For many children, learning to ride a bike is a luxury but for Christchurch six-year-old Dekken McClintock, it's a matter of necessity.
The Aranui boy was born with Prader-Willi syndrome, which causes weak muscles, obsessive eating and slow development.
And the rare genetic disorder has led to further complications. Over a period of time spinal deterioration has caused Dekken to develop scoliosis.
His mother, Rachelle Mitchell, is now on a desperate mission to raise $10,000 towards the cost of a specialised trike in order for her son to build muscle strength before it is too late.
She said because he was diagnosed early, there was still time for him to gain strength before running the risk of being wheelchair-bound and undergoing further operations later in life.
"Because he has a really low muscle tone, he can't sit on a normal bike and balance as he doesn't have the core strength," said Mitchell.
"In my eyes, the trike isn't a luxury item, it's a necessity. We don't have the luxury of being able to go to The Warehouse or Kmart to buy a $100 bike."
The specialised trike by Trikes NZ designed for disabled riders has an upright seat with a back, a harness and pedals at the front rather than the sides.
Dekken would be able to use the trike into adulthood because the base had the ability to extend as he got older, with the possibility of converting it to electric in the future.
"His legs will be outstretched, and there's something special on the pedal that means he doesn't need to have power behind the push as long as he can move them. It doesn't matter if he can't push strong," she said.
"It will stop the scoliosis from getting worse as he will get a healthy blood flow through his body and it will increase his cardio, strengthening core muscles.
"If it gets worse he'll end up really hunched over making it more difficult to walk than what it already is."
Dekken was born prematurely at 34 weeks weighing only 1500gm after six weeks in neonatal care.
He has had seven operations since then, including a double hip and femur surgery, and five surgeries to rectify obstructive sleep apnoea – a condition which can cause breathing to stop during sleep.
Said Mitchell: "He gets tired really easily and struggles to keep up with other kids his age. Because he can't regulate his emotions, he gets frustrated at not being able to do things like everyone else."
• Donations towards Dekken's cause can be made here.