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On the way to the Tokyo Summer Olympic Games (2020). Prevention of severe head and neck injuries in judo: it’s time for action
  1. Takeshi Kamitani1,2,
  2. Nikolaos G Malliaropoulos3,
  3. Masaki Omiya2,
  4. Yohei Otaka4,
  5. Kosei Inoue5,
  6. Natsuko Onidani2
  1. 1 Department of Orthopaedics, Japan Community Healthcare Organization, Tokyo Shinjuku Medical Center, Tokyo, Japan
  2. 2 Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Kanagawa, Japan
  3. 3 Center of Sports and Exercise Medicine, Queen Mary University of London, London, UK
  4. 4 Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan
  5. 5 Department of Physical Education, Tokai University, Kanagawa, Japan
  1. Correspondence to Dr Takeshi Kamitani, Department of Orthopaedics, Japan Community Healthcare Organization, Tokyo Shinjuku Medical Center, Tokyo, Japan; takeshikami0806{at}

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Severe head and neck injuries resulting in death or serious sequelae in judo have been recently reported in Japan,1 2 reaffirming the importance of establishing effective measures to reduce such serious injuries. We describe how and in whom the severe head and neck injuries occur in judo and outline the potentially preventive strategies.

Injuries in judo

Judo is a whole-body sport; however, injuries of the knee, shoulder and fingers are common.3 Head and neck injuries are rarer, with incidences of 2.44 and 1.47 cases per 100 000 judokas per year, respectively, but they tend to be more serious.1 According to accident reports submitted to the All Japan Judo Federation’s System, there were 30 cases of head injury and 19 cases of neck injury reported between 2003 and 2010.1

Young players aged <20 years accounted for 90% (27/30) of cases of head injury. Many of the victims of these injuries had <1 year of experience. Head injuries occurred while being thrown in approximately 70% (21/30) of cases during osoto-gari. Osoto-gari is a common leg throw in which judo players sweep their opponent’s leg out while throwing them backwards. The back of the head is impacted in approximately 60% (14/23) of cases, with the most commonly reported head injury being an acute subdural haematoma.1

In cases of neck injuries, young players aged <20 years account for approximately 58% (11/19); these players were more experienced, with 68% (13/19) having at least 5 years of judo experience. Approximately, 63% (12/19) of judokas are injured while throwing an opponent. The most common technique involved in neck-injured players is uchi-mata, followed by seoi-nage. In uchi-mata, judo players rotate their body and use their leg to kick their opponent’s inner thigh. Neck injuries may occur when judo players dive head first in a flexed neck position while throwing an opponent. In all but one individual, the diagnosis was cervical spinal cord injury.1 Severe head and neck injury in judo carries a poor prognosis. Of 30 judokas with head injuries, 15 died, 11 had severe sequelae and only four experienced full recovery. Of 19 judokas with head injuries, seven had complete quadriplegia, seven had incomplete paralysis and five experienced full recovery.1

Head injury prevention

Judo beginners practise ukemi first to mitigate the impact of being thrown and to prevent injury. The most common cause of head injuries occurs with osoto-gari; thus, backwards ukemi should be appropriately performed.4 When practising backwards ukemi, beginners are instructed to look at the knot in their belt or curl their body to keep the neck flexed. Although the precise mechanism of head injuries by osoto-gari remains unclear, rotational and shearing forces between the brain and dura from the impact to the back of the head may have a key role in bridging vein ruptures.5 When players cannot keep the neck flexed while being thrown backwards, the neck extends and the head rotates backwards and then rebounds after hitting the mat. The brain, however, continues to rotate backwards because of inertia, resulting in a gap between rotational movements of the brain and skull.5 To avoid this situation, it is important for players to suppress neck extension while being thrown backwards. Thus, increasing neck muscle strength and mastering ukemi are important, though scientific evidence of the effectiveness has not been established yet. Additionally, head protectors have the potential to attenuate impact to the head in judo, although official rules do not permit them. What can be done to prevent beginners sustaining head injuries? Since the All Japan Judo Federation has engaged in educational campaigns for safety, including safety guidance to coaches and parents from 2012,6 the number of serious injuries has decreased. These initiatives should be extended worldwide. Finally, physicians should pay attention to concussion symptoms in judokas who are hit to the head, because repeated injuries have been reported in several cases with severe head injury.7

Neck injury prevention

Neuromusculoskeletal examinations, X-rays and neck muscle training and stretching have been suggested for preventing neck injuries. However, considering that neck injuries occur when experienced judo players are putting all their effort into throwing their opponents, such training may be futile. Although the action of diving head first when performing a technique is currently listed as a grave infringement by the rules of judo, referees are reluctant to apply this rule because it decides the winner and ends the match. However, this rule must be strictly enforced for safety purposes. In American football, spearing tackles have been penalised since 1976; this rule successfully reduced neck injuries by 80%.8

Future perspective

Along with implementing all potentially preventive measures, in-depth analysis of the injury mechanisms in the actual situations as well as laboratory tests would help to develop more effective prevention programmes. Meticulous registration of all serious judo injuries both at national and international levels and video analysis of these injuries are strongly recommended.



  • Funding None.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.