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Part 0. A N A T The femi-nervofus bends the leg, and may likewife bend the thigh on the leg. By its infertion in the tuberofity of the ifchium, it likewife extends the thigh on the pelvis, and carries it backward; and may alfo extend the pelvis on the thigh, when it has been inclined forward with the reft of the trunk; and confequently prevent its being carried too far along with the trdnk, when we (loop forward, either ftanding or fitting. The femi-membranofus has the fame ules with the femi-nervofus. It bends the leg on the thigh, and the thigh on the leg ; it extends the thigh on the pelvis, and the pelvis on the thigh, and fuftains the pelvis when it is inclined forward. * The two portions of the biceps bend the leg on the thigh, and the thigh on the leg. The fuperior portion likewife extends the thigh on the pelvis, and the pelvis on the thigh. Thefe four ufes in general are common to this mufcle with the femi-membranofus, and in fome meafure with the femi-tendinofus. The particular ufe of the biceps, and which feems to belong more to the fliort portion than to the other, is to perform the rotation of the leg v^hen bent, by which motion the toes are turned outward, and the heel inward. The popliteus performs the rotation of the leg when bent, in a direction contrary to that of th.e biceps. The biceps turns the leg from before outward; the popliteus from before inward. Sect. XI. The Muscle's which move the Tarfus on the Leg. TIBIALIS ANTICUS. This is a Ion£ mufcle, flefhy at the upper part, and tendinous at the lower, fituated on the fore-fide of the leg, between the tibia and the extenfor digitorum longus. It is fixed above, by flefhy fibres, in the upper third part of the external labium of the crifta tibiae, and of the infide of the aponeurofis tibialis, or of that ligamentary expanfion which goes between the crifta tibiae and the anterior angle o£ the fibula. It is likewife fixed obliquely in the upper two thirds of the outfide of the tibia, or that next the fibula. From thence it runs down and ends in a tendon, which firft pafles through a ring of the common annular ligament, and then through another feparate ring fituated lower down. Afterwards the tendon is fixed, partly in the upper and inner part of the os cuboides, and partly in the infide of the firft bone of the metatarfus. Peronjeus Medius vulgo Peron^us Anticus. This is a long mufcle, fituated anteriorly on the middle part of the fibula. It is fixed above, by flefhy fibres, to more than the middle third part of the anterior or. outfide of the fibula, and to the neighbouring part of the aponeurofis tibialis. It is likewife fixed to a preduftion from the infide of that aponeurofis which runs to the upper part of the tiVol. I. No. 9.
O M Y. 509 bia, and there ferves for a middle feptsm between this1 mufcle and the extenfor digitorum longus. From thence it runs down and forms a tendon, which going in the direction of the oblique line on the fibula, pafles behind the external malleolus, and then through an annular ligament common to it and to the perensus maximus, and is afterwards inferted in the tuberofity at the bafis of the fifth metatarfal bone, fending off a fmall tendon to the firft phalanx of the little toe, PERONjEUS MINIMUS. This is a fmall mufcle, commonly thought to be a portion of the extenfor digitorum longus, though it is eafily feparable from it. It is fixed, by fleftiy fibres, in the lower half of the infide of the fibula, between two oblique bony lines, on one fide of the lower part of the extenfor digitorum longus, to which mufcle it is limply contiguous. From thence it runs down contracting in breadth, and pafles with the extenfor longus, through the common annular ligament, forming a flat tendon, which foon feparates from thofe of the extenfor, and is inferted near the bafis of the fifth metatarfal bone. GASTROCNEMII. These are two thick, pretty broad, and oblong mufcles, fituated laterally with refpeeft to each other, in the fame^plane, under the poples, and forming a great part of what is called the calf of the leg. That which liesnext the tibia is called intermit, and that next the fibula, >xV#r«ar,- and becaufe they form, as it were, the belly of the leg, they have been termed in Greek ga~ jtrocnemii. Each mufcle is fixed above, by a flat tendon, to the pofterior part of the lower extremity of the os femoris, behind the lateral tuberofity of each condyle, adhering clofely to the pofterior ligaments of the joint of the knee. From thence they run down, each forming a large and pretty broad flelhy body, irregularly oval. About the middle of the leg, they end in a ftrong, broad, common tendon, which contracts a little in breadth as it defeends, and is inferted in the pofterior extremity of the os calcis, together with the tendon of the foleus. S O L E U S. This is a large, flelhy, flat mufcle, nearly of an oval figure, and thicker in the middle than at -the edges. It is fituated on the back-fide of the leg, lower down than the gaftrocnemii, by which it is covered ; and thefe three mufcles form the calf of the leg. It is fixed above, partly to the tibia, and partly to the fibula. Afterwards leaving thefe two bones, it ends in abroad ftrong tendon, which, together with that of the gaftroc-' nemii, forms what is called tendi ^chillis. This ftrong tendon contracts a little in its paflage to t'qe os calcis, and then expanding a little, it is inferted obliquely in the back-fide of that bone, all the way to the tuberofity. 3G TIBI-
