CloseMenuYogaAnatomy:4StepstoHanumanasana(MonkeyPose)RayLongMD,FRCSCUpdated: June12,2020Original: June12,2020TweetToparaphrasethepoetWilliamBlake,youcanseetheworldinagrainofsand.Similarly,youcanlearnagreatdealaboutallasanasbycarefullystudyingone.Forthisblogpost,IfocusonHanumanasana(MonkeyPoseorFrontSplits).Iusethisposeinworkshopstoillustratesuchfactorsasposeanalysis,agonist/antagonistmusclepairs(andtheirsynergists),physiologicalreflexarcs,andstretchingbiomechanics. First,let’slookatthemuscle-tendonunit—themuscleanditstendon—toseewhatlengthensinthepose.Themuscle-tendon(MTU)unitiscomposedofseveralelements.Theseincludethecontractilestructures(sarcomeres)andthefascialelementsthatsurroundthemusclefibersandtendons.Althoughtheseelementsareoftenpresentedseparatelyinarticlesonthescienceofstretching,inreality,theyareinextricablylinkedtooneanother.  Alloftheseelementscontributetomusclecontractionandstretching.Inaddition,manyfactorscontributetothewayamusclelengthens,includingtheviscoelasticproperties,creep(atypeofdeformationthathasbeenpostulatedforfascialelements),neurological/psychologicalfactors(suchasmusclememoryandtolerance),andextramuscularlinkstosynergists.Individualmusclearchitectureorshapealsoplaysarole.Below,Iincludeseveralreferencesfromthescientificliteraturethatdiscussthesefactorsingreaterdetail.HowTimingAffectsStretchingNext,thereisthetimingofthestretchorhowlongtoholdit.IderivemypersonalapproachtotimingthestretchinHanumanasanafrompublishedbiomechanicalstudiesonstretching.Thesestudiesindicatethatthemajorityoflengtheningorreleaseofthemuscle-tendonunittakesplaceinthefirst20secondsofthestretch.Similarly,whenrepeatingastretch,thelengtheningofthemuscle-tendonunitappearstodiminishwitheachsuccessivestretch,reachingitsmaximumatthefourthstretch,afterwhichlittleadditionallengthisgainedbyfurtherstretching.(Imageright: Cross-sectionofmuscleillustratingthecontractilesarcomereswithfascialelementssuchastheperimysium.)Weprovideanillustrativecurveforthisprocessbelow.Youcanseetheexper