The three =flexors of the carpus= are like those of the horse.
The =superficial digital flexor= is somewhat blended at its origin with
the middle flexor of the carpus. It divides into two bellies,
superficial and deep, terminating on tendons at the distal part of the
forearm. The superficial tendon passes over the posterior annular
ligament (Ligamentum carpi transversum), perforates the metacarpal
fascia, and joins the deep tendon about the middle of the metacarpus.
The deep belly is connected with the deep flexor by a strong fibrous
band. Its tendon passes under the annular ligament in a groove on the
deep flexor, from which it receives fibers. The conjoined tendon soon
bifurcates, each branch receiving a reinforcing band from the suspensory
ligament, and forming near the fetlock a ring for the corresponding
branch of the deep flexor tendon. Passing under two digital annular
ligaments, they are inserted into the volar surfaces of the second
phalanges by three slips.
The =deep digital flexor= has the same heads as in the horse, the
humeral head, as before mentioned, being connected with the deep portion
of the superficial flexor. The tendon divides near the distal end of the
metacarpus into two branches which are inserted into the volar surfaces
of the third phalanges.
The synovial sheaths at the carpus present the following special
features: One is found in connection with the tendon of the superficial
part of the superficial flexor of the digits. There is a common sheath
for the tendons of the common extensor and the inner extensor.
Bursæ may occur under the tendons of the proper extensors of the digits
at the fetlock; they are constant only in old animals (Schmidtchen). The
branches of the tendon of the common extensor are provided with synovial
sheaths from their origin to the middle of the second phalanx. There are
two digital synovial sheaths for the flexor tendons; they may
communicate at their upper part, and extend from the distal third of the
metacarpus nearly to the distal sesamoids. Bursæ occur between the
latter and the branches of the deep flexor tendon.