RUPTUKE OF THE EXTERNAL ISCHIO-TIBIAL MUSCLE (BISfEPS FEMORIS). 71 



are dragged along the ground, and the affected limb, which can never be 

 completely advanced, is brought forward with a mowing movement. 



On local examination, the trochanter appears to be very prominent, 

 and situated directly above a rigid cord which extends parallel with 

 the anterior margin of the affected muscle. 



If the accident consists merely in the formation of a depression in 

 the muscle, in which the summit of the trochanter is fixed, and if there 

 is no fissuring, the muscle and the femur are certainly immobilised, but 



Fig. 29. — Arrangement of the external isohio-tibialis muscle, 

 margin of the muscle ; 2, fascia lata, 



1, Anterior 



the limb can be moved to a certain extent, the " mowing" movement is 

 less marked, and there is no well-defined rigid cord along the anterior 

 margin of the muscle. 



Diagnosis. The condition can only be confused with luxation of the 

 patella ; but manual examination of the affected parts revealing the 

 presence of a rigid cord below the trochanter at once removes any 

 doubt. 



Prognosis. The prognosis is only grave in working animals. More- 

 over, the accident is now much rarer than formerly, if only because 

 animals are better looked after and better fed. 



Treatment. If the accident results simply from the formation of a 

 depression in the musculo-aponeurotic layer which replacesthe muscle 



