Ask a PT Response: "It is probably a good idea to follow the recommendations made by your physical therapist. As far as your questions: 1) Stationary bikes and rowing machines are great machines to utilize to minimize stresses/impact on the knee. For my patients that utilizes these machines I would instruct them to perform to tolerance. Should they begin to experience increase symptoms, they are instructed to discontinue use immediately. 2) your knee will heal best if you avoid activities and exercises which aggravate it and continue with the exercises recommended by your physical therapist. For example, if deep squats aggravate your knee than avoid it. You can substitute with partial squats and compensatory functional patterns. Modalities such as icing after activitites which may aggravate your knee somewhat will also help prevent/minimize inflammation. Good luck and thanks for using CyberPT."