As they wobble on two wheels while you muster the courage to let them go it alone, helping your child ride a bike for the first time is an emotional moment for any parent.

But for one mum featured in a new documentary, it was particularly tear-jerking – as her 13-year-old son Oscar was born with no hands or feet.

4 Oscar and Simon Reeve (l-r) testing out Oscar’s custom-made bike Credit: BBC

“I cried when I saw him ride a bike for the first time,” says Lisa Johnson, 49, from the West Midlands.

“It was a life-changing moment for him. He was nervous at first, but then he thought: ‘Actually, I can do this.’ It was incredible. That day was very special.”

Oscar was born with a rare genetic condition called Moebius syndrome.

“It’s typically a weakness in the eyes, the muscles don’t work properly – Oscar has an extreme version,” explains Lisa.

“All four limbs are affected, the muscles in his eyes are affected, he has facial palsy, a short tongue and a heart defect. When he was three or four years old, we were going to up to 50 appointments

a year with doctors.”

4 Despite the difficulties Oscar faces in a day-to-day life he is determined to do as many things as possible that other teenage boys do Credit: BBC

Despite the difficulties he faces in day-to-day life, Oscar is determined to do as many things as possible that other teenage boys do – including wrestling with his younger brother Max, 10, and riding a bike to school.

“We were upset because he hadn’t been able to ride a bike,” says Lisa.

“When he started secondary school, a lot of his friends were riding their bikes to school and he wasn’t

able to do that, which really got us down.

“It’s completely normal for kids to not be completely thoughtful, so they’d just ride off and leave him. We weren’t upset or angry with them, but we were feeling for Oscar.

“Big Life Fix got in touch with Reach, a charity for kids with upper limb difference, and they posted an advert on social media asking if there was anything the programme could help with. My husband Chris got in touch with them and said: ‘How about this for an idea?’”

4 Keen photographer James Dunn has skin disorder epidermolysis bullosa and can’t use his hands. His camera can be controlled via his feet and a special app. Credit: BBC

Oscar’s story features in the second episode of Big Life Fix – hosted by Simon Reeve – which begins this week and sees leading engineers, designers and computer programmers come up with inventions to help people across the UK.

Led by award-winning designer and cycling enthusiast Yusuf Muhammad, the team created a custom-made bike for Oscar, who has two different prosthetics on his lower legs. Oscar’s brief was clear: it had to be modelled on a BMX so, in Oscar’s words, it would “look as normal as possible”.

In order to get the dimensions of the bike exactly right, Yusuf first encouraged a nervous Oscar to ride on a tandem with him. “My heart was in my mouth,” remembers Lisa.

The next challenge was designing handlebars and a brake that Oscar could operate without the use of hands.

After reversing the brake position so that Oscar could push the lever rather than pull, he tried it out for himself – and found himself in a heap on the ground.

But taking on board Oscar’s brave mantra: “If at first you don’t succeed, try, try, try again,” Yusuf came up with the idea of using Velcro wristbands that clip on to the handlebars.

4 Graphic designer Emma Laughton has Parkinson’s. She is given a special wristband to reduce the tremors in her hands and enable her to draw again Credit: BBC

Eighteen months on from their initial meeting, Yusuf successfully produced two bikes for Oscar: a mountain bike for gradient cycling and a BMX for him to take trips to the park with his mates – making his wish come true.

“Oscar particularly wanted the BMX, but the other one is more comfortable to ride,” says Lisa. “There are still a couple of adaptations on the handlebars to come, but it shouldn’t be too long before it’s finished.”

The whole experience was life-changing, not only for Oscar but for his mum too.

“Everyone was so lovely, willing to help and interested. From a mum’s point of view, seeing people wanting to help your child is special.

“It’s not just about a bike, it’s about the whole picture. It’s teaching Oscar he can do anything he puts his mind to. It’s saying: ‘You might not be able to do it in the same way

as everybody else, but you can do it.’

“We’re living in wonderful times when you can do whatever your heart desires. I believe

if you want to do it, you can do it.”

NEW! Big Life Fix Wednesday 9pm BBC2