There was a time when the only gay man on television was Mr Humphries in Are You Being Served?

and the only black man was Bill Reynolds in Love Thy Neighbour. Mr Humphries would say "I'm free" and Bill Reynolds would get called a nig-nog every week and the audience would laugh as a way of hiding the fact they were scared. Watching clips of those shows now is an exercise in discomfort and horror: notice how prejudiced and ignorant we used to be; squirm at all that nastiness to the sound of canned laughter.

So why aren't we talking more about the fact that as far as one other minority group is concerned, it is still the 1970s? Men and women with disabilities only ever turn up on television if it's an exploitative Channel 5 documentary with an exclamation mark in the title, even though there have been some fantastic trailers for the Paralympics in the last few weeks. Those little films have made disabled men and women look like pop stars and their wheelchairs like racing cars and we should be pleased they are there. They are, at last, a sign of hope.

Another positive sign was last week's documentary My Perfect Wheelchair (Thursday, BBC Two, 9pm), which followed a man called Andrew Slorance who is obsessed with the design project of the title. Andrew has been in a chair since he fell out of a tree when he was 14, and one of his first thoughts was that wheelchairs were ugly. "They all look the same," he said. "It's just a chair."

Slorance's solution is Black Carbon, a lighter, sleeker wheelchair made from black moulded carbon: the Death Star of wheelchairs. The principle behind it is that design is important: if the things we wear, and travel in, and live in, and indeed sit in look good, then we feel good as well.

But good design is usually expensive and so it was with Slorance's chair, which cost at least three times as much as any other. Not that it bothered Slorance. "It doesn't matter if I go to a user group and they tell me they don't like it," he said, "because I will carry on regardless."

Perhaps surprisingly, it was this bloody-mindedness rather than Slorance's status as a wheelchair user that emerged as the theme of the programme. Quite a few times, we saw how his commitment to his idea was having a negative impact on his family. His wife broke down and said she'd had enough. His daughter Sophie was studying for exams but her dad didn't have time to help. The question was: is this what you have to be like if you want to be successful – myopic, bad-tempered, unlikeable?

In the end, the fact that this was the programme's focus rather than disability may mean it makes an interesting contribution to how disabled people are portrayed on television. We only really moved on from Are You Being Served? and Love Thy Neighbour when gay men and black people started to appear on television not because they were gay or black but because they were people. Now, exactly the same process has to happen with the disabled and, despite the title, My Perfect Wheelchair may help.

It was ostensibly about a wheelchair, but it was really about a man.