Shoulder
Injuries and Disorders
Most Common Shoulder
Problems
The most movable joint in the body, the
shoulder is also one of the most potentially
unstable joints. As a result, it is the site
of many common problems. They include
sprains, strains, dislocations, separations,
tendonitis, bursitis, torn rotator cuffs,
frozen shoulder, fractures, and arthritis.
Specific shoulder problems will be discussed
later in this booklet.
According to the Centers for Disease Control
and Prevention, about 13.7 million people in
the United States sought medical care in
2003 for shoulder problems.
Origins and Causes of Shoulder Problems
The shoulder is easily injured because the
ball of the upper arm is larger than the
shoulder socket that holds it. To remain
stable, the shoulder must be anchored by its
muscles, tendons, and ligaments.
Although the shoulder is easily injured
during sporting activities and manual labor,
the primary source of shoulder problems
appears to be the natural age-related
degeneration of the surrounding soft tissues
such as those found in the rotator cuff. The
incidence of rotator cuff problems rises
dramatically as a function of age and is
generally seen among individuals who are
more than 60 years old. Often, the dominant
and nondominant arm will be affected to a
similar degree. Overuse of the shoulder can
lead to more rapid age-related
deterioration.
Shoulder pain may be localized or may be
felt in areas around the shoulder or down
the arm. Disease within the body (such as
gallbladder, liver, or heart disease, or
disease of the cervical spine of the neck)
also may generate pain that travels along
nerves to the shoulder. However, these other
causes of shoulder pain are beyond the scope
of this book, which will focus on problems
within the shoulder itself.
Dislocation
The shoulder joint is the most frequently
dislocated major joint of the body. In a
typical case of a dislocated shoulder,
either a strong force pulls the shoulder
outward (abduction) or extreme rotation of
the joint pops the ball of the humerus out
of the shoulder socket. Dislocation commonly
occurs when there is a backward pull on the
arm that either catches the muscles
unprepared to resist or overwhelms the
muscles. When a shoulder dislocates
frequently, the condition is referred to as
shoulder instability. A partial dislocation
in which the upper arm bone is partially in
and partially out of the socket is called a
subluxation.
Separation
A shoulder separation occurs where the
collarbone (clavicle) meets the shoulder
blade (scapula). When ligaments that hold
the joint together are partially or
completely torn, the outer end of the
clavicle may slip out of place, preventing
it from properly meeting the scapula. Most
often, the injury is caused by a blow to the
shoulder or by falling on an outstretched
hand.
Tendonitis
Tendonitis is
inflammation (redness, soreness, and
swelling) of a tendon. In tendonitis of the
shoulder, the rotator cuff and/or biceps
tendon become inflamed, usually as a result
of being pinched by surrounding structures.
The injury may vary from mild inflammation
to involvement of most of the rotator cuff.
When the rotator cuff tendon becomes
inflamed and thickened, it may get trapped
under the acromion. Squeezing of the rotator
cuff is called impingement syndrome.
Bursitis
Bursitis, or inflammation of the bursa sacs
that protect the shoulder, may accompany
tendonitis and impingement syndrome.
Inflammation caused by a disease such as
rheumatoid arthritis may cause rotator cuff
tendonitis and bursitis. Sports involving
overuse of the shoulder and occupations
requiring frequent overhead reaching are
other potential causes of irritation to the
rotator cuff or bursa and may lead to
inflammation and impingement.
Torn Rotator Cuff
Rotator cuff tendons often become inflamed
from overuse, aging, or a fall on an
outstretched hand or another traumatic
cause. Sports or occupations requiring
repetitive overhead motion or heavy lifting
can also place a significant strain on
rotator cuff muscles and tendons. Over time,
as a function of aging, tendons become
weaker and degenerate. Eventually, this
degeneration can lead to complete tears of
both muscles and tendons. These tears are
surprisingly common. In fact, a tear of the
rotator cuff is not necessarily an abnormal
situation in older individuals if there is
no significant pain or disability.
Fortunately, these tears do not lead to any
pain or disability in most people. However,
some individuals can develop very
significant pain as a result of these tears
and they may require treatment.
Fracture
A fracture involves a partial or total crack
through a bone. The break in a bone usually
occurs as a result of an impact injury, such
as a fall or blow to the shoulder. A
fracture usually involves the clavicle or
the neck (area below the ball) of the
humerus.
Arthritis of the Shoulder
Arthritis is a degenerative disease caused
by either wear and tear of the cartilage
(osteoarthritis) or an inflammation
(rheumatoid arthritis) of one or more
joints. Arthritis not only affects joints,
but may also affect supporting structures
such as muscles, tendons, and ligaments.
|
