judo kata

RevistadeArtesMarcialesAsiticasVolumen9(2),6996~JulioDiciembre2014

http://revpubli.unileon.es/ojs/index.php/artesmarcialesRAMAI.S.S.N.21740747

|692014UniversidaddeLen.www.unileon.es

Nanatsunokata, Endnokata, and Jgenokata A pedagogical andqualitative biomechanical evaluation of Hirano Tokios kuzushi(unbalancing) concept as part of skill acquisition for throwingtechniquesinKdkanjdCarlDECRE*

DepartmentofMedicineandSurgery,UniversityofRomeTorVergata(Italy)InternationalAssociationofJudoResearchers(UnitedKingdom)Recepcin:25/03/2014;Aceptacin:27/05/2014;Publicacininpress:14/06/2014;Publicacin:02/07/2014

ORIGINALPAPERAbstractHiranoTokio(19221993)wasatalentedjdchampionwhodevelopedhisownpedagogicalapproachtowardsteachingandpracticingkuzushi(unbalancing)andtsukuri(preparation),twocriticalskillsforsuccessfullyapplyingjdthrows.Inhisapproach,Hiranoemphasizestheuseofrotationalunbalancingprecededbystrategicmovementsthatmimicwaterwaves.NobiomechanicalanalysisofHiranoswavesystemhaspreviouslybeenattempted.ThepurposeofthispaperistoprovideadetailedsurveyofHiranosdidacticsystemcomparingitwithtraditionalKdkanteachings,andtoassessitsbiomechanical foundations. The fluid dynamic modeling of the several kinds of waves proposed by Hirano ismathematicallycomplicatedandheavilyreliesonBoussinesqdifferentialequations.Giventheinvolvementofnumerousparameters in determining the hydrodynamic behavior of water (depth, period of waves, saliency, temperatures,currents, shapeof the coastal line,water density,wind)which are absent in the surroundings of a pair of two jdkamovingindoorsonatatami,Hiranossystemappearslimitedtoamerevisualizationandmetaphysicalinterpretationofjd. The lack of empirical and experimental data available obtained in large groups of students taught according toHiranos approach make it so far impossible to conclude whether it facilitates kuzushi and tsukuri skill acquisition.Ultimately Hiranos wavebased kuzushi/tsukuri does not alter the biomechanical analysis previously proposed bySacripanti,asitstillisallaboutgeneralactioninvariantsaimedtoclosethedistancebetweenbothopponents,tobreaktheopponentssymmetry,andtoapplyoneoftheinfiniteoptionstoachievethis.Keywords:Hydrodynamics;JigoroKano;judo;kata;kinematics;kuzushi;martialarts

Nanatsunokata,Endnokata,yJgenokataUnaevaluacinpedaggicaybiomecnica

cualitativadelconceptodekuzushi(desequilibrio)deHiranoTokiocomopartedelaadquisicindehabilidadesdeproyeccinenelKdkanjd

ResumenHirano Tokio (19221993) fue un talentoso campen dejdquedesarrollsupropiaaproximacinpedaggicaalaenseanzaya laprcticadelkuzushi (desequilibrio)ydeltsukuri (preparacin), dos habilidades decisivas para laaplicacin exitosa de las proyecciones de jd. En suenfoque,Hiranoenfatiza lautilizacindeundesequilibriorotacional precedido de movimientos estratgicos queimitanolasdeagua.Hasta la fechaannoseharealizadoun anlisis biomecnico del sistemade olas deHirano. Elobjetivo de este artculo es proporcionar una visindetalladadelmtododidcticodeHirano,compararloconlas enseanzas tradicionales del Kdkan, y evaluar susbases biomecnicas. El modelado de la dinmica de losfluidosenlosdiversostiposdeolaspropuestasporHiranoesmatemticamentecomplicadoyse fundamentaengranmedida en las ecuaciones diferenciales de Boussinesq.

Nanatsunokata,EndnokataeJgenokataUmaavaliaopedaggicaebiomecnica

qualitativadoconceitodekuzushi(desequilbrio)deHiranoTokiocomoparteda

aquisiodashabilidadesdeprojeonoKdkanjd

ResumoHiranoTokio (19221993) foiumtalentosocampeodejd que desenvolveu a sua prpria aproximaopedaggica no ensinamento e na prtica do kuzushi(desequilbrio)edotsukuri(preparao),dashabilidadesdecisivasparaaaplicaodasprojeesdo jd.Noseuenfoque,Hiranoenfatizaautilizaodeumdesequilbriorotacional precedido de movimentos estratgicos queimitamondas.Ataomomento,noserealizounenhumaanlise biomecnica do sistema de ondas de Hirano. Oobjetivo deste artigo de proporcionar uma visodetalhadadomtododidticodeHirano,comparlocomos ensinamentos tradicionais do Kdkan e avaliar assuas bases biomecnicas. O modelo da dinmica defluidosnosdiversostiposdeondaspropostasporHirano matematicamente complicado e fundamentase, em

* Email: [email protected]. Address: Professor Carl DE CRE. P.O. Box 125. B2800 MALINES (Belgium).Fax:+448707621701.

DeCre,C.

|70 Rev.ArtesMarcialesAsit.,9(2),6996~2014

Debido a la implicacin de numerosos parmetros en ladeterminacin del comportamiento hidrodinmico delagua (profundidad, frecuencia de las olas, altura,temperaturas, corrientes, forma de la lnea costera,densidaddelagua,viento), loscualesestnausentesenelentornodedos jdkaenmovimientobajotechosobreuntatami, el sistema de Hirano parece estar limitado a unamera visualizacin y a una interpretacin metafsica deljd. La ausencia de datos empricos y experimentalesobtenidosengruposnumerososdeestudiantesentrenadosde acuerdo al mtodo de Hirano imposibilita concluir sieste facilita laadquisicinde lashabilidadesdelkuzushiydeltsukuri.Enltimotrminoelkuzushi/tsukurideHirano,basado en olas, no modifica el anlisis biomecnicopropuesto por Sacripanti, ya que de lo que se siguetratandoesdeaccionesgeneralesinvariantesorientadasareducir la distancia entre ambos oponentes, romper lasimetra del oponente, y aplicar una de las infinitasopcionesparalograrlo.Palabras clave: Hidrodinmica; Jigoro Kano; judo; kata;kuzushi;cinemtica;artesmarciales.

grandemedida,nasequaesdiferenciaisdeBoussinesq.Devido implicao de numerosos parmetros nadeterminaodocomportamentohidrodinmicodagua(profundidade, frequncia das ondas, altura,temperaturas, correntes, forma da linha costeira,densidade de agua, vento), os quais esto ausentes emtornodedoisjdkaemmovimentodebaixatcnicanumtatami,osistemadeHiranopareceestar limitadoaumamera visualizao e a uma interpretao metafsica dojd. A ausncia dos dados empricos e experimentaisobtidos em grupos numerosos de estudantes treinadosdeacordocomomtododeHiranoimpossibilitaconcluirseestefacilitaaaquisiodashabilidadesdokuzushiedotsukuri. Este termo de kuzushi/tsukuri de Hirano,baseado nas ondas, nomodifica a anlise biomecnicapropostaporSacripanti, jquenotratadeaesgeraisinvariveisorientadasareduziradistnciaentreambosos oponentes, romper com a simetria do oponente eaplicarumadasinfinitasopesparaconseguilo.Palavraschave:Hidrodinmica;JigoroKano;judo;kata;kuzushi;cinemtica;artesmarciais.

1.Introduction1

Kdkan Jd is a Japanese form of pedagogy, created by Kan Jigor (18601938). Its practical study consists of randori (free exercise) and tendifferent (Kdkan) kata (predetermined and choreographed physical exercises). The mainbuildingblocksofrandori andkata arenagewaza (throwing techniques) andkatamewaza(controllingtechniques);inaddition,thereareatemiwaza(strikingtechniquestothebodysvitalpoints)whicharepermittedinkataonly,andkapp(resuscitationmethods)(DeCre&Jones,2009;Kan,1931,Kdkan,1986;Mifune,1956).

Manyjdtechniquesoriginateinjjutsu,buthavebeenrefinedormodifiedforsafetyandefficiency,thoughmorerecentlyothershavebeennewlydevelopedorimportedfromothercombatsports, in order to potentially increase a competitors scoring chances during jd contests.Understandingthefundamentalprinciplesofthosetechniquesisinstrumentaltofullycapturehowmastering practical jd is underpinned by itsmaxims ofSeiryoku saizenkatsuy(Optimaluseofenergy)(usuallyabbreviatedtoSeiryokuzeny)andJyokugoseisuru(Nonresistanceovercomesforce)(Kan,2006).

Inadherencetothoseprinciples,theKdkansteachingapproachtypicallyexplainsthatajd throw consists of three sequential phases2: 1. kuzushi (unbalancing), 2. tsukuri (preparation),and3.kake (execution).Thus, thesethreeelementsarethefocusof technicalattention by teachers and jd books (Kdkan, 1986; Kud, 1967;Mifune, Kud,&Matsumoto,195556;Sacripanti,1987).

OneofthemostremarkableteachersofjdinWesternEuropeduringitsearlierstagesofevolution was Hirano Tokio (19221993) (Figure 1). Hirano had arrived in Europe in1951andafterabriefstayinGermanyandFrance,becameasignificantpropagatorofjd intheNetherlands andBelgium (Geels, 1979; Tegelaar, 2012a; van Gasse, 2009). Hirano argued that ajd throw in fact has four phases, most commonly: 1. kumu (gripping), 2. tsukuri

1SeeNotessection.2DeCreandEdmonds(2012)havepreviouslyarguedthatthisisinfactincorrect,andthatsevendifferentphasescanberecognized:1.Debana (theopportunity andoptimalmoment to succeed), 2.Tsukuri (preparation), 3.Kumu (gripping), 4.Kuzushi (unbalancing), 5.Kake (execution), 6.Nageru (throwing), and7.Zanshin (the follow through, literally, the continuation of the spirit). The order of phases #1 through #3may changedependingonthespecificcircumstance.

Nanatsunokata,Endnokata,andJgenokataApedagogicalandqualitativebiomechanicalevaluation

|71Rev.ArtesMarcialesAsit.,9(2),6996~2014

Figure1.HiranoTokio(19221993),atthetimeKdkan6thdan(later8thdan),duringavisittotheauthorsjdclub,theRoyalJd&JjutsuAcademyBushidKwaiMechelen(Belgium)intheearly1950s(probably1952or1953).

(preparation),3.kake(execution),and4.nageru(throwing),and#1and#2shouldbereversedthustsukuriprecedingkumu(Chen&Chen,2002).

Later, Hirano also developed three formal choreographic series (kata) to illustrate hisconceptualapproachofkuzushi to jd throws(Tegelaar,2012a).Mostnotable inhisphilosophyandpedagogywastheincorporationofdifferenttypesofselfdefinedwaves,andhowthosenaturaloccurringphenomenacouldformthebasisofonesdynamicjdgameandstrategy.

As explained, Hirano Tokio was aphenomenally gifted champion and fighter, with allthe accompanying attributes (physique, physiology,strategic insight, psychological determination) (Chen&Chen,2002;Tegelaar,2012a).HismastershipofthelocalWesternlanguagesofthecountrieshetaughtinwas, however, only minimal (Tegelaar, 2012a). Forthosereasons,transferringsuchacomprehensiveanddifferent model of jd to the point that his pupilswould acquire the full extent of its resultingpossibilitiespresentedamostchallengingtask.Whenconsiderable communication problems exist in jd,whether it is because of tangible language issues orbecause students due to their cultural backgroundlackadeeperunderstandingofthephenomenologicalbasis that underpins ones didactic strategies,students tend to focus on what they think they seeand try to copy it.Often though, in jdwhat canbeseenisonlytheproverbialtipoftheiceberg,hencewhy the contribution to ones development oftechnical insightbycopyingtheapparentmechanicalmovementswillhavelimitedsuccess(Kan,2011).

It is the purpose of this paper to clarifyHiranos conceptual view of kuzushi and to compareKansandHiranospedagogicalapproachtolearningand applying kuzushi in jd throws from both ahistoricandqualitativebiomechanicalperspective.

2.WhowasHiranoTokio?

HiranoTokiowasbornon6August1922inSumotoonAwajishima(AwajiIsland),anislandoffthecoastoftheseaportcityofKbeinHygoPrefecture(Hirano,1972a,1985a).Hetookup jdatage12,andinNovember1936justthreemonthsafterhis14thbirthdayhe obtainedhis blackbelt 1stdan. In1937he entered theHeianChgakk3(Heian JuniorMiddleSchool) in Kyto (Hirano, 1972a, 1985a).While there, he became an uchideshi (inliving apprentice) of Fukushima Seizabur (18901950) (Figure 2),whowaslater(in1948)promotedto9thdan,andwhowasafamousbujutsu4and jdteacherattheDaiNipponButokukai(GreatJapanMartialVirtuesAssociation)andaprofessorat theBudsenmongakk (MartialArtsVocationalSchool)orBusen (Hirano,1972a,1985a;Shishida,1994).In1936Fukushimahadbuiltanadditional80tatamidj(atraininghallthesizeof80Japanesemats,eachmathavingasurfaceofapproximately2m),theGihkaiwherehetaughtsomeofhisbeststudents.DuringthesametimeHiranoalsostudied jdunder

3 Since April, 2008 renamedRykokuDaigakuFuzokuHeianChgakk (RykokuUniversityHeianJuniorHighSchool).4FukushimaSeizabursenseiwasalsoqualifiedinkoryjjutsu(traditionaljjutsu),specificallyinKyshinryjjutsu.

DeCre,C.


Morishita Isamu5 (19011985) (Figure 2),whowas the principal of theBusen from June1935toMarch1942,andwhoalsowasonthejdteachingfacultyatthesameinstitutionandattheButokukai;Morishitatoowaslater(in1962)promotedto9thdan.WhilestillatKyto,Hiranolateralsobecameanuchideshi toUshijimaTatsukuma (19041985)(Figure2), famousforhiscompetitiveachievementsandwhotoowasaBusenjdteacherandfuture(1984)9thdanholder6.

Figure2.HiranoTokios(19221993)threelegendaryKytojdinstructorsattheHeianChgakk(HeianJuniorMiddleSchool),theDaiNipponButokukai(GreatJapanMartialVirtuesAssociation),andtheBudsenmongakk(MartialArtsVocationalSchool)orBusen,fromlefttoright:FukushimaSeizabur(18901950),MorishitaIsamu(1901

1985),andUshijimaTatsukuma(19041985),allthreelateratdifferentpointsintimepromotedto9thdan.ImageofMorishitaIsamureproducedfromHirano(1972a,p.68),withpermission.

In 1941 Hirano graduated from Heian Chgakk and entered Takushoku University in Tky (Hirano, 1985a). By then he had already developed his trademark taiotoshi (body drop) throwing technique (Hirano n.d.[b], 1985a). Ushijima, one of Hiranos formerKyto teachers and himself a formidably jd competitor, had been requested to become jdinstructoroftheImperialGuardinTky.Whileacceptingthis jobhedecidedtocombineitwithinstructorshipsatanumberofuniversitiesinTkyamongstwhichalsoTakushokuUniversity.InthiswayHiranowhowasstudying therewasable tocontinuehis jd trainingwithUshijima. InOctober1941attheageof19,Hirano,bythenasuperbjdtechnicianholdingtherankof4thdan,enteredthehalfyearlykhakushiai(redandwhitejdocontests)attheKdkaninTky,whereinlessthanhalfanhourtimehedefeatedalineupof15yodan(4thdan)holders,each with a different technique. After this unprecedented and hitherto unseen batsugun(extraordinary performance)7, Hirano received instant promotion to the jd rank of godan (5th5 The correct pronunciation of Morishitasenseis first name is not 100% certain. The kanji in is usuallypronouncedeither IsamuorY.However, rareuncommonotherpronunciations exist too. In this case,webelieve thepronunciationlikelytobeIsamu.6UshijimaTatsukumatoohadabackgroundinKyshinryjjutsu,similarlytoFukushimaSeizabur.Hewasa double prewar All Japan Championships winner, runnerup of the first (1929) Shwa Tenran Shiai(Contest Before the Shwa Emperor), and probably most famous as the main jd teacher of the legendary KimuraMasahiko(19171993).7 The achievementwas unprecedented and never repeated for such a high rank, however, there do exist jdkawhodefeated evenmore opponents but at a lower rank. KaminagaAkio (19361993), at that time 18 years old,duringthe1954khakushiaidefeated19opponentsandreceivedbatsuguninstantpromotionfrom1stto3rddan.Duringthespringkhakushiaiofthenextyearhedefeated12consecutiveopponentsthusagainreceivingbatsugunpromotionfrom3rdto4thdan.Kaminaga,contrarytoHirano,wasaheavyweightjdka.InthehistoryofKdkankhakushiaithree



dan)(Chen&Chen,2002;Hirano,1972a,1985a).Furthermore,Hiranowonmultiplejdtitlesinhisnative Japan, including theDaigakuKsenKojinsen (All JapanCollegiate JdChampionships) (1941and1942)aswell as the1948 thirdZenKokuKokuminTaiikuTaikaiZenNihon(AllJapanNationalAthleteJdChampionships)(Hirano,1985a).In 1946 he became chiefjdinstructor of the Imperial Guard (Kg Keisatsu Jd Shihan), and the next year he also was promoted to the rank of rokudan (6th dan)(Hirano,1985a).

A heavily disputed loss against sawa Yoshimi8 (born in 1927) during the thefinaloftheTkyChampionships,allegedlyduetothelackofimpartialityofrefereeMifuneKyz(18831965),10thdanoftheKdkan,infuriatedHiranowho,inconsequence,decidedtoleaveJapan.HewentontoplayamassiveroleinthepromulgationofjdinEurope(especially,inBelgium,France,Germany,andtheNetherlands).In1948HiranoarrivedinEuropeviaAntwerpinBelgiumandsettledinGermany,wherehebecameajdinstructorattherecently(1947)foundedDeutscheSporthochschuleKln (German Sport University Cologne).Hiswife and daughter joinedhim in Germany in February 1952. In February 1953, he became the technical director of theBelgische Amateur Judo Associatie (BELAJA) in Flanders, and after its merger with the WalloonAssociationFdraleBelgede Judoet Ju Jitsu (AFBJJ) into theBelgian JudoFederation (BJB)on18October 1959, he would share the same position with Abe Ichir, at the time also 6th dan andtechnicaldirectoroftheAFBJJ.In1964,HiranowaspromotedbytheKdkanto7thdan,andattheend of June 1966 he left Europe with his family to return to Japan. In 1967 he became jdinstructor atTakushokuUniversity, apositionhehelduntil 1982 (Hirano,1985a).HiranoTokio,then8thdan,passedawayon26July1993duetocirrhosisandcanceroftheliver.

3.ThehistoryofkuzushiinKdkanjd

KanshihancreatedKdkanjdin1882althoughitwouldtakemanyfurtherdecadestoconsolidatehisjdintoarefinedsystemofphysicalandmentaleducationandselfdefense(Kan,1932;Kdkan,1986;Maruyama,1939;Oimatsu,1976).Kandidnotcreatehisjdfromscratch.Rather,he largelycompiledmaterial fromotherexisting Japanesemartialartsschoolsmolding itintosomethingthatwasmorethanjustapracticalartforselfdefense.Thetwomainschoolswherehe obtained his ideas were Kitry and Tenjin Shinyry both schools oftraditional Japanese jjutsu (the art of giving way), and created in the early 17th and 19thcentury, respectively (De Cre, 2014;De Cre& Jones, 2009;Kan, 2006; Kan, 1932;Kdkan,1986;Maruyama,1939;Oimatsu,1976).

Thesetwoschoolswereverydifferent,withTenjinShinyrybeingKansmaininspirationfor atemi (strikes aimed at the bodys vital points) and katamewaza (controllingtechniques),whereasKitrydeliveredmostofKansinspirationforthrowsandforhisconceptofJyokugoseisuru(Nonresistanceovercomesforce),althoughthelattercanbe traced even further towards the roots of historic sum wrestling (De Cre, 2014; Kan,2006).Morespecifically,KanalsoobtainedhisconceptofkuzushiorbreakingbalancefromKitry jjutsu, where it is dealt with in the traditional makimono (scroll) Hontainomaki(ScrollofProperBodyPosition)andChinomaki(ScrolloftheEarth)(Figure3).

WhilepracticingKitryjjutsutheyoungKanrealized,around1885,duringmidaredori9training with his master Iikubo Knen10 the important role of breaking onespeoplehavedefeatedevenmoreopponentsinalineupthanKaminaga.uchiKenichiand+100kgheavyweightjdkanokoArata,in1958and2003,respectively,defeated24opponentswithoutasinglebreakinbetweencontests.TheabsoluterecordisheldbyYoshinoKentar(kanjinotknown),whoduringthe1934khakushiaidefeatedalineupof27consecutiveopponentshencelikeKaminagareceivingbatsugunpromotionfrom1stto3rddan,andalsofollowingupthisachievementbydefeatinganother11opponentstheyearafterandreceivingbatsugunpromotionfrom3rdto4thdan.8sawaYoshimicurrently,sinceJanuary2006,isarareKdkan10thdanholder.9Midaredori was Kitry jjutsus equivalent of what we know today in jd as randori. Kitry kata were oftenpracticedinmidaredoriform,thuswiththeopponentseriouslyresistingtoriandavoidingthelatterestablishingcontroloverhim(DeCre,2014).

DeCre,C.


opponentsbalancetoeffectbetterthrowingtechniquesandensureamoreefficaciousexecutionofthesetechniques.This isparticularlysobetweentwofighterswithsimilarphysiqueand force. Insuchcasesbreakingthebalanceofonesadversaryiscrucialtoobtainresults(Sacripanti,2012b,p.6).

Figure3.AHontainomaki(ScrollofProperBodyPosition)scrollissuedbyKanJigorshihaninhisfunctionasholderofmenkyokaiden(HolderoftheLicenseofFullTransmission)ofKitry

TakenakahabranchtoHoshinaShir(formernameofSaigShir)inthe6thmonthofthe18thyearofMeiji(June1885)(FromthelibraryofLanceGatling,Tky,reproducedbykind

permission,allrightsreservedFebruary2009).

Thus, even in classical Japanese jjutsu one is taught how to use to ones advantage thecondition in which the body of an opponent has lost equilibrium, the socalled kuzurenojtai (state of imbalance). During dynamic combat situations, this balance is sometimesspontaneouslylostbyonesopponent,whileatothertimesonewillpositivelycausethedestructionof the opponent's balancehenceputtinghim into aparticularly vulnerableposture (Kan, 2006;Sacripanti,2012b,p.6).

When between 1903 and 1915 the very first jd books in Japanese appeared, such asJdbyUchidaRyhei(1903)andJdTaii(Asynopsisofjd)byArimaSumitomo (1904), the concept ofkuzushiwas already verydeveloped inKdkan jdandhenceexplainedtothereader.ThesameistrueforthefirstjdbooksinWesternlanguagessuch asArima Sumitomos 1906 book in English Jd. Japanesephysical culture.Beinga furtherexpositionofjujitsuandsimilararts(Arima,1906),andSasakiKichisabursbookinHungarian Djudo. A Japn dzsiudzsicu tkletesitett mdszere (The Japanese jjutsu skillsmethod) (Sasaki, 1907), or Yokoyama Sakujir and shima Eisukes 1908bookJdkyhan(Learningtextofjd)inJapanese(Yokoyama&shima,1915)andits1911FrenchtranslationbyYvesLePrieur(Yokoyamaandshima,1911).

4.KanJigorsconceptofkuzushiinKdkanjd

The first known record of Kan Jigor discussing kuzushi was in his famous May 1889lecture11 for theDaiNippon Kyikukai in Hitotsubashi Kanda (De Cre,2014;Kan,2006).ThereinKanmentionedthathehadexperiencedkuzushithroughtheKitryschool,whilealso realizing that theKitrykata froma theoreticalpointofviewwere farmoredifficultthantheoftenmoredirectlypracticalkataofTenjinShinyry,jdsotherparentschool(Kan, 1932, 2006; Maruyama, 1939; Oimatsu, 1976). The concept was then more formallyintroduced intoKdkan jd inwriting in the June 1927 issue of theKdkanmagazine Sakk.Insubsequentyears,itwasthenextensivelydealtwithonaregularbasisintheKdkansold

10Later,inKdkanwritingsIikuboKnensenseistartedbeingreferredtoasIikuboTsunetoshi,forasofyetstillunknownreasons.IikubohimselfwasadeshiofTakenakaTetsunosukeandtaughtattheKbusho,whichwastheTokugawaclansbudtrainingplaceaswellasattheEishjitempleinTky,whereKanhadstartedhisKdkanschoolofjd(DeCre,2014).11TheexactdatewasMay11th,1889(Kan,2006,KansenseiDenkiHensankai,1984).



Figure4.SchematicrepresentationofHappnokuzushiorEight

directionsofunbalancing;afterSacripanti,2012,p.8,withpermission.

periodicals such as Yknokatsud (The Efficiency of Movement) and Jd, be itexplicitly or less explicitly. Similarly, it took up a central place in Kans many lectures aboutKdkanjdinJapanorabroad,andalsoinKansJdkyhonjkan(Atextbookofjd),publishedin1931andthefirstandonlyfulltextbookwhichKaneverwroteaboutjd,(Kan,1931;KansenseiDenkiHensankai,1984).

ifanopponentpushes,youmustpullinthesamedirection;ifhepulls,youpushhiminthesamedirection.ThisquoterepresentstheKdkanconceptofyawaraorj(Kan,1931,1932;KansenseiDenkiHensankai,1984;Kdkan,1986).Applying these forcesbecomesmuchmoreenergetically efficient if you also result in unbalancing your opponent. In that case, theminimalforceappliedbyyouwillamplifythat imbalance,sothateasyapplicationofa leverwouldenableyou to control your opponent and succeed in throwing himwith ease. For Kan this essentiallyrepresentstheproperuseofforceaconceptwhichhethoroughlyresearchedandusedasabaseforconstructingKdkanjdsgnokata,likelytheoldestchoreographedjdexercise(DeCre&Jones,2009).

Tsukuri initsclassicalformexistsintwoforms:aitenotsukuri(preparingoftheopponent) and jibunnotsukuri (preparing oneself)12. This preparing of the opponentconsistsofdestroying theopponentsbalancebeforeperforminga techniqueand thus intends toputhiminaposturethatfacilitatestheapplicationofatechnique.Simultaneously,theoneacting(tori) must be in a posture and position in which it is easy to apply a technique. This is thepreparingofoneself(Kud,1967;Sacripanti,2012b,p.7).

Inteachingthebasicskillsofkuzushi,KanadoptedadidacticmodelwhichpreexistedinTenjin Shinyry jjutsu and that was called Roppnokuzushi Six directions ofunbalancing,butwhichhehimselflaterexpandedandrenamedasHappnokuzushiorEightdirectionsofunbalancing(Figure4)(Kdkan,1986;Mifune,Kud,&Matsumto,195556).What really is meant, are straight horizontal directions parallel to the tatami. Linguistically inJapanese, the term happ in this context also often means all directions, thus in the sense ofcoveringeverythingovera360radius,thusnotliterallyjusteight.

However, in reality, kuzushi clearlyentails much more than just horizontaldirections. There is also a vertical component.This also illustrates the difficulty in skillstransfer of kuzushi when teaching jd tostudents. For example, leftfront kuzushi isrecommended for a simpleentry fundamentalperformance of basic koshiwaza (hiptechniques)suchasthethrowharaigoshi(sweepinghip)andseveraltewaza(handtechniques), such as the throw taiotoshi(bodydrop).Yet,despitethesamedirection,thekuzushiforboththrowsisverydifferent.Infact,ifconsideringjustasinglethrow,saytaiotoshi,while varying the hairikata (ways ofentering),forexample,tsurikomi(liftandpull entry) vs. mawarikomi (spinningentry), already then the kuzushi is quitedifferent(Hirano,n.d.[b]).

Thehappnokuzushimodelpostulatesonlytwodimensionsinsteadofthree,anddoesnotaccount for all those very important differences. Consequently, someone mastering happno12 In the West, most jdka are not familiar with these separate forms of tsukuri. This can create some confusionparticularly when some authors place the tsukuriphase following the kuzushiphase, whereas others prefer puttingkuzushi prior to tsukuri. When using the full terminology this confusion is prevented since typically preparing theopponentprecedeskuzushi,butpreparingoneselfmayindeedwellcomeafterthekuzushiphase.

DeCre,C.


kuzushiwill still experiencesignificantproblems in their skill acquisition toapplykuzushi toanythrowinadynamicorrealisticsituation.Unfortunately, theKdkan jd syllabusdoesnothaveother models to teach this kuzushi except for perhaps one example, the rinokata, such asespeciallyKoshikinokata13. Unfortunately,Koshikinokata is so complicated that the exercise istaughtonlyatthemostadvancedlevel,alevelwhichthemajorityofpeopleinjdwillneverreach(Figure5).Eventhen,thesheerdifficultyofthisexerciseformanyadvanced jdkapreventsanycomprehensionbeyondameremechanisticperception,sothat,sadlyandforthatreason,itdoesinmostcasesnotsignificantlycontributetotheirunderstandingofkuzushi.

Figure5.KanJigorshihan(tori)withYamashitaYoshitsugu (18651935),7thdan(later10thdan)(uke),performingKodaore(Fallinavoid),theseventhtechniqueofKoshikinokataattheoccasionoftheopeningoftheJundkaninKbe,HygPrefecture,onApril30thof

1916.

5.BiomechanicalappreciationofKanJigorskuzushisystem

Anumberofauthorshavelookedintothebiomechanicalpropertiesofkuzushi(Ikai,1958;Imamura, Hreljac, Escamila, & Edwards, 2006; Imamura, Iteya, & Ishii, 2007; Okada, 2008;Sacripanti2010a,2010b,2012a;Sannohe,1986;Tezuka,1983;Trilles,Blais,&Cadire,2010) injd.EspeciallytheworkofSacripantiinthisareahasbeenextensive.AccordingtoSacripanti,fromaphysicsviewpoint,itisnotedthat

Kan used kuzushi to synthesize the transfer of action in biomechanical elements, i.e. thebarycentricthrowingoftheopponentsbodyoutsideboththeoptimaltrapezoidsurfaceandthesupporting base. The action of kuzushi takes advantage of a human bodys erect position, aphysicspositionofunstableequilibrium,byintroducingeverythingthatpermitsthrowingthatbody after an unbalance, namely, through an appropriate barrier (e.g., taiotoshi (body

13Koshikinokata,before1901byKanreferred toasKitrynokata,was takenovervirtuallyintegrallybyKanfromhisTakenakahabranchofKitry,ashehadlearntit fromhisKitry teacherIikuboTsunetoshisensei.TheexerciseisoriginallycontainedinKitrysJinnomaki(ThescrollofMan)wherethefirstseriesoftechniquesisgroupedunderthenameOmotekata(thefundamental,visibleforms)andthesecond,dependingonthelineage,aseitherUrakata(theapplied,hiddenforms)orMudan(thenonstepwiseapplication).ThewholekataisinKitryusuallyreferredtoasKitrykumiuchinokata.



drop), hizaguruma (knee wheel)) or through merely causing a hyperextension of thebody in a space (e.g., ukiotoshi (floating drop), sumiotoshi (corner drop)). ()(Sacripanti,2012b,p.7)

ThequestionaboutthedirectionofforcesandtheirproperusepromptedKantoconsiderthedevelopmentofdynamicactionswithapurelystraightandtwodimensionalsymmetry.Evenifweonlyconsidertwodimensionallinearsymmetry,andbecauseofitscomplexityexcludespecificthreedimensional issues, thenthenumberofunbalancedirections is infinite,moreprecisely, aninfinity of the power of continuum (Sacripanti, 2012b, p. 8). The Happnokuzushi directionalprinciple is therefore only satisfactory on the condition that each of the eight fundamental andstraightdirectionsproposedbyKan is consideredas representativevectorof agroupormoreexactlyofaclassofdirections (Sacripanti,2010a,2012b).WemustthereforeapproachHappnokuzushiasadidacticexampledepictingwhatisessentiallyan innumerablenumberofhorizontalstraightdirectionsofunbalancenowdividedintoeightclasses.

OneofthemajorflawsinKansdescriptionofkuzushi isthatit isbasedonanerroneousphysicsassumptioninthesensethatthehumanbodyisconsideredtobearigidobject(Yokoyama&shima,1915,1911),whichitisnot.Inreality,thehumanbodyisflexibleandissegmentedwithvariousarticulations,hencetheconsiderableconceptualgapbetweenthetheoreticalexplicationofthehappnokuzushihorizontaltwodimensionaldirectionsconcept,andhowitcanbepracticallyappliedinshiaiorinthenovicejdkasskillacquisition(Sacripanti,2010a,2012a,2012b).

Inreality,thebodyscenterofmass(COM)changesitspositionbothinsideandoutsidethebody,thusalteringthesubjectsstabilityeventhoughitmaynotbetotallyunbalancingtheirbody(Sacripanti,2012b,p.12).Sacripantipointsoutthat

In jd,weareused toconsiderbalancewhilebeing inaneutral standingsituation, that is,apositionofunstableequilibrium,assumingthattheCOMoftheathleteisstillmoreorlessunderthe navel from a perspective of the bodys wellknown three planes of symmetry (frontal,sagittalandtransverse).Iftheopponentsbodyisrigid,youcaneasilyapplyKansunbalancingconcept;if,however,theopponentsupperbodypartturnsorbendstotheside,youcannot.Inthiscase,theCOMshiftsandchangesposition,and,consequently,boththebodysstabilityandmobilityarealtered.()(Sacripanti,2012b,p.12).

An expert jdka is able, through the proper application of debana (opportunity) to usethesesituationstogainanadvantage.However,nothingwithintheKdkandidacticalsystemotherthan practice, practice, practice provides clear guidelines or tools to help the novice jdkaacquiretheseessentialskills.Inreality,whatitreallyreducestoisthebreakingofsymmetryoftheopponentsbalance(Sacripanti,2012b,p.13).

By bending or turning ones body one can break the symmetry of the opponents bodyposition. In doing so, one reduces the opponents mobility by shifting its COM either inside oroutside of his body hence increasing his instability. Many modern jdka often with limitedtechnical skills try to achieve this through grip fighting and blunt pulling and pushing, whereaswellknown exemplary technicians such as Mifune Kyz (18831965), Okano Isao (born in 1944) or Hirano Tokio (19221993) achieve this through an optimalapproachofrecoilingaction/reactionorhazumi(Clause,2003;Hirano,1966;1972a;Mifune,2005;Okanon.d.;Okano&Sat,1973).AsSacripantipointsoutthough,neitherthenovicenortheexpert jdkausuallyhasanyconsciousknowledgeabouttheroleof thebreakingofsymmetryconcept, or the biomechanical objective of kuzushi (Sacripanti, 2012a, 2012b, p. 13). Whensomeonessymmetryisbroken,hisbodysstabilityisdiminishedhencelimitinghisabilitytoshiftandcompensatethusmakingiteasierfortheopponenttoapplyasuccessfulthrow.

Fromabiomechanicalview,successfulkuzushiinvolves,oratleastiscloselyintertwinedwith a twofold process, namely the debana14 (the opportunity and optimal moment to

14Sacripantiuseshazumitorefertoperfecttiming,however,hazumidoesnotreallysignifyperfecttiming,buttheuseofrecoilingofthebodytopromptlyandexplosivelyactwhenthatopportunitypresentsitself;theopportunityitselfthoughiscalleddebana.

DeCre,C.


succeed),andafinalcontactorbodycollisionorclashcalledbutsukari15.Thesetwostepsimmediately precede the kake or execution of the throwing phase and the nageru or actualthrowing phase16. Proper and effective use of such situation is often called handnokuzushi(Litt.:reactive/recoilingunbalancing)(DeCre,2014;Sacripanti,2010a,2012b).

Thesublimityofjdtechniquesliesnotintheactionofperformingtechniques,butratherintheskillwithwhichtheanticipatingwork, i.e. thepreparatoryphaseiscompleted(Sacripanti,2012b,p.78).

Tsukuri (preparation) is really aimed at bringing an opponent in an ideal position to bethrownwithminimal energy.Even though thepossibilitiesof tsukuri solutionsmaybe infinitive,theyallshareasacommongoalshorteningthedistancebetweenthetwojdka.Sacripantipointedout that from a biomechanical point of view the number of actions that simultaneously aim tomaximallyreducedistancewhileexpendingminimalenergy, is limitedtothreeclassesorActioninvariants(Sacripanti,2010a,b,2012a,b).AccordingtoSacripanti,eachoftheseclassesisdefinedbywhat is known in classicalNewtonianphysics as thePrincipiumof JacobiMinimum (orLeast)Action,andcanbereducedtotheHamiltonLagrangeEquationandtotheHamiltonActionPrinciple:

dttqqLtqS ),,(),( &= In this equation, S is the action of a physical system (i.e. the chosen throw), L is the

Lagrangian(thesystemsenergy)component,andqisthegeneralizedLagrangecoordinate,whilethe dot denotes the time derivative, and t is time.When considering the external energy of thesystem(gravitationalfield)onemayconcludethat:

0

0).(),(

),()(),(

1

2

1

=

=

====

qL

dtd

qL

qdtqL

dtd

qLdtqqLtqS

qqLEtqWtqSt

t

t

t

&

&&

&

whereWisthepotentialenergywithintheexternalfield,Eisthekineticenergy,andtis

time.

Foranonconservativesystemwemustwrite:

0=+

QqL

dtd

qL

& withQbeingtheheatemitted.

A conservative field is where the line integral depends solely on the end points of atrajectory, whereas a nonconservative field is when the line integral depends both on the endpointsandonthetrajectorybetweenthem.Thenetworkthatiscarriedoutbyaconservativefieldon an object that follows a closed loop is zero. This is an alternative way of expressing that aconservativefieldstoresenergywithoutloss,i.e.,ifanobjectgivesupacertainamountofenergytoaconservative field in traveling frompointA topointB, then the fieldreturns thisenergy to theobjectwithoutlosswhenittravelsbacktopointA.However,ifanobjectgivesupenergytoanonconservativefieldwhenmovingfromAtoB,thenthefieldreturnsonlypartofthisenergytotheobjectwhentravelingbacktoA.Gravitationalfields,butalsostaticelectricandmagneticfieldsare

15Sacripantiusesthetermikioitorefertothisbodycollision.However,bodycollisioninjdisactuallybutsukariwhereasikioisimplypointsoutthatanactionisdonevigorouslyandforcefully.16WeareadheringheretothesevenphasesofajdthrowasproposedbyDeCreandEdmonds(2012),inresponsetowhat these authors considered the incompleteness of the three stages suggested by the Kdkan: debana (theopportunityandoptimalmomenttosucceed),tsukuri (preparation),kumu (gripping),kake (execution),nageru(throwing),andzanshin(thefollowthrough,litt.thecontinuationofthespirit).



probablythemosttypicalexamplesofaconservativefield.Anexampleofanonconservativefieldwouldberepresentedbyanobjectmovingoveraroughhorizontalsurface,suchasajdkamovingovera tatami. In that case, frictional forcewouldcontinuouslydrainenergy fromtheobjectas itmovesoverthesurface,energywhichthenisdissipatedasheat.

ConsideringHamilton'sPrinciple17,thetrueevolutionofS(q,t)isanevolutionforwhichtheaction isstationary(aminimum,amaximum,orasaddlepoint).However, since jd isallaboutmaximalefficiency,oneinfactstrivesforaminimum,i.e.thesocalledPrincipleofMinimumAction(Sacripanti, 2010a, 2012a). The Action Invariants,mentioned in the previous paragraph, in jdrefertotheminimalpathintimethatthebodyneedstoshiftinordertoachievethebestkuzushiandtsukuripositionforeveryjdthrow.Generally,thisappliestoaconservativefield;if,however,weconsideranonconservativefield(seeabove),thenonealsoneedstoincludeafactorQ,i.e.theheatemitted,althoughthequicksuccessionofjdtechniquesduringrandoriorshiaiissuchthattemperature variations within the couple formed by both jdka are negligible and adiabatic(Sacripanti,2010c,2012b).Thesuccessionof throwsinrandoriorshiai representapplicationsoftheprincipleofminimumaction,whichhasleadtothembeingreferredtoasActionInvariants,andwhicharebothsummarizedasfollows:

The principle of minimal action is represented by the athletes (= the jdkas) energyconsumption,whilethebestoutcomeisrepresentedbytheappliedjdtechnique.

The principle of minimal action is represented by the athletes (= the jdkas) movementtrajectory in order to achieve optimal positioning for carrying out the throw,while the bestoutcomeisdeterminedbytheappliedjdtechnique.

6.HiranoTokiosconceptofkuzushiinjd

Inpractical terms,many jdkaseriouslystrugglewithtechnicallymasteringanumberofthrowsbecauseofthedifficultyinlearningcorrectkuzushi,whichisahighlycoordinativeprocessrequiringsubstantialneurologicalandmotorskills.HiranoTokiofullyrecognizedtheseproblemsandappliedanentirelynewandoriginalapproach.Firstly, toKansessentially twodimensionalmodel of directions of kuzushi contained in the happnokuzushi, he added a third dimension,namelyaverticalone.Healso identifiedsevendifferentwaysofusing thearms to realizea fullythreedimensionalmodelofkuzushi:andincludedthoseinadidacticsetofformswhichhecalledJgenokata (Forms of up and downward movement) (Hirano, 1972a). The sevenverticalformsofkuzushicontainedthereinare:

1. Katatesabaki(Singlehandedpreparation)2. Rytesabaki(Doublehandedpreparation)3. Taikotataki(Drumbeating)4. Tobiagari(Jumpingup)(seeFigure6)5. Ayumiashi(Normalwalking)6. Hizamage(Kneebending)7. Sutemi(Sacrificing)

Thesekuzushimovementsaretypicallyprecededbyanexplosivepulldownwardsfollowedbyasuriashi slidingstep that leads toa tsurikomilikeupwardspulling.Thesestrongpulsessenttotheopponentwillelicitaresponsewhichtorilearnstoanticipate,andwhichhethenoptimallyfollowsupwithone(ormultiple)oftheabove7kuzushioptions.

17Hamilton's principle isWilliam Rowan Hamilton's (18051865) formulation of the principle of stationary action. Itstatesthatthedynamicsofaphysicalsystemisdeterminedbyavariationalproblemfora functionalbasedonasinglefunction,theLagrangian,whichcontainsallphysicalinformationconcerningthesystemandtheforcesactingonit.Thevariationalproblemisequivalenttoandallowsforthederivationofthedifferentialequationsofmotionofthephysicalsystem.

DeCre,C.


Furthermore,Hiranofeltthatcontrarytowhatthemajorityofjdkadoestoday,grippingshould not be a predetermined starting point, but should be a logical consequence (followingKansmaxims)aftertsukuri(Chen&Chen,2001;Hirano,1972a,1985;vanGassen.d.),withthattsukurisimplyrepresentingthatwhattheopponent isdoing,eitheroutofhisowninitiativeor inresponse to waves sent out by tori in a pulsatile fashion. One can argue whether Hirano trulydistinguishesaseparatekuzushiphaseornot,sincetheopponentasaresultofhisownmovementswillalwayshavearelative imbalancesomewhere,whichtheensuingchoiceofgrippingthenwillsimply reinforce. Importantly, Hiranos tsukuri always contains a solid action/reaction responsethat involves considerablehazumi (rebound, recoil, spring, reaction). To do so,Hirano alsomakesampleuseofamyriadofhairikatadependingonthesituationalcircumstances(Hiranon.d.[a,b]),andwhichincludes,amongstothers:

Tsurikomi(liftandpullentry) Mawarikomi(spinningentry) Tobikomi(jumpingentry) Hand(reactiveentry) Oikomi(chasingentry) Hikidashi(pullingopenentry)

Figure6.HiranoTokiodemonstratinghisfamousTobiagari(Jumpingup)entryincombinationwithhisimmenselysuccessfultaiotoshi(bodydrop);FromHirano(n.d.[b]),withpermission.

Oneapproachthatincreasesorfacilitatestheeffectofkuzushi istoapplyit inarotationaltrajectory,sinceasubjectenduresgreaterdifficultyinrecoveringfromsidewaysorrotationallossofbalancethanfromastraightforwardorbackwardimbalance(Sacripanti,2010c,2012a,b).TheconceptoftaisabakiisintegraltoKdkanjdandconsideredimportantasclearlyshowninthehistoric footage inwhichKan Jigordemonstrateshis tokuiwaza (specialty):hidariukigoshi (left floating hip throw) (Figure 7), although its biomechanical relationship tokuzushiisnotcommonlyexplainedwithintheKdkansyllabus.Notethat,particularly,inDaitryaikijjutsuandaikidthesecircularpathwaysandtaisabakiareconstantlyemphasized.

In rotational kuzushi, the kuzushi actions form straightline tangents on an otherwisecircularpathormovement(Figure8).

Rotationalunbalancingalmost invariably is integratedwithamoredynamic formof jd,hence it is no surprise that Hirano Tokio proposed a didactic form of rotational flows, unlikeKdkanwhere thedidacticapproachof rotationalkuzushi is really limited toareassurance thattaisabakiisimportantandthatmastershipinitwillcomewithpractice.Instead,HiranoproposedEndnokata (Forms of circular motion) (Tegelaar, 2012a). He distinguished 6 suchforms:

1. Daien(Largecircle)2. Katatedaien(Singlehandedlargecircle)3. Ryteshoen(Doublehandedsmallcircle)4. Nanameen(Diagonalcircle)



5. Itosabaki(Surpriseturn)6. Kaitenen18(Rotatingcircle)

Figure7.KanJigordemonstratinghistokuiwaza(specialty):hidariukigoshi(leftfloatinghipthrow)onYamashitaYoshitsugu(1865

1935),oneofhismostloyalandseniorstudents.

Figure8.Schematicrepresentationofrotationalkuzushi(unbalancing);afterSacripanti2012b,p.

9,withpermission.

Figure9.HiranoTokioshowingaKonpasuen(compasscircle)entrytoapplykosotogari(minorouterreapthrow).FromTegelaar,(2012a),withpermission.

Jgenokata and Endnokata are forms neither intended nor suited for ceremonialdemonstrationscompletewithreih(formalbowingetiquette).Theyarepracticalformsthatserveasthegrammarofpuretechnicalskill,exactlyaskata(forms)wereintendedtobe.

Thesemethods for rotational unbalancing can be applied to several throwing techniques(Figure 10), although they are particularly suited to some.Hirano devised suchmethodsmostlybased on his own tokuiwaza (preferred technique), which included sotogari(major outside reap),sotootoshi (major outer drop), ipponseoinage (onepoint backcarry throw),uchigari (major inner reap), taiotoshi (body drop), anduchimata(innerthigh).Forexample,thelargecirclemethodisparticularlysuitedforuchimata,whereas the singledhanded large circle is particularly suited for ipponseoinage; on theotherhand,thediagonalcircleworksparticularlywellwithsotootoshi.

Oneof themajordifficulties in jd is choosing therightmomentofopportunity (debana) to initiate a certain throw, and thus also to initiate the appropriatekuzushi.However, oneshouldnotjustwaitpassivelyuntilthismomentoccursspontaneously.Ajdkahaswaystocreateor provoke such opportunities, or increase the frequency at which they occur, for example, byincreasingthetempoofthefight.Hirano,however,goesonestepfurtherbyattemptingtovisualizeanumberoftsukuri/kuzushistrategiesthatcouldeffectivelybeappliedtoeachthrow,andthatthusprecedethesevenverticalorthesixrotationalkuzushi formswhichwediscussedintheprevious18AlsothetermKonpasuen(compasscircle)appearstohavebeenusedbyHiranotorefertothesixthtypeofcircularentry(Figure9).

DeCre,C.


paragraphs. Hirano postulated that in addition to those forms of kuzushi there existed sevendifferenttypesofwaterwavesnamiorhand(reactions)thatprovidedthebasisonwhichhe modeled seven different tsukurikuzushi entities (Hirano, 1972b; Tegelaar, 2012a, 2012b).Thesewould exist separately from the chosen entryof the throw,with thewavesproducing thedebanaorrightmomentofopportunity.

Figure10.HiranoTokiosenseiduringavisittotheauthorsoriginaljdclub,theJdandJjutsuClubArsenaalMechelenin1955,demonstratinghismastershipofrotationalkuzushi,hereperformedon4

adversaries.Hiranowasknownonoccasionstoshowthesameapplicationonnolessthan10adversariesatthesametime.

HiranocollectedthedifferentkindsofwaterwavesornamiwhichhepostulatedinakatahedevisedandthathelaternamedHandnokata(Formsofreactions)(Hirano,1972b,pp.220221).ThetypesofwavesincludedinthisHandnokataarenamedasfollows:

1. nami(largeorsurgingwave)2. Yokoshibukior(sidewayssplash)3. Uchiage(upshootingwave)orJuwa19kudaki(squashingwave)4. Oinami(overtakingwave)/Uchigaeshi20(branding)5. Tatsumaki(waterspout)6. Naminohana(foamingwave)/Sakamaki21(clapotis22wave)7. Uzumaki(whirlpool)

19ASwisssource(Soave&Goetz,2007)suggeststhatthenameofthethirdtechniquewouldbeJuwakudakiorJwakudakiwithastranslationprovidedGroerFelsen.ItisunclearexactlywhichJapanesewordismeant,astheredoesnot exist a commonly used Japanese word with that pronunciation. Likely the name is a misunderstanding with theGerman translation Groer Felsen coming from the English Big rock, butwith theword rock here indicating arockingorshakingmovementratherthatrockinthesenseofalargestone.AwordforrockinginJapaneseisyura,andmaybewhatisintendedheremightbeyurakudaki(violenttremortillthepointofbreakingorsquashingwave).20ASwisssource(Soave&Goetz,2007)suggeststhatthenameofthefourthtechniquewouldbeUchigaeshiwithastranslationprovidedbranding.21ASwisssource(Soave&Goetz,2007)suggeststhatthenameofthesixthtechniquewouldbeSakamakiwithastranslationprovidedSturmwelle(Stormwaveorclapotiswave).22ThetermclapotisisderivedfromtheFrenchclapotiswhichreferstoasoundmadebythesea,calledclapoterandclapotement,whichisdefinedbymostFrenchdictionariesasaparticularsoundproducedbyaslightlyagitatedsea.In hydrodynamics the term clapotis has come to mean a nonbreaking standing wave pattern, often caused by thereflectionofasuccessionoftravelingsurfacewavesfromanearverticalshorelinelikeabreakwater,seawallorsteepcliff.Inmoremainstreamliteraturethetermoftensimplyimpliesalargestandingwave(Figure11).



Hirano would demonstrate these inceremonial kata form, showing how verylarge movements from one side of the matwoulddevelopall theway to theother sideandresultinthebestchoiceofkuzushiandaparticularly efficient throwing technique(Hirano, 1966, 1985b, 1986; Tegelaar,2012a, 2012b). The demonstration isreminiscent of Itsutsunokata (TheFive Forms), a formal series of fivetechniqueswhichKanJigorimportedfromTenjin Shinyry jjutsus Kuden gohon (The Five OralTransmissions)asawaytopayhisrespecttohisteachersandoneoftheparentschoolsofKdkan jd, as well as to edify jdsunwritten most advanced teachings (DeCre,2014).

Suchlargeandcontinuedmovementsare perhapsmore of a metaphysical naturehaving in thatwaya strict energyefficiency(Figure 12). However, their applicationcertainly can produce valuable results, asillustrated by Hiranos extremely dynamicandefficientjd.Thebestwayperhapsistocompare itwitha sonar system.The jdkasendsoutapulse,awave,anddependingonwhathappenstothatpulseorwave(doesitstop? is it returned? does it diminish? is itabsorbed?andifso,afterwhattimeintervalandwithhowmuchpower?),hewillchoosean efficient response optimizing rotationalkuzushi.Whentheseprinciplesareappliedina throw or randori they are much moresubtle to the extent that one will often notactuallyobservethesewavesinthedynamicarmmovementsofthepersoncreatingthem.

One starts awave (in reality often a series of subtle pushing or pulling action) and youropponentwilldosomethinginresponsewiththat:resist,givein,ignoreit,whatever.Thewaytheopponentdoesthisresisting,givingin,orignoringitwilldependonhisphysique,hisjdlevel,theextenttowhichhefeelsthreatened,etc.Thushemayblockinanexaggeratedway,orhemaybeveryskilledandevadeit.Allthesearewaystodealwithwaves,justlikewavesoftheocean(atleastinthewayHiranophilosophicallyperceivedthis, irrespectiveifhydrodynamicallythisiscorrect).Forexample,theycanbreakonrocksinthesea,theycandissipate,theycanreturnanddragyouwiththem,andtheycanevenrotateinthecaseofawhirlpoolorwaterspout.

In this way Hirano devised that he could transmit several types of waves and that theopponentcoulddealwiththosewavesinasetnumberofways.Dependingonhowtheopponentresponded, the logical answer would be a particular kuzushi and throw. The waves that oneinitiated, would not be merely pushing actions, but could be an entire throw with which oneattacked because there too the opponent would react in a limited number of ways, such as forexample: he is thrown, heblocks, he evades, he attempts to counter it, foreward, backward, left,right,etc(Kan,2011).

As such, Hiranos ideas are original, pedagogically very different from Kans and alsointeresting.However,oneof theaspectsthatHiranodidnotreallyaddresswasthat ...hehimself

Figure11.Aclapotisorlargestandingwave,i.e. anonbreakingstandingwavepattern,oftencausedbythereflectionofasuccessionoftravelingsurface

wavesfromanearverticalshorelinelikeabreakwater,seawallorsteepcliff.

Figure12.HiranoTokiosenseidemonstratinghisnami[wave]conceptasformingthebasisofkuzushi/tsukuriasappliedinhisHandnokata

[FormsofReactions].

DeCre,C.


alsopossessedincrediblestamina,speed,andwasextremelytalentedinjd.Thisthenraisesthequestionhoweffectiveandrealistictheapproachisfromadidacticpointofviewintermsofskilltransfer when it has to be applied by ordinary or average jdka and not worldclass athletesblessedwithextraordinaryskillsorcapabilities?DuringrandoriHiranodidnottendtomakethoselargepreparatorymovementsyouseeinhiskata.Insuchsituations,thosemovementsreallycouldbe so short that he could apply them while not making any movements greater than a fewcentimeters, beforehehad gained all the informationheneeded to followupwith adevastatingipponscoringthrow.

7.BiomechanicalappreciationofHiranoTokioskuzushisystem

Recallthat,accordingtoSacripanti(2010),KansfundamentalmaximofKdkanjd,i.e.,hisprincipleofSeiryokusaizenkatsuy(Optimaluseofenergy)inthebiomechanicsofjdcanbeclarifiedbytheJacobiformoftheleastaction,whichifexpressedmathematicallyis:

0)(21

=+ dWE withEbeingthekineticenergyandWbeingthepotentialenergy.

WehaveindicatedpreviouslythatthereexistthreetypesofGeneralActionInvariants,whichcoverthewholeplethoraofactionsofthebodymeanttoreducethedistancebetweenbothjdkaand to optimize ones ownbodyposition relative to that of the opponent in order to succeed inperforming a chosen throw (2010). Sacripanti proposed that these General Action Invariantsincludedinthekuzushitsukuriphaseare:

1. Reducingthedistancebetweenbothopponentsusingnorotation.2. Reducingthedistancebetweenbothopponentsusingacomplete(0to180)clockwise

orcounterclockwiserotation.3. Reducing the distance between both opponents using a half (0 to 90)

clockwise/counterclockwiserotation.

In theabove listwhich reflectson the trajectory completedby theentity formedbybothjdka,thefirstclassofGeneralActionInvariantsconsistsofanearlystraightline,whichpreferablywouldbe sideways (frontal plane) for simple reasonsof efficiency, namely that the humanbodyappearslessskilledtoresistorrecoverfromasidewaysunbalancingattack(Sacripanti,2012b).

When considering the other classes of General Action Invariants, i.e. those that includeeitherhalforcompleterotations,Sacripantiproposed23thatthemovementproducedbythejdkashows similarities to the rolling of a body according to an inertial ellipsoid (without slipping)trajectory on a specific plane. The jdkas body is cylindrical and symmetrical, and the inertialellipsoid becomes an ellipsoid of revolution. The curve created by the point of contact on theinertial ellipsoid is then a circle around the athletes axis of symmetry, and the curve on thetransversalplaneformedbythetatamialsorepresentsacircle(Sacripanti,2010a,b,c,2012a,b).Unfortunatelythisdescriptionisonlyaccurateiftheentityformedbybothathletesmovesfreelyasone, i.e. has no opposing interaction. In reality, jdka complete complex threedimensionaltrajectories that include frictions which exist between both jdka and between them and thetatami, and there are also pushpull actions between both jdka, thus making an accuratecalculationoftheirforcetimeevolutioninspaceextremelydifficult(Sacripanti,2010a,2012b).

However,atleasttheentityformedbybothjdkaisisolatedfromexternalforces.Afterall,the external gravity force is stopped by the tatami, and the entity formed by both jdka issubjectedtotherandompush/pullforcesthatoccurinternallywithinthesystemconsistingofbothjdka,andtothefrictionbetweentheirfeetandthetatami.Whentherandompushpullforcesaresubtracted, then this system follows a Langevintype Equation, as previously demonstrated bySacripanti(2010,2012):23ThissuggestionwasbasedonthePoinsotgeometricaldescriptionofafreeforcesmotionofabody(Sacripanti,2010,2012).



yfjj

j FFttmF +=+= )()1(

whereFisthetotalforceactingonthesystem,isthefrictioncoefficientactingagainstthedirectionofthetotalforce,visthesystemsvelocity,isKroneckersdeltawhichisafunctionoftwointegersthatinsomepointofspaceis1ifthevariablesareequaland0otherwise;tandtjaretwogenerictimeintegersoftheKroneckerdelta.Ifso,thenthetotalforceiscomposedbytwotermswithFfrepresentingthefrictionforcevandFybeingthestochasticforcecontribution(orterm) that is the sum of all the push/pull contributions which in the end and over a long timeinterval average zero because the push/pull contributions do not have any specific preferreddirectionandarerandom.

Trilles,Blais,andCadire(2010)ontheotherhandproposedtheNewtonianmathematicalform,inwhichonlytoris(theoneattacking)actionsandmovementsareconsidered:

)(// GTTTgroundTUT VMdtdRPF =++

orTgroundTGTTUT RPVMdt

dF // )( =

TgroundTGiii

UT RPVmdtdF T /

15

1/ )( =

= In this way attention is devoted to the possible variations in function of time of the

movementsproducedbythevarioussegmentalarticulations ingeneratingtheforceortheactualaction (FT/U) of tori on uke, on the weight (PT) and the ground reaction force Rground/T. Thecoordination requiredbetween thevariousbody segments24 accordingly canbeevaluated takingintoaccountthevectorialsumoftheirindividualmovement(Sacripanti,2010a,2012b).

While the possible choices of tsukuri/kuzushi actions are infinite, Hiranosensei proposedsomeunusualandapparentlyquiteefficientwaysoftsukuri/kuzushimanyofwhichmadeoptimaluse of rotational dynamics. Some of these tsukuri may have very particular biomechanicalproperties.Forexample,HiranosinfamousTobiagari(jumpingupentry)(seeFigure5)fromaphysicspointofviewisdifferentfromconventionalentrybecauseiteliminatesthefrictionthatisotherwiseproducedbythesolesofbothfeetturningonthetatami.However,themethodrequirestheadditionalenergyofhavingtojumpupandtemporarilymoveagainsttheEarthsgravity(9.81m/satsea level),aswellasairresistanceandovercomingacertainpulling forceappliedbytheopponentsgrip;elasticenergystorageinthemusclemaypositivelycontributetotheheightofthejump,butstillanunknownamountofworkwillbeputintotheactionofjumpingupwards:

= sdFW However,theamountofworkcreatedbyhavingtojumpupcouldwelloutweighthatwhat

isgainedbycancelingoutthefrictionbetweenthefeetandthetatamiduringnormalmovement.Ifindeed greater, then strictly speaking it would not longer be an application of Kans bestapplicationofenergyprinciple.

Trilles,Blais,&Cadire (2010)have studied the contributionof thedifferent segmentsofthebodytorotationanddifferenttypesofentryincludingtobikomi(jumpingentry).Between6570%oftherotationreliesonthelowerlimbs,withtrunkandheadrepresentingabout22%,andthe remainingapproximately10%being representedby theupper limbs.During tobikomientry

24 Trilles, Blais, and Cadire (2010) postulate the existence of fifteen different segments which the jdka uses ingenerating his movements, namely: head, hands, forearms, upperarms, trunk, pelvis, thighs, lower legs, and feet.According to these authors the articulations involved in connecting these segments can essentially be reduced tofourteen: between head and trunk (1), between upperarms and shoulders (2), between upperarms and forearms (2),betweenforearmsandhands(2),betweentrunkandpelvis(1),betweenpelvisandthighs(2),thighsandlowerlegs(2),betweenlowerlegsandfeet(2).

DeCre,C.


this is somewhatdifferent,withahigher contributionof the trunkandhead than inmanyothertypesof entry.At thepoint after tori has reachedhishighestpoint and isdescending, theupperlimbs contribute to almost 60% of the rotation and the trunk and head to 40% with thecontributionofthelegshavingfallenbacktonearzeropercentagecontribution.Timeofentrywithtobikomi isgenerallyabout1020%longerthanwhenforexampleusinghikidashi25(pulloutentry),likelybecauseofthelongerdistance(onehastoaddanupwardsdistanceinadditiontoa lateral displacement) covered during tobikomi. Trilles, Blais, & Cadire found for hikidashi atsukuriphasewhichlastedapproximately0.70s,andanoverlappingkuzushiphaseof1.40s,andakakephaseofapproximately0.30s, totalingabout1.70s,whereas fortobikomientriesthesameauthorsfoundatsukuriphaseof0.64sandanoverlappingkuzushiphase26of1.40s,butalongerkakephaseofapproximately0.50stotalingabout1.90s(Trilles,Blais,&Cadire,2010).

Inaddition,theseauthorsnotethatincaseoftobikomiduringthedescendingphasetoriisparticularlywellsuitedtorapidlyandforcefullybringinghiscenterofmassbelowthatofuke,andmayaddthemomentumcausedbyhisownmasstobringtheopponentoutofbalance.Therefore,thelongertimedoesnotimplyitwouldbelesssuccessful.

Figure13.ArtistsimpressionofSanbonme,thethirdtechniquefromItsutsunokata(TheFiveForms),whichaccordingtocurrentKdkanclaimswouldrepresentthenaturalphenomenonofa

whirlpoolandhowitcanbeappliedtojdtechniques.Notethatthereisactuallynohistoricfoundationtothisclaim,notinKdkan,andnotinitsparentschoolTenjinShinyryjjutsusfromwhichthekatawasimported(DeCre,2012,2014)(ArtworkcreatedbyJandeWringer,Amsterdam,

reproducedbykindpermissionoftheauthor,allrightsreserved2011).

25Ahikidashipulloutentryimpliesthatyoustepawayfromyouropponentwhilepullinghimtowardsyoutoclosethedistanceinpreparationofenteringathrow,insteadofmovingtowardshim.26Wenotethatthedivisionintokuzushiandtsukuri(andotherphases)isapedagogicalapproach,asexplainedinDeCreand Edmonds (2012). However, according to some authors, in terms of muscle activation and contraction those twophasescannotbeseparated.Forexample,alreadyin1978,Matsumotoetal, foundthatinallthenagewaza(throwingtechniques),themovementsofthetsukuriandthekakehavealreadybegunatthetimewhentheelectricaldischargeofthegastrocnemiusmuscleswasobservedattheinceptionofthekuzushi,indicatingthattheseriesconsistingofkuzushi,tsukuri,andkakestartssimultaneously.(Matsumoto,etal.,1978,p.38).However,thesolidityofthisconclusionwasnotclearsince thestudycontainedonlya singlepairof jdka. In suchcases itbecomesdifficult toconcludewhether theobservationshouldbeattributedtojditselfortothespecificjdstyleofthatathlete.Nevertheless,findingsbyTrilles,Blais&Cadire (2010) seem topoint in the samedirectionas these authors too appear to use the term overlappingkuzushiphase.Fromabiomechanicalpointofviewthewholemotionpatternconsistsofmeasurabletimestepsthatarenotstrictlyconnectedwithakuzushi,tsukuriorkakephase,astheyclearlyoverlapeachother.



Very characteristic and unusual in Hiranos didactic and practical approach oftsukuri/kuzushi ishisheavyrelianceonpostulatedwaterwaves.Withtheexceptionof the fourthtechniqueofKdkanjdsItsutsunokatathereisvirtuallynoprecedentforthisinjd.Itsutsunokata (Figure 13) is, however, one of Kdkans two most advanced kata, andgenerally very poorly understood due to its reliance on metaphysical, naturalistic, and Taoistprinciples.While this kata is a rinokata (Theoretical Forms), meaning that it is one ofmainly theoretical importance, Hiranos system as subsequently conceived in hisHandnokataalsoknownunderthenamesNanatsunokata,NaminokataorHiranonokata27(Kan,2011)isfarmoreappliedandpracticallyoriented.

Noprior scientific studyofHiranospostulatedwaveshas, however,beenattempted, andsuch study is timely to: further define the nature and meaning of those waves as part oftsukuri/kuzushi, establishwhether these different categories ofwaves truly exist and differ, andwhetherhydrodynamicmodelingdeservesaplaceinunderstandingandimprovingjdtechnique,especiallytsukuri/kuzushi.

8.Physicsandfluiddynamicprinciplesofstandardwind(surgingwave,clapotis,branding)andnonwind(whirlpool,waterspout,tsunami)propagatedwaterwaves

Most generally in physics waves are defined as a disturbance or oscillation that travelsthroughspacetime,accompaniedbyatransferofenergyfromonepointtoanother,oftenwithnopermanentdisplacementoftheparticlesofthemedium,meaningthatthisoccurswithlittleornoassociated mass transport. When waves are of a mechanical nature, they propagate through amediumwithdeformationofthatmedium.Inthecaseofwavesthatoccurintheseaortheoceanthe waves can be either wind or nonwindgenerated, and represent perturbations where themedium they propagate through is water. Windgenerated waves are generated by the windpassingoverthesurfaceoftheseaortheocean(Janssen,2004;Philips,1957,1977;Young,1999).ThemajorityofwavespostulatedbyHiranoinhisHandnokataarestandardorwindpropagatedwaterwaves;suchisthecaseforthenami(largeorsurgingwave),theyokoshibukior (sideways splash), theuchiage (upshootingwave), theoinami (overtakingwave)oruchigaeshi(branding),andthenaminohana(foamingwave)orsakamaki(clapotiswave).Toexaminetowhatextentthedidacticvalueofthesepostulatedwavesinjdisareflectionofhowtheyexistinrealliferatherthanbeingofamerelymetaphoricnature,weneedtodevotesomeattentiontothehydrostaticfoundationsandphysicsbehindtheoriginofthesewindpropagatedwaves.

Manyofthewavesweseeonapondornondeeppartsoftheoceanaresocalledshallowwater waves.Whenwaves travel into areas of shallowwater, they begin to be affected by thebottomofthesea.Thefreeorbitalmotionofthewaterisdisrupted,andwaterparticlesinorbitalmotion no longer return to their original position. As the water becomes shallower, the swellbecomeshigherandsteeper,ultimatelyassumingthefamiliarsharpcrestedwaveshape.Afterthewavebreaks,itbecomesawaveoftranslationthatisintensifiedbytheerodedbottomoftheseaorocean(Dean&Dalrymple,1991;Holthuijsen,2007;Jansen,2004;Lamb,1994;Munk,1950;Philips,1977;Young,1999).

27UsingthetermHiranonokatatorefertoHiranosHandnokataisamisnomer.Nevertheless,thiserroriscommittedfrequently. Hiranonokata implies the (one)katamadebyHirano,which is confusing andmisleading even thoughgrammatically in Japanese, the term alsomeans the (various) katamade byHirano (thus plural). The average nonJapanesespeakingjdkadoesnotrealizethis,andneitheristhetermreallymeantinthatwaysincemostpeopledonotknow that there existmultiple kata conceived by Hirano Tokio. The second term in use, andmuchmore common isNanatsunokata, thus Forms of Seven or Seven Forms. There are, however, problems with this term too. LikeItsutsunokata (Forms of Five or Five Forms), Nanatsunokata is a temporary name thatmerely refers to thenumberoftechniquesitcontains.MifuneKyz,forexample,usestheprobablenameofNanatsunokataforItsutsunokataanticipatingitsexpansionfromfivetosevenoreventenforms(Mifune,1956).Forthatreason,historicallyandfrom a scholarly viewpoint using that name for Hirano's Handnokata, is undesirable; an even stronger argumentevidently is that there is no credible evidence that Hirano ever formally assigned that name to this kata; rather heformallynameditHandnokata(Hirano,1972b).

DeCre,C.


Bothairpressuredifferencesbetweentheupwindandtheleesideofawavecrest,aswellasthe friction on thewater surface by thewind, cause thewater to go into the shear stress hencetriggering the growth of the waves (Dean & Dalrymple, 1991; Holthuijsen, 2007; Jansen, 2004;Lamb,1994;Miles,1957;Munk,1950;Philips,1977;Young,1999).Theheightofawaterwaveisdetermined by wind speed, the duration of time the wind has been blowing, the fetch, i.e. thedistanceoverwhichthewindexcitesthewaves,andbythedepthandtopographyoftheseafloor(whichcaneitheramplifyandfocusordispersethewavesenergy).Generally,thelargerthewave,themorepowerfulit is,however,amplitudeisnottheonlycriterionthatmatters.Wavepowerisalso determined by wave speed, wave length, and water density. The oscillatory motion of thewavesisthehighestatthesurfaceanddiminishesexponentiallywithdepth,withtheexceptionthatfor socalled clapotisor standingwaves, if theyoccurneara reflecting coast, thewaveenergywill also continue and be present as pressure oscillations at great depth, even leading to theproductionofsmallormicroseismicevents(Dean&Dalrymple,1991;Holthuijsen,2007; Jansen,2004;Lamb,1994;Munk,1950;Philips,1977;Reynolds,1877;Young,1999).

Theseconsiderationssuggestthatthefactorsandmechanicsinvolvedinthegenerationofwindpropagatedwaterwavesareofatotallydifferentnaturethanthemechanicsusedbyhumanspracticingjdandwhoaremimickingtheexternalappearanceofthesewavesinanenvironmentthat does not involve any water or other or forces of nature. In other words, as far as windpropagatedwaterwavesareconcernedtheseappeartobeusedorreferredtobyHiranomerelyinametaphoricalsense.

It is alsopossible to createavarietyof artificialwaves inwater includingcircularwaves,planewaves,reflection,refraction,diffractionandinterferencewaves,andeveninertialwaves,byputting objects of different shapes at different depths. However, this cannot be what Hiranointendedinhisvision.

InhistotalofsevendifferentwaterwavesHiranoalsoincludedanumberofnonstandardornonwindpropagated water waves. For example, the fifth type of water wave which Hiranodefined is the tatsumaki (waterspout). In reality a waterspout is not a water wave. Awaterspoutisafunnelshapedortubularcolumnofrelativelyweakrotatingcloudfilledairorwindusuallyextendingfromtheundersideofatoweringcumulusorcumulonimbusclouddowntothesurfaceofanoceanor lake.Therotationoccursat low levels in theatmosphere, so theresultingvortexdoesnotextendveryfarup intothecloud,andthephenomenonis largelyconfinedtotheregionbelowcloudbase(Dean&Dalrymple,1991;Lamb,1994).Whilemostwaterspoutscloselyresembleweaktornadoes,itisdebatedwhethertheyactuallyaretornadoesornot.Theyarereallyananomalyofnature,attributabletothedeviationinthemechanismoftheirformation.Theyformwhen cold air moves over warmwater, and they churn at speeds up to 350 km/h, but quicklydissipatewhenrainbeginstofallfromtheirhostcloud.Theatmosphericconditionsareobviouslysuchthattheyareimpossibletobecreatedbyanindividualhumanbeingonatatami...

The lastwavewhich Hirano defined is theuzumaki (whirlpool). Awhirlpool is aswirlingbodyofwater that isnotdirectlycausedbywindbutby themeetingofopposingwatercurrents,althoughthecurrentsthemselves,ifoccurringatthesurface,aremainlywinddrivenandinfluencedbytheCorioliseffect,althoughverticalandoceanbottomcurrentsarecausedmainlybydensitydifferencesasaresultofdifferencesintemperatureandsalinity(Dean&Dalrymple,1991;Holthuijsen,2007;Lamb,1994).Forexample,cold,saltywaterscomingfromthepolessinktotheocean bottom and move to opposite poles where they will again surface, although verticalupwelling currents canalsobecausebywindsblowing from the coastline.Whirlpoolsmayoccurbothinshallowordeepwater(Figure14).

Whirlpoolsreallyrepresenttheinertiaofwater.Whentryingtomovealargebodyofwater,thewatermolecules startmoving in a tangent because of their inertia, with the activated forcebeingcentrifugalforce.However,thedeeperonegoes,themoregravityactsonthewater,andthisgravityexertsapressureproportionaltohowmuchwaterisaboveit;thusthedeeperonegoesthehigherthepressure.Thispressureispushingagainsttheoutwardpressurecreatedbytherotationof the water, and forces the water back to the center, but proportional to the depth. Thus, thedeeperthewaterthemorepressureandgravitythatwillbepresent.



Therefore,atdepth,thewaterwillpushobjectscaughtinthewhirlpooltothemiddleofit,while at the surface such objectswill initially be pushed outwards (Dean and Dalrymple, 1991;Holthuijsen,2007;Lamb,1994).

A whirlpool technically is a freevortexorlinevortexinwhichthetangentialvelocityvvariesinverselywiththedistancerfrom the center of rotation so that theangular momentum rv is uniformeverywherethroughouttheflow;thevorticalmotion(vorticity)iszeroeverywhereexceptatthecenterline,andthevelocityatwhichaone circulation r=0 is completed has anidenticalvalueeverywhere, though the timetocompletethatrotationwillbelongerwhenfurther away from the center (Bradt,2001).In otherwords, the fluid near the center ofthe vortex completes one revolution in ashorter time than the fluid far from thecenter.

The speed of the fluid also decreases as the distance from the center increases. A leaffloatinginafreevortexwillmaintainanorientationthatremainsconstant,eventhoughitismovingaroundthecenterofthevortex.Ifthereisafreesurfacepresentthenitwillsharplydip(asr2)asthecenterlineisapproached(Bradt,2001).

Thetangentialvelocityofawhirlpoolvortexisgivenby:

rv 2

=

Intheabovemathematicalexpressionisthecirculationandristheradialdistancefromthecenterofthevortex.

It is also possible to integrate the nonconservative force exerted by a whirlpool on anobject suchasaboat. If the radial component isnegligible, and theazimuthal forcea functionofradius,thusaforcewithonlyanazimuthalcomponentF,itcanbeexpressedas(Bradt,2001):

urkuFF)) 1+==

Intheaboveequationisaunitvectorintheazimuthaldirection,kisaconstant,andthe

'+'indicatesthattheforceisinthepositiveazimuthaldirection.

If one integrates the quantity Fds around a circular path C2 at a constant radius r0 (SeeFigure15),then:

kdrrkdrrkdrFdsFWC

22001

001

0

2

00

2

02+==+===

Theoutcomewillnotbezeroasworkisdonebythenonconservativeforcethatcarriesthe

objectarounditscirculartrajectoryinthedirectionoftheforcevector.Becauseofthis,theworkW,asperformedbytheforce,willbepositive(Bradt,2001).

We assume that the objectmoves in a positive counterclockwise direction,which is alsowhatweassumedfortheforcecomponentFandforthedirectionofincreasingangle.Thereforethecounterclockwisedirectionoftheangulardisplacementinthiscasewillalsobepositive,whichisalsoreflectedbythelimitsontheintegral.Theselimitsimplythattheobjectmovesfrom=0to=2; if,ontheotherhandthepositivedirectionhadbeendefinedasclockwise,theintegrationlimitsforcounterclockwisedisplacementswouldhavebeen,forexample,0to2or2to0(Bradt,2001).

Figure14.Awhirlpooloccurringinshallowriverwater.

DeCre,C.


Figure15.Schematicdrawingofavectorfieldshowingaforcewithonlyanazimuthal

componentF,andindicatingthenonconservativeforceexertedbyawhirlpoolon

aboat(fromBradt,2001,p.11).

ForanyazimuthalforceF,independentof,theintegrationcanberewrittenas:

)0(2 02

002==== rC FrFdrFdsFW

Thus, the integral becomes quite simple iftheForceF isazimuthalandaxiallysymmetric. Inthiswayitpresentsinatransparentwaytheworkperformed by the force that moves the objectaround the circle, which simply is the constantazimuthal forcemultipliedbythedistancearoundthecircle(Bradt,2001).

The same concerns would apply to fortsunami which obviously also create waves,although to be fair, it is not one of the wavesconceptualizedinHiranos jd.However,tsunamiare neither wind nor objectpropagatedtransversewaves. Instead,atsunami isapressurewave with a longitudinal mode, which travels atvery high velocities or approximately 700 km/hr.Althoughittravelsasapressurewaveintheopenocean, the wave is reflected partially upwardswhenitreachesacontinentalshelf.

This has the effect of converting it into a transversewave aswatermoving along is nowpushedupwards.Thisisaverynonlinearprocessandnontrivialtomodel.Thispushingupofthewater does initially causewater at the shore to recede outwards. Thewavewhich seconds laterreachesshoreismuchmoreslowmoving,andalargepartofthatwaveenergyisconvertedintothetoweringwavefrontthatconsequentlywillsweepin(Dean&Dalrymple,1991;Holthuijsen,2007;Lamb, 1994). Because such phenomena involve gigantic natural forces they are irrelevant herewhendiscussinginterplaybetweentwohumans.

Amoreindepthanalysisofthephysicsandthemathematicalexpressionof fluiddynamicpropertiesofwaterwaves28and theirdifferent formsarebeyond thescopeof thepresentpaperandbeyondwhatisnecessarytounderstandinordertoseriouslyexaminethephysicsthatmightunderpinHiranoswavebasedtsukuri/kuzushisystem.

9.HydrodynamicprinciplesofwaterwavesandtheirpossiblebiomechanicalapplicationinHiranostsukuri/kuzushiphase

Thus,ofthesevenwavesdefinedbyHiranoonlyfivearerealwindpropagatedwaterwaves,whereastwoofthem(thewhirlpoolandwaterspout)arenotreallywavesbutariseastheresultofotherfactors,whichinthecaseofwhirlpoolshastodowithconflictingcurrentsofwater,andinthecaseofwaterspoutswithconflictingcurrentsofair.Itshouldbeobviousfromthereflectiononthephysics behind all these phenomena,whichwe have presented in the previous paragraphs, thatnoneofthemanycontributingfactors,suchasdensityofwater,saltconcentration,depthofwater,heightofwaves,temperaturesofwater,andgeographyoftheoceanbottomareinvolvedatall in

28 Investigating thephysicalpropertiesofwaterwaves isnot a simple affair and theirmathematical representation israthercomplicated.Theshallowwaterequationsarederivedfromequationsofconservationofmassandconservationofmomentum (socalled NavierStokes equations) and are often called shallow water equations or Saint Venantequations (Dean&Dalrymple, 1991; Lamb, 1994; Peregrine, 1972; Philips, 1977). Thesewere named afterAdhmarJeanClaudeBarrdeSaintVenant(17971886),aFrenchmathematicianandmechanicsexpert,whodevisedanumberofhyperbolic partial differential equations that describe the flow below a pressure surface in a fluid. Later, in 1872 theFrenchmathematicianandphysicistJosephValentinBoussinesq(18421929)inapaper(Boussinesq,1872)proposedanumberof specificdifferential equations that furtherapproximatedwaterwaves thatareweaklynonlinearand fairlylong,equationswhichtodayareoftenreferredtoasBoussinesqequations(Dean&Dalrymple,1991;Holthuijsen,2007;Lamb,1994;Philips,1977;Peregrine,1972).



jdinteractionsbetweentwopeoplewhoarenotevenimmersedinwater.Thereforeitisalsonotpossible to trulybiomechanicallyapply to jd thehydrodynamicbehaviorofwateras itdoes inwindpropagated water waves or in water behavior due to other meteorological phenomena.Rather, Hiranos water wavebased modeling of tsukuri/kuzushi represents a metaphysicalpedagogical approach and visualization aid. Despite these limitations, the discrepancy betweenwhat a true hydrodynamic analysis of those waves shows us, and how Hirano was able toincorporate his ideas in his jd, it did not prevent him from becoming a hugely successfulchampionfighterwhowasabletodefeatmuchheavierandstrongerjdka,thankstohissuprememastershipoftsukuri,kuzushiandotherfactorsessentialineffectingjdthrows.

AsSacripantihadalreadydemonstrated,thepotentialchoicesoftsukuri/kuzushiactionsareinfinite(Sacripanti,2010a,b,2012b).Thechoicesoftsukuri/kuzushiproposedbyHiranosenseiareoften unusual and apparently quite efficient partly because of their optimal use of rotationaldynamicsandNewtonsThirdLawofaction/reaction.However,toquantifyormeasureexactlyhowmuch more efficient they are than other selected examples of tsukuri/kuzushi is a rathercomplicatedtaskasitwouldneedtoisolatedthetsukuri/kuzushimethoditselffromtheskillsofthejdkaandrequireagoodreplicabilityofthoseformsoftsukuri/kuzushi.Sofar,Trilles,Blais,andCadire (2010) are some of the few researchers to have compared different forms oftsukuri/kuzushi, such as notably hikidashi vs. tobikomi entries. Even then, the outcomes werelimitedtoquantificationofvelocitiesandforcesandnotnecessarilytoefficiencyintermsofsuccessof breaking symmetry.Moreover, it did not appear that their approachwas able to separate theforms of hikidashi/tobikomi from the skills of the performer, meaning that another performermighthaveacompletelydifferentdistributionofforcesandvelocitiesdependingonhisskillinthechosenmovements.

Visualization is a useful tool in learning motor skills, and perhaps whether what onevisualizes being scientifically correct or notmay be secondary to thatwhat one is attempting toachieve.Ifonesucceedsinoptimallyapplyinggeneralactioninvariantsorbreakingthesymmetryoftheopponentbecauseoneimaginesoneappliesamovementasatsunamiortornadooranimal,itprobablydoesnotmatter that in realityboth in termsof force, actingmechanismsornaturewhatoneisdoinghasmateriallynothingtodowiththeimageoneisreferringto.AstothesuccessofHiranospedagogicalsystemandwhetheritfacilitatesskillacquisitionmorethanthetraditionalKdkandidacticalapproach,ishardtosaybecauseofalackofharddatathathavecomparedthisin longitudinalstudies.Rathertheapproachmaybetterwork insomesimplybecausetheymightsee a rolemodel inHiranosensei and are fascinated by his system or its originality,whichmaymotivate them to train harder or differently. One major problem is that of those who had theprivilegetotrainunderHirano,virtuallynooneproperlyunderstoodhisapproach.Thiswaslikelythe consequenceof a relative lackof experience still amongmanyWestern jdka in thosedays,andbecauseofcommunicationchallengeswithHiranosenseiduetolimitationsinhismasteringofnonJapaneselanguages.Thus,foremostbeforebeingabletobetterevaluatethevalueofHiranosdidacticalapproachonewouldneedinstructorswhoproperlyandcomprehensivelyunderstandhissystemandarewillingtodevotetimeandeffortintoteachingtheirstudentsinthatway.

10.Conclusions

The fluid dynamic modeling of the several kinds of waves proposed by Hirano ismathematicallycomplicatedinvolvingclassicBoussinesqdifferentialequations(Boussinesq,1872;Dean & Dalrymple, 1991; Peregrine, 1972). Numerous parameters which determine thehydrodynamicbehaviorofwater(depth,periodofwaves,saliency,temperatures,currents,shapeofthecoastalline,densityofthewater,wind)areabsentinthesurroundingsoftwojdkaindoorsona tatami, hence Hiranos system appears limited to a mere visualization and metaphysicalinterpretationofjd.

ThelackofempiricaldataavailableobtainedinlargegroupsofstudentstaughtaccordingtoHiranosapproach,makeitsofarimpossibletoconcludewhetheritfacilitateskuzushiandtsukuriskillacquisition,withonemajordifficultybeingseparatingHiranossystemfromtheskillsof theindividual. Hiranos success in competitive jd may as well be explained by him being

DeCre,C.


exceptionallygiftedandskilledratherthanbyhisuseofthewavesystemitself.UltimatelyHiranoswavebasedkuzushi/tsukuridoesnotalterthebiomechanicalanalysisproposedbySacripanti,asitstillinvolvesgeneralactioninvariantsaimedtoclosethedistancebetweentheopposingjdka,tobreaktheopponentssymmetry,andtoapplyoneoftheinfiniteoptionstoachievethis.

Notes

1. Preliminary data from this studywere presented in part at the 5th European Science of JudoSymposiumonApril23rd,2014 inMontpellier,France,organizedby theEuropean JudoUnion(EJU).

2. Japanesenamesinthispaperarelistedbyfamilynamefirstandgivennamesecond,ascommonintraditional Japaneseusageandtomaintainconsistencywiththeorderofnamesof Japanesehistoricfigures.

3. For absolute rigor, long Japanese vowel sounds have been approximated usingmacrons (e.g.Kdkan) in order to indicate their Japanese pronunciation as closely as possible. However,whenreferringtoorquotingfromWesternliterature,therelevanttextorauthoriscitedexactlyaspertheoriginalsource,withmacronsusedoromittedaccordingly.

Acknowledgements

WeareindebtedtoProfessorAttilioSacripanti,PhD,UniversityofRomeTorVergata,forhishelpinunderstandingandanalyzingthebiomechanicalfoundationsandphysicsbehindthepreparationandunbalancingaspects thatprecede jd throws.Weare indebtedtoMriOsamu,Satte, Saitama Prefecture, Japan, and Hirano Kiyo, Paris, daughter of HiranoTokiosensei, for themanydiscussions Ihad thepleasureofengaging inwith them,and inwhichtheyprovidedhelpfulremarksandinformation.Dr.LlyrC.Jones,PhD,London,kindlyproofreadthemanuscriptandmadeusefulsuggestions,andDrs.ir.StijnCoertjens,MEng,DepartmentofChemicalEngineering(CIT),CatholicUniversityofLeuven,Belgium,kindlyofferedhisassistancewithsomeofthelinedrawings.

References

Arima,S.().(1904).JdTaii()[Asynopsisofjd].Tky:OkasakiOkushoten()[inJapanese].

Arima,S.(1906).Jd.Japanesephysicalculture.Beingafurtherexpositionofjujitsuandsimilararts.Tky:Mitsumura&Co.,Ltd.

Boussinesq, J. V. (1872). Thorie des ondes et des remous qui se propagent le long d'un canalrectangulaire horizontal, en communiquant au liquide contenu dans ce canal des vitessessensiblement pareilles de la surface au fond [Theory of waves and eddies that propagatealong a horizontal rectangular channel by communicating with the fluid contained in thatchannel at notably similar velocities from surface to the deep]. Journal deMathmatiquesPuresetAppliques,DeuximeSrie17,55108[InFrench].

Bradt, H. (2001). Series approximations integration (line integrals, double and triple integrals,integratingvectordotproducts,closedandopenlinesandsurfaces).Physics8.02:Mathematicssupplement for 18.01 Graduates. Cambridge, MA: Massachusetts Institute of Technology,DepartmentofPhysics.

Chen, J.,&Chen,Th. (2002).TokioHirano (19221993)8thDan.Themanwhorevolutionized judo.[retrievedJuly24th,2011].Availablefrom:URL:http://judoinfo.com/hirano.htm.

Clause,M. (2003). Clinic. Demonstration. [Video clip] [retrieved July 24th, 2011]. Available from:http://www.youtube.com/watch?v=pEYLQKEEwN8[inFrench].

Dean,R.G.,&Dalrymple,R.A.(1991).Waterwavemechanicsforengineersandscientists.AdvancedSeriesonOceanEngineering2.Singapore:WorldScientific.



DeCre,C.(2014).Rysetsu.Jdnomushashugy()Assnowonawillow.Apilgrimageinjd.Cambridge:CambridgeUniversityPress.Inpreparation.

DeCre, C. (2012).TheOrigin,essence,biomechanical foundations,and teachingandperformancechallengesof Itsutsunokata [TheFormsofFive]Kdkan jdsesotericsixthkata.ThesisMScinTeachingandCoachingJudo,SchoolofMedicineandSurgery,UniversityofRomeTorVergata.

De Cre, C., & Edmonds, D. A. (2012). A technicalpedagogical reflection on the conceptual andbiomechanical properties of Kdkan jds kouchigari [minor inner reaping throw].ComprehensivePsychology,1(1),113.

DeCre,C.,& Jones,L.C. (2009).Kdkan jdselusive tenthkata:TheGnokataFormsofproperuseofforce(Part13).ArchivesofBudo,5(1),OF5595.

Geels, A. (1979). Judo: het ne waza van "Opa Schutte [Judo: the newaza of Opa Schutte].Helsingborg,Sweden:PlusUltra[inDutch].

Hirano,T. (1966). Judo isbeweging [8mm film]. 12th International SummerSchool,KasteelWell,Well, Limburg, the Netherlands. [retrieved April 13th, 2008]. Available from: URL:http://www.youtube.com/watch?v=S6Kd570Gfzc.

Hirano,T.().[1969](1972a).Jdsekainagearuki()[Chronicleofwalking around throwing through the world of jd]. Tky: Tbu shob () [inJapanese].

Hirano, T. (). [1969] (1972b). Hirano jd no jizen tsukuri to kata()[ThemakeupofHiranosjdandkata]:Hiranoshikikatanoiroiro()[VariousaboutexpressingHiranoinkata].In:Jdsekainagearuki()[Chronicleofwalkingaroundthrowingthroughtheworldofjd](pp.219230).Tky:Tbushob()[inJapanese].

Hirano,T.().(1985a).Honnojd:kyshaenomichi()[Jdoffire:the way of an exceptional man]. Tky: Tky Masahiro Insatsu Kabushiki Kaisha()[TkyMasahiroPrintingCorporation][inJapanese].

Hirano, T. (1985b). Nanatsunokata [videoclip]. Hirano Tokio, 8th dan (tori) & Unknown uke.France. [retrieved February 13th, 2010]. Available from: URL:http://www.youtube.com/watch?v=nhh4xLxoynw.

Hirano,T.(1986).Nanatsunokata[videoclip].HiranoTokio,8thdan(tori)&Unknownuke.France.[retrieved February 16th, 2010]. Available from: URL:http://www.youtube.com/watch?v=IwyZxbsZqV4

Hirano, T. (no date [a]). Judo. Technique N 1 (a). Bruges, Belgium: Judo Centrum [BilingualFrench/Dutch].

Hirano, T. (no date [b]). Judo. Taiotoshi. DeurneAntwerp: P.V.B.A. Lucky [QuadrilingualEnglish/French/German/Dutch].

Holthuijsen, L.H. (2007).Waves inoceanicand coastalwaters. Cambridge: CambridgeUniversityPress.

Ikai,M.,&Matsumoto,Y.(1958).Thekineticsofjudo.In,BulletinoftheAssociationfortheScientificStudiesonJudoReportI(pp.4961).Tky:Kdkan.

Imamura,R.T.,Hreljac,A.,Escamilla,R.F.,&Edwards,W.B.(2006).Athreedimensionalanalysisofthecenterofmassforthreedifferentjudothrowingtechniques.JournalofSportsScienceandMedicine,5(CSSI),122131.

Imamura, R. T., Iteya, M., & Ishii, T. (2007). Kuzushi and tsukuri and the theory of reactionresistance.In,BulletinoftheAssociationfortheScientificStudiesonJudoReportXI(pp.4957).Tky:Kdkan.

Janssen, P. (2004). The interaction of oceanwaves andwind. Cambridge: Cambridge UniversityPress.

Kan, C. (2011). Nanatsu no kata. [retrieved September 29th, 2011]. Available from: URL:http://judoforum.com/index.php?/topic/45563nanatsunokatatokiohirano/

Kan, J. (). (1931). Jd kyhon jkan () [A textbook of jd]. Tky:ShushikiKaisha[inJapanese].

Kan,J.(1932).Thecontributionofjudotoeducation.JournalofHealthandPhysicalEducation,3,3740&58.

DeCre,C.


Kan,J.(2006).MindoverMuscle:WritingsfromtheFounderofJudo.MurataNaoki,editor&RossNancyH.,translator.Tky:KdanshaInternational.

Kansensei Denki Hensankai () [Editorial Committee for the Biography ofKansensei](Eds.).(1984).KanJigor().Tky:Kdkan[inJapanese].

Kdkan(Eds.).(1986).IllustratedKodokanJudo.Tky:Kdansha.Kud,K.().(1967).Dynamicjudo:Throwingtechniques.Tky:JapanPublications.Lamb,H.(1994).Hydrodynamics(6thed.).Cambridge:CambridgeUniversityPress.Maruyama,S.().(1939).DaiNihonjdshi()[CompleteHistoryofJapanese

Judo].Tky:Kdkan()[inJapanese].Matsumoto, Y., Takeuchi, Y., Nakamura, R., Tezuka, M., & Takahashi, K. (1978). Analysis of the

kuzushi in the nagewaza. InBulletin of theAssociation for the Scientific Studies on Judo ReportV.(pp.3139).Tky:Kdkan.

Mifune,K.(1956).Canonofjudo.K.Sugai,transl.Tokyo,Japan:SeibundShinkshaPublishingCo.Mifune, K. (). [1955] (2005). Shingi Mifune Jdan [kanzenhan]: Jd no shinzui (

)[Mifune10thdan[completeedition]:Theessenceofjd].[DVD]NihonEigaShinsha(),1955.Tky:QuestCo.,Ltd.;DVDSPD3514[inJapanese].

Mifune, K. (), Kud, K. (), &Matsumoto, Y. (), (Eds.). (195556). JdKza()[Courseofjd].Vol.15.Tky:Shiromizusha()[inJapanese].

Miles,J.W.(1957).Onthegenerationofsurfacewavesbyshearflows.JournalofFluidMechanics,3(2),185204.

Munk, W. H. (1950). Origin and generation of waves (pp. 14). Proceedings 1st InternationalConferenceonCoastalEngineering,LongBeach,CA:ASCE.

Oimatsu, S. (). (1976). Kaitei shinpan jd hyakunen () [Brand newrevised edition of Hundred Years of Jd] (pp. 4053). K. Sat (Ed.). Tky: TokimuneTsshinsha()[inJapanese].

Okada,H.().(2008).JissainoshiainiokerunokuzurenikansurukenkyKanJigorhata Kokusai Taikai ni okeru sotogari (w)o taish ni. ( )[Studyofbreakingtheopponent'sbalance insotogariduringtheJigorKanCup2005].TsukubaDaigakuTaikuKagakuKeiKiy()[BulletinoftheInstituteofHealth&SportsScience,UniversityofTsukuba],31,171174[inJapanese].

Okano,I.().(nodate).OkanoIsaonovaitarujd.WatakushinotokuiwazaDaiikkan&Dainikan ( 1 &2) [Okano Isaos Vital Judo.MypreferredtechniquesVol.1&2].[VHSVideotapes].Selfpublished[inJapanese]

Okano,I.,&Sat,T.(1973).Vitaljudo:Throwingtechniques.Tky:JapanPublications.Peregrine,D.H. (1972).Equations forwaterwavesand the approximationsbehind them. InR.E.

Meyer (Ed.),Waves onBeaches andResulting SedimentTransport (pp. 95121). New York:AcademicPress.

Phillips,O.M. (1957).On the generationofwavesby turbulentwind. JournalofFluidMechanics,2(5),417445.

Phillips,O.M.(1977).Thedynamicsoftheupperocean(2nded.)Cambridge:CambridgeUniversityPress.

Reynolds,O.(1877).Ontherateofprogressionofgroupsofwavesandtherateatwhichenergyistransmittedbywaves.Nature,16d,343344.

Sacripanti, A. (1987). Biomechanical classification of judo throwing techniques (NageWaza) (pp.181194).5th InternationalSymposiumofBiomechanics inSport,Greece:Athens.[retrievedSeptember4th,2012].AvailablefromURL:http://cdsweb.cern.ch/record/1111755.

Sacripanti,A. (2010a).Advances in judobiom

judo kata

Documents