350 



STRAIN OF THE COFFIN JOINT. 



Fig. 1 



Fig. 1. 



a The upper pastern. 

 b The lower pastern. 

 c The navicular bone. 

 d The coffin-bone. 



Fig. 2. 



a The sessamoid bone. 



b The upper pastern. 



c The lower pastern. 



d The navicular bone. 



e The coffin-bone, with the horny lamir.i 



The lower pastern (d, p. 345, and 6 in the first figure, and c in the 

 second in this cut) is a short and thick bone with its larger head downward. 

 Its upper head has two depressions to receive the protuberances on the lower 

 head of the upper bone, bearing some resemblance to a pulley, but not so 

 decidedly as the lower head of the shank-bone. Its lower head resembles that 

 of the other pastern, and has also two prominences, somewhat resembling a 

 pulley, by which it articulates with the coffin-bone ; and a depression in front, 

 corresponding with a projection in the coffin-bone. There are also two slight 

 depressions behind, receiving eminences of the navicular bone. Neither of 

 these joints admit of any lateral motion. The ligaments of this joint, both the 

 capsular and the cross ones, are like those of the pastern-joint, exceedingly 

 strong. The tendon of the extensor muscle is inserted into the fore part, both 

 of the upper and lower pastern-bones as well as into 

 the upper part of the coffin-bone (/, p. 345) ; and at 

 the back of these bones the suspensory ligament is ex- 

 panded and inserted, while a portion of it goes over the 

 fore part of the upper pastern to reach the extensor ten- 

 don. These attachments in front of the bones are seen 

 in the accompanying cut, in which a represents the 

 lower part of the shank-bone ; b the sessamoid -bones ; 

 c the upper pastern ; d the lower pastern ; and e the 

 coffin-bone ; / are the branches of the suspensory liga- 

 ments going to unite with the extensor tendon ; g the 

 long extensor tendon ; h ligaments connecting the two 

 pastern-bones together ; and i the lateral cartilages of 

 the foot. 



SPRAIN OF THE COFFIN-JOINT. 



The proof of this is when the lameness is sudden, and the heat and tender- 

 ness are principally felt round the coronet. Bleeding at the toe, physic, fomen- 

 tation, and blisters are the usual means adopted. This lameness is not easily 

 removed, even by a blister ; and if removed, like sprains of the fetlock and of 

 the back sinews, it is apt to return, and finally produce a great deal of disor- 

 ganization and mischief in the foot. Sprain of the coffin-joint sometimes 

 becomes a very serious affair. Not being always attended by any external 

 swelling and being detected only by heat round the coronet, the seat of the 

 lameness is often overlooked by the groom and the farrier ; and the disease is 

 suffered to become confirmed before its nature is discovered. 



