RUPTURE OF THE FLEXOR METATARSI. 



979 



advanced, whilst the relaxation of the tendon favours excessive 

 flexion of the stifle-joint. This want of harmony in the function 

 of both joints produces an uncertain movement of the limb, which 

 may give the impression of a broken bone, and has been so inter- 

 preted by some. The absence of fracture, however, is at once shown 

 by the fact that the limb can still support weight. The serious 

 symptoms apparent during movement disappear when the animal 

 is at rest. In rupture ' of the flexor metatarsi, the function of its 

 tendon is in abeyance ; while its antagonist, i.e., the tendo Achillis 



Fig. 530. — Rupture of flexor metatarsi muscle (from a photograph). 



is unopposed, appears relaxed, and when the limb is relieved of 

 weight and extended lies flaccid. This appearance is very charac- 

 teristic, and only occurs in two other conditions, viz., rupture of 

 the tendo Achillis and fracture of the tibia. It is most marked when 

 the hock is excessively extended, as, for instance, by the farrier lifting 

 the limb to remove the shoe. In recent cases the anterior surface of 

 the tibia is sometimes slightly cedematous, in others absolutely 

 nothing abnormal can be seen. Severe swelling with pain on pressure 

 over the course of the flexor metatarsi is quite exceptional, the muscles 

 being clothed in a strong fascia. 



Course. The affection is naturally of sudden onset, and at once 

 produces a peculiar lameness. As weight can still be placed on the 



