episode of plantar fasciitis within six to eight
weeks. With appropriate preventive measures,
many people are able to keep symptoms from
returning.
See also LIGAMENT; MUSCLE; REPETITIVE MOTION
INJURIES; TENDON; WEIGHT LOSS AND WEIGHT MANAGE-
MENT.
polydactyly Extra fingers or toes. Polydactyly
may occur spontaneously and isolated (without
apparent cause) or in conjunction with GENETIC
DISORDERSsuch as PATAU’S SYNDROME(trisomy 13).
Most often the extra digit is on the little finger or
little toe side of the hand or foot, respectively, and
is so rudimentary as to be functionless. Nearly
always the doctor recommends removing the
extra digit, which may be done with banding (the
doctor places a band tightly around the base of a
rudimentary digit, cutting off its BLOODsupply so it
slowly withers and falls off) or as a surgical AMPU-
TATION.
See also AUTOSOMAL TRISOMY; SYNDACTYLY.
polymyositis A chronic condition of widespread
INFLAMMATIONof the muscles. The inflammation
causes weakness and difficulty with everyday
movements including walking, reaching for
objects, bathing, and dressing. Polymyositis is a
type of inflammatory MYOPATHY that many
researchers believe is autoimmune in its origins.
Other researchers believe polymyositis and other
inflammatory myopathies develop after viral
INFECTIONor as side effects of cholesterol-lowering
therapy with statin medications. Polymyositis has
alternating periods of RECURRENCE and REMISSION
that tend to be lifelong. Most people are age 50 or
older when they develop the condition.
Symptoms and Diagnostic Path
The severity and range of symptoms vary among
individuals as well as across episodes within the
same person. Symptoms of polymyositis may
include
- MUSCLEweakness throughout the body though
most pronounced in the shoulders, upper arms,
hips, and thighs - both sides of the body equally affected
- JOINT PAIN
- fatigue
- difficulty swallowing
- JOINT PAIN
The diagnostic path includes BLOOD tests to
detect antibodies and elevated enzymes that indi-
cate muscle injury within the body. Muscle biopsy
may show the inflammation within the sample of
muscle tissue. Sometimes MAGNETIC RESONANCE
IMAGING(MRI) presents a pattern of the inflamma-
tion’s presence in the body. Because there are no
conclusive diagnostic tests for polymyositis, the
diagnostic journey can be arduous and frustrating.
Treatment Options and Outlook
Treatment for polymyositis is a combination of
CORTICOSTEROID MEDICATIONSand IMMUNOSUPPRESSIVE
MEDICATIONS, which work together to mitigate the
IMMUNE SYSTEM’s inflammatory response. Physical
therapy for passive and active range of motion
exercises helps maintain optimal joint function.
Daily physical activity has similar effect.
Polymyositis is a lifelong condition that, when
symptoms are severe, can result in permanent dis-
ability.
Risk Factors and Preventive Measures
Because researchers do not know what causes
polymyositis, there are no known measures to
prevent its development. Early diagnosis and
treatment offer the most effective approach for
minimizing the course of the disease and reducing
the seriousness of its symptoms.
See also ANTIBODY; AUTOIMMUNE DISORDERS;
CHRONIC PAIN; QUALITY OF LIFE; SYSTEMIC LUPUS ERYTHE-
MATOSUS(SLE); VIRUS.
proprioception The body’s sense of its location
within its physical environment. Proprioceptors
are specialized molecules on PERIPHERAL NERVESin
the muscles that send a continuous barrage of
NERVE impulses to the basal ganglia and other
structures of the BRAINthat have roles in balance
and movement. The balance functions in the
vestibular structures of the inner EARalso con-
tribute sensory information. Proprioception is
essential for all voluntary movement. Propriocep-
tion diminishes in neuromuscular disorders such
350 The Musculoskeletal System