246 KNEE JOINT LAMENESS. 



expressing so accurately the manner of a horse's progression under 

 certain states of lameness, it was worthy of being more closely in- 

 vestigated before it was thrown aside. 



" It was not until I became acquainted with disease of the knee 

 joint that I fully understood the applicability of their appellation ; 

 but reflection has led me to believe that the old farriers' term of 

 ' chest-founder' must be considered a recognition of that disease to 

 which I have given the name of ' carpitis,' albeit they described 

 and treated of a symptom alone. 



"The gait in chronic carpitis affecting both knee joints gives to 

 a rider the sensation of the chest being displaced from its right 

 position, a sinking or ' foundering,' and which feels as if it would 

 increase at every step of the horse. When attention is drawn to 

 this peculiar gait, it is easy to be distinguished from the short cat- 

 like step in navicularthritis, which gives to a rider a sensation of 

 the chest being raised up, or an attempt at doing so : further, the 

 feet in navicularthritis are brought to the ground with the toe first, 

 and in consequence the step is short and stilty. from the weight 

 being thrown as much as possible on the column of bones, to 

 relieve the affected tendon or surface over which it plays; and 

 from the same cause there is great inclination to canter, a pace 

 which, when slow, brings into play but slightly the flexor tendons 

 or navicular joint. In carpitis, on the contrary, these symptoms 

 are reversed, from the cause of lameness being seated on or 

 amongst the carpal bones. The effort is not now to throw the weight 

 on the bony column, but on to the tendons and ligaments, and 

 by this means to avoid concussion ; hence the limb is carried for- 

 wards as nearly straight as possible ; and, still farther to effect 

 this object, it is thrown with a circumductive motion outwards, 

 and brought to the ground with the heels first, as is shewn by 

 the wearing away of the points of the heels of the shoe. This 

 mode of progression produces a long step, and at the same time 

 the fore-quarters are dropped or lowered, which has been, I doubt 

 not, the origin of the term ' chest-founder.' There is also a dis- 

 inclination to canter ; and if this pace is attempted, it gives 

 increased pain, and a rocking motion exceedingly unpleasant to 

 the rider. 



