[A case of long thoracic nerve palsy, with winged scapula, as a result of prolonged exertion on practicing archery].

: Reports of isolated long thoracic nerve palsy are rare in Japan. We reported a case of isolated long thoracic nerve palsy, resulted from recurrent injury to the nerve. Muscle CT and electrodiagnostic study were useful for confirming diagnosis of this cases. This patient was a student aged 20 years, with nothing of importance in his family or past history. After he started practicing archery, winging of left scapula was gradually developed. Physical examination revealed weakness and atrophy of left serratus anterior muscle. There was no wasting and weakness of other should girdle muscles. Hematochemical tests were normal, except slight hyperthyroidism. Radiography and myelography of the cervical spine were normal. Muscle CT of upper thoracic level demonstrated atrophy of left serratus anterior muscle, and no abnormality were found in other muscles. Electromyogram of the left serratus anterior revealed discrete activity of reduced amplitude, and fibrillation potentials and positive sharp waves. Conduction time for left long thoracic nerve was prolonged, and amplitude of the evoked response was small and there were temporal dispersion. Muscle CT and electrodiagnostic studies were suggestive of neuroapraxia of left long thoracic nerve. Over stretching or compression during exercises may be responsible for the damage to the long thoracic nerve.