nsion of the arm; a spastic condition of the lower
limbs--Little's disease--resulting from tearing of blood vessels on
the surface of the brain with haemorrhage and interference with the
function of the cortical motor area.

3. _Deformities acquired after birth_ arise from widely different
causes, of which diseases of bone, including rickets, diseases of
joints, and affections of the nervous system attended with paralysis,
are amongst the commonest. Other deformities are produced by
unsuitable clothing, such as a tight corset, or ill-fitting shoes
distorting the toes, prolonged standing in growing subjects
overstraining the mechanism of the foot and giving rise to the common
form of flat-foot.

The part played by the palsies of children in the surgical affections
of the extremities necessitates a short description of their more
important features.

#Anterior poliomyelitis# is the lesion underlying what was formerly
known as _infantile paralysis_--a name to be avoided, because the
condition is not confined to infants and it is not the only form of
paralysis met with in young children. Anterior poliomyelitis is
characterised by an illness attended with fever, in which the child is
found to have lost the power of one, less frequently of both lower
extremities; or, it may be, of one or both arms. After a period,
varying from six weeks to three months, the paralysis tends to
diminish both in extent and degree, and in the majority of cases it
ultimately persists only in certain muscles or groups of muscles. At
the onset of the paralysis the affected limb is helpless and relaxed,
the reflexes are lost, the muscles waste, and those that are paralysed
exhibit the reaction of degeneration. In severe cases, and especially
if proper treatment is neglected, the nutrition of the limb is
profoundly affected; its temperature is subnormal, the skin is bluish
in cold weather and readily becomes the seat of pressure sores. In
course of time the limb lags behind its fellow in growth, and tends to
assume a deformed attitude, which at first can easily be corrected,
but later becomes permanent.

[Illustration: FIG. 127.--Female child showing the results of
Poliomyelitis affecting the left lower extremity; the limb is short
and poorly developed, the pelvis is tilted and the spine is curved.]

When the acute stage of the illness is past, the chief question is to
what extent recovery of function can be looked for in the paralysed
muscles.