Rupture of latissimus dorsi muscle in a tennis player.

Spontaneous rupture of the latissimus dorsi muscle is a rare injury, and few reported cases were avulsion injuries at their humeral insertion. Seven cases of spontaneous rupture of the latissimus dorsi muscle have been reported, but only 1 occurred at the myotendinous junction. The mechanism of this injury is reported to be forceful resisted arm adduction or extension, and reported injuries were rock climbing and attempting to pull up on an overhead handhold, waterskiing injury during pull-up with ski rope, overuse in golf in the leading arm, and abduction-external rotation with horizontally extended arm during a professional steer wrestling performance. The latissimus dorsi muscle is not a critical muscle for activities of daily living; however, the significance of the muscle is increased in professional or elite athletes. This article presents a case of rupture of the latissimus dorsi muscle at the myotendinous junction that occurred during a sports activity.