ead of lower bone (tibia) is moved to
one side; knee slightly bent.

_First Aid Rule 1.--Put patient on back._

_Rule 2.--Flex thigh on abdomen and hold it there._

_Rule 3.--Grasp leg below knee and twist it back and forth, and
straighten knee._

=DISLOCATIONS.=--A dislocation is an injury to a joint wherein the
ends of the bones forming a joint are forced out of place. A
dislocation is commonly described as a condition in which a part (as
the shoulder) is "out of joint" or "out of place." A dislocation must
be distinguished from a sprain, and from a fracture near a joint. In a
sprain, as has been stated (p. 65), the bones entering into the
formation of the joint are perhaps momentarily displaced, but return
into their proper place when the violence is removed. But, owing to
greater injury, in dislocation the head of the bone slips out of the
socket which should hold it, breaks through the ligaments surrounding
the joint, and remains permanently out of place. For this reason there
is a peculiar deformity, produced by the head of the bone's lying in
its new and unnatural situation, which is not seen in a sprain.

Also, the dislocated joint cannot be moved by the patient or by
another person, except within narrow limits, while a sprained joint
can be moved, with the production of pain it is true, but without any
mechanical obstacle. In the case of fracture near a joint there is
usually increased movement in some new direction. When a dislocated
joint is put in proper place it stays in place, whereas when a
fractured part is reduced there is nothing to keep it in place and, if
let alone, it quickly resumes its former faulty position.

Only a few of the commoner dislocations will be considered here, as
the others are of rare occurrence and require more skill than can be
imparted in a book intended for the laity. The following instructions
are not to be followed if skilled surgical attendance can be secured;
they are intended solely for those not so fortunately situated.

=DISLOCATION OF THE JAW.=--This condition is caused by a blow on the
chin, or occurs in gaping or when the mouth is kept widely open during
prolonged dental operations. The joint surface at the upper part of
the lower jaw, just in front of the entrance to the ear, is thrown out
of its socket on one side of the face, or on both sides. If the jaw is
put out of place on both sides at once, the chin will be found
projecting so that lower front teet