536 THE MUSCLES AND FASCIA. 



lower tendon of the Adductor magnus can be distinct!}' felt as a short ridge extending down to 

 the Adductor tubercle on the internal condyle, between the Sartorius and Vastus internus. 

 The Adductor group of muscles fills in the triangular space at the upper part of the thigh, 

 formed between the oblique femur and the pelvic wall, and to them is due the contour of the 

 inner border of the thigh, the Gracilis largely contributing to the smoothness of the outline. 

 These muscles are not marked off on the surface from those of the posterior femoral region by 

 any intermuscular marking ; but on the outer side of the thigh these latter muscles are denned 

 from the Vastus externus by a distinct marking, corresponding to the external intermuscular 

 septum. The Glutens maximus and a part of the Glutens medius are the only muscles of the 

 buttock which influence surface form. The other part of the Gluteus medius, the Gluteus 

 minimus, and the External rotators are completely hidden. The Gluteus maximus forms the 

 full rounded outline of the buttock : it is more prominent behind, compressed in front, and 

 terminates at its tendinous insertion in a depression immediately behind the great trochanter. 

 Its lower border does not correspond to the gluteal fold, but is much more oblique, being 

 marked by a line drawn from the side of the coccyx to the lower part of the great trochanter. 

 From beneath the fold of the buttock the hamstring muscles appear, at first narrow and not well 

 marked, but as they descend becoming more prominent and widened out, and eventually divid- 

 ing into two well-marked ridges, which form the upper boundaries of the popliteal space, 

 being formed by the tendons of the inner and outer hamstring muscles respectively. In the 

 upper part of the thigh these muscles are not to be individually distinguished from each other, 

 but lower down, the separation between the Semitendinosus and Semimembranosus is denoted 

 by a slight intermuscular marking. The external hamstring tendon formed by the Biceps is 

 seen as a thick cord running down to the head of the fibula. The inner hamstring tendons 

 comprise the Semitendinosus, the Semimembranosus, and the Gracilis. The Semitendinosus is the 

 most internal of these, and can be felt, in certain positions of the limb, as a sharp cord ; the 

 Semimembranosus is thick, and the Gracilis is situated a little farther forward than the other 

 two. All the muscles on the front of the leg appear to a certain extent somewhere on the 

 surface, but the form of this region is mainly dependent upon the Tibialis anticus and the 

 Extensor longus digitorum. The Tibialis anticus is well marked, and presents a fusiform 

 enlargement at the outer side of the tibia, and projects beyond the crest of the shin-bone. 

 From the muscular mass its tendon may be traced downward, standing out boldly, when the 

 muscle is in action, on the front of the tibia and ankle-joint, and coursing down to its insertion 

 along the inner border of the foot. A well-marked groove separates this muscle externally 

 from the Extensor longiis digitorum, which fills up the rest of the space between the upper 

 part of the shaft of the tibia and fibula. It does not present so bold an outline as the Tibialis 

 anticus, and its tendon below, diverging from the tendon of the Tibialis anticus, forms a sort of 

 plane, in which may be seen the tendon of the Extensor proprius hallucis. A groove on the 

 outer side of the Extensor longus digitorum, seen most plainly when the muscle is in action, 

 separates from it a slight eminence corresponding to the Peroneus tertius. The fleshy fibres of 

 the Peroneus longus are strongly marked at the upper part of the outer side of the leg, especi- 

 ally when the muscle is in action. It forms a bold swelling, separated by furrows from the 

 Extensor longus digitorum in front and the Soleus behind. Below, the fleshy fibres terminate 

 abruptly in a tendon which overlaps the more flattened form of the Peroneus brevis. At the 

 external malleolus the tendon of the Peroneus brevis is more marked than that of the Peroneus 

 longus. On the dorsum of the foot the tendons of the Extensor muscles, emerging from 

 beneath the anterior annular ligament, spread out and can be distinguished in the following 

 order : The most internal and largest is the Tibialis anticus, then the Extensor proprius hallucis : 

 next comes the Extensor longus digitorum, dividing into four tendons to the four outer toes ; and 

 lastly, most externally, is the Peroneus tertius. The flattened form of the dorsum of the foot is 

 relieved by the rounded outline of the fleshy belly of the Extensor brevis digitorum, which forms a 

 soft fulness on the outer side of the tarsus in front of the external malleolus, and by the Dorsal 

 interossei, which bulge between the metatarsal bones. At the back of the knee is the popliteal 

 space, bounded above by the tendons of the hamstring muscle ; below, by the two heads of the 

 Gastrocnemius. Below this space is the prominent fleshy mass of the calf of the leg, produced 

 by the Gastrocnemius and Soleus. When these muscles are in action, as in standing on tiptoe, 

 the borders of the Gastrocnemius are well defined, presenting two curved lines, which converge 

 to the tendon of insertion. Of these borders, the inner is more prominent than the outer. 

 The fleshy mass of the calf terminates somewhat abruptly below in the tendo Achillis. which 

 stands out prominently on the lower part of the back of the leg. It presents a somewhat 

 tapering form in the upper three-fourths of its extent, but widens out slightly below. When 

 the muscles of the calf are in action, the lateral portions of the Soleus may be seen, forming 

 curved eminences, of which the outer is the longer, on either side of the Gastrocnemius. 

 Behind the inner border of the lower part of the shaft of the tibia a well-marked ridge, pro- 

 duced by the tendon of the Tibialis posticus, is visible when this muscle is in a state of con- 

 traction. 



On the sole of the foot the superficial layer of muscles influences surface form ; the 

 Abductor minimi digiti most markedly. This muscle forms a narrow rounded elevation along 

 the outer border of the foot, while the Abductor hallucis does the same, though to a less ex- 

 tent, on the inner side. The Flexor brevis digitorum, bound down by the plantar fascia, is not 

 very apparent ; it produces a flattened form, covered by the thickened skin of the sole, which 

 is here thrown into numerous wrinkles. 



