I'm in the Mexican gallery in front of what looks like a giant stone horseshoe-it's about 20 inches (50 cm) long and about 4 inches (10 cm) thick and is made of a very beautiful grey-green speckled stone. When it first came to the British Museum in the 1860s they thought that it was a yoke for something like a carthorse-but there were two immediate problems with this theory: first the object is very heavy, it's about five or six stone (35 kg)-too heavy even for a horse's neck-and secondly, there were no carthorses or draught animals in Central America until the Spaniards brought them from Europe in the sixteenth century.

It was only just over 50 years ago that it was generally understood that these stone carvings had nothing to do with animals; they were meant to be worn by men. They represent the padded belts made of cloth or basketwork worn to protect the hips during ancient Central American ball games. Indeed some of these stone belts may have been moulds used to shape lighter cloth or leather padding, but the one we have in the British Museum is made of solid stone, so heavy that if it was worn it can only have been very briefly. Nowadays it would perhaps be for a quick photo call, but we don't actually know exactly when or how it might originally have been worn.

We asked the leading expert on these games, Michael Whittington, what he thought these stone belts were for:

"I believe these were ceremonial objects.Wearing an object that's 75-100 lbs around your waist during an athletic competition will slow you down considerably, so they probably were worn as part of the ritual ceremonies at the beginning of the game.