tendon.

Contraction of the superficial digital flexor (perforatus), when
uncomplicated, is characterized by volar flexion of the pastern joint.
The foot is flat on the ground and the heel is not raised because the
superficial flexor tendon does not have its insertion to the distal
phalanx (os pedis) and therefore can not affect the position of the
foot.

By causing the subject to stand on the affected member, one may outline
the course of the flexor tendons by palpation, and in this way recognize
any lack of tenseness or contraction of tendons or of the suspensory
ligament.

[Illustration: Fig. 21--Contraction of the deep flexor tendon
(perforans) of the right hind leg, due to tendinitis.]

Contraction of the suspensory ligament would cause the pastern joint to
assume the same position as is occasioned by contraction of the
superficial digital flexor (perforatus) tendon, but when the subject is
bearing weight on the affected member, it is easy to determine that no
contraction of the suspensory ligament exists, by noting an absence of
abnormal tenseness of this structure. And finally, contraction of the
suspensory ligament is of rare occurrence.

Contraction of the deep flexor tendon (perforans) causes an elevation of
the heel. The foot can not set flat because the insertion of the deep
flexor tendon to the solar surface of the distal phalanx (os pedis)
causes when the tendon is contracted--a rotation of the distal phalanx
on its transverse axis--hence the raised heel. No other tendon has this
same effect on the distal phalanx and the condition is correctly
diagnosed without difficulty.

[Illustration: Fig. 22--A chronic case of contraction of both flexor
tendons of the phalanges. In this case (presented at a clinic of the
Kansas City Veterinary College) because of long continued contraction of
the flexors, which prevented weight being supported with any degree of
comfort, there resulted a partial paralysis of the extensors, and
consequently the extremity was dragged on the ground.]

Course and Complications.--This condition may exist for years without
causing the subject any serious inconvenience, if the affected animal is
kept at suitable work. In other instances recurrent attacks of lameness
are of such frequent occurrence that the subject is not fit for service.
Many affected animals that are kept in service in spite of lameness (and
in some instances where no lameness is present), soon become
unserviceabl