where I tried on its extensive range

She made the nylon backpack fashionable in the early Nineties and sent an entire collection made from lace down the catwalk in 2008, sparking a trend which is still filling rails on the High Street today.

And now Miuccia Prada, creative head of the brand that is about to celebrate its 100th birthday, has given us the strangest trend of all: the flatform.

This very high shoe looks like a building block, something as big and solid as Ayers Rock.

If someone threw you into the Thames wearing a pair of these babies, you would undoubtedly sink to the bottom.

The flatform is not to be confused with the wedge, which has an incline, tipping the foot at a slight angle, or the platform, which generally has a stubby toe and a high heel.

No, as its name suggests flatforms are very flat — like Norfolk — and are also very, very high.
These shoes were first seen on the catwalk at Prada last September: towering Japanese geisha-girl platforms worn with colourful soft leather Tabi socks (the leather sock effect was also seen at Victoria Beckham).

These monoliths cost ￡830, are covered in daisies, and were featured in Vogue last month as the last  word in edgy shoes-as-art form.

But, of course, even Ms Prada got the idea for these shoes from somewhere else: undoubtedly in this case from David Bowie, who wore a pair of red patent flatforms as long ago as 1973 (in fact, these flatforms can be seen in the excellent exhibition, David Bowie Is, at the V&A museum).

So, we understand that they are fashionable. We understand they make the wearer extremely tall. But the key question is, can you walk in them?

Unlike summer’s alternative hot shoe, the pointy, feminine high stiletto, best executed in white or sugary pink, these shoes are very heavy, which gives the wearer a rather ungainly gait, with knees  that are permanently bent.

Because of the weight and rigidity of the flatform, the foot has to land flat on the ground, not heel or toe first, which means you will walk and sound like  an elephant.

The biggest problem comes when you encounter uneven ground, which means the whole foot can go over, like a domino, significantly increasing your risk of twisting your ankle.

All in all, the whole experience is a strain on the old knee joints, although the ball of the foot does not feel the pain you get after a day in high heels.

After a day in my Prada flatforms, my shins felt very painful, too, due to the weight and the strange, creeping gait I developed. Imagine comedian Dick Emery after a very long, hard day, and that was me.

I think the flatform is a shoe exclusively for the young (the Prada Daisy flatforms were worn by 14-year-old movie actress Elle Fanning at the premiere of Breaking Dawn last November).

But if you must wear a flatform, avoid an over-long trouser or skirt, because you will look as though you are on castors. Instead, flatforms look best with a mini skirt, shorts, or at least a cropped cigarette pant.

At Topshop last week, where I tried on its extensive range, young shoppers told me the reason they love the shoes is they make their legs look ultra, ultra thin.

‘Like Olive Oyl?’ I ventured, to be met by blank stares. These girls are too young to have heard of Popeye.

There are a few less vertiginous flatforms around, such as the ones seen here (right) from Asos.
And a less skyscraperish design comes from Louboutin, featuring an ankle strap and fashioned from raffia and studded leather for ￡395 — as the shoe is flat, though, no one will see your trademark red leather sole, which is a shame, but that’s a price you have to pay to be up-to-the-minute.

I love, too, the flatform from Celine: it’s not too high, has a faux furry lining, and is as comfy as a pair of slides or Birkenstocks.
Add a pair of shocking pink leather socks with a separate compartment for your big toe, and people will think you are wearing Prada — if you care about such things.