number of tackle injuries suggests that improved tackle skills would help reduce injuries. The IR among Japanese collegiate rugby players was higher than that reported previously. Injury prevention training for collegiate players is necessary to reduce the number of injuries.

This systematic review aimed to identify sports injury surveillance systems (ISSs) and injury surveillance guidelines (ISGs) developed and currently used in Japan. Additionally, the extent to which ISSs and ISGs developed overseas are employed in Japan was also examined. A systematic search of electronic databases was performed in March 2021. Prospective studies that investigated sports injuries and targeted Japanese athletes or sports in Japan were included to identify the following: (1) details of the ISSs or ISGs developed among sports in Japan, and (2) characteristics of studies focusing on sports in Japan employing ISSs or ISGs developed overseas and the method of use. A total of five ISSs developed among sports in Japan were included, most of which were based on insurance benefits or condolence payment systems. In total, 23 studies used ISSs or ISGs developed overseas, more than half of which were used as a resource for the development of other data collection tools or methods, indicating that the definition of injury and/or classification of items are modified based on the needs among sports in Japan. This review highlights the necessity of establishing club-based or organisational ISSs and ISGs that are appropriate for sports in Japan.

Background: Rugby is a high risk of injury to the ankle, but epidemiological data on ankle injury is limited to specific competition levels and generations. This study aimed to clarify the epidemiological characteristics of ankle sprain by longitudinally investigating the incidence, severity and burden of ankle sprains in men's collegiate rugby players. Methods: The study recorded ankle sprains in rugby matches and training across three seasons from 2017 to 2019, investigating 128 male collegiate rugby players.Results: The incidence of ankle sprain was 1.21 injuries/1000 Player-hours (1000 PHs), and the risk of occurrence during matches (18.18 injuries/1000 PHs) was 25.6 times higher than during training (0.71 injuries/1000 PHs). Thus, it was thought that reducing the incidence of ankle sprains during matches would contribute greatly to reducing the loss of competition time due to injury of team members. The results suggested that the main injury mechanism was related to contact play and steps, and that contact skills and physical fitness characteristics were also involved in the risk of sprains. The incidence of ankle sprains in collegiate rugby players was higher than that reported in a previous study on professional-level players, and the rate of initial sprains was high in this study. Conclusions: This suggests that prevention of ankle sprains is important in university age rugby players.

The purpose of this study was to describe the incidence, severity, mechanism, and intrinsic risk factors for knee injuries in Japanese collegiate rugby union players. Initially, 119 rugby union players from one university club were registered in this prospective cohort study. The occurrence of knee injuries was recorded by a team doctor and athletic trainers during the 2009-2012 playing seasons. The number of knee injuries recorded during these four seasons was 64. The incidence of knee injuries was significantly higher during matches (10.5 injuries/1000 player hours [ph]) than that during training (0.3 injuries/1000 ph). The most common match injury was the medial collateral ligament injury (4.4 injuries/1000 ph). The greatest severity and burden were observed for anterior cruciate ligament injuries (severity: 182.5 days, burden: 310.3 days/1000 ph). A majority of knee injuries were sustained during ruck/maul (26.6%) and step/cutting (20.3%). In addition, a history of injury (odds ratio [OR]: 3.3, 95% confidence interval [CI]: 1.3-8.4, p = 0.01) and rugby experience (

[Purpose] This study aimed to examine whether or not friction massage of the popliteal fossa would be effective for achieving dynamic changes in muscle oxygenation and ankle flexibility. [Subjects and Methods] Twelve healthy male university students participated. Before and after friction massage, dynamic changes in muscle oxygenation and ankle flexibility were measured by near-infrared spectroscopy to evaluate its efficacy. [Results] Oxygenated hemoglobin was significantly higher after as compared to before massage. The range of ankle dorsiflexion tended to increase after massage. [Conclusion] These results suggest that friction massage of the popliteal fossa stimulates venous return in the lower leg.

Single-legged drop jumps (SDJ), single-legged repetitive jumps (SRJ), and single-legged side hops (SSH) are often used as plyometric training and functional performance tests. Differences in the kinetics and kinematic characteristics of lower extremity joints during these jumps are unclear.The purpose of this study was to investigate the joint motion and mechanical work of the takeoff leg from foot contact to foot-off during SDJ, SRJ, and SSH in the sagittal and frontal planes in female athletes. It was hypothesized that the joint motion and mechanical work of the lower extremity joints during the SDJ and SRJ would be larger than the SSH in the sagittal plane, those during the SSH would be larger than the SDJ and SRJ in the frontal plane, and during SRJ would be larger than SDJ.Cross-sectional study.Seventeen female collegiate athletes participated and performed the SDJ (0.15-m box height), and SRJ and SSH (by crossing two lines 0.3 m apart). Three-dimensional coordinate data and ground reaction forces were collected. Contact time, jump height, jump index (i.e., the jump height divided by the contact time) of the SDJ and SRJ, and the total times of the SSH were calculated. Range of motion (ROM) from touchdown to the lowest center of mass, and the positive and negative (mechanical) work from touchdown to foot-off were analyzed.There were no significant differences in jump performance variables. Compared to the SSH, the SDJ and SRJ had significantly larger ankle and knee ROM and positive and negative work at the lower extremity joints, except for positive work at the hip joint, in the sagittal plane (p 0.05). Compared to the SDJ and SRJ, the SSH had a significantly larger ankle ROM and positive work at the knee joint in the frontal plane (p 0.05). Compared to the SDJ, the SRJ had a significantly larger ROM and negative work at each lower extremity joint in the frontal plane (p 0.05).Although there were no significant differences in the jump performance variables, different characteristics of the takeoff leg ROM and mechanical work were found between three kinds of rebound-type jump tests. These findings may help clinicians choose jump methods to assess lower extremity function and to design plyometric training programs in sports and clinical fields.3b.