The foot is thus sectionised and described by Delaware P. Elaine, Esq.:—
“On examining a perpendicular section of the foot and pasterns, there appear the coffin-bone (a), the navicular or nut bone (b), the coronary or little pastern bone (c), the large pastern bone (d), the back sinew or great flexor tendon of the foot (e), the same tendon sliding over the navicular bone (f), its termination or insertion into the bottom of the coffin-bone (g), the elastic matter of the sensible frog (h), the insensible or horny frog (i), the horny sole (k), which includes the parts of the sensible foot; the outer wall of the hoof (l), the elastic processes (m), the attachment of the extensor tendon to the coffin-bone (n), and its attachment to the coronary bone (o), which completes the section.
“The coffin-bone (a) adapts itself to the figure of the hoof, or rather is adapted by nature to this eligible form. The eminence in its front receives the insertion of the tendon of the great extensor muscle of the foot. This important muscle has its upper attachment to the humerus or arm-bone, where it is principally fleshy; but as it passes downwards it becomes tendinous, expanding over every joint, both to prevent friction and to embrace and give firm attachment to each bone with its opposed bone, by which a firm connection of the various parts is maintained, and a simultaneous movement of the whole limb is effected. In the hinder limb this extensor tendon and its two less or tendinous adjuncts arise from the tibia, and in part from the femur, but in their origin are fleshy.
“In the sides of the coffin-bone are attached lateral cartilages, and around its surface are marks of the attachment of the laminated substance.
“The coronary, or small pastern bone (c), is seen to rest on the coffin-bone (a), with which it articulates by its lower end; its posterior part also may be seen to be closely articulated both with the coffin and with the navicular or nut bones (f), whose attachments to them are effected by ligaments of great power and some elasticity. Nor is it possible to view this horny box and its contents without being struck with the admirable display of mechanism and contrivance which meets our eye. We are apt to say, ‘as strong as a horse,’ and some of us use horses as though they were made of imperishable stuff; but surely, when we well consider the subject, we shall see both the necessity and the morality of using them with discretion.”
This description of the structure of the foot will probably better enable the uninitiated to understand the seat and nature of various ailments of that part of the horse which are here touched upon.
Fig. 3.
Fig. 4.