BIRMINGHAM, Ala. — Glenn Fleisig’s rather unusual laboratory has a pitcher’s mound and a home plate, and when he rigs people up to throw a baseball, their motion is analyzed with sensors feeding into computers.

Nearby is a second lab, and that is where Fleisig, the research director at the American Sports Medicine Institute, keeps the body parts, dead shoulders, elbows and knees. These appendages, severed from cadavers, can be stretched until the ligaments and tendons are stressed enough to snap.

Fleisig, a biomedical engineer, knows what an arm can handle, and years of research give him the confidence to answer one of baseball’s more intriguing questions: Is there a limit to how fast a human being can throw?

His answer: Yes, there is.

And, he adds: That limit already has been reached.

“Oh, there may be an outlier, one exception here or there,” he said. “But for major league baseball pitchers as a group of elites, the top isn’t going to go up anymore. With better conditioning and nutrition and mechanics, more pitchers will be toward that top, throwing at 95 or 100. But the top has topped out.”