It is desirable, in some cases, to cause an animal to move from side to
side; in other instances the subject is best made to walk or trot in a
circle, and if the circle be very small the animal then particularly
employs the inner fore leg as a pivotal supporting member. To augment
the manifestation of certain affections, it is necessary to cause the
patient to walk backward, and each one of these tests of locomotion
serves to point out in a more or less characteristic manner, the site of
the affection which is causing lameness in different cases.

Sprains or injuries of lateral ligaments of the extremities, ringbone
and certain foot affections, are made manifest by a side to side
movement or a pivotal movement. In fact, wherever it is possible to
cause undue or unusual tension to be exerted upon an inflamed structure,
manifestation of pain is the response. In an inflamed condition of the
lateral side of the phalanges, unequal weight-bearing such as a rough
road surface will, by virtue of the leverage which the solar surface of
the foot affords, cause undue strain upon such inflamed parts, and
increased lameness is evident.

When an animal is made to travel in a circle, when a member affected
with supporting-leg-lameness is on the inner side of the circle,
lameness is accentuated because weight is borne by the lame leg for a
greater length of time, the result of such circuitous manner of
locomotion. In swinging-leg-lameness, on the other hand, because pain is
increased at the time an affected member is being advanced, lameness is
increased when the subject is made to travel in a circle, with the lame
leg on the outside of a circle thus described.

In supporting-leg-lameness, the transientness of the weight-bearing