incidental injuries

[keannu]

Does this "incidental" in "incidental injuries" mean "by chance" or "secondary or subordinate"?

50)Unlike soccer, skiing and swimming, in which there may be some incidental injuries from accidents, in contact sports, injuries result from the central activity of the sport...

[SoothingDave]

Secondary. To the main activity of the sport. A skier may get injured if something goes horribly wrong on his way down the slopes. An American football player or hockey player is more likely to be injured because of the nature of the sport, which is based on physical contact.