sequelae.

LAMENESS OF THE SHOULDER.

The frequency of the occurrence of lameness in the shoulder from sprains
entitles it to precedence of mention in the present category, for,
though so well covered with its muscular envelope, it is often the seat
of injuries which, from the complex structure of the region, become
difficult to diagnosticate with satisfactory precision and facility. The
flat bone which forms the skeleton of that region is articulated in a
comparatively loose manner with the bone of the arm, but the joint is,
notwithstanding, rather solid, and is powerfully strengthened by tendons
passing outside, inside, and in front of it. Still, shoulder lameness or
sprain may exist, originating in lacerations of the muscles, the tendons
or the ligaments of the joint, or perhaps in diseases of the bones
themselves. "Slip of the shoulder" is a phrase frequently applied to
such lesions.

The identification of the particular structures involved in these
lesions is of much importance, in view of its bearing upon the question
of prognosis. For example, while a simple superficial injury of the
spinatus muscles, or the muscles by which the leg is attached to the
trunk, may not be of serious import and may readily yield to treatment,
or even recover spontaneously and without interference, the condition is
quite changed in a case of tearing of the flexor brachii, or of its
tendons as they pass in front of the articulation, or, what is still
more serious, if there is inflammation or ulceration in the groove over
which this tendon slides, or upon the articular surfaces or their
surroundings, or periostitis at any point adjacent.

_Causes._--The frequency of attacks of shoulder lameness is not
difficult to account for. The superficial and unprotected position of
the part and the numerous movements of which it is capable, and which,
in fact, it performs, render it both subjectively and objectively
preeminently liable to accident or injury. It would be difficult and
would not materially avail to enumerate all the forms of violence by
which the shoulder may be crippled. A fall, accompanied with powerful
concussion; a violent muscular contraction in starting a heavily loaded
vehicle from a standstill; a misstep following a quick muscular effort;
a jump accompanied with miscalculated results in alighting; a slip on a
smooth, icy road; balling the feet with snow; colliding with another
horse or other object--indeed, the list ma