I was told my OS didn't use the CPM after the hospital stay, but my flex was pretty limited, so I did use it the 10 days at rehab. It probably was a good thing for me because I was not mobile for the first week. I had both done, and had issues of passing out, or lightheadedness for the first week. It was more than a week before I made it to the bathroom. By two weeks, I was home and was a new woman!