But in general, pitching like a girl is very little different from pitching like a boy, Dr. Fleisig says. In a 2009 study of the biomechanics of elite (but not professional) male and female pitchers that he conducted with colleagues, the female pitchers produced slightly less force throughout their fastball pitching motion, from the cocking of the arm behind the back, to the stride forward, and through to the release of the ball itself, than did the male pitchers. Consequently, the top velocity of the pitches by the women was a few miles per hour slower than among the men.
Female pitchers might even have a slight physical advantage because their physiology may insulate them against some of the worst physical effects of high-speed pitching, says Dr. Steve Jordan, an orthopedic surgeon at the Andrews Institute for Orthopaedics and Sports Medicine, who treats many professional and amateur baseball players.
“Women tend to have somewhat more laxity in their tendons than men,” he says. “They are more limber.” That looseness, combined with the slower overall velocity of their pitching speed, “could mean that women would be less likely” to suffer the kinds of soft-tissue injuries in their shoulders and elbows, he says, that often fell male pitchers and result in season- and even career-ending surgeries.