Performing a back flip is always an impressive feat, so doing one despite having only one leg takes some beating.
However, gymnast Adam Starr, who lost a leg to cancer in 2009, can do them for fun and has posted the evidence on YouTube.
Titled Adam's First Time Back At The Gym, the footage - shot at Northfield Gymnastics Club in Minnesota - shows the 21-year-old proving that even losing a limb is no barrier to pulling off amazing tricks.
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In a spin: Adam's video starts with a show of upper body strength
The video starts with Adam, who wears a prosthetic limb, spinning around on a tub and finishing the routine with a big smile into the camera.
Then, startlingly, the American positions himself on a mat and performs a graceful backward somersault.
After that, it’s time to hit the trampoline. With the prosthetic leg discarded, Adam flips backward and forwards through the air.
Agile: Adam soon gets into the swing of things
Acrobatic: Adam launches into a back-flip
Nearly there: Adam makes a back-flip look easy, even with one leg
Ta-tah! The trick is complete with the gymnast making a perfect landing
Adam lost his leg after suffering lymphangiosarcoma, a rare cancer of lymphatic vessels, and made the video in the hope that it might inspire other amputees, as well as impress his loved ones.
He told MailOnline: 'I was hoping to show my friends and family what I was able to do again, but I also hoped that other amputees would enjoy it. I've been inspired by videos of other amputees on YouTube, such as Sarah Reinertsen.'
Adam trained as a gymnast for 11 years, but the day he shot the video was the first time he'd tried flips since losing his leg.
He said: 'I had been thinking that I felt strong enough to do a standing back-flip off of one leg - it wasn't until this week that I finally got to the gym to try it!
'Landing is probably the hardest part - its all about balance!
'I've tried to stay active since my amputation, but recovery has been a very long process. However, I've gotten back into downhill skiing, swimming, and biking. I weight train most days of the week.'
His acrobatics are an incredible sight and have drawn plenty of praise from YouTube users.
TheTregster writes ‘You are awesome man, that’s all I can say’, while MccRus posted ‘much respect to you for getting back up and facing the challenges you have with a big smile on your face… inspired’.
OMGHuygens was also amazed, saying: ‘Even with one leg you're 10 times as agile as I am.’
Smiles better: Adam clearly enjoys his acrobatic work-outs