The teenage sisters have a rare neurological condition called Charcot-Marie-Tooth disease, which they inherited from father Peter. It causes muscle weakness that can lead to debilitating impairment of the feet and ankles.
“It’s hard not to feel guilty for passing on the disease,” Mr Critchley, 51, said. All three have never been able to play sport, have endured surgery and rely on walking aids.
“It’s difficult to walk and we don’t have the balance most people have, so we are always falling down all the time,” he said.