SURGICAL ANATOMY OF THE LOWER EXTREMITY. 451 



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

 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 haUncfs does the same, though to a less extent, on the 

 inner side. The Flexor brevis diyitorum, bound down by the plantar fascia, is not very appa- 

 rent ; it produces a flattened form, covered by the thickened skin of the sole, which is here 

 thrown into numerous wrinkles. 



SURGICAL ANATOMY OF THE LOWER EXTREMITY. 



The student should now consider the effects produced by the action of the various muscles 

 in fractures of the bones of the lower extremity. The more 

 common forms of fractures are selected for illustration and de- 

 scription. 



In fracture of the neck of the femur internal to thecapsular 

 ligament (Fig. 206) the characteristic marks are slight shorten- 

 ing of the limb and eversion of the foot, neither of which 

 symptoms occurs, however, in some cases until some time after 



PYRIFORMIS. 



EMELLUS SUPERIOR. 

 OBTURATOR INTERNUS. 

 GEMELLUS INFERIOR. 

 OBTURATOR EXTERNUS. 



UADRATUS FEMORIS. 



SEMI- 

 MEMBRANOSUS. 



SEMI- 

 TENDINOSUS. 



FIG. 266. Fracture of the neck of the femur within the capsular 

 ligament. 



FIG. 267. Fracture of the femur 

 below the trochanters. 



the injury. The eversion is caused by the weight of the limb rotating it outward. The short- 

 ening is produced by the action of the Grlutei, and by the Rectus femoris in front and the 

 Biceps, Semitendinosus, and Semimembranosus behind. 



In fracture of the femur just Mow the trochanters (Fig. 267), the upper fragment, the 

 portion chiefly displaced, is tilted forward almost at right angles with the pelvis by the combined 

 action of the Psoas and Iliacus, and, at the same time, everted and drawn outward by the 

 External rotator and Grlutei muscles, causing a marked prominence at the upper and outer side 

 of the thigh, and much pain from the bruising and laceration of the muscles. The limb is 

 shortened, in consequence of the lower fragment being drawn upward by the Rectus in front, 

 and the Biceps, Semimembranosus, and Semitendinosus behind, and is at the same time 

 everted. This fracture may be reduced in two different methods : either by direct relaxation 

 of all the opposing muscles, to effect which the limb should be put up in such a manner that 

 the thigh is flexed on the pelvis and the leg on the thigh ; or by overcoming the contraction of 

 the muscles by continued extension, which may be effected by means of the long splint. 



Oblique fracture of the femur immediately above the condyles (Fig. 268) is a formidable 



