LAMENESS IN THE FOEE-LEG. 33 



Supporting-leg lameness, with abnormal position and 

 movement of individual parts of the leg : 



1. Abduction of the shoulder at the moment the sup- 

 porting leg is in a- perpendicular position, as in paralysis of 

 the teres minor, postea-spinatus and deltoid muscles. If the 

 suprascapular nerve is paralyzed the animal cannot step 

 sideways. 



2. Abnormal flexion of the shoulder joint, as in rupture 

 of the flexor brachii. 



3. Abnormal flexion of the elbow joint, as in rupture of 

 the flexors of the metacarpus and in fractures, causing a 

 loosening of their insertion. 



4. Abnormal extension of the elbow joint, as in contrac- 

 tions of the olecranian muscles. 



5. Abduction of the leg from the elbow downwards, as in 

 rupture of the external ligament of the elbow joint. 



6. Volar flexion of the carpus, as in corns, contracted 

 heels. In these cases the horse usually points backward 

 and the fetlock is upright. 



7. Dorsal flexion of the carpus, as in rupture of the 

 flexors of the metacarpus, fracture of the pisiform bone and 

 imperfectly healed fracture of one of the condyles of the 

 humerus. It is usually seen at the moment the function of 

 the supporting leg begins, or, more rarely, while the animal 

 is standing quietly. 



8. Dorsal flexion of the phalanges, especially the fetlock 

 joint, as in rapture of the flexor tendons. If all tear at 

 once, the fetlock may descend to the ground ; if the suspen- 

 sory ligament only ruptures, the fetlock goes dowu some- 

 what ; if the perforatus, the toe is turned up a little ; while 

 rupture of the perforans causes the fetlock to descend 

 materially, and the toe of the hoof is turned up decidedly, 



