Marge is put under a lot of stress with all of her responsibilities, which include solving the problems of the rest of the family. She gradually is negatively affected by all the stress and ultimately reaches her tipping point, causing her to put herself and Maggie in danger. Her handling of the situation suggests she has poor stress management skills.
Olympic athlete, Jenny Simpson was injured after the 2008 Olympics as a direct result of repeated stress on her legs and feet from running. The risk of injury for runners is higher for their joints and bottom torso because of the constant impact of forces on their bodies.