Ten cases of isolated, complete paralysis of the serratus anterior
muscle were diagnosed in young athletes during a three-year period. One
patient had recurrent partial paralysis of the serratus anterior muscle,
the first such case reported. From studies on cadavera and clinical
observations, we concluded that paralysis of the serratus anterior muscle
results from a traction injury to the long thoracic nerve of Bell. Since
full recovery usually occurs in an average of nine months, surgical methods
of treatment should be reserved for patients in whom function fails to
return after a two-year period. Non-strenuous use of the involved extremity
with avoidance of the precipitating activity, followed by exercises
designed to maintain the range of motion of the shoulder and to increase
the strength of associated muscles, is advocated for treatment of acute or
repetitive injuries to the long thoracic nerve of Bell.