he radial
nerve, there is manifested more or less impairment of function.
Remembering the structures supplied by the radial nerve and its
branches, one can readily understand that there should occur as
Cadiot[11] has stated:

In complete paralysis, the joints of the affected limb with the
exception of the shoulder are usually flexed when the horse is
resting. In consequence of loss of power in the triceps and
anterior brachial muscles, the arm is extended and straightened on
the shoulder, the scapulohumeral angle is open, and the elbow
depressed. The forearm is flexed on the arm by the contraction of
the coracoradialis (biceps brachii), while the metacarpus and
phalanges are bent by the action of the posterior antibrachial
muscles. The knee is carried in advance, level with, or in front
of, a vertical line dropped from the point of the shoulder. The
hoof is usually rested on the toe, but when advanced beyond the
above mentioned vertical line, it may be placed flat on the ground,
the joints then being less markedly bent. When the limb as a whole
is flexed, it may be brought into normal position by thrusting back
the knee with sufficient force to counteract the action of the
flexor muscles.

[Illustration: Fig. 9--Merillat's method of fixing carpus in radial
paralysis. Courtesy, Alex. Eger.]

When made to walk, the animal being unable to exert muscular action with
the paralyzed structures, limply carries the member as a whole, and
there is shortening of the anterior portion of the stride. There being
loss of function of the triceps brachii, it is impossible for the
subject to straighten the leg in the normal position for supporting
weight; therefore, any attempt to bear weight results in further
flexion of the affected member and the animal will fall if the body is
not suddenly caught up with the sound leg.

Differential Diagnosis.--In making examination of these cases, one can
exclude fracture by absence of crepitation and usually, also, swelling
is absent in radial paralysis. In a typical case of radial paralysis,
the affected leg can sustain its normal share of weight if placed in
position, that is, if the carpal joint is extended in such manner that
the leg is positioned as in its normal weight-bearing attitude. In
brachial paralysis, whether due to fracture of the first rib or to other
serious injury, it is impossible for the subject