Overuse Shoulder Injuries In The Young Athlete
Overuse injuries can be
caused by repetitive stress upon muscles,
tendons, nerves and bones.
This stress causes microscopic damage
to these tissues. Often the body
does not have enough time to
repair the damage between bouts of
exercise. About 750,000 overuse
injuries will occur in young athletes
each year. Many of these are
avoidable.
The shoulder joint is
highly mobile and allows us to reach
overhead, out to the side, behind the
back, and across our body to
touch the opposite shoulder. This mobility
also allows to us to
throw overhand. The price we pay for such mobility
is that we have
less stability of the shoulder joint than other joints in the
body.
The stabilizing forces about the shoulder are quite complex.
There
are a set of ligaments that attach the head of the arm
bone
(humerus) to the socket of the shoulder (glenoid). These
ligaments
provide static stability to the shoulder joint. There are
four
muscles known as the rotator cuff, these supply much of the
dynamic
stability to the shoulder joint. There are other muscles
that
stabilize the wing bone (scapula) to the body. These are
also
important for shoulder stability.
In a physically immature
athlete, the development of these muscles,
tendons, and ligaments are not
complete. They have not reached
their maximal strength and are
susceptible to being stretched,
torn, and overwhelmed by repetitive stresses,
such as throwing.
This tearing, stretching, etc. often presents itself as
pain to the
young athlete.
Young athletes who are most likely
to experience overuse injuries
in the shoulder are pitchers, swimmers, and
quarterbacks. Many
times the overuse injuries can be rehabilitated
through a program
of rest, followed by exercises to strengthen these
shoulder
muscles.
Often the presenting signs or symptoms of a young
athlete who is in
the throws of overuse syndrome include a change in body
mechanics
during activity. ie. a change in mechanics while pitching
a
baseball. In fact, young throwing athletes, because of this
change
in mechanics, will place increased stress across the elbow
and
often complain of elbow pain before they complain of shoulder
pain.
The velocity and accuracy of their throwing will be decreased
as
their overuse syndrome continues. They will eventually complain
of
shoulder pain.
Some of the syndromes in the shoulder related to
repetitive
throwing include “little leaguer shoulder”. This is actually
a
stress fracture of the growth plate located in the upper arm bone.
This
has been well documented with x-ray examination and requires
absolute rest
from throwing, if not, there is potential to disrupt
and alter the growth
plate of the upper arm.
Another syndrome called tendonitis can
occur in one of the rotator
cuff tendons or in the biceps tendon. It is
a painful condition
that is usually the result of poor mechanics or throwing
too hard
with a tired arm. The muscle-tendon unit can become
inflamed
secondary to microsopic tearing. A burning pain is often
felt
especially with release and follow-through of the ball.
When the rotator cuff tendons are over stressed and become
tired.
They can no longer protect the integrity of the joint.
The
ligamentous capsule of the joint is the next structure to
be
stressed. This capsule can be stretched which then may lead
to
permanent instability problems of the shoulder.
Shoulder injuries
in the young athlete need to be recognized and
treated promptly. The
classic signs are pain, favoring the limb,
change in throwing mechanics, or a
change in accuracy and velocity.
Treatment of these conditions should
include rest and ice for
several days followed by therapy to strengthen the
appropriate
muscles. Many of the organized little leagues now restrict
the
amount of throwing by a child, including innings pitched per
game
and/or per week.
To avoid overuse injuries, youngsters involved
in throwing sports
need to be monitored closely by their parents and
coaches. At the
first sign of a problem, treatment should ensue.
This rest period
should be approximately two weeks before return to limited
throwing
is undertaken. In a skeletally immature athlete, it is much
better
to be safe than sorry when dealing with overuse
injuries.
Joseph J.
Calandra, M. D.
