Oct. 14, 2004 — Michelangelo's David, the towering sculpture acclaimed for its depiction of male physical perfection, has a "hole" in the back, two anatomy professors announced at a recent conference in Florence.

Computer measurements of David's body taken by professors Massimo Gulisano and colleague Pietro Bernabei of Florence University show a hollow instead of a muscle on the right side of the back, between the spine and the shoulder blade.

"Michelangelo's David is the result of intense anatomy studies. Here the artist achieved an absolute perfection except for that muscle in the back," Gulisano said.

But it wasn't really a mistake. Michelangelo was aware of the flaw.

"In one of his letters, he wrote that a defect in the marble block made it impossible to reproduce the muscle," the researchers said.

Indeed, David was carved from a single block of marble discarded for an imperfection by two other sculptors, Agostino di Duccio and Antonio Rossellino.

Representing the biblical hero who killed Goliath, the sculpture marked a watershed in Renaissance art and established Michelangelo as the foremost sculptor of his time at the age of 29.

"The grace of this figure and serenity of its pose have never been surpassed ... to be sure, anyone who has seen Michelangelo's David has no need to see anything else by any other sculptor, living or dead," the 16th century painter and art historian Giorgio Vasari wrote in his "Lives of the Artists."

David was displayed on Sept. 8, 1504, beside the main doorway of the Piazza della Signoria in Florence and remained there, at the mercy of the elements, until 1873, when it was moved to its present location in the Galleria dell'Accademia. Today it attracts 1.2 million visitors a year.

"It is one of the five or six most famous masterpieces in the world, a universal totem of art," Florence's art superintendent Antonio Paolucci said, presenting this year's cleaning.

The first one in 130 years, the cleaning removed gypsum and yellowish spots of beeswax leaving the masterpiece "the same as ever," according to the restoration team.

One of the several studies presented during the series of conferences organized to celebrate the 500th anniversary of the unveiling of the statue, Gulisano and Bernabei's research highlighted Michelangelo's mastery in depicting the tension in the muscles of the biblical hero as he was about to challenge Goliath with his slingshot.

"We can see the dilated nostrils and the muscle contraction on the forehead and over the nose," the professors said.

Even David's genitals, which seem out of proportion to most viewers, are anatomically correct for a male body in a "pre-fight tension," the researchers said.

However, from an art history's point of view, the study doesn't help, according to James Beck, professor of art history at Columbia University, and the author of "The Three Worlds of Michelangelo."

"The doctors do not understand Michelangelo and they do not understand Renaissance views. Michelangelo was not a realist who wished to imitate nature. He had an ideal type in his artistic language and actually, his figures are never anatomically correct," Beck told Discovery News.