I am an ice skater myself, skating 9 times a week. I have never broken a bone or even cut myself badly whilst ice-skating. Of course, you fall numerous times whilst ice skating and/or roller skating, but concrete often does more damage than ice. Also, leaning back on your heel to break whilst roller skating is highly dangerous. The chances of you falling backwards and injuring your back are high. Whereas in ice skating, you slide your blade to stop, and if you do fall, you either just fall to the side, or fall straight down into a sitting position. I have learnt from experience that ice skating is less dangerous than roller skating. Thankyou!