Doing nothing after a training injury

Her injury really scared her. She's never been in so much pain before, and her knee was really swollen. The ER doctor was a bit overwhelming and even talked about surgery if she wasn't careful enough. He said that people with osteoarthritis need to understand the reality of the disease, that is a "wear and tear" condition of the joints and that anyone living with the disease should be aware of the limitations and exercise with light to moderate intensity activities, always in direct proportion to their prior physical shape and condition. 

She thinks about all that, and in the meantime her pain is getting worse.