LETTERS FROM

A LETTER FROM OKINAWA, JAPAN Injuries

in sumo via Getty Images Kon/Bloomberg Akio wrestling ©

– Written Tomoyuki Shimakawa and Tomohiko Tateishi, Japan

HISTORY: THE ORIGINS OF SUMO There are six Grand Sumo tournaments a in sumo followed by Ozeki, Sekiwake, The first sumo matches were held year, three are held in Tokyo and one each in Komusubi and Maegashira. as Shinto rituals dedicated to the gods, Osaka, Nagoya and Kyushu. A tournament celebrating and praying for bountiful lasts for 15 days, each wrestler fights once In the past 10 years, sumo has experienced harvests and peace. They were performed each day against a different opponent. some globalisation, there are a lot of together with sacred dancing and dramas, wrestlers from countries outside Japan, for within the precincts of shrines. During The rules of sumo are very simple. A bout example Mongolia, the USA, Brazil, Russia the 8th century sumo was introduced into is won by forcing an opponent out of the etc. In 2014, there were four Yokozuna, all of the ceremonies of the Imperial Court and inner circle or throwing him down in the them from Mongolia. performed at an annual festival, the ‘sechie- dohyo (the sumo ring). Other less common zumo’ which included music and dancing in ways a loss is awarded include injury, no In 2014, 4000 people over the age of 20 which the victorious wrestlers participated. show, a loose Mawashi (belt) and Kinjite (an participated in a survey that asked about Early sumo combined elements of boxing illegal move). Of course, there are no weight favourite sports in Japan3. The results and wrestling, in which there were categories as in boxing or western wrestling. showed the following: relatively few rules and unarmed fights 1. Baseball to the death were also regarded as ‘sumo’1. Professional sumo is divided into 6 2. Football Under the patronage of the Imperial court, ranked divisions. Wrestlers are also ranked 3. Sumo rules and techniques were introduced for within each division. There are at present 4. Golf the first time. However, sumo continued about 800 rikishi (wrestlers) in professional Although Sumo is a traditional sport, to evolve over history into the form we sumo from trainees to the Yokozuna (Grand it is not the most popular sport in Japan. recognise today. In 1192, a long period of Champion). After each tournament the Japanese enjoy watching sumo, however do intense warfare ensued at which time rankings are revised, each wrestler being not have much opportunity to participate in sumo was regarded chiefly for its military either promoted or demoted depending on it. usefulness and as a means of increasing the their performance throughout the 15 days. fighting efficiency of warriors. Interestingly, Makuuchi (幕内), or makunouchi (幕の内), INJURIES IN SUMO in the hands of the samurai, jujitsu was is the top division and has 42 wrestlers, the Tsuchiya4 reported on 4849 injured later developed as an offshoot of sumo and titleholders or champions and are ranked wrestlers from 1982 to 2007. They were thereafter professional sumo came into its among five categories: Yokozuna – or Grand categorised by the type of injury; trunk, own as the national sport of Japan2. Champion – the highest ranked wrestler upper extremity and lower extremity. The

590 most frequent type of injury was lower was significantly lower among the sumo by Matawari, which can place large stress extremity 2502 (51.2%), followed by trunk wrestlers. on these muscles, particularly among new 1274 (26.3%), upper extremity 1017 (21.3%) apprentices. However, this exercise is a very and others at 56 (1.1%). The trunk included TRADITIONAL TRAINING METHODS: useful as stretch when training the adductor neck and head injury which together To prevent neck injury. and hamstrings muscles. totalled 348 (7.2%) Wrestlers often butt their heads against each other at the start of a match, which Shiko During the 16 years studied, seven is often the cause of burner syndrome and Sumo wrestlers perform a stomping Jefferson fractures were reported, mean age Jefferson fracture. Recommended training is technique called Shiko to build lower body 19.9 years old, mean body weight 123.9 kg. to hit the head with a hand for low impact strength. The exercise begins with the None of these wrestlers had neurological and muscle strengthening for neck. wrestler standing with his feet wide apart symptoms and were treated with and his hands on his knees or thighs. While conservative therapy. All cases resulted Suriashi keeping one foot anchored, he will then in nonunion and all wrestlers returned to One of the traditional exercises is known lift his other leg high in the air, driving it competition. The suggested reason for the as Suriashi. It’s a leg strengthening exercise down into the mat with tremendous force. cause of nonunion is that injured wrestlers done in a crouched position. A wrestler The wrestler will then execute the same were not allowed ample rest compared bends his elbows with his hands extended exaggerated stomp with the other foot. with union cases. The authors of this paper in front and steps forward with alternating suggest that the sumo ranking system is legs, keeping low to the ground. PREVENTION too strict – once a wrestler stops competing Change the regulations and is absent from a tournament due to Matawari Nakagawa et al6 presented a case report injury, his rank steadily decreases. For One of the traditional stretching of a high-level collegiate sumo wrestler who this reason, wrestlers often continue to techniques is known as Matawari. A sumo suffered anterior dislocation of C7 on Th1 compete, regardless of symptoms. The wrestler sits with his legs splayed apart cervical spinal cord injury. The mechanism focus of Tsuchiya’s research was Jefferson as far as possible. While keeping his knees of injury was by being pushed toward the fractures. They collected ‘Baseline’ data locked, the wrestler must then lean forward edge of the dohyo while the back of the including annual measurements of neck until his chest touches the ground. Shimizu wrestler’s head is placed on the abdomen muscle strength at the beginning of each et al5 studied lower extremity injuries in of his opponent, resulting in hyperflexion season. They compared the data with sumo between 1993 and 2009 and recorded of his cervical spine (Figure.4). The authors American football players and Rugby that hamstrings were the most frequent reported that the same mechanism is players, two sports which also require site of strain followed by quadriceps and often seen in rugby and American football. neck muscle strength and pose a risk of adductor muscles. It was suggested that As some reports show that changes in Jefferson fracture. Neck muscle strength adductor muscle strains were often caused the rules decrease cervical spine injuries,

once a wrestler stops competing and is absent from a tournament due to injury, his rank steadily decreases. For this reason, wrestlers often continue to compete regardless of symptoms

591 LETTERS FROM © The Asahi Shimbun via Getty Images © The Asahi Shimbun

the refereeing regulations of the Japan were several instances of sudden cardiac Tomoyuki Shimakawa M.D. Sumo Association prohibit techniques death among professional sumo wrestlers. Orthopaedic Surgeon that are considered risky. With the aim The authors concluded LV hypertrophy is Aspetar – Orthopaedic and Sports of preventing injuries, these regulations more prevalent among newly recruited Medicine Hospital are applied to wrestlers of all levels, from professional sumo wrestlers than among Doha, Qatar sumo championships through to grassroots. the general population, but ECG has a very Techniques thought to be risky include limited capacity to detect LV hypertrophy in strong gripping of the neck of an opponent these very large individuals. LV hypertrophy Urasoe General Hospital below his axilla, fixing the back of one’s and its prognostic significance is likely to Okinawa, Japan head onto the abdomen of an opponent be overlooked in large, muscular athletes and fixing both partner’s necks under their if ECG is solely relied upon for detection. Rokuto Orthopaedic Clinic opponent's axilla. To decrease spinal injuries Nevertheless medical checks using ECG and Okinawa, Japan in sumo, these refereeing regulations should ultrasound continue for new recruits. be strictly obeyed and all sumo wrestlers should be taught proper techniques. CONCLUSION Tomohiko Tateishi M.D., Ph.D. Sumo is a traditional sport with a Orthopaedic Surgeon Medical Screening long history. The type of injuries suffered 7 Department of Sports Orthopaedic Surgery, Kinoshita et al showed the efficacy of are similar to other high-contact sports, Arthroscopy and Sports Medicine electrocardiography (ECG) in the diagnosis including Jefferson fracture, a characteristic Doai Memorial Hospital of left ventricular-hypertrophy (LV) using injury in sumo. For injury prevention, some 890 newly recruited Japanese professional traditional exercises are used but sufficient Tokyo, Japan sumo males, from 1992 to 1997. They were evidence is lacking as to whether they in fact tested by comparing simple ECG criteria help to prevent injuries or not. Some doctors Contact: [email protected] with echocardiographic evaluations of LV. have tried to change certain regulations LV hypertrophy could not be classified as and initiate more stringent medical a cardiomyopathy, but was quite probably screenings. If in the future, traditional sumo the aetiology for sudden death among training techniques prove successful in the youngsters. Unfortunately, before medical prevention of injuries, sumo may become a supervision of the recruits began, there more popular sport throughout the world.

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