520 



THE MUSCLES AND FASCIAE. 



Tibi 



rr 



leg. 



FIG. 330. Muscles of the front of the 



knee is semiflexed, the Biceps, in consequence 

 of its oblique direction downward and outward, 

 rotates the leg slightly outward ; and the Semi- 

 tendinosus, and to a slight extent the Semimem- 

 branosus, rotate the leg inward, assisting the Pop- 

 liteus. Taking their fixed point from below, these 

 muscles serve to support the pelvis upon the head 

 of the femur and to draw the trunk directly back- 

 ward, as in feats of strength, when the body is 

 thrown backward in the form of an arch. 



Surgical Anatomy. The tendons of these muscles 

 occasionally require subcutaneous division in some forms of 

 spurious ankylosis of the knee-joint dependent upon per- 

 manent contraction and rigidity of the Flexor muscles, or 

 from stiffening of the ligamentous and other tissues sur- 

 rounding the joint, the result of disease. This is effected by 

 putting the tendon upon the stretch, and inserting a nar- 

 row, sharp-pointed knife between it and the skin : the cut- 

 ting edge being then turned toward the tendon, it should 

 be divided, taking great care that the wound in the skin is 

 not at the same time enlarged. The relation of the external 

 popliteal nerve to the tendon of the Biceps must always be 

 borne in mind in dividing this tendon. 



THE LEG. 



Dissection (Fig. 325). The knee should be bent, a 

 block placed beneath it, and the foot kept in an extended 

 position ; then make an incision through the integument in 

 the middle line of the leg to the ankle, and continue it along 

 the dorsum of the foot to the toes. Make a second incision 

 transversely across the ankle, and a third in the same direc- 

 tion across the bases of the toes ; remove the flaps of integu- 

 ment included between these incisions in order to examine 

 the deep fascia of the leg. 



The Deep fascia of the Leg forms a complete 

 investment to the muscles, but is not continued 

 over the subcutaneous surfaces of the bones. It is 

 continuous above with the fascia lata, receiving an 

 expansion from the tendon of the Biceps on the 

 outer side, and from the tendons of the Sartorius, 

 Gracilis, and Semitendinosus on the inner side ; in 

 front it blends with the periosteum covering the 

 subcutaneous surface of the tibia, and with that 

 covering the head and external malleolus of the 

 fibula ; below it is continuous with the annular 

 ligaments of the ankle. It is thick and dense in 

 the upper and anterior part of the leg, and gives 

 attachment, by its deep surface, to the Tibialis 

 anticus and Extensor longus digitorum muscles, 

 but thinner behind, where it covers the Gastro- 

 cnemius and Soleus muscles. Over the popliteal 

 space it is much strengthened by transverse fibres 

 which stretch across from the inner to the outer 

 hamstring muscles, and it is here perforated by the 

 external saphenous vein. Its deep surface gives 

 off, on the outer side of the leg, two strong inter- 

 muscular septa which enclose the Peronei muscles, 

 and separate them from the muscles on the anterior 

 and posterior tibial regions and several smaller and 

 more slender processes which enclose the indi- 



