Answer:
Reversibility
Step-by-step explanation:
Based on the information provided within the question it seems that the doctor recommended swimming in order to minimize the reversibility principle. In the context of sports training, this principle states that an athlete may being to lose the abilities gained from training if they suddenly stop their training routine, but can regain them if they pick up the training once again. Swimming in a pool would minimize this principle as it would allow her to continue training her body without putting force on her ankle.