Osteopathic MedicalOsteopathic MedicalOsteopathic Medical Osteopathic Medical History and PhilosophyHistory and Philosophy

H. James Jones, DOH. James Jones, DOThis material is

Associate Professor of Associate Professor of Neurology/OMMNeurology/OMM

protected by copyright law (Title 17 U.S. Neurology/OMMNeurology/OMM

Diplomate of the American Board Diplomate of the American Board of Psychiatry and Neurologyof Psychiatry and Neurology

17 U.S. Code)

of Psychiatry and Neurology of Psychiatry and Neurology College of Osteopathic Medicine College of Osteopathic Medicine f th P ifi /W t U i itf th P ifi /W t U i itof the Pacific/Western University of the Pacific/Western University

of Health Sciences of Health Sciences

The Challenge of InnovationThe Challenge of InnovationAbout 133 years ago, Andrew Taylor Still, MD About 133 years ago, Andrew Taylor Still, MD (1828(1828--1917) struggled with the medical 1917) struggled with the medical (( ) gg) ggarmamentarium of his day as he observed armamentarium of his day as he observed helplessly while conventional medicine of his helplessly while conventional medicine of his

f il d t hi hild t i k ithf il d t hi hild t i k ithera failed to cure his children stricken with era failed to cure his children stricken with cerebrospinal meningitis.cerebrospinal meningitis.Dr Still ho practiced for man ears as anDr Still ho practiced for man ears as anDr. Still, who practiced for many years as an Dr. Still, who practiced for many years as an orthodox physician, came to the conclusion orthodox physician, came to the conclusion that the contemporary orthodox medicalthat the contemporary orthodox medicalthat the contemporary orthodox medical that the contemporary orthodox medical treatment of his day, was unscientifically treatment of his day, was unscientifically based and was largely ineffective, or at times based and was largely ineffective, or at times g yg youtright harmful. outright harmful.

The Challenge of InnovationThe Challenge of InnovationThe Challenge of InnovationThe Challenge of InnovationStill practiced as an orthodox physician Still practiced as an orthodox physician i t l t 1849 H tt d d thi t l t 1849 H tt d d thsince at least 1849. He attended the since at least 1849. He attended the

Kansas City School of Physicians and Kansas City School of Physicians and S i di t l ft th Ci ilS i di t l ft th Ci ilSurgeons immediately after the Civil Surgeons immediately after the Civil War, but left before receiving his formal War, but left before receiving his formal dddegree.degree.He received his medical training in a He received his medical training in a manner similar to most American manner similar to most American physicians of the time, via a process of physicians of the time, via a process of apprenticeship, scholarly reading and apprenticeship, scholarly reading and observation and treating of patients. observation and treating of patients.

Dr Still’s Medical LicenseDr Still’s Medical LicenseDr. Still s Medical LicenseDr. Still s Medical License

Andrew Taylor Still, MD (1828Andrew Taylor Still, MD (1828--1917)1917)

The Challenge of InnovationThe Challenge of InnovationStill sought a different approach to understandingStill sought a different approach to understandingStill sought a different approach to understanding Still sought a different approach to understanding disease that would permit an alternative to the disease that would permit an alternative to the common remedies of his day that included blood common remedies of his day that included blood letting (the medical practice of opening a vein and letting (the medical practice of opening a vein and bleeding the patient for “therapeutic” purposes; and bleeding the patient for “therapeutic” purposes; and the use of lead or mercury [“Calomel”] based the use of lead or mercury [“Calomel”] based y [ ]y [ ]purgatives to induce bowel movements). This purgatives to induce bowel movements). This medical approach of the day, espoused by Benjamin medical approach of the day, espoused by Benjamin Rush of the University of Pennsylvania was known asRush of the University of Pennsylvania was known asRush of the University of Pennsylvania was known as Rush of the University of Pennsylvania was known as “heroic medicine”“heroic medicine”Still explored many types of medical philosophies of Still explored many types of medical philosophies of y yy yhis day, but again found them wanting. The central his day, but again found them wanting. The central issue of medicine, he would later maintain was not issue of medicine, he would later maintain was not which drug to use but whether drugging the patientwhich drug to use but whether drugging the patientwhich drug to use, but whether drugging the patient which drug to use, but whether drugging the patient in and of itself was always an appropriate form of in and of itself was always an appropriate form of therapy. therapy.

Bleeding BowlBleeding BowlBleeding BowlBleeding Bowl

Bloodletting KnifeBloodletting KnifeBloodletting KnifeBloodletting Knife

The Challenge of InnovationThe Challenge of InnovationThe Challenge of InnovationThe Challenge of InnovationStill felt that the body possessed an efficient Still felt that the body possessed an efficient “chemical laboratory” capable in health of creating“chemical laboratory” capable in health of creatingchemical laboratory , capable in health, of creating chemical laboratory , capable in health, of creating all of the substances that it needed.all of the substances that it needed.Thus in sickness, the answer would not by his Thus in sickness, the answer would not by his yyreasoning, be found necessarily in administering reasoning, be found necessarily in administering more drugs (remember in his era, most of the somore drugs (remember in his era, most of the so--called “medicines” were arguably mostly poisons ofcalled “medicines” were arguably mostly poisons ofcalled medicines , were arguably mostly poisons of called medicines , were arguably mostly poisons of unproven efficacy).unproven efficacy).Still felt the solution to disease was to find out what Still felt the solution to disease was to find out what was creating the bodily disturbance and remove that was creating the bodily disturbance and remove that interference so that the body could return to its interference so that the body could return to its normal state of healthful homeostasisnormal state of healthful homeostasisnormal state of healthful homeostasisnormal state of healthful homeostasis..

Caduceus Vs. Rod (Staff) of Caduceus Vs. Rod (Staff) of A l iA l iAesculapiusAesculapius

DO and the Rod of AesculapiusDO and the Rod of AesculapiusDO and the Rod of AesculapiusDO and the Rod of Aesculapius

Guinea Worm Dracunculus Guinea Worm Dracunculus di i ) R ldi i ) R lmedinesis) Removal medinesis) Removal

The Four Principles of The Four Principles of Osteopathic MedicineOsteopathic Medicine

The human being is a dynamic unit of function.The human being is a dynamic unit of function.The human being is a dynamic unit of function.The human being is a dynamic unit of function.The body possesses selfThe body possesses self--regulatory regulatory mechanisms, with inherent self healing mechanisms, with inherent self healing , g, gproperties.properties.Structure and function are interStructure and function are inter--related at all related at all levels.levels.Rational therapy is then based upon this Rational therapy is then based upon this understanding of body unity, selfunderstanding of body unity, self--regulatory regulatory mechanisms and the intermechanisms and the inter--relatedness of relatedness of t t d f tit t d f tistructure and function.structure and function.

Mark Twain: “The Educated Mark Twain: “The Educated Physician will Himself be anPhysician will Himself be anPhysician will Himself be an Physician will Himself be an

Osteopath”Osteopath”

The Challenge of InnovationThe Challenge of InnovationThe Challenge of InnovationThe Challenge of InnovationStill’s philosophical beliefs led him to Still’s philosophical beliefs led him to investigate drugless forms of healinginvestigate drugless forms of healinginvestigate drugless forms of healing, investigate drugless forms of healing, including “boneincluding “bone--setting”. setting”. Hi i ith ti tHi i ith ti tHis experiences with many patients His experiences with many patients demonstrated that a variety of ailments demonstrated that a variety of ailments th t h d t b li d b th dth t h d t b li d b th dthat had not been relieved by orthodox that had not been relieved by orthodox ministrations of the day, were receiving ministrations of the day, were receiving

id bl b fit f hi lid bl b fit f hi lconsiderable benefits from his manual considerable benefits from his manual manipulations.manipulations.“Seek Health In Your Patients, Anyone “Seek Health In Your Patients, Anyone Can Find Disease”.Can Find Disease”.

The Challenge of InnovationThe Challenge of InnovationStill ld th t th ff t f di dStill ld th t th ff t f di dStill would argue that the effects of disease were due Still would argue that the effects of disease were due to obstruction or imbalances of the fluids of the body, to obstruction or imbalances of the fluids of the body, principally the blood (denoted by the metaphor: “the principally the blood (denoted by the metaphor: “the p p y ( y pp p y ( y pArtery Rules Supreme”). He believed that these Artery Rules Supreme”). He believed that these physiological disturbances were caused by physiological disturbances were caused by misalignment of the musculoskeletal systemmisalignment of the musculoskeletal system ThisThismisalignment of the musculoskeletal system. misalignment of the musculoskeletal system. This This concept was later expanded to other vascular concept was later expanded to other vascular systems of the body including the venous, systems of the body including the venous,

t i l d l h ti tt i l d l h ti tarterial and lymphatic systemsarterial and lymphatic systems. . In 1874 he announced his medical philosophy of In 1874 he announced his medical philosophy of “osteopathy”. Dr. Still attempted to incorporate this“osteopathy”. Dr. Still attempted to incorporate thisosteopathy . Dr. Still attempted to incorporate this osteopathy . Dr. Still attempted to incorporate this medical doctrine at Baker University in Baldwin medical doctrine at Baker University in Baldwin Kansas, but the university was not accepting of his Kansas, but the university was not accepting of his ideas In 1892 Still established the first school ofideas In 1892 Still established the first school ofideas. In 1892 Still established the first school of ideas. In 1892 Still established the first school of Osteopathy in Kirksville, Missouri to train others in Osteopathy in Kirksville, Missouri to train others in this philosophy.this philosophy.

Baker UniversityBaker UniversityBaker UniversityBaker University

The Challenge of InnovationThe Challenge of InnovationStill’s first faculty at the Kirksville school Still’s first faculty at the Kirksville school (American School of Osteopathy=ASO), (American School of Osteopathy=ASO), i t d th k l d f th di t d th k l d f th dincorporated the knowledge of more orthodox incorporated the knowledge of more orthodox medical traditions into the philosophy of medical traditions into the philosophy of OsteopathyOsteopathyOsteopathy.Osteopathy.They argued that the “germ theory” of disease which They argued that the “germ theory” of disease which was controversial for its day (Still did not initially was controversial for its day (Still did not initially endorse the “germ theory”), while bacteria or viruses endorse the “germ theory”), while bacteria or viruses might be the causative agent of infectious disease, might be the causative agent of infectious disease, musculoskeletal dysfunctions may predisposemusculoskeletal dysfunctions may predisposemusculoskeletal dysfunctions may predispose musculoskeletal dysfunctions may predispose towards physiologic derangement that would place towards physiologic derangement that would place the person in a state of lowered resistance, permitting the person in a state of lowered resistance, permitting infection to gain a foothold in the body andinfection to gain a foothold in the body andinfection to gain a foothold in the body and infection to gain a foothold in the body and expressing itself as manifest disease (host control of expressing itself as manifest disease (host control of illness and susceptibility).illness and susceptibility).

American School of Osteopathy American School of Osteopathy (ASO)(ASO)

Medical Infirmary at ASOMedical Infirmary at ASOMedical Infirmary at ASOMedical Infirmary at ASO

The Challenge of InnovationThe Challenge of InnovationThe Challenge of InnovationThe Challenge of InnovationBy correcting the musculoskeletal By correcting the musculoskeletal y gy gderangements, the body’s natural defenses derangements, the body’s natural defenses (e.g. the immune system in the case of an (e.g. the immune system in the case of an

f )f )infectious disease process) would then be infectious disease process) would then be more effectively expended to address more effectively expended to address whatever process was affecting itwhatever process was affecting itwhatever process was affecting it. whatever process was affecting it. The musculoskeletal system is primary to The musculoskeletal system is primary to how humans express their interaction within ahow humans express their interaction within ahow humans express their interaction within a how humans express their interaction within a given environment. Without it, we would be given environment. Without it, we would be unable to move or interact with this unable to move or interact with this environment (metaphor for “mind, matter and environment (metaphor for “mind, matter and motion”).motion”).

The Challenge of The Challenge of I tit ti li tiI tit ti li tiInstitutionalizationInstitutionalization

As a social movement, osteopathy was As a social movement, osteopathy was p yp yoff to a successful beginning. off to a successful beginning. By 1898, more than 700 students wereBy 1898, more than 700 students wereBy 1898, more than 700 students were By 1898, more than 700 students were enrolled in ASO. enrolled in ASO. The American Osteopathic AssociationThe American Osteopathic AssociationThe American Osteopathic Association The American Osteopathic Association (AOA) established itself in 1901.(AOA) established itself in 1901.Osteopath m ch to the s rprise ofOsteopath m ch to the s rprise ofOsteopathy, much to the surprise of Osteopathy, much to the surprise of early detractors, would not prove to be a early detractors, would not prove to be a transitory fad or fashion but rather antransitory fad or fashion but rather antransitory fad or fashion, but rather an transitory fad or fashion, but rather an ongoing phenomenon.ongoing phenomenon.

First Graduating Class of ASO (Dr. Still First Graduating Class of ASO (Dr. Still is centered in the picture with hisis centered in the picture with hisis centered in the picture with his is centered in the picture with his teaching skeleton, “Columbus”)teaching skeleton, “Columbus”)

Anatomy Class at ASOAnatomy Class at ASOAnatomy Class at ASOAnatomy Class at ASO

The Challenge of the Scope of The Challenge of the Scope of PracticePractice

A few years after Still established ASO heA few years after Still established ASO heA few years after Still established ASO, he A few years after Still established ASO, he announced that he wished his graduates announced that he wished his graduates to be general practitioners caring forto be general practitioners caring forto be general practitioners, caring for to be general practitioners, caring for patients with a wide variety of medical patients with a wide variety of medical complaints able to perform surgery andcomplaints able to perform surgery andcomplaints, able to perform surgery, and complaints, able to perform surgery, and deliver babies. He also sanctioned the deliver babies. He also sanctioned the use of some types of drugs: anestheticsuse of some types of drugs: anestheticsuse of some types of drugs: anesthetics, use of some types of drugs: anesthetics, antidotes, and antiseptics which he antidotes, and antiseptics which he believed had been demonstrated to bebelieved had been demonstrated to bebelieved had been demonstrated to be believed had been demonstrated to be effective.effective.

Dr Still’s Surgical InstrumentsDr Still’s Surgical InstrumentsDr. Still s Surgical InstrumentsDr. Still s Surgical Instruments

The Challenge of the Scope of The Challenge of the Scope of PracticePractice

However many of Still’s follower’s believedHowever many of Still’s follower’s believedHowever many of Still s follower s believed However many of Still s follower s believed that a more wide based materia medica that a more wide based materia medica (pharmacopeias) including vaccines(pharmacopeias) including vaccines(pharmacopeias), including vaccines, (pharmacopeias), including vaccines, serums, and other agents should be serums, and other agents should be employedemployedemployed.employed.Many of the DO’s of the era argued that if Many of the DO’s of the era argued that if a drug had practical value then it shoulda drug had practical value then it shoulda drug had practical value, then it should a drug had practical value, then it should be integrated into osteopathic methods. be integrated into osteopathic methods.

The Challenge of the Scope of The Challenge of the Scope of PracticePractice

During the great pandemic (worldwide)During the great pandemic (worldwide)During the great pandemic (worldwide) During the great pandemic (worldwide) influenza of 1918influenza of 1918--1919 (which killed 1919 (which killed millions of people worldmillions of people world--wide) the DOwide) the DOmillions of people worldmillions of people world wide), the DO wide), the DO profession gained much success in profession gained much success in treating patients with a considerable lowertreating patients with a considerable lowertreating patients with a considerable lower treating patients with a considerable lower mortality rate than their MD counterparts.mortality rate than their MD counterparts.In 1929 the AOA gave its permission forIn 1929 the AOA gave its permission forIn 1929, the AOA gave its permission for In 1929, the AOA gave its permission for the schools to integrate a complete course the schools to integrate a complete course in materia medica and pharmacologyin materia medica and pharmacologyin materia medica and pharmacology. in materia medica and pharmacology.

The Challenge to the Scope of The Challenge to the Scope of PracticePractice

Osteopathy (“Osteopathic Medicine”) isOsteopathy (“Osteopathic Medicine”) isOsteopathy ( Osteopathic Medicine ) is Osteopathy ( Osteopathic Medicine ) is not limited to the mere adjustment of not limited to the mere adjustment of bonesbonesbones.bones.Osteopathy is a knowledge of anatomy Osteopathy is a knowledge of anatomy applied to the healing of diseasesapplied to the healing of diseasesapplied to the healing of diseases…..applied to the healing of diseases…..

The Challenge of The Challenge of AmalgamationAmalgamation

During the 1930’s and 1940’s theDuring the 1930’s and 1940’s theDuring the 1930 s and 1940 s, the During the 1930 s and 1940 s, the osteopathic and osteopathic and allopathicallopathic (MD) professions (MD) professions (a term coined by Samuel Hanneman, MD to (a term coined by Samuel Hanneman, MD to ( y ,( y ,mean “allo”=other, “pathos”=disease, a mean “allo”=other, “pathos”=disease, a system of therapeutics in which diseases are system of therapeutics in which diseases are treated by producing a condition incompatible treated by producing a condition incompatible to the medical condition to be cured) and to the medical condition to be cured) and standards of practice grew closer togetherstandards of practice grew closer togetherstandards of practice grew closer together. standards of practice grew closer together. Some DO’s questioned whether they should Some DO’s questioned whether they should maintain their separatenessmaintain their separatenessmaintain their separateness. maintain their separateness.

The Challenge of The Challenge of AmalgamationAmalgamationAmalgamationAmalgamation

In 1962,, the California Osteopathic In 1962,, the California Osteopathic A i ti d th C lif i M di lA i ti d th C lif i M di lAssociation and the California Medical Association and the California Medical Association, with the blessing of the AMA, Association, with the blessing of the AMA, some 2000 of the then existing 2500 statesome 2000 of the then existing 2500 statesome 2000 of the then existing 2500 state some 2000 of the then existing 2500 state DO’s agreed to accept a new MD degree.DO’s agreed to accept a new MD degree.The College of Physicians and SurgeonsThe College of Physicians and SurgeonsThe College of Physicians and Surgeons The College of Physicians and Surgeons (COP & S) ceased to exist and was (COP & S) ceased to exist and was transformed into the California College of transformed into the California College of ggMedicine and was affiliated with the Medicine and was affiliated with the University of California at Irvine. Licensure of University of California at Irvine. Licensure of

DO’ i th St t hibit d bDO’ i th St t hibit d bnew DO’s in the State was prohibited by new DO’s in the State was prohibited by referendum (Proposition 22).referendum (Proposition 22).

The Challenge of The Challenge of AmalgamationAmalgamationAmalgamationAmalgamation

The debacle in California galvanized much of The debacle in California galvanized much of the osteopathic profession. Much to the the osteopathic profession. Much to the consternation and surprise of many, consternation and surprise of many, osteopathic medicine successfully resistedosteopathic medicine successfully resistedosteopathic medicine successfully resisted osteopathic medicine successfully resisted further state mergers and grew academically further state mergers and grew academically and organizationally strongerand organizationally strongerand organizationally stronger. and organizationally stronger. In 1968, the US postal service created a In 1968, the US postal service created a stamp to honor the osteopathic profession.stamp to honor the osteopathic profession.stamp to honor the osteopathic profession.stamp to honor the osteopathic profession.In 1974, the California Medical Association In 1974, the California Medical Association was challenged in the state supreme court was challenged in the state supreme court g pg pand Proposition 22 was declared and Proposition 22 was declared unconstitutionalunconstitutional. .

Osteopathic StampOsteopathic StampOsteopathic StampOsteopathic Stamp

The Profession TodayThe Profession TodayCurrently there are about 61 000 DO’s practicing medicine in the UnitedCurrently there are about 61 000 DO’s practicing medicine in the UnitedCurrently there are about 61,000 DO s practicing medicine in the United Currently there are about 61,000 DO s practicing medicine in the United States (comparable or more to the number of podiatrists, chiropractors, States (comparable or more to the number of podiatrists, chiropractors, optometrists, and veterinarians).optometrists, and veterinarians).DO’s are represented in DO’s are represented in allall medical branches, with equivalent practice medical branches, with equivalent practice rights to MD’s. They have practiced as physicians in the military since rights to MD’s. They have practiced as physicians in the military since 1967.1967.Internationally, US trained DO’s have recently gained full practice rights Internationally, US trained DO’s have recently gained full practice rights i th U it d Ki d (2005) d G (1993) d h f lli th U it d Ki d (2005) d G (1993) d h f llin the United Kingdom (2005), and Germany (1993), and have full in the United Kingdom (2005), and Germany (1993), and have full practice rights in several of the provinces of Canada (Ontario, New practice rights in several of the provinces of Canada (Ontario, New Brunswick, Nova Scotia, Northwest Territories, Manitoba, British Brunswick, Nova Scotia, Northwest Territories, Manitoba, British Columbia*, Alberta). A complete list of foreign countries that grant Columbia*, Alberta). A complete list of foreign countries that grant ) p g g) p g gmedical practice rights to US trained DO’s can be viewed in the medical practice rights to US trained DO’s can be viewed in the accompanying PDF file. accompanying PDF file. Thus there are DO family physicians, internists, obstetricians, Thus there are DO family physicians, internists, obstetricians,

di t i i l i t hi t i t di l i t tdi t i i l i t hi t i t di l i t tsurgeons, pediatricians, neurologists, psychiatrists, radiologists, etc.surgeons, pediatricians, neurologists, psychiatrists, radiologists, etc.Currently there are 23 colleges of Osteopathic Medicine in the Currently there are 23 colleges of Osteopathic Medicine in the United States in 26 locations.United States in 26 locations. There are many “satellite” COM’s. There are many “satellite” COM’s.

* one pathway for full practice rights, the other * one pathway for full practice rights, the other only for manipulationonly for manipulation

Colleges of Osteopathic Colleges of Osteopathic MedicineMedicine

US Distribution of Osteopathic US Distribution of Osteopathic Ph i i (200 )Ph i i (200 )Physicians (2005)Physicians (2005)

Principles of TreatmentPrinciples of TreatmentPrinciples of TreatmentPrinciples of Treatment

Restore physiologic motion where it isRestore physiologic motion where it isRestore physiologic motion where it is Restore physiologic motion where it is appropriate (“lengthen those structures appropriate (“lengthen those structures that are pathologically short andthat are pathologically short andthat are pathologically short and that are pathologically short and strengthen those structures that are strengthen those structures that are weak”)weak”)weak )weak )Enhance or maintain optimal fluid flow via Enhance or maintain optimal fluid flow via the arterial venous and lymphatic systemsthe arterial venous and lymphatic systemsthe arterial, venous and lymphatic systems the arterial, venous and lymphatic systems as appropriate (as previously stated, as appropriate (as previously stated, implied in the metaphor: “the artery rulesimplied in the metaphor: “the artery rulesimplied in the metaphor: the artery rules implied in the metaphor: the artery rules supreme”). supreme”).

Models of Systemic Function Models of Systemic Function & Dysfunction& Dysfunction& Dysfunction& Dysfunction

BiomechanicalBiomechanical--NeuromusculoskeletalNeuromusculoskeletalAlterations in the mechanics of the bonesAlterations in the mechanics of the bones--joint relationships, joint relationships, muscles and fascial elements that may compromise muscles and fascial elements that may compromise neurologic, and circulatory functions.neurologic, and circulatory functions.

NeurologicNeurologicNervous system reflexes (somatovisceral, somatosomatic, Nervous system reflexes (somatovisceral, somatosomatic, viscerosomatic and viscerovisceral), and the autonomic viscerosomatic and viscerovisceral), and the autonomic nervous system may have inappropriate setnervous system may have inappropriate set--points or points or imbalances that may predispose to pathologic conditions imbalances that may predispose to pathologic conditions and pain.and pain.

RespiratoryRespiratory--CirculatoryCirculatoryDysfunctions of the respiratory system (including the thoracic Dysfunctions of the respiratory system (including the thoracic diaphragm), in conjunction with other circulatory diaphragm), in conjunction with other circulatory impediments, may result in a lack of proper oxygenation and impediments, may result in a lack of proper oxygenation and nutrient distribution and impaired immune function and the nutrient distribution and impaired immune function and the removal of toxic metabolites. removal of toxic metabolites.

Models of Systemic Function & Models of Systemic Function & DysfunctionDysfunction

NutritionalNutritionalNutritionalNutritionalDietary and nutritional factors as dietary Dietary and nutritional factors as dietary indiscretions contributing toindiscretions contributing toindiscretions contributing to indiscretions contributing to hypercholesteremia, alcoholism,etc. hypercholesteremia, alcoholism,etc.

BehavioralBehavioralBehavioral Behavioral Inability to cope with emotional stress, such Inability to cope with emotional stress, such as poor lifestyle choices such as tobaccoas poor lifestyle choices such as tobaccoas poor lifestyle choices such as tobacco as poor lifestyle choices such as tobacco abuse and inadequate exercise in relation to abuse and inadequate exercise in relation to caloric consumption.caloric consumption.