Stress fracture of the ulna in a softball pitcher.

BACKGROUND/AIMS: We present a rare case of stress fracture of the diaphysis of the ulna in a softball pitcher. CASE: A thirteen-year-old girl felt pain over the distal third of the right forearm during pitching. Stress fracture was detected as callus formation of the ulna before fracture displacement. When windmill pitching for softball, the pitcher rotates their arm around the shoulder joint and powerfully hits their forearm to their thigh, which is accompanied by simultaneous pronation of the forearm and flexion of the wrist. The ball is then released and this movement is known as "brushing".
CONCLUSIONS: The typical throwing form in a softball pitcher can play an important role in stress fractures of the ulna.