OBSERVATIONS ON CURB. 
17 
to inspect a purer specimen, or, should there be any want of leisure 
for the investigation, I would humbly offer my assistance, and grate- 
fully acknowledge the obligation. 
Perhaps I am to blame if I venture to argue upon a single case, 
and when I do so it will be more in the hope of instigating inquiry, 
than of establishing opinions which I put forth only as speculations 
for the consideration of others. Let it be clearly understood that 
I insist on nothing which I may advance in this paper. I only 
seek through the medium of your liberality to communicate with 
the members of my profession; and as there is unfortunately yet no 
college or other place where veterinarians assemble and debate, 
I wish in the pages of your Journal to commence a discussion that 
may ultimately lead to the recognition of truth. 
Reasoning, therefore, on what I saw, the cause of curb became 
of the utmost importance ; for unless the cause could be made to 
agree with the supposed effect, of course further notice of the 
subject at present would be injudicious. In the first place, curbs 
are found generally in young animals, and in such the tendinous 
structures are most liable to injury. Children are more exposed 
to sprains than adults. The immediate cause of curb is muscular 
activity. The horse is always in a state of violent action when a 
curb is sprung, and leaping is, perhaps, the most ordinary source 
of the disease. I need not fill your space by recapitulating all the 
causes which may give rise to curb. One instance is, for the pre- 
sent purpose, as good as a hundred. 
During the act of leaping the feet are firmly planted on the 
earth, and, the fore legs being raised, the whole weight is thrown 
for a time upon the posterior extremities. This burden, increased 
by that of the rider, the flexor muscles have to project suddenly 
over the obstacle which is to be cleared. The effort is a sudden 
and a violent one. In such an action both the flexors — perforans 
and perforatus — are brought into play, but the principal strain will 
be on the former. The perforatus being inserted into the pastern 
bones, moves the foot only in a secondary degree. The main 
flexor of the os pedis is the perforans, which is attached to the pos- 
terior of the coffin-bone ; and as it is the sudden propulsion of the 
toe against the earth which gives the animal the upward spring, 
so is the perforans the primary and principal agent in leaping, and, 
consequently, the part most likely to be injured in the act by the 
contractile power of the muscle. 
A further inquiry into the anatomy of the perforans tendon will 
also give some idea why that tendon should suffer lesion at the 
particular point which answers to the seat of curb. Where the 
tendon originates from the muscle, it is of considerable thickness, 
and gradually diminishes till it has passed over the os calcis, when 
VOL. XX. D 
