Bma Illustrated Medical Dictionary

walkingMovement of the body by lifting
the feet alternately and bringing 1 foot
into contact with the ground before the
other starts to leave it. A person’s gait is
determined by body shape, size, and
posture. The age at which children first
walk varies enormously.
Walking is controlled by nerve signals
from the brain’s motor cortex (see cere-
brum), basal ganglia,and cerebellumthat
travel via the spinal cord to the muscles.
Abnormal gait may be caused by joint
stiffness, muscle weakness (sometimes
due to conditions such as poliomyelitis
or muscular dystrophy), or skeletal abnor-
malities (see, for example, talipes; hip,
congenital dislocation of; scoliosis; bone
tumour; arthritis). Children may develop
knock-kneeor bowleg; synovitisof the hip
and Perthes’ diseaseare also common.
Adolescents may developa painful limp
due to a slipped epiphysis (see femoral
epiphysis, slipped) or to fracture or dis-
ease of the tibia, fibulaor femur.
Abnormal gait may also be the result
of neurological disorders such as stroke
(commonly resulting in hemiplegia), par-
kinsonism, peripheral neuritis, multiple
sclerosis, various forms of myelitis, and
chorea. Ménière’s diseasemay cause sev-
ere loss of balance and instability.
walking aidsEquipment for increasing
the mobility of people who have a dis-
order that affects their ability to walk.
Aids include walking sticks, crutches,
and walking frames.
walking, delayedMost children walk
by around 15 months of age. Delayed
walking may be suspected if the child is
unable to walk unassisted by 18 months
(see developmental delay).
warfarinAn anticoagulant drugused to
treat and prevent abnormal blood clot-
ting. Warfarin is used to treat deep vein
thrombosis, pulmonary embolism, and
people with atrial fibrillationwho are at

risk of an embolism. It is also prescribed

to prevent emboli from developing on

replacement valves (see heart-valve sur-

gery). A faster-acting anticoagulant, such

as heparin, may also be prescribed for

the first few days following a deep-vein

thrombosis or pulmonary embolism.

Warfarin may cause abnormal bleeding

in different parts of the body, so regular

tests are carried out to allow careful

regulation of dosage. Warfarin may also

cause nausea, diarrhoea and a rash.

wartA common, contagious, harmless

growth that occurs on the skin or mucous

membranes. Only the topmost layer of

skin is affected. An overgrowth of cells

in this layer causes a visible lump to

develop. Warts are caused by the human

papillomavirus, of which at least 30 dif-

ferent types are known. These cause

different types of warts at various sites,

such as on the hands or genitals.

Flat warts are flesh-coloured, sometimes

itchy lumps with flat tops that occur

mainly on the wrists, backs of hands, and

face. About 50 per cent of warts disap-

pear in 6–12 months without treatment.

However, genital warts should be treated

promptly. Common, flat, and plantar

warts can sometimes be destroyed using

a wart-removing liquid or special plaster.

Several treatments may be necessary,

and sometimes the wart returns. Warts

are commonly treated by cryosurgery.

WALKING WART

W

Raised surface of wart

Epidermis

Dermis

Excess cells

produced

Basal cell

layer

WART

Nerve

fibre

Blood vessels

W