Driver negligently drove his car into Pedestrian, breaking her leg. Pedestrian's leg was put in a cast, and she used crutches to get about. While shopping at Market, her local supermarket, Pedestrian nonnegligently placed one of her crutches on a banana peel that had been negligently left on the floor by the manager of Market's produce department. Pedestrian's crutch slipped on the peel, and she fell to the floor, breaking her arm. Had Pedestrian stepped on the banana peel at a time when she did not have to use crutches, she would have regained her balance. Pedestrian sued Driver and Market for her injuries. Pedestrian will be able to recover from 
Driver, for her broken leg only.  Driver, for both of her injuries.  Market, for both of her injuries.  Driver, for her broken leg only, and Market, for her broken arm only. 