Hard to imagine, I know, but I'm writing this while looking extremely unalluring. Lunging to catch a stumbling child (my child) on the escalator at Euston Tube station while also lugging a suitcase I did my back in and am now in a permanent crouch as if sitting on an imaginary toilet.

Obviously, it's all because I'm not 25 any more. Once I would have shrugged off such an injury with aspirin and a couple of stretches. Now I need a Nurofen Plus hit to get out of bed and make old-person noises - “eeeeesh”/ “aaaah”/“bhoaah” - while lowering myself into chairs.

It's all very undignified but has afforded me a small insight into what it is to be a proper Old Lady - stooped, slow and invisible to a world rushing by and knocking you over. I have probably been guilty myself of tutting as some spindly old soul got in my way because I had to be somewhere. Well now I am that laggard, Quasimodo-ing it to the newsagents at the top of our road, griping about the papers being stacked on the floor because you have to bend to pick them up and wondering, in the words of George Burns, if there's anything else I can do while I'm down there.

In this country we are not kind to old or frail people, not that you need to be decrepit to be deemed a Crimplene-trousered waste of space. Just failing to be “young” is enough. Take The Courtyard bar in Leeds, currently under investigation by its owners after door staff allegedly barred some middle-aged women for being “too old”. The group, comprising civil servants, teachers and bank officials, ranged in age from 22 to 67, but was told that over-35s were not welcome. Staff reportedly said: “The daughters can come in but not your mums.”

Hear that, womenfolk? Don't go out drinking in public over the age of 35 or you might curdle the beer. Probably best to stay at home, where the incontinence pads are handy and you can flick through your brochure on static caravans.

Figures released this week by the Tribunal Service showed that the number of people making discrimination claims on grounds of age more than tripled between 2006 and 2007 when the law was changed to recognise ageism. It is this legislation which enabled Selina Scott, 57, to stick it up Channel Five, sorry, “accept a £250,000 settlement” after she claimed she was overlooked to cover Natasha Kaplinsky's maternity leave because she was considered past it.

Over at the BBC's Countryfile there are more raised eyebrows as fresher-faced Julia Bradbury, 36, is brought in to present the new series in place of Michaela Strachan, 42 (who is now based in South Africa). Three female reporters on the show - all in their 40s and 50s - are dropped. John Craven, 68, meanwhile, will remain. And then there's the irony of Nicky Hambleton-Jones, 37, the authoritative presenter of 10 Years Younger, being replaced by a woman seven years younger - the wrinkle-free, but spectacularly dull Myleene Klass. “It does seem to me like a classic case of replacing any women over 35, regardless of how suitable she is for the role, with a younger face”, Hambleton-Jones said. That's right. It's called “television”.

The beady-eyed among you will have spotted there were no men on that list. Ageism doesn't apply to men on telly. Grey hair, comb-overs, jowls - it's all fine as long as you possess a penis. Sir Trev and Brucie do their jobs well enough, but honestly, the day we see an 80-year-old woman presenting a primetime Saturday night show is the day pigs get their BA pilots' licences. If aliens landed and watched a day of British TV they'd presume the country was inhabited purely by middle-aged men and bendy young women and that older females must be shot at the first hint of a creped neck.

Hence many women spend life after 30 dreading being asked how old they are. Females add years to their age at only two points in their life: during primary school (“I'm five and three quarters!”) and when they are an octogenarian (“I'm 89 next year, you know”). All other times require vagueness, selective deafness or outright lies.

It is a revolting state of affairs that women are written off when they are no longer deemed luscious, dewy and ripe for impregnation. Men might claim to “phwooar” over Helen Mirren in a bikini, but given the choice between a roll around with her and Kelly Brook, who do you reckon they'd really pick?

And yet, admirable though her victory was, I can't help thinking that Selina Scott is the wrong poster girl for anti-ageism. Television, as everyone knows, is a profoundly shallow, vain industry in which people will milk anything they've got - youth, beauty, nepotism - to get a foothold on its greasy ladder. Scott wasn't, as far as I could see, averse to enjoying the benefits of her own considerable beauty in the 1980s, when her career rocketed. I may be wrong but I don't recall her flying the flag for older women then or complaining much when she was voted Sexiest Woman TV Presenter. Let's be clear - I don't blame her; I'd be doing cartwheels of happiness down the street.

But former TV newsreaders are not the most sympathetic victims when it comes to age discrimination. There are far more deserving and outrageous cases out there: highly qualified women (and men) who apply for hundreds of jobs but don't get a single interview because their CV says they were born in the 1950s; mothers who don't even get a reply to their application because they admit to having school-age children.

With thousands now having to work past retirement, it is a problem that clearly needs to be fixed. For starters, women can help by refusing to have facelifts or Botox, every nip and tuck hammering another nail into the coffin of the middle-aged female's acceptability. Men can help by not ogling members of Girls Aloud.

Oh, and I've just seen a pig at the controls of a Boeing 747.

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