The four were evacuated by helicopter and are now being treated in Ålesund hospital.
"We have been incredibly lucky," Geir Kvam, 55, told Norway's VG newspaper. "I think that if we had been just a few yards closer to the top, we would have died."
Kvam was walking with his daughter, a friend and his friend's son. He and his friend were both seriously injured, while the children were largely unharmed.
"The doctors have learned that my condition is worse than first thought. Electricity passed through my heart, so I need to be in hospital for one more night," he told the paper.