Encyclopedia of Health and Medicine

sprains and strains 355
posture. A child may need to wear a scoliosis
brace only at night or all the time, depending on
the severity of the scoliosis. Severe scoliosis or scoliosis
that persists despite treatment may require
surgery, in which the surgeon realigns the vertebrae,
sometimes bracing them with steel or titanium
rods to maintain them in proper position.
Most scoliosis, when detected early, responds very
well to treatment and is gone by the time the child
reaches late ADOLESCENCE.
Risk Factors and Preventive Measures
Because doctors do not know what causes most
scoliosis, there are no known risk factors or preventive
measures. Scoliosis often accompanies
other conditions such as CEREBRAL PALSY, MUSCULAR
DYSTROPHY, and SPINA BIFIDA. Health experts urge
women of childbearing age to take folic acid supplements,
which can prevent many NEURAL TUBE
DEFECTS such as spina bifida. It also tends to run in
families, leading doctors to suspect there are
hereditary factors at play.
See also KYPHOSIS; LORDOSIS; SURGERY BENEFIT AND
RISK ASSESSMENT.
skeletal dysplasia Dysfunctional growth of the
SKELETON such that the person is of significantly
short stature. There are numerous forms of skeletal
dysplasia, commonly and collectively called
dwarfism, most of which are hereditary. Skeletal
dysplasia may also occur as a result of HORMONE
deficiencies during childhood. Each type of skeletal
dysplasia presents characteristic symptoms. In
general, skeletal dysplasias result in extremely
short stature. The structures of the skeleton are
nearly always disproportionate. Disorders of
growth that are metabolic cause proportionate
smallness. HORMONE THERAPY may increase skeletal
growth when the cause is endocrine or metabolic.
There are no treatments to alter the skeleton
when the cause of the dysplasia is genetic.
See also ACHONDROPLASIA; GENETIC DISORDERS;
INHERITANCE PATTERN; OSTEOGENESIS IMPERFECTA; RICK-
ETS; SCURVY.
skeleton The organization of the bones in the
body. The skeleton has two primary organizational
divisions: the axial skeleton and the appendicular
skeleton. The axial skeleton consists of the bones
that form the body’s axis or perpendicular line,
which include the head, rib cage, and spine. It
contains 80 bones. The remaining 126 bones—
arms, hands, legs, feet, shoulders, pelvis, hips—
form the appendicular skeleton.
The primary functions of the skeleton are to
give the body structure, support and protect the
body’s internal organs, and enable mobility.
Within certain bones is the BONE MARROW, which
produces the body’s BLOOD cells. The skeleton also
serves as the body’s “calcium bank,” storing calcium
when levels in the blood circulation are adequate
and pulling calcium from the bones when
blood levels of calcium drop too low.
For further discussion of the skeleton within
the context of the structures and functions of the
musculoskeletal system, please see the overview
section “The Musculoskeletal System.”
See also BONE; CALCIUM AND BONE HEALTH; OSTEO-
MALACIA; OSTEOPOROSIS.
sprains and strains Acute, traumatic injury to
muscles, tendons, and ligaments, typically as a
consequence of rapid and unexpected stretching
such as may occur with a stumble, sudden twisting
movement, or fall. A sprain is an injury to a
LIGAMENT; ligaments connect bones to each other.
A strain is an injury to a MUSCLE or TENDON; tendons
extend from muscles to connect them to
bones. Sprains and strains nearly always occur in
or near joints. A muscle, tendon, or ligament may
rupture (tear completely) under the force of a
sudden stretch. Though immediate treatment—
RICE (rest, ice, compression, elevation)—remains
the same, a rupture may later require surgical
repair.
A severe strain or sprain often is difficult
to distinguish from a FRACTURE and
should be treated as a fracture until
medical assessment determines it is not.
Symptoms and Diagnostic Path
The main symptoms of a sprain or strain are PAIN
and swelling following a sudden movement that
involves a JOINT. Both are often immediate, and it
may be difficult to use the limb. Grade 1 sprains
and strains are painful but minor and do not necessarily
require a visit to the doctor. However, it is