One Case of Pronator Syndrome

55 year-old repairman had feeling of numbness and weakness of flexion in his right fingers. Muscle atrophy on his right thenar eminence and no sensory changes were noticed.EMG findings and subjective symptomes which were made worse with supination of the forearm suspected the pronator syndrome.Surgical exploration was taken because of no relief of 2 months' rest. The median nerve was compressed by tendinous thickening at the lower portion of humeral head of pronation muscle. But we couldn't find macroscopically the abnormal findings of the median nerve.Fortunately feeling of numbness disappered after operation.It seemed difficult case to diagnnsis from other differential diseases.