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Davis's law is used in anatomy and physiology to describe how soft tissue models along imposed demands. It is the corollary to Wolff's law, which applies to osseous tissue. It is a physiological principle stating that soft tissue heal according to the manner in which they are mechanically stressed.〔Ellenbecker, Todd, "Effective Functional Progessions in Sport Rehabilitation", Human Kinetics 2009, ISBN 0-7360-6381-1〕 It is also an application of the Mechanostat model of Harold Frost which was originally developed to describe the adaptational response of bones; however - as outlined by Harold Frost himself - it also applies to fibrous collagenous connective tissues, such as ligaments, tendons and fascia.〔Frost, Harold "New targets for fascial, ligament and tendon research: A perspective from the Utah paradigm of skeletal physiology" J Musculoskel Neuron Interact 2003; 3(3):201-209〕〔Frost, Harold "The physiology of cartilagenous, fibrous, and bony tissue. C.C. Thomas, 1972〕 The "stretch-hypertrophy rule" of that model states: "Intermittent stretch causes collagenous tissues to hypertrophy until the resulting increase in strength reduces elongation in tension to some minimum level".〔Frost, Harold "The physiology of cartilagenous, fibrous, and bony tissue. C.C. Thomas, 1972, page 176〕 Similar to the behavior of bony tissues this adaptational response occurs only if the mechanical strain exceeds a certain threshold value. Harold Frost proposed that for dense collagenous connective tissues the related threshold values are around 23 Newton/mm2 or 4% strain elongation.〔Frost, Harold "Does the anterior cruciate have a modeling threshold? A case for the affirmative". J Musculoskel Neuron Interact 2001; 2(2):131-136〕 ==Origin== The term ''Davis's law'' is named after Henry Gassett Davis, an American orthopedic surgeon known for his work in developing traction methods. Its earliest known appearance is in John Joseph Nutt's 1913 book ''Diseases and Deformities of the Foot'', where Nutt outlines the law by quoting a passage from Davis's 1867 book, ''Conservative Surgery'': :"Ligaments, or any soft tissue, when put under even a moderate degree of tension, if that tension is unremitting, will elongate by the addition of new material; on the contrary, when ligaments, or rather soft tissues, remain uninterruptedly in a loose or lax state, they will gradually shorten, as the effete material is removed, until they come to maintain the same relation to the bony structures with which they are united that they did before their shortening. Nature never wastes her time and material in maintaining a muscle or ligament at its original length when the distance between their points of origin and insertion is for any considerable time, without interruption, shortened." Davis's writing on the subject exposes a long chain of competing theories on the subject of soft tissue contracture and the causes of scoliosis. Davis's comments in ''Conservative Surgery'' were in the form of a sharp rebuke of lectures published by Louis Bauer of the Brooklyn Medical and Surgical Institute in 1862.〔http://books.google.com/books?id=1yMg7gdUXPAC&pg=PA518&lpg=PA518&q=%22muscular%20antagonism%22%20delpech〕 In his writing, Bauer averred that "a contraction of ligaments is a physiological impossibility".〔http://books.google.com/books?id=Em8PAQAAIAAJ&q=%22a%20contraction%20of%20ligaments%22〕 Bauer sided with work published in 1851 by Julius Konrad Werner, director of the Orthopedic Institute of Konigsberg, Prussia; Bauer and Werner, in turn, were contradicting research published by Jacques Mathieu Delpech in 1823.〔http://books.google.com/books?id=NqC-b3TEJO0C&q=sixty%20theses〕〔http://www.whonamedit.com/person_bibliography/2964/〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Davis' law」の詳細全文を読む スポンサード リンク
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