What is the Rotator Cuff?
The rotator cuff consists of four muscles (supraspinatus,
infraspinatus, teres minor, and subscapularis) that
originate at the shoulder blade and attach to the ball
of the shoulder joint. The four rotator cuff muscles
coalesce to form one continuous tissue that resembles
the "cuff" of a shirt sleve. It controls the
rotation of the ball-shaped head of the upper arm bone
(humerus) in the shoulder socket and keeps the ball
centered in the socket as it is rotating. The top of
the shoulder is called the acromion. Between the acromion
and the rotator cuff muscles is lubricated tissue, called
the bursa sac, which cushions and decreases friction
in the shoulder.
When force is applied to the shoulder or the shoulder
is raised over the head, the rotator cuff squeezes against
the top of the shoulder, compressing the bursa sac.
This pinching of the tendons and muscles, called impingement,
causes a condition called bursitis. This irritation
in the bursa leads to inflammation and damage in the
rotator cuff as muscles and tendons grind in the shoulder
joint. Wear and tear to the rotator cuff may first cause
slight muscle pulls or mild strains. As this process
proceeds, frank tearing of the rotator cuff may occur.
Depending on the amount of strain put on the shoulder,
rotator cuff tendons may be partially torn (partial
thickness rotator cuff tear) or completely ruptured
(full thickness rotator cuff tear).
Overuse, especially in people who
engage in repeated overhead motions, commonly causes
rotator cuff tears. Excessive or traumatic force also
can cause rotator cuff tears that develop quickly. Trying
to catch a heavy falling object or lifting heavy weights
with your arms straight can cause what is called an
acute traumatic rotator cuff tear. Contact sports like
boxing, wrestling, and football also can cause acute
| Considerations for Treatment
Some rotator cuff tears, particularly
partial tears in young people, may not cause much pain
and not require surgery. The initial treatment is often
rest, ice, and anti-inflammatory medication to control
pain. But complete tears in the rotator cuff that hinder
you from raising your arm usually require surgery.
There usually are three parts to an
orthopedic evaluation: medical history, a physical examination,
and tests that your doctor may order.
likely will ask about your activities, which may be
causing the pain in your shoulder. He will probably
ask when the soreness or pain began. If you have had
any prior shoulder injuries, your physician will ask
about treatments you have tried in the past. You may
be asked about your work environment to determine if
any continuous overhead activities are causing your
pain. Physicians also typically ask about other conditions,
such as arthritis, diabetes, and allergies, and medications
currently being taken. You may also be asked about your
physical and athletic goals – information that
will help your physician decide what treatment might
be best for you in achieving those goals.
Your physician usually presses on
many different areas of the shoulder and tries to pinpoint
your pain. Your shoulder may be lifted and rotated in
many directions to determine its range of motion. If
your doctor can move your arm in a normal range of motion
but you cannot do the same on your own, you may have
a rotator cuff tear. The following physical tests may
help your doctor check the strength of specific rotator
lift-off test – With your arm rotated behind your
back and your elbow flexed, you try to push away against
resistance. Inability to push away signals injury to
the subscapularis muscle.
test – Your arms are held straight out at shoulder
height with your thumbs pointing down. You attempt to
hold your arms at shoulder height while your doctor
presses your arms down. If you cannot hold your arms
up, your supraspinatus muscle has a weakness.
Your doctor also may perform other tests to determine
if you have rotator cuff impingement, which is a pinching
of the tendons and the protective bursa sac; or shoulder
instability, a general condition where the upper arm
bone is not held securely in the socket.
Should your doctor need to take a closer look, the
following tests may be ordered:
are used to check for bone spurs or for abnormal alignment
of the bones in the shoulder blade that could be pinching
the rotator cuff. X-rays also may reveal calcium deposits,
which can harden rotator cuff muscles and tendons.
can reveal tears in rotator cuff tissues. A dye is injected
into the shoulder joint and X-rays are taken. If the
dye leaks out into the bursa, a tear is confirmed.
(magnetic resonance imaging) can create images with
magnetic waves that help doctors look at tendons in
the rotator cuff.