Sumo baby-shaking spectacle

For westerners raised on the teachings of child-care guru Benjamin Spock, it is an alarming sight.

Parents willingly hand their offspring to Sumo wrestlers, who lift them over their heads and shake them until they cry.

The tradition, carried out each spring, may sound like a form of child abuse.

There aren't many smiles in these pictures

But in Japan, tradition has it that the loudest, most tearful baby, will grow up strong and healthy.

First, the child is ritually purified and blessed by a priest.

Then parents - many recording the event on camera for posterity - sit back and enjoy the performance.

Sociologists have pondered whether the popularity of Sumo has anything to do with the baby-like appearance of the wrestlers.

If all else fails ...

After all, they share the same voracious appetite, the same puppy fat, and the same mode of dress - all wrapped up in a nappy-like loincloth.

The ceremony is an opportunity for Japanese women to indulge two of their obsessions - Sumo and children.

The ritual is also a good opportunity for the Sumo stars to get to grips with a new generation of fans.

And if the wrestlers do not have the required effect, there are others around to lend a hand in a more conventional way - by wearing frightening masks.