The 54-year-old singer has been advised to stay as still as possible to allow his back to heal as, unlike his elbow, on which he underwent a five-hour operation to have three metal plates and 18 screws inserts, he hasn't had surgery there.
The Edge explained to KROQ's Kevin & Bean Show: "The poor guy. Basically his left elbow was shattered so a lot of the work was reconstructing the joints and putting in wires and plates. He actually showed us an X-Ray a couple of days later and it looked like a miniature of the Eiffel Tower was in his elbow and then the same had to happen with a fracture of his pinky, the joint there was totally messed up, so that needed a bone graft.
"And the most vulnerable was actually his upper back, the scapula because they couldn't put any plates in there or they decided not to do surgery. So he has got to be very still and not move around 'til that's really healed.
"He's doing physio to keep the joints active twice a day."
The Edge admitted the accident happened because the One singer "wasn't paying enough attention" to his surroundings.
He said: "It was a Sunday, a lot of people in the park and he just wasn't paying enough attention. He was going fast down a bit of a hill and somebody came out onto the cycle way, he swerved to avoid them and just went straight over the bars."
- Bang! Showbiz